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Evidence evaluation report —

Cell-free DNA testing for chromosomal anomalies

DRAFT 16 May 2017

Prepared by Ampersand Health Science Writing for the

Australian Government Department of Health

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Contents

EVIDENCE EVALUATION REPORT — CELL-FREE DNA TESTING FOR CHROMOSOMAL ANOMALIES .................. 1 PROCESS OF THE REVIEW ........................................................................................................................................ 4

Research questions .......................................................................................................................... 4 Search strategy ................................................................................................................................ 4 Exclusion criteria ............................................................................................................................... 4 Assigning level of evidence ............................................................................................................ 7 Study design definitions ................................................................................................................... 7 Selection of outcomes for GRADE analysis ................................................................................... 9

EVIDENCE TABLES .................................................................................................................................................. 10 1. Are there additional benefits and costs associated with replacing the first trimester serum and

nuchal translucency screening with non-invasive prenatal testing (cell-free DNA testing)? ......... 10 1.1 Evidence summary ...................................................................................................................................... 10

Systematic literature reviews ........................................................................................................ 10 Observational studies .................................................................................................................... 10 Implementation of cell-free DNA as a first- or second-line test ................................................ 11 Cell-free DNA testing as a replacement for combined first trimester screening .................... 11 Cell-free DNA testing as second-line testing............................................................................... 12 Impact of cell-free DNA testing on screening practices and invasive procedures ............... 12 Factors affecting women’s uptake of cell-free DNA testing .................................................... 13 Cost-effectiveness of cell-free DNA testing ................................................................................ 13 Additional information ................................................................................................................... 13 Advice to EWG ............................................................................................................................... 13

1.2 Evidence statements .................................................................................................................................. 14 1.3 Summary of findings .................................................................................................................................... 15

Cell-free DNA testing compared to cFTS for detection of fetal chromosomal anomalies ... 15 Second-line cfDNA testing compared to cFTS for detection of fetal chromosomal

anomalies ....................................................................................................................................... 16 1.4 Reported rates of detection and false positives and positive predictive values with cell-free

DNA testing .................................................................................................................................................... 17 Systematic reviews ......................................................................................................................... 17 Observational studies .................................................................................................................... 22

1.5 Cell-free DNA testing as a replacement for first trimester serum and nuchal translucency

screening ........................................................................................................................................................ 30 Systematic reviews ......................................................................................................................... 30 Prospective cohort studies ............................................................................................................ 31 Retrospective cohort studies ........................................................................................................ 32 Modelling studies ........................................................................................................................... 38

1.6 Cell-free DNA combined with cFTS......................................................................................................... 41 Prospective cohort studies ............................................................................................................ 41 Retrospective cohort studies ........................................................................................................ 43 Modelling studies ........................................................................................................................... 52

1.7 Impact of cell-free fetal DNA testing on screening practices and invasive procedures ....... 55 1.8 Factors affecting uptake of cell-free fetal DNA testing by women.............................................. 70 1.9 Cost-effectiveness of cell-free DNA testing ......................................................................................... 77

Australian studies ............................................................................................................................ 77 Overseas studies............................................................................................................................. 79

1.10 Guidelines and statements for research question 1 .......................................................................... 87 1.11 Excluded studies for research question 1.............................................................................................. 91

Background papers ....................................................................................................................... 91

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Systematic reviews excluded due to low quality or overlap with high-quality systematic

reviews............................................................................................................................................. 98 Studies included in high-quality systematic reviews included in this review ........................... 99 Level IV studies ............................................................................................................................. 105 Other excluded studies ............................................................................................................... 106

2. Are there specific issues for Aboriginal and Torres Strait Islander women and rural and remote

populations? ......................................................................................................................................................... 116 REFERENCES ......................................................................................................................................................... 117

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PROCESS OF THE REVIEW

Research questions

1. Are there additional benefits and costs associated with replacing the first trimester serum and nuchal

translucency screening with non-invasive prenatal testing (cell-free deoxyribonucleic acid [cfDNA]

testing)?

2. Are there specific issues for Aboriginal and Torres Strait Islander women and rural and remote

populations?

Search strategy

Databases searched:

• MEDLINE (OVID) and PSYCHINFO (OVID) = 547

• EMBASE = 1388

• COCHRANE LIBRARY = 24

• CINAHL = 133

• AUSTRALIAN INDIGENOUS HEALTHINFONET = 0

Date of searches: 10/05/2016

Dates searched: 2008 to present

Full search strategies

MEDLINE AND PSYCHINFO (OVID)

1. Exp Pregnancy/

2. Exp Prenatal Care/

3. Exp Fetus/

4. (prenatal* or pre-natal* or pre natal or antenatal* or ante-natal* or ante-natal or maternal* or

pregnan* or fetus* or foetus* or fetal* or foetal*).tw.

5. 1 or 2 or 3 or 4

6. ((noninvasive or non-invasive or non invasive) adj3 (diagnos* or test* or detect* or screen*)).tw.

7. (NIPT or NIPD).tw.

8. (cfDNA or cffDNA or ccffDNA or ffDNA or cell free DNA or free fetal DNA or free foetal DNA).tw.

9. 6 or 7 or 8

10. exp Down Syndrome/

11. exp Aneuploidy/

12. (down* adj syndrome).tw.

13. (trisomy* or aneuploid*).tw.

14. 10 or 11 or 12 or 13

15. 5 and 9 and 14

16. 2008 to current

EMBASE

1. 'pregnancy'/exp

2. 'prenatal care'/exp

3. 'fetus'/exp

4. prenatal*:ab,ti OR 'pre natal*':ab,ti OR 'pre-natal*' OR antenatal*:ab,ti OR 'ante natal*':ab,ti

OR 'ante-natal*' OR maternal*:ab,ti OR pregnan*:ab,ti OR fetus*:ab,ti OR foetus*:ab,ti

OR fetal*:ab,ti OR foetal*:ab,ti

5. Or 1-4

6. ((noninvasive OR 'non-invasive' OR 'non invasive') AND

(diagnos* OR test* OR detect* OR screen*)):ab,ti

7. nipt:ab,ti OR nipd:ab,ti

8. cfdna:ab,ti OR cffdna:ab,ti OR ccffdna:ab,ti OR ffdna:ab,ti OR 'cell free dna':ab,ti OR 'free

fetal dna':ab,ti OR 'free foetal dna':ab,ti

9. Or 6-8

10. 'down syndrome'/exp

11. 'trisomy'/exp

12. 'aneuploidy'/exp

13. trisom*:ab,ti OR aneuploid*:ab,ti

14. (down* NEXT/1 syndrome):ab,ti

15. Or 10-14

16. 5 AND 9 AND 15

17. 2008 to current

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COCHRANE LIBRARY

1. MeSH descriptor: [Pregnancy] explode all trees

2. MeSH descriptor: [Prenatal Care] explode all trees

3. MeSH descriptor: [Fetus] explode all trees

4. (prenatal* or 'pre natal*' or pre-natal* or antenatal* or 'ante natal*’or ante-

natal* or maternal* or pregnan* or fetus* or foetus* or fetal* or foetal*):ti,ab,kw

5. 1 or #2 or #3 or #4

6. ((noninvasive or 'non-invasive' or 'non invasive') and

(diagnos* OR test* OR detect* OR screen*)):ti,ab,kw

7. (nipt or nipd):ti.ab,kw

8. (cfdna or cffdna or ccffdna or ffdna 'cell free dna' or 'free fetal dna'or 'free foetal

dna'):ti,ab,kw

9. #6 or #7 or #8

10. MeSH descriptor: [Down Syndrome] explode all trees

11. MeSH descriptor: [Aneuploidy] explode all trees

12. (trisom* or aneuploid*):ti,ab,kw

13. (down* next/1 syndrome):ti,ab,kw

14. #10 or #11 or #12 or #13

15. #5 and #9 and #14

16. 2008 to current

CINAHL

1. (MH “Pregnancy+”)

2. (MH “Prenatal Care+”)

3. (MD “Fetus+”)

4. (prenatal* or 'pre natal*' or pre-natal* or antenatal* or 'ante natal*’or ante-

natal* or maternal* or pregnan* or fetus* or foetus* or fetal* or foetal*)

5. S1 OR S2 OR S3 OR S4

6. ((noninvasive or 'non-invasive' or 'non invasive') and

(diagnos* OR test* OR detect* OR screen*))

7. (nipt or nipd)

8. (cfdna or cffdna or ccffdna or ffdna 'cell free dna' or 'free fetal dna'or 'free foetal dna')

9. S6 OR S7 OR S8

10. (MH “Down Syndrome+”)

11. (MH “Aneuploidy+”)

12. (trisom* or aneuploid*)

13. (down* N1 syndrome)

14. S10 OR S11 OR S12 OR S13

15. S5 AND S9 AND S14

16. 2008 to current

AUSTRALIAN INDIGENOUS HEALTHINFONET

Title: Non invasive prenatal testing

Title: NIPT

2008 to current

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Prisma flow diagram

Exclusion criteria

Full texts of studies were reviewed. Studies were excluded for the following reasons:

• background information

• systematic review of low quality or overlapping with high-quality systematic review

• already included in high quality systematic reviews

• level IV evidence

• does not answer research question

• not in English

• does not meet criteria for grading (eg no outcomes reported, reporting too limited to establish risk

of bias)

• narrative review or opinion paper (editorial, letter, comment)

• potential conflict of interest (industry study).

The remaining 59 studies were analysed in the review.

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Assigning level of evidence

Levels of evidence were assigned using the NHMRC levels (screening intervention as cfDNA testing is

considered a screening rather than a diagnostic test) and the definitions given below. No evidence

was identified for research question 2.

Designations of levels of evidence according to type of research question

Level Screening intervention

I A systematic review of level II studies

II A randomised controlled trial

III-1 Pseudo-randomised controlled trial

(ie alternate allocation or some other method)

III-2 A comparative study with concurrent controls:

▪ Non-randomised, experimental trial

▪ Cohort study

▪ Case-control study

III-3 A comparative study without concurrent controls:

Historical control study

Two or more single arm study

IV Case series

Source: NHMRC (2009) NHMRC levels of evidence and grades of recommendations for developers of guidelines.

Study design definitions

• A study of test accuracy with: an independent, blinded comparison with a valid reference standard,

among consecutive patients with a defined clinical presentation — a cross-sectional study where a

consecutive group of people from an appropriate (relevant) population receive the test under

study (index test) and the reference standard test. The index test result is not incorporated in (is

independent of) the reference test result/final diagnosis. The assessor determining the results of the

index test is blinded to the results of the reference standard test and vice versa.

• A study of test accuracy with: an independent, blinded comparison with a valid reference standard,

among non-consecutive patients with a defined clinical presentation — a cross-sectional study

where a non-consecutive group of people from an appropriate (relevant) population receive the

test under study (index test) and the reference standard test. The index test result is not

incorporated in (is independent of) the reference test result/final diagnosis. The assessor

determining the results of the index test is blinded to the results of the reference standard test and

vice versa.

• Case series — a single group of people exposed to the intervention (factor under study). Post-test –

only outcomes after the intervention (factor under study) are recorded in the series of people, so no

comparisons can be made. Pre-test/post-test – measures on an outcome are taken before and

after the intervention is introduced to a series of people and are then compared (also known as a

‘before- and-after study’).

• Case-control study — people with the outcome or disease (cases) and an appropriate group of

controls without the outcome or disease (controls) are selected and information obtained about

their previous exposure/non-exposure to the intervention or factor under study.

• Diagnostic (test) accuracy – in diagnostic accuracy studies, the outcomes from one or more

diagnostic tests under evaluation (the index test/s) are compared with outcomes from a reference

standard test. These outcomes are measured in individuals who are suspected of having the

condition of interest. The term accuracy refers to the amount of agreement between the index test

and the reference standard test in terms of outcome measurement. Diagnostic accuracy can be

expressed in many ways, including sensitivity and specificity, likelihood ratios, diagnostic odds ratio,

and the area under a receiver operator characteristic (ROC) curve.

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• Diagnostic case-control study – the index test results for a group of patients already known to have

the disease (through the reference standard) are compared to the index test results with a

separate group of normal/healthy people known to be free of the disease (through the use of the

reference standard). In this situation patients with borderline or mild expressions of the disease, and

conditions mimicking the disease are excluded, which can lead to exaggeration of both sensitivity

and specificity. This is called spectrum bias because the spectrum of study participants will not be

representative of patients seen in practice. Note: this does not apply to well-designed population

based case-control studies.

• Historical control study – outcomes for a prospectively collected group of people exposed to the

intervention (factor under study) are compared with either (1) the outcomes of people treated at

the same institution prior to the introduction of the intervention (ie. control group/usual care), or (2)

the outcomes of a previously published series of people undergoing the alternate or control

intervention.

• Non-randomised, experimental trial - the unit of experimentation (eg. people, a cluster of people) is

allocated to either an intervention group or a control group, using a non-random method (such as

patient or clinician preference/availability) and the outcomes from each group are compared. This

can include:

— a controlled before-and-after study, where outcome measurements are taken before and after

the intervention is introduced, and compared at the same time point to outcome measures in

the (control) group.

— an adjusted indirect comparison, where two randomised controlled trials compare different

interventions to the same comparator ie. the placebo or control condition. The outcomes from

the two interventions are then compared indirectly.

• Prospective cohort study — where groups of people (cohorts) are observed at a point in time to be

exposed or not exposed to an intervention (or the factor under study) and then are followed

prospectively with further outcomes recorded as they happen.

• Pseudo-randomised controlled trial - the unit of experimentation (eg. people, a cluster of people) is

allocated to either an intervention (the factor under study) group or a control group, using a

pseudo-random method (such as alternate allocation, allocation by days of the week or odd-even

study numbers) and the outcomes from each group are compared.

• Randomised controlled trial — the unit of experimentation (eg. people, or a cluster of people4) is

allocated to either an intervention (the factor under study) group or a control group, using a

random mechanism (such as a coin toss, random number table, computer-generated random

numbers) and the outcomes from each group are compared.

• Retrospective cohort study — where the cohorts (groups of people exposed and not exposed) are

defined at a point of time in the past and information collected on subsequent outcomes, eg. the

use of medical records to identify a group of women using oral contraceptives five years ago, and

a group of women not using oral contraceptives, and then contacting these women or identifying

in subsequent medical records the development of deep vein thrombosis.

• Study of diagnostic yield — these studies provide the yield of diagnosed patients, as determined by

the index test, without confirmation of the accuracy of the diagnosis (ie. whether the patient is

actually diseased) by a reference standard test.

• Systematic literature review — systematic location, appraisal and synthesis of evidence from

scientific studies.

• Two or more single arm study – the outcomes of a single series of people receiving an intervention

(case series) from two or more studies are compared.

Source: NHMRC (2009) NHMRC levels of evidence and grades of recommendations for developers of guidelines.

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Selection of outcomes for GRADE analysis

Seven outcomes were selected on the basis of clinical impact and acceptability.

Outcome Importance Inclusion

Detection of trisomy 21 (Down syndrome) 9

Detection of trisomy 18 (Edwards syndrome) 9

Detection of trisomy 13 (Patau syndrome) 9

Detection of sex chromosome anomalies 9

Detection of atypical aneuploidies 9

Rates of invasive procedures 9

Rates of test failure 7

Costs to the health system 6

Procedure-related miscarriage 9

Key: 1 – 3 less important; 4 – 6 important but not critical for making a decision; 7 – 9 critical for making a decision

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EVIDENCE TABLES

1. Are there additional benefits and costs associated with replacing the first trimester serum

and nuchal translucency screening with non-invasive prenatal testing (cell-free DNA

testing)?

1.1 Evidence summary

Reported rates of detection and false positives and positive predictive values with cell-free DNA testing

The review identified three systematic literature reviews (SLRs) in which cell-free DNA (cfDNA) testing was

validated against the results of invasive tests (amniocentesis or chorionic villus sampling [CVS]). There was

considerable overlap in included studies between SLRs and all were based on observational evidence. The

earliest SLR (Gil et al 2015b) did not include the two largest studies. The majority of studies included in the

systematic reviews used samples from women with a high risk of fetal aneuploidy.

In addition, observational studies from Australia (McLennan et al 2016), China (Shi et al 2015), France (Benachi et al

2015), Thailand (Manotaya et al 2016), the United States (Meck et al 2015; Neufeld-Kaiser et al 2015) and the United

Kingdom (Gil et al 2013; Nicolaides et al 2014) were identified. The study population comprised women at high risk

of fetal aneuploidy in all but three of the studies (Gil et al 2015b; Manotaya et al 2016; McLennan et al 2016).

Systematic literature reviews

SLRs reported pooled detection and false positive rates (FPRs) in the ranges given below (Gil et al 2015b; Mackie

et al 2016; Taylor-Phillips et al 2016).

Chromosomal anomaly Pooled detection rate (95%CI) Pooled false positive rate (95%CI)

Trisomy 21 99.2% (98.5 to 99.6%) to 99.4% (98.3 to 99.8%) 0.09% (0.05 to 0.14%) to 0.1% (0.0 to 0.1%)

Trisomy 18 96.3% (94.3 to 97.9%) to 97.7% (95.2 to 98.9) 0.01% (0.0 to 0.1%) to 0.13% (0.07 to 0.20%)

Trisomy 13 90.6% (82.3 to 95.8%) to 97.4% (86.1 to 99.6%) 0.0% (0.0 to 0.1%) to 0.13% (0.05 to 0.26%).

Monsomy X 90.3% (85.7 to 94.2%) to 92.9% (99.5 to 99.9%) 0.1% (0.1 to 0.5%) to 0.23% (0.14–0.34%)

Other sex chromosome

anomalies

93.0% (85.8–97.8%) 0.14% (0.06–0.24%)

Inclusion of test failures in an intention-to-screen analysis in the meta-analysis decreased detection rates by

1.7% for trisomy 21, 1.6% for trisomy 18 and 7.1% for trisomy 13 (Taylor-Phillips et al 2016).

Observational studies

In observational studies that reported detection and FPRs, these were as given below.

Chromosomal anomaly High-risk population

(Benachi et al 2015)

Mixed-risk population

(Manotaya et al 2016)

Detection* FPR* Detection (95%CI) FPR*

Trisomy 21 100% 0.1% 100% (89.72 to 100.0%) 0.02%

Trisomy 18 88% 0.1% 100% (78.2 to 100.0%) 0.08%

Trisomy 13 100% 0.1% 100% (59.04 to 100.0%) 0.02%

* 95% confidence intervals not reported.

One study reported that cfDNA testing detected all cases of triploidy (n=4) in cases where the extra haploid

set was of paternal origin (Nicolaides et al 2014).

In studies where positive predictive value1 (PPV) was reported, for trisomies 21, 18, 13 and sex chromosome

aneuploidies taken together, this was 77.4 % (n=55; 95%CI, 63.4 - 87.3) (Neufeld-Kaiser et al 2015). For individual

chromosomal aneuploidies, PPV was as given below.

1 The probability that subjects with a positive result are true positives, calculated as true positives divided by total positives.

Higher prevalence of the condition being screened increases the PPV.

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Chromosomal

anomaly

High-risk population Mixed-risk population

(Meck et al 2015) (Manotaya et al 2016) (McLennan et al 2016)

n PPV (95%CI) n PPV (95%CI) n PPV*

Trisomy 21 99 93% (86.0 to 97.1) 31 94.4% (81.34 to 99.32%) 44 91.4%

Trisomy 18 24 58% (36.6 to 77.9%) 16 79.0% (54.43 to 93.95%) 11 58.3%

Trisomy 13 11 45% (16.7 to 76.6%) 5 87.5% (47.35 to 99.68%) 2 50.0%

Monsomy X 26 23% (9 to 43.6%) — 24 25.0%

XXY 6 67% (22.3 to 95.7%) — 11 54.5%

* 95% confidence intervals not reported.

One study (Benachi et al 2015) found that rates of additional aneuploidies (sex chromosome anomalies and

triploidy) not identified by cfDNA were significantly higher among women with fetal anomalies on ultrasound

(structural or ‘soft’ markers) than among those without (7.9 vs 0.4%; p<0.01). Another noted that ultrasound

detection of fetal structural anomalies resulted in detection of additional chromosomal anomalies not

identified by cfDNA testing (McLennan et al 2016).

Rates of inconclusive primary test results (eg due to assay failure or low fetal fraction) were reported as 0.6%

(Neufeld-Kaiser et al 2015), 0.7% (Benachi et al 2015), 2.4% (McLennan et al 2016) and 4.8% (Gil et al 2015b). Repeated

test failure was reported to be associated with body mass index greater than 30 kg/m2 (fetal fraction is lower

due to increased maternal circulatory volume) (Benachi et al 2015; McLennan et al 2016). One study (Shi et al 2015)

noted that median fetal fraction was lower in the first trimester than in the second but that an increase was

only observed in 59% of pregnancies.

Studies noted that, given that both false negative and false positive results occur, cfDNA is an advanced

screening test rather than a diagnostic test and that this is an important aspect of pretest counselling (Gil et al

2015b; Meck et al 2015; Neufeld-Kaiser et al 2015; McLennan et al 2016).

Implementation of cell-free DNA as a first- or second-line test

Studies identified considered a range of models for antenatal testing for chromosomal anomalies. This review

focuses on those that considered cfDNA testing as a first-line test (ie as a replacement for combined first

trimester screening [cFTS], which involves maternal serum and nuchal translucency screening) and as a

second-line screen (ie offered to women identified as at high-risk by cFTS).

One SLR was identified that aimed to derive pooled detection and false positive rates for aneuploidies other

than trisomy 21 with different antenatal screening approaches (Metcalfe et al 2014).

Additional observational studies identified comprised:

• prospective cohort studies from Australia (McLennan et al 2016) and the United Kingdom (Gil et al 2013)

• studies that reviewed retrospective data from cohorts in Australia (Susman et al 2010; O'Leary et al 2013;

Maxwell et al 2015), Belgium (Gyselaers et al 2015), Denmark (Petersen et al 2014), Germany (Kagan et al 2015a;

Kagan et al 2015b), the Netherlands (Lichtenbelt et al 2015), Sweden (Conner et al 2015), the United Kingdom

(Syngelaki et al 2014; Khalil et al 2015) and the United States (Kaimal et al 2015) and estimated the detection of

chromosomal anomalies had cfDNA testing been used as first- or second-line testing

• studies that investigated outcomes from different models of cfDNA testing in a hypothetical cohort of

women (Morris et al 2014; Kaimal et al 2015; Mersy et al 2015)

• an Australian study that investigated risk thresholds for eligibility for cfDNA as second-line testing (Maxwell et

al 2016).

There was some inconsistency in the evidence, largely due to assumptions underlying modelling (ie the

chromosomal anomalies included in the cfDNA test panel, sensitivity and specificity ascribed to cfDNA testing,

inclusion of cfDNA test failures in calculations and risk thresholds used for invasive testing).

Cell-free DNA testing as a replacement for combined first trimester screening

Prospective cohort and retrospective cohort and modelling studies were consistent in finding higher detection

rates for trisomy 21 with cfDNA testing than with cFTS (Susman et al 2010; Morris et al 2014; Syngelaki et al 2014;

Gyselaers et al 2015; Kagan et al 2015a; Kagan et al 2015b; Mersy et al 2015; McLennan et al 2016), lower numbers of

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invasive procedures (Susman et al 2010; Syngelaki et al 2014; Kagan et al 2015a) and procedure-related miscarriages

(Morris et al 2014; Gyselaers et al 2015; Mersy et al 2015).

A systematic review (Metcalfe et al 2014) found that, compared to cFTS, cfDNA testing had higher detection

rates and lower FPRs for trisomy 13 (90.3 vs 83.1%; FPR 0.2 vs 4.4%), trisomy 18 (98.1% vs 91.9%; FPR 0.2 vs 3.5%)

and 45X (92.2 vs 70.1%; FPR 0.1 vs 5.4%). Most estimates on cfDNA testing came from high-risk samples.

In a prospective cohort study, detection of trisomy 18 was higher with cfDNA testing than with cFTS (McLennan

et al 2016). In retrospective cohort studies, rates of detection of trisomies 18 and 13 with cfDNA testing were

estimated to be higher (Petersen et al 2014; Syngelaki et al 2014), similar (Kagan et al 2015a) or lower (Susman et al

2010). Detection of sex chromosome aneuploidies was estimated to be higher (Kagan et al 2015a) or lower

(Susman et al 2010; Syngelaki et al 2014) and atypical aneuploidies were not detected (Petersen et al 2014; Kagan et

al 2015a). One study found that nuchal translucency measurement (in addition to cfDNA testing) would identify

an additional 0.01% of chromosomal anomalies (Lichtenbelt et al 2015). One modelling study suggested that

cfDNA would be optimal for women aged 40 years and older (Kaimal et al 2015).

Rates of primary test failure were estimated to be in the range of 1.7–2.4% (Gil et al 2013; Syngelaki et al 2014).

Studies noted the importance of counselling women about the ability of the test to identify chromosomal

anomalies other than trisomy 21 (Susman et al 2010; Metcalfe et al 2014).

Cell-free DNA testing as second-line testing

There was some inconsistency in findings on detection of trisomy 21 with second-line cfDNA testing compared

to cFTS alone — some studies estimated that rates of detection would be increased (Syngelaki et al 2014; Conner

et al 2015; Kagan et al 2015a; Kagan et al 2015b; McLennan et al 2016), while others estimated that rates of detection

would be similar (O'Leary et al 2013; Morris et al 2014; Gyselaers et al 2015; Mersy et al 2015).

Rates of detection with second-line cfDNA testing were estimated to be higher than with cFTS alone for trisomy

18 (Syngelaki et al 2014; Kagan et al 2015a; McLennan et al 2016), higher (Syngelaki et al 2014) or similar (Kagan et al

2015a) for trisomy 13, higher for sex chromosome aneuploidies (Syngelaki et al 2014; Kagan et al 2015a), and lower

for triploidy (Syngelaki et al 2014) and atypical aneuploidies (Syngelaki et al 2014; Kagan et al 2015a).

One study, in which women were screened by cfDNA at 10 weeks and the combined test at 12 weeks, found

that while detection was similar between the two approaches, false positives were higher for cFTS alone (3.4 vs

0.1%) (Gil et al 2013).

Studies estimated that numbers of invasive diagnostic procedures (O'Leary et al 2013; Syngelaki et al 2014; Kagan et

al 2015a; Kaimal et al 2015; Mersy et al 2015) and procedure-related miscarriage would be lower (Gyselaers et al

2015; Khalil et al 2015) with second-line cfDNA testing than with cFTS alone.

Relevant considerations in implementing second-line testing were maternal age (Kaimal et al 2015; Maxwell et al

2016), risk threshold (Maxwell et al 2016) and the need for clear indicators for invasive testing over cfDNA testing

to optimise detection of rare pathogenic anomalies (Maxwell et al 2015).

Impact of cell-free DNA testing on screening practices and invasive procedures

Studies have described changes in practice following the introduction of cell-free DNA testing in Australia

(Robson & Hui 2015), China (Li et al 2016), Hong Kong (Chan et al 2015; Poon et al 2015), Japan (Hasegawa et al 2015),

Switzerland (Manegold-Brauer et al 2014; Manegold-Brauer et al 2015) and the United States (Chetty et al 2013; Friel et

al 2014; Larion et al 2014b; Larion et al 2014a; Pettit et al 2014; Platt et al 2014; Shah et al 2014; Larion et al 2015; Palomaki et

al 2015; Tiller et al 2015; Williams et al 2015).

The Australian study (Robson & Hui 2015) found that, in the 2 years following introduction of cell-free DNA testing,

the number of amniocenteses fell by 51% and that of chorionic villus sampling (CVS) procedures by 37%. The

study noted that this has implications for training in and maintenance of skills for these procedures.

Studies in the United States found that introduction of cell-free DNA testing reduced rates of first trimester

combined screening (Larion et al 2014b; Larion et al 2014a; Larion et al 2015), although one found only a minor

impact on serum testing rates (Palomaki et al 2015) and another that first trimester screening was only reduced

among high-risk women (Larion et al 2015). One found a considerable decrease in invasive testing (Tiller et al

2015).

Other overseas studies were largely consistent in finding a decrease in invasive testing (Larion et al 2014b; Larion

et al 2014a; Manegold-Brauer et al 2014; Pettit et al 2014; Platt et al 2014; Shah et al 2014; Chan et al 2015; Hasegawa et al

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2015; Poon et al 2015; Williams et al 2015), although one found no difference (Manegold-Brauer et al 2015) and one

found a decrease occurred among women referred between 14 and 22 weeks and not among those referred

at <14 weeks (Friel et al 2014). A Chinese study found that invasive testing had not decreased following

introduction of cell-free DNA testing (Li et al 2016).

Factors affecting women’s uptake of cell-free DNA testing

Factors identified as affecting uptake of cell-free DNA testing included increasing risk of trisomies (Vahanian et

al 2014; Gil et al 2015a; Maiz et al 2016), increasing maternal age (Gil et al 2015a; Maiz et al 2016), nulliparity (Chan et

al 2015; Gil et al 2015a; Poon et al 2015; Maiz et al 2016) and being screened in the first rather than the second

trimester (Chetty et al 2013; Poon et al 2015). Financial issues may also affect decision-making (Vahanian et al 2014;

Han et al 2015; Poon et al 2015). None of these studies were conducted in Australia.

Cost-effectiveness of cell-free DNA testing

Two studies evaluated the cost-effectiveness of incorporating cfDNA testing for trisomy 21 into Australian

practice:

• in comparing universal cfDNA testing with current practice (combined FTS with women with a probability

of 1:300 counselled for invasive diagnostic testing), an incremental analysis (Ayres et al 2014) estimated

increased detection (an additional 123 in a theoretical population of 300,000 women) and lower rates of

procedure-related miscarriage (90 fewer) at an incremental cost of $1,094,608 per case (assuming a cost

of $575 for cfDNA testing)

• in comparing second-line cfDNA testing with current practice, one study found that the number of

procedure-related miscarriages was decreased by 51% and the cost per trisomy 21 case confirmed

increased by 9.7% (assuming 100% uptake of the screening strategy) (O'Leary et al 2013) while the other

found 0.6% reduction in detection and a 3.4–4.1% decrease in costs (Ayres et al 2014)

• the most cost-effective strategy was cfDNA for women aged >40 years, costing an incremental $81,199

per additional trisomy 21 case detected and avoiding 95 procedure-related miscarriages (Ayres et al 2014).

No Australian studies investigated the costs associated with cfDNA testing for other chromosomal anomalies.

Overseas cost-effective studies were largely consistent in finding that second-line cfDNA testing was more

cost-effective when compared with universal cfDNA testing:

• among studies conducted in the United States, one found that universal cfDNA testing would reduce

health care costs if it can be provided for $744 or less (Benn et al 2015), three found that second-line cfDNA

testing was more cost-efficient than universal cfDNA testing (Cuckle et al 2013; Evans et al 2015; Walker et al

2015) and two (with potential conflict of interest) that cfDNA testing was more cost-efficient than cFTS

(Fairbrother et al 2016; Garfield & Armstrong 2016)

• a Canadian study (Okun et al 2014) found that second-line models of cfDNA testing can improve overall

screening performance with modest increase in costs and a decrease in cost per trisomy 21 case

detected prenatally

• a Belgian study (Neyt et al 2014) found that introduction of second-line cfDNA testing (but not first-line

testing at the current price) results in cost savings

• a study in the Netherlands (Beulen et al 2014) estimated a cost increase of 21% with cfDNA implemented as

a second-line test and of 157% when implemented as a primary test compared to cFTS.

Additional information

The Medicare Benefits Schedule does not include cfDNA testing.

Sonic Genetics (for example) provides the test for $450, with repeat testing performed for no additional

charge and costs refunded if the test is unable to provide an assessment for trisomies 21, 18 and 13.

Advice to EWG

While cfDNA testing has a higher detection rate for the more common trisomies compared with combined first

trimester screening, and fewer invasive procedures are required, invasive diagnostic testing is still required for

women who test positive and costs are higher. As well, cfDNA testing does not detect less common

chromosomal anomalies that may currently be identified through ultrasound assessment (Low quality

evidence, see Summary of Findings table).

14

As cfDNA testing is already available in Australia (although not currently covered by Medicare or private

health insurance), it is important that health professionals counsel women about the chromosomal anomalies

that may (or may not) be identified by the test.

Note that while this document refers to ‘risk’ of fetal chromosomal anomaly, consistent with the literature, the

review of the guideline chapter will ensure that neutral language is used (ie ‘probability’ used rather than

‘risk’).

1.2 Evidence statements

Cell-free DNA testing compared to cFTS for detection of fetal chromosomal anomalies

• Cell-free DNA testing has a higher detection rate for the more common trisomies (trisomies 21, 18 and 13),

lower detection rates for sex chromosome and atypical aneuploidies and a lower risk of invasive

procedures compared with combined first trimester screening (low quality evidence).

Second-line cfDNA testing compared to cFTS for detection of fetal chromosomal anomalies

• Second-line cfDNA testing has a higher detection rate for the more common trisomies (trisomies 21, 18 and

13), lower detection rates for atypical aneuploidies, lower risk of invasive procedures compared with

combined first trimester screening and the difference in detection of sex chromosome aneuploidies did

not reach significance (low quality evidence).

No new recommendations were developed.

15

1.3 Summary of findings

Cell-free DNA testing compared to cFTS for detection of fetal chromosomal anomalies

Patient or population: high-risk and mixed-risk populations

Setting: Australia, Belgium, Denmark, Germany, United Kingdom

Intervention: cfDNA testing

Comparison: combined first trimester screening (maternal serum and nuchal translucency)

Outcomes Anticipated absolute effects* (95% CI) Relative effect (95% CI)

№ of participants (studies)

Quality of the evidence (GRADE)

Studies

Detection with combined FTS*

Detection with cfDNA testing#

Trisomy 21

891 per 1,000

1,000 per 1,000 (963 to 1,000)

RR 1.13 (1.08 to 1.18)

3,766 (6 observational studies)

⨁⨁◯◯

LOW 1

(Petersen et al 2014;

Syngelaki et al 2014;

Gyselaers et al 2015; Kagan

et al 2015a; Kagan et al

2015b; McLennan et al 2016)

Trisomies 18 and 13 807 per 1,000

985 per 1,000 (953 to 1,000)

RR 1.22 (1.18 to 1.26)

891 (4 observational studies)

⨁⨁◯◯

LOW 1


Syngelaki et al 2014; Kagan

et al 2015a; McLennan et al

2016)

Sex chromosome aneuploidies

655 per 1,000

153 per 1,000 (106 to 219)

RR 0.23 (0.16 to 0.33)


⨁⨁◯◯

LOW1

(Syngelaki et al 2014; Kagan


2016)

Atypical aneuploidies 367 per 1,000

4 per 1,000 (0 to 15)

RR 0.01 (0.00 to 0.04)


⨁⨁◯◯

LOW 1



et al 2015a)




Studies

Risk with combined FTS

Risk with cfDNA testing

Invasive

procedures 59 per 1,000 10 per 1,000

(10 to 11)

RR 0.17 (0.17 to 0.18)


⨁⨁◯◯

LOW 1

(Susman et al 2010; Syngelaki

et al 2014; Kagan et al 2015a)

*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; RR: Risk ratio

GRADE Working Group grades of evidence High quality: We are very confident that the true effect lies close to that of the estimate of the effect Moderate quality: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different Low quality: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect Very low quality: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect

* Risk thresholds for invasive procedures ranged from 1:100 to >1:300.

# Assumptions about the chromosomal anomalies that could be detected by cfDNA testing varied between studies.

1 Data from observational studies

16

Second-line cfDNA testing compared to cFTS for detection of fetal chromosomal anomalies

Patient or population: high-risk and mixed-risk populations

Setting: Australia, Belgium, Denmark, Germany, United Kingdom

Intervention: second-line cfDNA testing

Comparison: combined FTS alone




Studies

Detection with cFTS*

Detection with second-line cfDNA testing#

Trisomy 21

863 per 1,000

932 per 1,000

(915 to 958)

RR 1.08 (1.06 to 1.11)


⨁⨁◯◯

LOW 1


Syngelaki et al 2014;

Gyselaers et al 2015; Kagan


2016)

Trisomies 18 and 13 864 per 1,000

916 per 1,000 (890 to 950)

RR 1.06 (1.03 to 1.10)


⨁⨁◯◯

LOW 1




2016)

Sex chromosome aneuploidies

655 per 1,000

692 per 1,000 (605 to 791)

RR 1.04 (0.91 to 1.19)


⨁⨁◯◯

LOW 1



2016)

Atypical aneuploidies 415 per 1,000

299 per 1,000 (237 to 382)

RR 0.72 (0.57 to 0.92)


⨁⨁◯◯

LOW 1


et al 2015a)




Studies

Risk with cFTS

Risk with second-line cfDNA testing

Invasive procedures 57 per 1,000

27 per 1,000 (25 to 28)

RR 0.48 (0.45 to 0.50)


⨁⨁◯◯

LOW 1

(O'Leary et al 2013; Syngelaki

et al 2014; Kagan et al 2015a)

*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; RR: Risk ratio

GRADE Working Group grades of evidence High quality: We are very confident that the true effect lies close to that of the estimate of the effect Moderate quality: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different Low quality: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect Very low quality: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect

* Risk thresholds for invasive procedures ranged from 1:100 to >1:300.

# Risk thresholds for invasive procedures ranged from 1:51–1:1,000 to >1:300.

1 Data from observational studies

17

1.4 Reported rates of detection and false positives and positive predictive values with cell-free DNA testing

Systematic reviews

Trisomy 21

Study ref Design LoE N Aim, setting, population, methods Results Comments

(Gil et al

2015b)

SLR I 24

studies

Studies reported on the performance of

screening by cfDNA analysis for trisomy 21, in

a combined total of 1,051 trisomy-21 and

21,608 non-trisomy-21 singleton pregnancies.

Among individual studies, the detection rate

varied between 94.4% and 100% and the

false positive varied between 0% and 2.05%.

The pooled weighted detection and false

positive rates were 99.2% (95% CI, 98.5–

99.6%) and 0.09% (95% CI, 0.05–0.14%),

respectively.

(Mackie et

al 2016)

SLR I 31

studies

148,344 tests Bivariate meta-analysis produced a

summary sensitivity of 0.994 (95% CI 0.983–

0.998) and specificity of 0.999 (95% CI 0.999–

1.000), a positive likelihood ratio of 1720

(95%CI 1111–2662) and a negative likelihood

ratio of 0.006 (95%CI 0.002–0.017).

Of 14/31 studies reporting inconclusive

results, 7 documented an explanation (in

order of frequency): assay failure; confirmed

low fetal fraction; no reason given;

presumed low fetal fraction/inadequate

sequencing depth. The most common

reasons given for false results were:

confirmed low fetal fraction; confirmed

mosaicism; no reason given; test failure;

maternal copy number variant.

Risk of bias was

high in most

studies; all were

observational

18


(Taylor-

Phillips et al

2016)

SLR I 40

studies

The pooled sensitivity from bivariate

random-effects regression was 99.3% (98.9%

to 99.6%) and the pooled specificity was

99.9% (99.9% to 100%).

Including test failures in an intention to

diagnose analysis in the meta-analysis

decreased sensitivity estimates by 1.7% and

specificity estimates by nearly 2%.

Risk of bias was

high in most

studies; all were

observational

Trisomy 18


(Gil et al

2015b)

SLR I 21

studies



a combined total of 389 trisomy-18 and


In individual studies, the detection rate


false positive rate varied between 0% and

1.98%. The pooled weighted detection and

false positive rates were 96.3% (95% CI, 94.3–

97.9%) and 0.13% (95% CI, 0.07–0.20),

respectively.

SLR includes

case-control

studies (Level III-

3) and does not

include the two

largest studies.

19


(Mackie et

al 2016)

SLR I 24

studies

146,940 tests Bivariate meta-analysis produced a

summary sensitivity of 0.977 (95% CI0.952–


1.00), a positive likelihood ratio of 1569 (95%

CI 810–3149) and negative likelihood ratio of

0.023 (95% CI 0.011–0.048).

Of 12/ 24 studies reporting inconclusive

results, seven documented an explanation

(in order of frequency): low fetal fraction;

test failure; no reason given; mosaicism. The

most common reasons given for false results

were: confirmed low fetal fraction;

confirmed mosaicism; presumed low fetal

fraction/human error; maternal CNV; no

reason given.

Neither test

technique nor

population risk

had a significant

effect.

(Taylor-

Phillips et al

2016)

SLR I 33

studies

The pooled sensitivity was 97.4% (95.8% to

98.4%) and specificity was 99.9% (99.9% to

100%).





SLR included

case-control

studies (Level III-

3).

Trisomy 13


(Gil et al

2015b)

SLR I 18

studies



a combined total of 139 trisomy-13 and







95.6%) and 0.13% (95% CI, 0.05–0.26%),

respectively.

SLR includes

case-control

studies (Level III-

3) and does not

include the two

largest studies.

20


(Mackie et

al 2016)

SLR I 16

studies

134,691 tests There was a summary sensitivity of 0.906

(95% CI 0.823–0.958) and specificity of 1.00

(95% CI 0.999–1.00). The positive likelihood

ratio was 453 (95% CI 26–7864) and negative

likelihood ratio was 0.188 (95% CI 0.080–

0.44039), with a diagnostic odds ratio of

2788 (95%CI 285–27252).

Of 6/16 studies reporting inconclusive results,

4 documented an explanation for

inconclusive results: low fetal fraction;

different fragmentation rate; contamination;

assay failure; and human error. The only

reason given for false results was confirmed

low fetal fraction.

(Taylor-

Phillips et al

2016)

SLR I 24

studies

The pooled sensitivity was 97.4% (86.1% to

99.6%) and specificity was >99.9% (99.9% to

100%).





SLR included

case-control

studies (Level III-

3).

Monsomy X


(Gil et al

2015b)

SLR I 16

studies

Studies reported on the detection of

monosomy X by cfDNA analysis, for a

combined total of 177 singleton

pregnancies with fetal monosomy X and

9,079 with no monosomy X.






94.2%) and 0.23% (95% CI, 0.14–0.34%),

respectively.

SLR includes

case-control

studies (Level III-

3) and does not

include the two

largest studies.

21


(Mackie et

al 2016)

SLR I 8 studies 6,712 tests Bivariate meta-analysis produced a

summary sensitivity of 0.929 (95% CI 0.741–


0.999), a positive likelihood ratio of 1337 (95%

CI 213–8407) and negative likelihood ratio of

0.071 (95% CI 0.017–0.292).

Of five of eight studies reporting

inconclusive result, three documented an

explanation (in order of frequency): low

fetal fraction; presumed human error; and

no reason given. The most common reasons

given for false results were: mosaicism and

no reason given.

The five studies that evaluated an

unselected obstetric population reported

inconclusive results, with rates of 0.29–5.10%,

and provided the same reasons for their

false and inconclusive results as with the

high-risk aneuploidy populations.

There was no

significant

difference with

test technique. It

was not possible

to assess the

effect of

population risk,

as there were

insufficient low-

risk studies.

Other sex chromosomal anomalies


(Gil et al

2015b)

SLR I 12

studies


screening by cfDNA analysis for sex

chromosome anomalies other than

monosomy X, in a combined total of 56

affected and 6,699 non-sex chromosome

aneuploidy singleton pregnancies.

The pooled weighted detection and false

positive rates were 93.0% (95% CI, 85.8–

97.8%) and 0.14% (95% CI, 0.06–0.24%),

respectively.

SLR includes

case-control

studies (Level III-

3) and does not

include the two

largest studies.

22

Observational studies


(Benachi et

al 2015)

Cohort III-2 892 Aim: To evaluate the utility of noninvasive

prenatal testing using cell-free circulating

fetal DNA for detection of the three main

autosomal fetal trisomies in the setting of

ultrasonographically identified fetal

anomalies.

Setting: France

Population: women at risk of fetal

aneuploidy with or without ultrasonography

anomalies and who underwent invasive

procedures

Methods: Cell-free DNA analysis was

performed by massive parallel sequencing

and the results were compared with a fetal

karyotype.

Outcomes: Detection of trisomies 21, 18, 13,

sex chromosome anomalies, triploidy

Cell-free DNA identified 76/76 (100%) fetal

Down syndrome, 22/25 (88%) trisomy 18, and

12/12 (100%) trisomy 13.

In those with a normal ultrasonogram and

normal cfDNA analysis, karyotype identified

2/483 (0.4%) additional aneuploidies other

than trisomies 13, 18, and 21.

In those with an abnormal ultrasonogram

and a normal cell-free DNA analysis, there

were 23/290 (7.9%) additional pathogenic

karyotypes. These additional aneuploidies

included sex chromosome anomalies and

triploidy.

The rates of additional aneuploidies not

identifiable by standard cell-free DNA

screening in the two groups is significantly

different (P<0.01).

23


(Gil et al

2013)

Cohort III-2 1,005 Aim: To explore the feasibility of routine

maternal blood cell-free (cf) DNA testing in

screening for trisomies 21, 18 and 13 at

10 weeks gestation.

Setting: United Kingdom

Population: women with singleton

pregnancy and live fetus with CRL 32-45mm.

Median maternal age was 36.7 (range, 20-

49) years.

Methods: women were screened for

trisomies 21, 18 and 13 with blood taken for

maternal serum tests from cFTS and CFDNA

TESTING at 10 weeks and ultrasound

conducted at 12 weeks. Patient-specific risk

was assessed based on results of cFTS tests,

maternal age and history of trisomic

pregnancy.

Outcomes: Detection of trisomies 21, 18 and

13

In 11 cases the risk score for trisomy 21 and in

five cases that for trisomy 18 was >99%, in

one the risk for trisomy 13 was 34% and in

968 the risk for each of the three trisomies

was <0.01%.

The suspected trisomies were confirmed by

karyotyping after CVS, except in one case

of trisomy 18 in which the karyotype was

normal.

Both cfDNA and combined testing detected

all trisomies, but the estimated false-positive

rates (FPR) were 0.1% and 3.4%, respectively.

Risks for trisomies were provided for 957

(95.2%) cases and in 98.0% these were

available within 14 days from sampling.

In 48 (4.8%) cases no result was provided

due to problems with delivery to the

laboratory, low fetal fraction or assay failure.

Repeat sampling was performed in 40 cases

and a result obtained in 27 (67.5%) of these.

24


(Manotaya

et al 2016)

Cohort III-2 4,736 Aim: to report the clinical experience and

performance of massively parallel

sequencing-based cDNA as a screening

method in detecting trisomy 21, 18, and 13

in a mixed-risk population in Thailand.

Setting: Thailand

Population: high-risk pregnancies either with

advanced maternal age or positive serum

biochemical tests (n=2,840) and low-risk

pregnancies without conventional

indications (n=1,889).

Methods: In a 30-month period, 121 medical

centers in Thailand offered cfDNA as clinical

screening tests for fetal T21, T18, and T13 in

the mixed-risk population. All cfDNA-positive

cases were recommended to undergo

invasive prenatal diagnosis.


13

99.9% (4732/4736) of the participants with a

median maternal age of 35 years old

received reports, and 1.3% (63/4732) were

classified as test positive, including 36 T21, 19

T18, and 8 T13; 82.5% (52/63) took prenatal

diagnosis, and 11.5% (6/52) false-positive

cases were observed.

There were 31 T21, 16 T18, 5 T13, and 4669

euploid cases. We observed one FP of T21,

four FPs of T18 and one FP of T13 in our test,

giving the sensitivities of 100.00%, 100.00%,

and 100.00% and specificities of 99.98%,

99.92%, and 99.98% for detecting T21, T18,

and T13, respectively. The PPV for T21, T18,

and T13 were 96.77% (n=31; 83.3 to 99.9%),

75.00% (n=16; 47.6 to 92.7%), and 80.00%

(n=5; 28.4 to 99.5%), respectively. The overall

specificity for detecting these three

chromosomal anomalies combined was

99.87%, and the overall sensitivity and PPV

were 100.00% and 88.46%, respectively. The

incidence of T21, T18, and T13 were 0.64%,

0.25%, and 0.08%, respectively.

25


(McLennan

et al 2016)

Cohort III-2 5,267 Aim: To assess the implementation of CFDNA

TESTING into clinical practice utilising both

first- and second-line screening models.

Setting: Metropolitan private practices in

Australia

Population: Singleton pregnancies in a

mixed risk population

Methods: cfDNA testing was offered as a

first-line screen, ideally followed by

combined first-trimester screening (cFTS), or

as a second-line test following cFTS,

particularly in those with a calculated risk

between 1:50 and 1:1000.

Outcomes: Detection of trisomies 21, 18 13,

sex chromosome aneuploidies and other

anomalies

cfDNA screening was performed in 5,267

women and as a first-line screening method

in 3,359 (63.8%). Detection rates were 100%

for trisomies 21 and 13 and 88% for

trisomy 18. Of cases with known karyotypes,

the positive predictive value (PPV) of the

test was highest for trisomy 21 (97.7%) and

lowest for monosomy X (25%).

Ultrasound detection of fetal structural

anomaly resulted in the detection of five

additional chromosome anomalies, two of

which had high-risk cFTS results.

For all chromosomal anomalies, cfDNA

alone detected 93.4%, cfDNA in a second-

line model detected 81.8% and cFTS alone

detected 65.9% (P < 0.005).

If women had only had cFTS, the rate of

invasive procedures would have been 5.5%

higher (p<0.0001).

Given the false-positive rate for all

aneuploidies, cfDNA is an advanced

screening test, rather than a diagnostic test.

Study

population may

not be

generalisable to

the Australian

obstetric

community as

women were

predominantly

older,

Caucasian and

from higher

socioeconomic

groups

26


(Meck et al

2015)

Cohort III-2 216 Aim: to determine the positive predictive

value (PPV) of noninvasive prenatal

screening (NIPS) for various aneuploidies

based on cases referred for follow-up

cytogenetic testing. Secondarily, to

determine the false-negative (FN) rate for

those cases with a negative NIPS result.

Setting: United States

Population: Pregnancies at high-risk of fetal

aneuploidy

Methods: We compared the cytogenetic

findings (primarily from chromosome

analysis) from 216 cases referred to our

laboratories with either a positive or

negative NIPS result, and classified NIPS

results as true positive, false positive, true

negative, or FN. Diagnostic cytogenetic

testing was performed on the following

tissue types: amniotic fluid (n = 137),

chorionic villi (n = 69), neonatal blood (n=6),

and products of conception (n = 4).

Outcomes: Detection of trisomies 21, 18, 13,

monosomy X, XXY

The PPV for cfDNA were as follows: 93% for

trisomy (T)21 (n=99; 95%CI 86-97.1%), 58% for

T18 (n=24; 95%CI 36.6-77.9%), 45% for T13

(n=11; 95% CI 16.7-76.6%), 23% for

monosomy X (n=26; 95% CI 9-43.6%), and

67% for XXY (n=6; 95% CI, 22.3-95.7%).

Of the 26 cases referred for follow-up

cytogenetics after a negative cfDNA result,

1 (4%) was false negative (T13). Two cases of

triploidy, a very serious condition but one

not claimed to be detectable by the test

providers, were among those classified as

true negatives.

T21, which has the highest prevalence of all

aneuploidies, demonstrated a high true-

positive rate, resulting in a high PPV.

However, the other aneuploidies, with their

lower prevalence, displayed relatively high

false-positive rates and, therefore, lower

PPV. Patients and physicians must fully

understand the limitations of this screening

test and the need in many cases to follow

up with appropriate diagnostic testing to

obtain an accurate diagnosis.

27


(Neufeld-

Kaiser et al

2015)

Cohort III-2 632 Aim: to present independent data on the

PPVs of cfDNA testing in actual clinical

practice.


Population: Pregnancies at high risk of fetal

aneuploidy

Methods: Charts were retrospectively

reviewed for patients who had cfDNA and

were seen March 2012 to December 2013 in

a tertiary academic referral center. cfDNA

results were compared to diagnostic

genetic test results, fetal ultrasound results,

and clinical phenotype/outcomes. The PPV

was calculated using standard

epidemiological methods. Correlation

between screen results and both maternal

age at delivery and gestational age at time

of screening was assessed using Wilcoxon's

rank sum test.

Outcomes: Detection of trisomies 21, 18, 13

and sex chromosome aneuploidies

41 of 55 abnormal cfDNA results were

concordant with abnormal fetal outcomes,

12 were discordant, and 2 were

undetermined. The PPV for all conditions

included in the screen was 77.4 % (95 % CI,

63.4 - 87.3).

Of 578 patients with normal cfDNA results,

normal pregnancy outcome was confirmed

for 156 (27%) patients. This incomplete

follow-up of normal NIPS results does not

affect PPV calculations, but it did preclude

calculations of sensitivity, specificity, and

NPV.

Maternal age at delivery was significantly

lower for patients with abnormal discordant

results, compared to patients with abnormal

concordant results (P = 0.034). Gestational

age at time of screening was not associated

with concordance of screen results

(P=0.722).

The experience of using cfDNA in clinical

practice confirms that abnormal results

cannot be considered diagnostic. Pre-test

counseling should emphasize this.

Diagnostic genetic testing should always be

offered following abnormal cfDNA results.

28


(Nicolaides

et al 2014)

Case-

control

III-2 56 Aim: To investigate potential performance

of cell-free DNA (cfDNA) testing in maternal

blood in detecting fetal triploidy.


Population: Pregnancies at high-risk of

trisomies 13, 18 and 21

Methods: Plasma and buffy coat samples

obtained at 11-13 weeks' gestation from

singleton pregnancies with diandric triploidy

(n=4), digynic triploidy (n=4), euploid fetuses

(n=48) were sent to Natera, Inc. for cfDNA

testing. Multiplex polymerase chain reaction

amplification of cfDNA followed by

sequencing of single nucleotide

polymorphic loci covering chromosomes 13,

18, 21, X, and Y was performed. Sequencing

data were analyzed using the NATUS

algorithm which identifies copy number for

each of the five chromosomes.

Outcomes: detection of fetal triploidy

cfDNA testing provided a result in 44 (91.7%)

of the 48 euploid cases and correctly

predicted the presence of two copies each

of chromosome 21, 18 and 13.

In diandric triploidy, cfDNA testing identified

multiple paternal haplotypes (indicating

fetal trisomy 21, trisomy 18 and trisomy 13)

suggesting the presence of either triploidy or

dizygotic twins. In digynic triploidy the fetal

fraction corrected for maternal weight and

gestational age was below the 0.5th

percentile.

cfDNA testing by targeted sequencing and

allelic ratio analysis of single nucleotide

polymorphisms covering chromosomes 21,

18, 13, X, and Y can detect diandric triploidy

and raise the suspicion of digynic triploidy.

29


(Shi et al

2015)

Cohort III-2 182 Aim: to determine the feasibility of early

gestational (51–84 days) cfDNA testing.

Setting: China

Population: High-risk pregnancies

Methods: Plasma DNA libraries were

subjected to MPS and chromosomal read

counts normalized to reference.

Chromosomal aneuploidy was determined

by z-scores (- 3. <. z<. 3, normal range). The

cff DNA fraction in 96 male pregnancies was

calculated by the relative proportion of Y

chromosomal reads.

Outcomes: Detection of trisomies 21, 18, 13

and 45X.

cfDNA results were obtained in the first (8-12.

weeks) and second (15-18. weeks) trimester

for 182 high-risk women.

cfDNA testing identified T21, T13 and 45,X in

3 pregnancies that were confirmed by

karyotyping, but missed a T15 pregnancy

that eventually miscarried. In the remaining

178 pregnancies, results for first and second

trimester cfDNA testing were normal.

The median fetal fraction in the first trimester

was 7.6. ±. 4.18% (compared with 10.47±4.7%

in the second trimester) and 15.6% of

samples were identified with a cff fraction

below 4%. Different trends of cff DNA

fraction change were observed between

the first and second trimester, with 59% of

pregnancies showing an increase, 17%

showing no change and 24% showing a

decrease.

30

1.5 Cell-free DNA testing as a replacement for first trimester serum and nuchal translucency screening

Systematic reviews


(Metcalfe

et al 2014)

SLR I 65

studies

Aim: to systematically review the literature

and use diagnostic meta-analysis to derive

pooled detection and false positive rates for

aneuploidies other than trisomy 21 with

different prenatal screening tests.

Non-invasive prenatal testing had the

highest detection (DR) and lowest false

positive (FPR) rates for trisomy 13 (DR: 90.3%;

FPR: 0.2%), trisomy 18 (DR: 98.1%; FPR: 0.2%),

and 45,X (DR: 92.2%; FPR: 0.1%); however,

most estimates came from high-risk samples.

The first trimester combined test also had

high DRs for all conditions studied (trisomy 13

DR: 83.1%; FPR: 4.4%; trisomy 18 DR: 91.9%;

FPR: 3.5%; 45,X DR: 70.1%; FPR: 5.4%).

31

Prospective cohort studies


(McLennan

et al 2016)





Australia











anomalies
















detected 65.9% (P < 0.005).



higher (p<0.0001).




Study

population may

not be

generalisable to

the Australian

obstetric

community as

women were

predominantly

older,

Caucasian and

from higher

socioeconomic

groups

32

Retrospective cohort studies

Trisomy 21 only


(Gyselaers

et al 2015)

Cohort

study

III-2 99,619 Aim: To evaluate costs and benefits of

different scenarios for cfDNA screening.

Setting: Belgium

Population: Pregnancies screened by

combined first trimester screening (78.5%) or

second trimester screening (21.5%) in 2011

Methods: Data from the Belgian National

Institute for Health and Disability Insurance

and the Study Centre for Perinatal

Epidemiology were used in modeled

calculations of medical and economic

impact of cfDNA after prior conventional

screening (1) at thresholds 1:300 and 1:600,

and (2) at current and improved screening

sensitivity.

Outcomes: Detection of trisomy 21, rate of

procedure-related miscarriage, costs

With cfDNA screening as a first-line test, live

birth prevalence of Down syndrome was

5.10/000 compared with 7.90/000 with current

screening (combined first trimester

screening or second trimester screening).

Rates of procedure-related miscarriage

were lower than with current screening (0.02

vs 0.06%).

Study assumed

that cfDNA

testing has a

sensitivity of

99.3% and a

specificity of

99.84% for

trisomy 21 (Neyt

et al 2014)

33


(Kagan et

al 2015b)

Cohort

study

III-2 675,332 Aim: to examine the screening performance

of a trisomy 21 screening strategy based on

maternal age, cFTS and cfDNA testing as

well as the combinations maternal age and

cfDNA and FTS and cfDNA.

Setting: Germany

Population: all births in 2012

Methods: a model-based approach was

used to evaluate all births together with the

percentage of euploid and trisomic

pregnancies. Detection rates (DR), false

positive rates (FPR), the costs of different

screening strategies for trisomy 21 and

combinations of these strategies were

compared. The number of fetuses with

trisomy 21 at 12+0 weeks of gestation was

estimated based on maternal age

distribution.

Outcomes: Detection of trisomy 21 and

costs

Screening based on FTS (1:250) resulted in a

detection rate (DR) of 92.2% and a false

positive rate (FPR) of 8.0%.

Screening based on cfDNA resulted in a DR

of 99.9% and a FPR of 0.1%. If a 3% fail rate

requiring subsequent invasive testing was

postulated, the total FPR was 3.1% and the

DR remained the same.

When maternal age was combined with

cfDNA (ie testing only offered to women

over 30 years), this resulted in a DR of 85.2%

and a FPR of 1.7%.

Estimates were

based on a

detection rate

of 99.9% and a

false positive

rate of 0.1%

34

Trisomy 21 and other chromosomal anomalies


(Kagan et

al 2015a)

Cohort

study

III-2 21,052 Aim: To examine cFTS, cfDNA testing and a

two-step policy that combines FTS and

cfDNA in screening for aneuploidy.

Setting: Germany

Population: pregnancies where cFTS was

performed

Methods: The following screening policies

were examined: cfDNA or FTS with sum risk

cut-offs of 1 in 50 and 1 in 250 in all patients

or a two-step-policy with FTS in all patients

followed by cfDNA in the intermediate sum

risk group. For the intermediate risk group,

sum risk cut-offs of 1 in 50 and 1 in 1000 and

1 in 150 and 1 in 500 were used.

Outcomes: detection of all aneuploidies

FTS with a sum risk cut-off of 1:50 and 1:250

detects 81% and 91% of all aneuploidies.

cfDNA in all cases detects 87.7% of all

aneuploidies.

Detection rates using FTS 1:250 were trisomy

21: 91.3%; trisomy 18: 97.1%; trisomy 13:

92.3%; sex chromosome aneuploidies: 80.0%;

atypical aneuploidies: 87.0%, with invasive

testing in 9.5%.

For cfDNA alone, detection rates were

trisomy 21: 99.2%; trisomy 18: 97.1%; trisomy

13: 92.2%; sex chromosome aneuploidies:

100.0%; atypical aneuploidies: 0%, with

invasive testing in 6.9%

Study assumed

that cfDNA

detects 99%,

98%, 90% and

99% of cases

with trisomy 21,

18, 13 and sex

chromosomal

anomalies and

that the false-

positive rate is

0.5 %.

(Lichtenbel

t et al 2015)

Cohort

study

III-2 25,057 Aim: to determine what percentage of fetal

chromosomal anomalies remains

undetected when first trimester combined

testing is replaced by non-invasive prenatal

testing for trisomies 13, 18, and 21. We

focused on the added clinical value of

nuchal translucency (NT) measurement.

Setting: The Netherlands

Population: singleton pregnancies in which

first trimester combined testing was

performed

Methods: Fetal karyotype, ultrasound

findings and pregnancy outcome of all

pregnancies with an NT measurement

>3.5mm were retrospectively collected.

Two hundred twenty-five fetuses (0.9 %) had

an NT >3.5mm. In 24 of these pregnancies, a

chromosomal anomaly other than trisomy

13, 18, or 21 was detected. Eleven resulted

in fetal demise, and ten showed fetal

ultrasound anomalies. In three fetuses with

normal ultrasound findings, a chromosomal

anomaly was detected, of which one was a

triple X.

In 3 of 25,057 pregnancies (0.01%), non-

invasive prenatal testing and fetal

ultrasound would have missed a

chromosomal anomaly that would have

been identified by NT measurement.

35


(Petersen

et al 2014)

Cohort

study

III-2 193,638 Aim: to determine the risk of missing other

abnormal karyotypes of probable

phenotypic significance by cfDNA testing.

Setting: Denmark

Population: singleton pregnancies booked

for combined first trimester screening over a

4-year period

Methods: Data concerning maternal

demographics, cFTS and prenatal or

postnatal karyotypes were collected from

the Danish Fetal Medicine database.

Karyotypes were classified according to

whether the chromosomal anomaly would

have been detected by cfDNA testing and

whether it was likely to affect phenotype.

10,205 (5.3%) pregnancies had cytogenetic

or molecular analysis performed. Of these,

1,122 (11.0%) had an abnormal karyotype,

of which 262 (23.4%) would have been

missed by CFDNA TESTING, but would

probably have been clinically significant.

The prevalence of such 'atypical abnormal

karyotypes' was increased in women over 45

years of age, in pregnancies with increased

nuchal translucency (NT) thickness (> 3.5

mm), with abnormal levels of free beta-

human chorionic gonadotropin (<0.2 or >

5.0 multiples of the median [MoM]) or

pregnancy-associated plasma protein-

A<0.2 MoM. One or more of these factors

was present in 3% of women, and the

prevalence of atypical abnormal

karyotypes in this high-risk cohort was 1.6%.

Study assumed

that cfDNA

testing would

have 100%

sensitivity for

trisomies 21, 18

and 13 and sex

chromosome

aneuploidy.

36


(Susman et

al 2010)

Cohort

study

III-2 143,051 Aim: To compare the number and types of

chromosome anomalies prenatally

diagnosed and the number of invasive

procedures between current prenatal

testing pathways (a combination of first or

second trimester screening plus ultrasound

and/or diagnostic testing) and a pathway

where cfDNA testing replaces Down

syndrome screening tests.

Setting: Victoria, Australia

Population: women participating in prenatal

diagnostic testing

Methods: Numbers and types of

chromosome anomalies for each referral

category were extracted from prenatal

diagnostic testing reports routinely collected

in Victoria, Australia, in 2006 and 2007. These

data were then applied to the proposed

implementation strategy.

If cfDNA testing for Down syndrome had

replaced Down syndrome screening tests in

2006 and 2007, in Victoria, there would have

been 25 (7%) additional Down syndrome

diagnosed, a 28% reduction in detection of

chromosomal anomalies. Specifically, 56%

non-Down syndrome chromosome

anomalies would no longer detected

(including trisomy 13, trisomy 18, sex

chromosome anomalies, balanced and

unbalanced rearrangements, polyploidy,

and mosaic results).

With the inclusion of trisomy 13, trisomy 18,

and sex chromosome aneuploidy in the

cfDNA panel, the number of missed

anomalies would decrease to 11%.

There would have been 6,896 (84%) fewer

invasive procedures with cfDNA testing for

Down syndrome; 83% fewer with an

aneuploidy panel.

37


(Syngelaki

et al 2014)

Cohort

study

III-2 74,561

(screen)

14,684

(karyo-

type)

Aim: To estimate the proportion of other

chromosomal anomalies that could be

missed if combined screening was replaced

by cfDNA testing as the method of

screening for trisomies 21, 18 and 13.


Population: singleton pregnancies

undergoing CVS following screening for

trisomies 21, 18 and 13 by the combination

of maternal age, fetal NT and FHR and

maternal serum-free β-hCG and PAPP-A at

11–13 weeks’ gestation

Methods: The prevalence of trisomies 21, 18

or 13, sex chromosome aneuploidies,

triploidy and other chromosomal anomalies

was examined in pregnancies undergoing

first-trimester combined screening and CVS.


13, sex chromosome aneuploidies, triploidy

and other chromosomal anomalies

A policy of universal screening by cfDNA

testing for trisomies 21, 18 and 13 would lead

to an invasive testing rate of about 1% and

a detection rate of 98.6% for trisomy 21 and

95.7% for trisomies 18 and 13, but no

detection of sex chromosome aneuploidies,

triploidies or other anomalies at high risk of

adverse outcome. The rate of invasive

testing would be 0.9% and the rate of no

result 2%.

Current combined screening with invasive

testing at risk ≥1:100 would detect 87% of

trsiomy 21, 91.8% of trisomies 13 and 18,

86.0% of monosomy X, 8.1% of other sex

chromosome aneuploidies, 89.3% of triploidy

and 13.0% of other high-risk outcome, with

an invasive test rate of 2.6%.

Estimates based

on cfDNA

detection rates

of 99.0% for

trisomy 21, 96.8%

for trisomy 18,

92.1% for trisomy

13 and a false

positive rate of

0.2%

38

Modelling studies

Trisomy 21 only


(Mersy et al

2015)

Modelling

study

— 100,000 Aim: to conduct a quantitative analysis of

different cfDNA testing strategies.


Population: Theoretical cohort of pregnant

women

Methods: Decision trees were created to

illustrate all plausible alternatives in five

screening programmes: classical screening

by the first-trimester combined test (FCT),

pre-selection of high-risk women prior to

cfDNA by the FCT, cfDNA as the first

screening test at 10 weeks and at 13 weeks,

and the simultaneous conductance of

cfDNA and the FCT.

Outcomes: Detection of trisomy 21, rates of

amniocentesis and procedure-related fetal

loss.

cfDNA as the first screening test detects

almost all fetal Down syndrome cases (87.5%

at 10 weeks, 82.5% at 13 weeks compared

to 78.5% with classical first trimester

screening).

Rates of fetal loss due to amniocentesis

complications are lower (n=2 at 10 weeks or

13 weeks versus 25 with classical first

trimester screening) as fewer women

undergo amniocentesis (n=234 vs 4,056).

Model assumed

a sensitivity of

99.6% and

specificity of

99.9% for cfDNA

testing for

trisomy 21 in

high- and low-

risk pregnancies

and a sensitivity

of 89% and

specificity of

95.4% for cFTS.

39


(Morris et al

2014)

Modelling

study

— 10,000 Aim: To investigate the costs and outcomes

of CFDNA TESTING for Down syndrome (DS)

as first- and second-line testing compared

with combined first trimester screening.


Population: Cohort of hypothetical pregnant

women

Methods: We used a pre-existing model to

evaluate the costs and outcomes

associated with CFDNA TESTING compared

with the current DS screening programme.

Model inputs were taken from published

sources.

Outcomes: The main outcome measures

were number of DS cases detected, number

of procedure-related miscarriages and total

cost.

As first-line testing, cfDNA testing detects

more trisomy 21 cases (16.49 vs 13.24),

reduces rates of amniocentesis (22.03 vs

160.59), has fewer procedure-related

miscarriages (0.11 vs 0.8), and is more

expensive than current screening (£449,000

vs £279,000 for 10,000 women at a cost of

£50 per cfDNA). When cfDNA uptake

increases, cfDNA detects more trisomy 21

cases with a small increase in procedure-

related miscarriages and costs.

40



(Kaimal et

al 2015)

Modelling

study

— — Aim: To use a decision-analytic model to

assess a comprehensive set of outcomes of

prenatal genetic testing strategies among

women of varying ages.


Population: theoretical cohort of women

desiring screening

Methods: We assessed outcomes of six

testing strategies incorporating diagnostic

testing with chromosomal microarray,

multiple marker screening, cell-free DNA

screening, and nuchal translucency

screening alone, in combination, or in

sequence.

Outcomes: prenatal detection or birth of a

neonate with a significant chromosomal

anomaly and diagnostic procedures

performed. Other outcomes included

maternal quality-adjusted life-years and

costs. Sensitivity analyses were conducted

to examine the robustness of the findings.

When considering all detectable

chromosomal anomalies as well as patient

preferences and baseline risks, multiple

marker screening with the option for

diagnostic testing for screen positive results is

the most effective (highest quality-adjusted

life years) at ages 20–38 years. At age 40

years and older, cfDNA as a primary screen

becomes optimal and is cost-effective.

Potential conflict

of interest

41

1.6 Cell-free DNA combined with cFTS

Prospective cohort studies


(Gil et al

2013)

Cohort III-2 1,005 Aim: To explore the feasibility of routine

maternal blood cell-free (cf) DNA testing in

screening for trisomies 21, 18 and 13 at

10 weeks gestation.



pregnancy and live fetus with CRL 32-45mm.

Median maternal age was 36.7 (range, 20-

49) years.

Methods: women were screened for

trisomies 21, 18 and 13 with blood taken for

maternal serum tests from cFTS and CFDNA

TESTING at 10 weeks and ultrasound

conducted at 12 weeks. Patient-specific risk

was assessed based on results of cFTS tests,

maternal age and history of trisomic

pregnancy.


13

In 11 cases the risk score for trisomy 21 and in

five cases that for trisomy 18 was >99%, in

one the risk for trisomy 13 was 34% and in

968 the risk for each of the three trisomies

was <0.01%.

The suspected trisomies were confirmed by

karyotyping after CVS, except in one case

of trisomy 18 in which the karyotype was

normal.

Both cfDNA and combined testing detected

all trisomies, but the estimated false-positive

rates (FPR) were 0.1% and 3.4%, respectively.

Risks for trisomies were provided for 957

(95.2%) cases and in 98.0% these were

available within 14 days from sampling.

In 48 (4.8%) cases no result was provided

due to problems with delivery to the

laboratory, low fetal fraction or assay failure.

Repeat sampling was performed in 40 cases

and a result obtained in 27 (67.5%) of these.

42


(McLennan

et al 2016)





Australia











anomalies
















detected 65.9% (P < 0.005).



higher (p<0.0001).




Study

population may

not be

generalisable to

the Australian

obstetric

community as

women were

predominantly

older,

Caucasian and

from higher

socioeconomic

groups

43

Retrospective cohort studies

Trisomy 21 only


(Conner et

al 2015)

Cohort

Study

III-2 35,780 Aim: To evaluate the performance and cost

efficacy of different first-trimester second-

line screening strategies based on an initial

analysis of biochemical markers.

Setting: Swedish National Quality Register for

prenatal diagnosis.


pregnancies.

Methods: Serum values from first trimester

biochemistry were re-analyzed in a second-

line approach. For risks between 1:40 and

1:1000, risk estimates from nuchal

translucency measurements were added

and outcomes were compared using either

a final cut-off risk of 1:200 to proceed with

invasive testing or offering non-invasive

prenatal testing. The costs of detecting one

case of aneuploidy were compared.


13 (only trisomy 21 reported for cfDNA).

Offering cfDNA testing to the intermediate

risk group (double serum test risk between

1:40 and 1:1,000) would result in a trisomy 21

detection rate of 98% (compared to 87% for

combined screening and second-line

screening using nuchal translucency as a

second-tier test), but the cost to detect one

case of trisomy 21 would be 83% higher than

the cost associated with traditional

combined screening.

44


(Gyselaers

et al 2015)

Cohort

study

III-2 99,619 Aim: To evaluate costs and benefits of

different scenarios for second-line cfDNA

screening.

Setting: Belgium

Population: Pregnancies screened by

combined first trimester screening (78.5%) or

second trimester screening (21.5%) in 2011

Methods: Data from the Belgian National

Institute for Health and Disability Insurance

and the Study Centre for Perinatal

Epidemiology were used in modeled

calculations of medical and economic

impact of cfDNA testing after prior

conventional screening (1) at thresholds

1:300 and 1:600, and (2) at current and

improved screening sensitivity.

Outcomes: Detection of trisomy 21, rate of

procedure-related miscarriage, costs

Second-line cfDNA screening under current

screening conditions would maintain today's

7.90/000 live birth prevalence of Down

syndrome (LBPD) at an 11% reduction of

overall short-term costs. Lowering the

screening threshold to 1:600 or increasing

sensitivity by 10% would reduce LBPD to

70/000 at a maximum 3% increase of overall

short-term costs.

Rates of procedure-related miscarriage

were lower with cfDNA than with current

screening (0.03 vs 0.06%) with a risk threshold

of 1:300 or 1:600.

The study

assumed that

cfDNA testing

has a sensitivity

of 99.3% and a

specificity of

99.84% for

trisomy 21 (Neyt

et al 2014)

45


(Kagan et

al 2015b)

Cohort

study

III-2 675,332 Aim: to examine the screening performance

of a trisomy 21 screening strategy based on

maternal age, first trimester screening (FTS)

and cfDNA testing as well as the

combinations maternal age and cfDNA and

FTS and cfDNA.

Setting: Germany

Population: all births in 2012

Methods: a model-based approach was

used to evaluate all births together with the

percentage of euploid and trisomic

pregnancies. Detection rates (DR), false

positive rates (FPR), the costs of different

screening strategies for trisomy 21 and

combinations of these strategies were

compared. The number of fetuses with

trisomy 21 at 12+0 weeks of gestation was

estimated based on maternal age

distribution.

Outcomes: Detection of trisomy 21 and

costs

Screening based on FTS (1:250) resulted in a

detection rate (DR) of 92.2 and a false

positive rate (FPR) of 8.0.

When maternal age was combined with

cfDNA (ie only offered to women over a

certain age); if a cut-off of 30 years was

used, this resulted in a DR of 85.2 and a FPR

of 1.7.

If primary screening consisted of FTS with

cfDNA testing when the risk was between

1:10 and 1:1000, the detection rate was 96.7

and the false positive rate was 1.2.

Estimates were

based on a

detection rate

of 99.9% and a

false positive

rate of 0.1%

46


(Maxwell et

al 2016)

Cohort

study

III-2 90,352 Aim: To provide data on how screen-

positive and detection rates of first trimester

prenatal screening for fetal Down syndrome

vary with changes in the risk cut-off and

maternal age to inform contingency criteria

for publicly funded noninvasive prenatal

testing.

Setting: Australia

Population: all women attending for first

trimester fetal aneuploidy screening in

Western Australia between 2005 and 2009

Methods: First trimester screening and

diagnostic data were collected and were

linked to pregnancy outcomes, including

data from the Midwives' Notification System

and the Western Australian Registry of

Developmental Anomalies.

Outcomes: Prevalence of trisomy 21 and

performance of risk cut-offs

The current screening risk cut-off of 1:300 has

screen-positive and detection rates of 3.5%

and 82%. The screen-positive rate increases

by 0.7-0.8% for each 100 point change in

risk, up to 19.2% at 1:2500 (96% detection

rate). Including all women >35 years as

screen positive would increase the screen-

positive rate and detection rates to 30.2%

and 97.2%.

Variation in screening risk cut-off and the

use of maternal age to assess eligibility for

noninvasive testing could significantly

impact the demand for, and cost of, the

test. A second-line first trimester screening

approach for risk assessment is superior to

the use of a combination of screening and

maternal age alone.

47


(O'Leary et

al 2013)

Cohort

study

III-2 32,478 Aim: To analyse the cost-effectiveness and

performance of cfDNA testing for high-risk

pregnancies following first-trimester

screening compared with current practice.

Setting: West Australia, Australia

Population: singleton pregnancies screened

between January 2005 and December 2006

Methods: A decision-tree analysis was used

to compare the costs and benefits of

current practice of first-trimester screening

with a testing pathway incorporating cfDNA

testing for women with combined first

trimester screening risk of 1:300. We applied

the model, adding Medicare rebate data

as a measure of public health system costs.

The analyses reflect the actual uptake of

screening and diagnostic testing and

pregnancy outcomes in this cohort.

Outcomes: Detection of trisomy 21, numbers

of invasive tests and procedure-related

miscarriages, costs

If cfDNA testing was adopted by all women

identified as high risk by cFTS, up to 7 (2 per

10,000 women) additional trisomy 21 fetuses

could be confirmed.

The introduction of second-line cfDNA

testing would reduce the number of invasive

diagnostic procedures in high-risk women by

88%.

48



(Kagan et

al 2015a)

Cohort

study

III-2 21,052 Aim: To examine combined first trimester

screening (FTS), cfDNA testing and a two-

step policy that combines FTS and cfDNA in

screening for aneuploidy.

Setting: Germany

Population: pregnancies where FTS was

performed

Methods: The following screening policies

were examined: cfDNA or FTS with sum risk

cut-offs of 1 in 50 and 1 in 250 in all patients

or a two-step-policy with FTS in all patients

followed by cfDNA in the intermediate sum

risk group. For the intermediate risk group,

sum risk cut-offs of 1 in 50 and 1 in 1000 and

1 in 150 and 1 in 500 were used.

Outcomes: detection of all aneuploidies

FTS with a sum risk cut-off of 1:50 and 1:250

detects 81% and 91% of all aneuploidies.

cfDNA in the 2-step approach with sum risk

cut-offs of 1:50 and 1:1000 detects 94% of all

aneuploidies. With sum risk cut-offs of 1:150

and 1:500, the detection rate is 93%.

Detection rates using FTS 1:250 were trisomy

21: 91.3%; trisomy 18: 97.1%; trisomy 13:



testing in 9.5%.

Using a 2-step approach with cfDNA for

1:50–1:1,000, detection rates were trisomy

21: 97.6%; trisomy 18: 100.0%; trisomy 13:



testing in 4.1%.

Using a 2-step approach with cfDNA for

1:150–1:500, detection rates were trisomy 21:

95.3%; trisomy 18: 97.1%; trisomy 13: 92.3%;

sex chromosome aneuploidies: 80.0%;


testing in 6.9%.

Study assumed

that CFDNA

TESTING detects

99%, 98%, 90%

and 99% of

cases with

trisomy 21, 18, 13

and sex

chromosomal

anomalies and

that the false-

positive rate is

0.5 %.

49


(Khalil et al

2015)

Cohort

study

III-2 5,306 Aim: to investigate aneuploidy detection

using an approach based on nuchal

translucency (NT) and cfDNA testing.


Population: Pregnancies identified as high-

risk by combined first trimester screening

Methods: analysis of NT measurements and

chorionic villus samples (CVS) tested for full

karyotype to estimate the potential impact

of:

• current practice, where high-risk women

have a CVS

• relying entirely on cfDNA to replace CVS

for all high-risk women or

• using cfDNA as the main method of

prenatal screening, with CVS reserved

for increased NT thickness and a family

history of chromsomal anomalies

Outcomes: Detection of aneuploidies, rates

of invasive tests and procedure-related

miscarriage.

A policy of relying solely on cfDNA as a

second-tier screen for women identified as

high-risk by combined first trimester

screening would have led to the diagnosis

of 88.9% of clinically significant anomalies

and avoid miscarriage in 98% of

pregnancies compared to CVS for all.

A strategy whereby cfDNA is the main

second-tier test, with CVS reserved for cases

with NT ≥3.0 mm, would require CVS in 21.7%

of cases, identify 94.8% of significant

anomalies and avoid miscarriage in 77%

pregnancies compared to CVS for all.

Study assumed

that trisomies 21,

18 and 13, 45X,

other sex

chromosome

aneupleudies,

triploidy and

tetraploidy were

detectable by

cfDNA testing

and assumed a

0% failure rate.

Potential conflict

of interest

50


(Maxwell et

al 2015)

Cohort

study

III-2 1,488 Aim To describe the potential impact of

using cfDNA testing as a second-tier test, on

the diagnosis and outcomes of pregnancies

identified as high risk through first trimester

screening (FTS) in a cohort of real

pregnancies.

Setting: Australia

Population:

Methods: Western Australian FTS and

diagnostic data (2007-2009) were linked to

pregnancy outcomes. Karyotype results

from invasive prenatal testing in high-risk

women were analysed.

Outcomes: abnormal results that would not

be detected by cfDNA testing, assuming a

panel of trisomy 21/18/13 and sex

chromosome aneuploidies, and the

likelihood of diagnosis in a screening model

using CFDNA as a second-tier test.

Abnormal karyotype results were reported in

224 (15%) women with high-risk pregnancies

having invasive diagnostic testing. cfDNA

testing potentially would have identified

85%. The 33 anomalies unidentifiable by

CFDNA were triploidies (n=7, 21%), balanced

(n=8, 24%) and unbalanced rearrangements

(n=10, 30%) and level III mosaicisms (n=8,

24%).

For conditions not identifiable by CFDNA,

fetal sonographic appearance was likely to

have led to invasive testing for 10 of 17 (59%)

pathogenic anomalies.

A screening model with cfDNA as a second-

tier for high-risk pregnancies would be

unlikely to have changed the outcome for

the majority of pregnancies. Optimising the

diagnosis of rare pathogenic anomalies

requires clear indicators for invasive testing

over cfDNA.

Don’t have full

text

51


(Syngelaki

et al 2014)

Cohort

study

III-2 14,684 Aim: To estimate the proportion of other

chromosomal anomalies that could be

missed if combined screening was replaced

by cell-free (cf) DNA testing as the method

of screening for trisomies 21, 18 and 13.



undergoing CVS following screening for

trisomies 21, 18 and 13 by the combination

of maternal age, fetal NT and FHR and

maternal serum-free β-hCG and PAPP-A at

11–13 weeks’ gestation

Methods: The prevalence of trisomies 21, 18

or 13, sex chromosome aneuploidies,

triploidy and other chromosomal anomalies

was examined in pregnancies undergoing

first-trimester combined screening and

chorionic villus sampling (CVS).


13, sex chromosome aneuploidies, triploidy

and other chromosomal anomalies

Combined screening followed by CVS for

risk >1:10 and cfDNA testing for risk 1:11-

1:2,500 could detect 97% of trisomy 21 and

98% of trisomies 18 and 13. Additionally, 86%

of monosomy X, half of 47,XXY, 47,XYY or

47,XXX, half of other chromosomal

anomalies and one third of triploidies that

are currently detected by combined

screening and CVS for risk>1:100, could be

detected.

Screening by cfDNA testing, contingent on

results of combined testing, improves

detection of trisomies, but misses a few of

the other chromosomal anomalies detected

by screening with the combined test.

Current combined screening with invasive

testing at risk ≥1:100 would detect 87% of

trsiomy 21, 91.8% of trisomies 13 and 18,

86.0% of monosomy X, 8.1% of other sex

chromosome aneuploidies, 89.3% of triploidy

and 13.0% of other high-risk outcome, with

an invasive test rate of 2.6%.

Estimates based

on cfDNA

detection rates

of 99.0% for

trisomy 21, 96.8%

for trisomy 18,

92.1% for trisomy

13 and a false

positive rate of

0.2%

52

Modelling studies

Trisomy 21 only


(Mersy et al

2015)

Modelling

study

— 100,000 Aim: to conduct a quantitative analysis of

different CFDNA implementation strategies.


Population: Theoretical cohort of pregnant

women

Methods: Decision trees were created to

illustrate all plausible alternatives in five

screening programmes: classical screening

by cFTS, pre-selection of high-risk women

(>1:200) prior to cfDNA by the cFTS, cfDNA

as the first screening test at 10 weeks and at

13 weeks, and the simultaneous

conductance of cfDNA and the cFTS.

Outcomes: Detection of trisomy 21, rates of

amniocentesis and procedure-related fetal

loss.

Detection rate for trisomy 21 in the first

trimester was the same for cFTS and cFTS

plus cfDNA (78.5%) but the false positive rate

was lower in the latter (n=4 vs 4,412)

Pre-selection by cFTS prior to cfDNA reduces

the number of amniocenteses to a minimum

(136 vs 234 with cfDNA used as a first-line test

and 4,056 with cFTS) because of a reduction

of false-positive cfDNA results (4 vs 95–96

with cfDNA used as a first-line test).

Model assumed

a sensitivity of

99.6% and

specificity of

99.9% for cfDNA

testing for

trisomy 21 in

high- and low-

risk pregnancies

and a sensitivity

of 89% and

specificity of

95.4% for cFTS.

53


(Morris et al

2014)

Modelling

study

— 10,000 Aim: To investigate the costs and outcomes

of CFDNA TESTING for Down syndrome (DS)

as first- or second-line screening compared

with combined first trimester screening.


Population: Cohort of hypothetical pregnant

women

Methods: We used a pre-existing model to

evaluate the costs and outcomes

associated with cfDNA testing compared

with the current trisomy 21 screening

programme. Model inputs were taken from

published sources.

Outcomes: Number of trisomy 21 cases

detected, number of procedure-related

miscarriages and total cost.

At a screening risk cut-off of 1:150 in a

population of 10,000 women, cfDNA as

second-line testing detects slightly fewer

trisomy 21 cases (11.26 vs 13.24), has fewer

procedure-related miscarriages (0.06 vs 0.8),

and costs the same as current screening

(around UK280,000) at a cost of 500 per

cfDNA.

54



(Kaimal et

al 2015)

Modelling

study

— — Aim: To use a decision-analytic model to

assess a comprehensive set of outcomes of

prenatal genetic testing strategies among

women of varying ages.


Population: theoretical cohort of women

desiring screening

Methods: We assessed outcomes of six

testing strategies incorporating diagnostic

testing with chromosomal microarray,

multiple marker screening, cell-free DNA

screening, and nuchal translucency

screening alone, in combination, or in

sequence.

Outcomes: Clinical outcomes included

prenatal detection or birth of a neonate

with a significant chromosomal anomaly

and diagnostic procedures performed.

Other outcomes included maternal quality-

adjusted life-years and costs. Sensitivity

analyses were conducted to examine the

robustness of the findings.

At all ages assessed, screening strategies

starting with multiple marker screening

offered the highest detection rate when all

chromosomal anomalies were considered

Incorporating cfDNA as an optional

secondary screen decreased the number of

diagnostic procedures, but also decreased

the number of anomalies diagnosed

prenatally, resulting in a similar number of

procedures per case diagnosed at age

30 years; the option of secondary cfDNA

screening becomes more favorable at older

ages.

Potential conflict

of interest

55

1.7 Impact of cell-free fetal DNA testing on screening practices and invasive procedures


(Chan et al

2015)

Historical

control

III-3 Aim: to evaluate the uptake of non-invasive

cell-free fetal DNA screening test (NIDT) after

a high-risk screening result for trisomy 21

Setting: Hong Kong

Population: Chinese women who had a

high-risk (term risk >1:250) first-trimester or

second-trimester screening test at three

public hospitals.

Measurements: Association between

maternal and pregnancy characteristics on

women's test choice was assessed after

adjusting for confounding factors

Outcomes: rate of declining further testing

and obstetric and maternal factors

impacting on patient's selection of testing

options.

Compared with the pre-cfDNA period, the

availability of cfDNA resulted in a 45%

(P<0.001) reduction in the rate of refusal for

further testing and a decrease from 92.2% to

66.7% in the use of invasive diagnostic test

after a positive screening test.

56


(Chetty et

al 2013)

Historical

control

III-3 1,036 Aim: to investigate how the introduction of

cfDNA testing impacted women's testing

choices following a positive prenatal

screening (PNS) result.


Population: Women with a positive prenatal

screening test result (first and/or trimester

serum analytes and nuchal translucency

ultrasound)

Method: Women were offered cfDNA or


Outcomes: Rates of invasive testing and

declining follow-up were compared with

testing decisions the prior year. Differences

were compared using t-test and chi-square.

Multivariable logistic regression was

performed to identify predictors of test

choice.

Year before introduction: 638 screen positive

patients were seen: 301 (47.2%) had invasive

testing and 337 (52.8%) declined.

Year post introduction: 156 (39.2%)

underwent invasive testing, 157 (39.4%) had

cfDNA and 84 (21.1%) declined further

testing.

The rate of invasive testing declined

significantly (p=0.012). Moreover, fewer

women declined follow-up testing after

introduction of cfDNA, 21.2% versus 52.8%,

p<0.001.

(Friel et al

2014)

Historical

control

III-3 982 Aim: to determine the impact of cfDNA on

the uptake of first trimester screening (FTS)

and invasive genetic testing.


Population: women referred for advanced

maternal age or abnormal screening.

Method: Patients who presented before

clinical introduction of cfDNA were

compared with patients who presented

after its introduction.

Outcomes: rates of FTS and invasive genetic

testing

In patients referred between 14 and 22

weeks gestational age, invasive genetic

testing was significantly reduced following

the introduction of cfDNA (35.4 vs. 17.9%,

p<0.05).

For patients referred at <14 weeks

gestational age, FTS was significantly

reduced with cfDNA introduction (89.1 vs.

59.1%, p<0.05); however, invasive genetic

testing was not significantly different (20.0 vs.

14.0%, p>0.05).

57


(Hasegawa

et al 2015)

Historical

control

III-3 1,247 Aim: To clarify the trends in the use of the

prenatal diagnosis of and screening for

aneuploidy after cfDNA was made

available.

Setting: Japan

Population: consecutive pregnant women

who visited our hospital for maternal

checkups and delivery.

Methods: Subjects were divided into those

who desired a prenatal diagnosis or

screening before the availability of cfDNA

and those who did after the availability of

cfDNA.

Outcomes: frequencies of various prenatal

diagnosis and screening procedures.

Among women who attended before

cfDNA was available (n=544), 16.2 %

received prenatal screening or diagnosis.

Among women who attended after cfDNA

was available, 27.5% considered

undergoing a prenatal diagnosis or

screening before genetic counseling and

24.0 % ultimately received a prenatal

diagnosis or screening following genetic

counseling. Of these patients, 7.7 %

underwent cfDNA. First trimester ultrasound

screening for chromosomal anomalies was

unlikely to be selected (from 12.9 to 10.5 %,

p=0.212), although the rate of

amniocentesis significantly increased after

genetic counseling (from 1.5 to 3.7 %,

p=0.021).

58


(Larion et al

2014b)

Historical

control

III-3 15,418

tests

Aim: To describe the changes over a 9-year

period in the number and rate of diagnostic

testing after the introduction of the

combined first-trimester screen and

subsequent cfDNA testing.


Population: women participating in prenatal

screening at a maternal-fetal medicine

group practice.

Methods: The number of prenatal screening

and diagnostic tests was recorded over a 9-

year period from billing records. Three time

intervals were considered: 20 months before

a combined first-trimester screen was

offered; 72 months after a combined first-

trimester screen was offered; and 16 months

after cfDNA testing introduction. Prenatal

testing was compared per year, per time

interval, and per 100 morphologic

ultrasonograms to account for fluctuations

in patient number.

Outcomes: rates of combined first trimester

screening, CVS and amniocentesis

Combined first-trimester screen peaked at

1,836 in 2009-2010 but declined by 48.1%

after cfDNA testing was introduced.

Combined first-trimester screen per 100

morphologic ultrasonograms also

significantly decreased (P<0.05) after cfDNA

testing introduction.

CVS peaked after combined first-trimester

screen introduction in 2007-2008 with 100

procedures, representing an 81.8% increase

from prefirst-trimester screen. After the

introduction of cfDNA, CVS declined by

68.6% during 2012-2013. CVS per 100

morphologic ultrasonograms followed the

same trend.

Amniocentesis declined every year of the

study period (78.8% overall), including 60.3%

after combined first-trimester screen and a

further 46.7% after noninvasive prenatal

testing. Monthly amniocentesis procedures

per 100 morphologic ultrasonograms

significantly decreased (P<.05) after

introduction of a combined first-trimester

screen and cfDNA.

59


(Larion et al

2014a)

Historical

control

III-3 9,287

procedu

res

Aim: to assess cfDNA uptake and

subsequent changes in the utilization of first-

trimester screen (FTS), chorionic villus

sampling (CVS), and amniocentesis.


Population: singleton pregnancies of women

who desired prenatal screening and

diagnostic testing in a single referral center

Method: Monthly numbers of cfDNA (in high-

risk patients), FTS, CVS, and amniocentesis

were compared between a 35-month

baseline period (April 2009 through February

2012) before introduction of cfDNA, and the

initial 16 months following cfDNA

introduction divided in 4-month quarters

beginning in March 2012 through June 2013.

Outcomes: rates of FTS, CVS and

amniocentesis

A total of 1,265 cfDNA, 6,637 FTS, 251 CVS,

and 1,134 amniocentesis were recorded

over the 51-month study period in. cfDNA

became the predominant screening

method by the second quarter following its

introduction, increasing by 55.0% over the

course of the study period.

Total first-trimester risk assessments

(cfDNA+FTS) were not statistically different

following cfDNA (P=0.312), but average

monthly FTS procedures significantly

decreased following cfDNA introduction,

decreasing by 48.7% over the course of the

study period.

Average monthly CVS and amniocentesis

procedures significantly decreased

following cfDNA introduction, representing a

77.2% and 52.5% decrease in testing,

respectively. Screening and testing per 100

morphological ultrasounds followed a similar

trend.

60


(Larion et al

2015)

Historical

control

III-3 10,125 Aim: To report changes in the use of cFTS in

patients classified as high and low risk for

fetal aneuploidy, including after

introduction of cfDNA testing.


Population: first trimester screening tests in

high and low-risk women

Methods: A prospectively collected

database was reviewed to investigate

changes in cFTS use before and after

American College of Obstetricians and

Gynecologists recommended that all

patients be offered aneuploidy screening

(2007), and after cfDNA introduction.

Statistical significance was defined as

P<0.05.

Outcomes: numbers of FTSs per 100

morphological ultrasound examinations.

In the 88-month study period, there were

2,962 FTSs in high-risk patients and 7,163 in

low-risk patients. The total number of FTSs

performed per 100 morphological

ultrasound examinations significantly

increased after the ACOG

recommendation and significantly

decreased after cfDNA introduction.

In high-risk patients, the total number of FTSs

performed per 100 morphological

ultrasound examinations significantly

increased after the ACOG

recommendation but significantly

decreased after cfDNA introduction.

In contrast, in low-risk patients, the total

number of FTSs performed per 100

morphological ultrasound examinations

significantly increased after the ACOG

recommendation but was not statistically

different after cfDNA introduction.

61


(Li et al

2016)

Historical

control

III-3 7,536 Aim: to examine changes over a 4-year

period in the number of diagnostic testing

after the introduction ofcfDNA testing.

Setting: China

Population: all consecutive patients with a

singleton pregnancy who received

amniocentesis at 16–22 weeks at a regional

maternal-fetal medicine center

Methods: The rate of cfDNA as an indication

in women who received amniocentesis, and

the number of amniocentesis required for

detection of one case with major

aneuploidy were compared between a 1-

year baseline period before the introduction

of cfDNA, and the 3 years following cfDNA

introduction.

Outcomes: Indications for amniocentesis

and indications for amniocentesis

A total of 7,536 amniocentesis procedures

were performed over the 4-year study

period. During the baseline period of the

year 2011, the number of invasive testing

required for detection of one common

trisomy was 57. During the first 2 years that

cfDNA was offered, cfDNA averaged 1.7%

of the total indications for amniocentesis,

and the required number of invasive testing

decreased to 30. With the increase of the

percentage of cfDNA during the 3rd year,

the required number of invasive testing

further decreased to 26.

After the clinical introduction of cfDNA,

invasive prenatal diagnostic testing had not

decreased at a Chinese prenatal diagnostic

unit, but a remarkably improved detection

rate of major aneuploidies in diagnostic

procedures was observed.

62


(Manegold

-Brauer et

al 2014)

Historical

control

III-3 951 Aim: to describe the current impact of

cfDNA testing on prenatal care.

Setting: Switzerland


pregnancies who presented for first trimester

screening (FTS)

Methods: According to the results of FTS the

women were categorised into three risk

groups: low risk for aneuploidy (<1:300),

intermediate risk (1:300-1:50) and high risk

(>1:50). They were counselled about the

available options for invasive prenatal

testing (IPT) and cfDNA available at the time

of FTS. The nine months before and after the

introduction of cfDNA were evaluated

Outcomes: further testing after FTS.

Since the introduction of cfDNA testing,

there has been an overall increase of 3.6%

of additional prenatal tests including both

IPT and cfDNA testing after FTS (8.5% vs

12.1%, p = 0.068).

In the low risk category this increase

amounted to 4.7% (2.2% vs 6.9%, p <0.149),

whereas in the intermediate risk category

this increase was 10.7% (35.1% vs 45.8%, p =

0.016).

In the high risk category an increase of 1.8%

(55.0% vs 56.8%, p = 0.149) was noted.

In contrast, the overall decrease of IPT was

5.5% (8.8% vs 3.1%, p = 0.001). The decrease

was 1.1% in the low-risk group, 29.4% in the

intermediate-risk group and 16.8% in the

high-risk group.

Since the introduction of cfDNA, the total

number of invasive prenatal procedures

decreased by 67.4% (43 vs 14).

63


(Manegold

-Brauer et

al 2015)

Historical

control

III-3 2,271 Aim: to investigate the algorithm of prenatal

testing before and after the introduction of

cfDNA in a tertiary referral center and to

investigate the influence of cfDNA on the

frequency of invasive procedures.

Setting: Switzerland


presenting for first trimester screening

Method: Retrospective data analysis was

conducted of all singleton pregnancies that

presented for first trimester screening 17

months before and after the introduction of

cfDNA (n = 2271). Women were categorized

into three risk groups: low risk for trisomy 21

(<1:1000), intermediate risk (1:101-1:1000)

and high risk (>1:100).

Outcomes: The choice of diagnostic testing

after FTS.

1,093 (group 1) presented before and 1,178

(group 2) after the introduction of cfDNA.

The rate of high-risk patients was equal in

both groups (14.4 vs. 15.4 %). No differences

were found with regard to invasive testing

(11.6 vs. 11.3 %).

cfDNA was chosen by 3.7% (n=44) in group

2. Of those with cfDNA, 72.7% had a risk

estimate of <1:100, but 90.9% were >35 years

old. The rate of cfDNA among high-risk

patients with a normal ultrasound

examination was 25%.

64


(Palomaki

et al 2015)

Historical

control

III-3 82 lab

surveys

Aim: to determine whether tests for fetal

aneuploidy based on cfDNA in maternal

circulation have had an impact on routine

serum-based screening.


Population: Pregnant women aged ≥35

years

Methods: We compared results from

laboratory surveys in 2011 and 2014 that

reported types of prenatal serum screening

tests and numbers of tests performed.

Testing records from two prenatal serum

screening laboratories examined temporal

trends in the proportion of screened women

35 years of age and older from 2008 (or

2009) to 2014.

Outcomes: serum screening rates

The survey results available for comparison

showed that 1.7 million women were

screened in 2014, a 5% increase over 2011.

In the two screening laboratories, the

proportion of screened women ≥35 years

increased for several years but then

experienced reductions of 8 and 18% by

mid-2014 when compared with the highest

rates observed.

As of 2014, maternal plasma DNA testing

appears to have had only a minor impact

on serum screening rates in the United

States. Ongoing surveillance has the

potential to determine if, and when, DNA

testing begins to replace serum testing as a

primary screen for trisomy 21 in the United

States.

Behind paywall

65


(Pettit et al

2014)

Historical

control

III-3 206 Aim: To evaluate trends in the use of

invasive diagnostic procedures.


Population: Women undergoing cfDNA

testing at a large academic center.

Method: cfDNA testing was universally

offered to all high-risk patients as

recommended by ACOG. Women were

also offered invasive diagnostic testing as an

alternative. The study period was compared

to a similar time period before universal offer

of cfDNA testing.

Outcomes: indications for cfDNA testing,

results of aneuploidy screening, ultrasound

examination findings, and CVS or

amniocentesis results

During the study period, 206 patients had

cfDNA testing. Of those, 75% (155/206) were

aged ≥35 years. Of those undergoing cfDNA

testing, 41% had positive aneuploidy

screening and 38% had abnormal

ultrasound findings. Only 7% of the patients

with negative cfDNA testing opted for an

invasive diagnostic procedure compared

with 60% with positive testing (P<0.01).

The rate of invasive procedures decreased

from 5.9% of all visits to the center during a

similar 8-month period in 2010 to 4.1% of all

visits during the study period (P<0.01).

(Platt et al

2014)

Cohort

study

III-2 1,477 Aim: to assess the impact of regional

location on cfDNA testing implementation

and downstream invasive prenatal

procedure use


Population: Women who underwent cfDNA

Methods: Six different regionally based

centers collected data. Statistical analyses

were performed using the 2-proportion Z-

test.

Outcomes: cfDNA testing indication and

results and invasive prenatal procedure

rates before and after offering cfDNA testing

Advanced maternal age (AMA-only) was

the most frequent indication in five of six

sites (range, 21.8-62.9%)

More invasive procedures were performed

following negative cfDNA testing results

(n=61) than abnormal cfDNA testing results

(n=30).

The overall rate of patients undergoing

invasive procedure after an abnormal

cfDNA testing result was 32.6% (30 of 92).

All six centers reported a decrease in

amniocentesis rates (from –23.6% to –50.0%).

Four of six centers reported a decrease in

rates of CVS (from –14.2% to –65.7%) and 2

centers reported no change.

66


(Poon et al

2015)

Historical

control

III-3 1,069 Aim: To investigate how the introduction of

cfDNA testing influenced women's testing

choices following a positive trisomy 21

screening.

Setting: Hong Kong

Population: Women (largely Chinese) with a

singleton pregnancy and a positive trisomy

21 screening (first trimester combined screen

or second trimester screening depending on

gestational age at presentation).

Methods: With the use of descriptive

statistics and a χ2 test, rates of women

choosing the invasive test and those who

declined further testing were compared

before and after the introduction of CFDNA

TESTING. We also compared demographic

factors with rates of different options

including an invasive test, cfDNA or

‘declined further testing’. Predictors of

accepting cfDNA and an invasive test were

analyzed with multiple logistic regression.

Conventional screening was funded

publicly, but cfDNA was not.

Outcomes: differences in the uptake rates of

invasive prenatal diagnosis (IPD) or no


cfDNA and factors affecting choices.

In pre-cfDNA and in years 1 and 2 after the

introduction of cfDNA, 306, 362 and 401

women who screened positive were seen,

respectively.

In year 1 and year 2, 12.6 and 26.7% of

women underwent cfDNA while IPD was

decreased by 16.3 and 25.6%, respectively

(p<0.001). Both chorionic villus sampling and

amniocentesis decreased in year 1, but only

the former in year 2. The rate of declining

further testing was similar before and after

introduction of cfDNA (p = 0.213).

67


(Robson &

Hui 2015)

Historical

control

III-3 Aim: to assess changes in rates of invasive

diagnostic prenatal procedures associated

with combined first trimester screening and

cfDNA

Setting: Australia

Population: invasive procedures claimed

through Medicare from 1994 to 2014

Method: analysis of data from the Medicare

Australia Medical Benefits Scheme (MBS)

database on procedural item numbers

16600 (diagnostic amniocentesis) and 16603

(chorionic villus sampling [CVS] by any

route) for the period 1994 to 2014 inclusive,

by calendar year

Outcomes: changes in rates of invasive

diagnostic tests

Following the introduction of cfDNA, the

number of amniocenteses performed in

Australia fell by 51% between the first

quarter of 2013 and the final quarter of 2014

(1,560 vs 758. OR 0.48; 95% CI: 0.44–0.53; 2 =

282, P<0.005). The total number of CVS fell

by 37% over the same period (767 vs 481. OR

0.63; 95% CI: 0.56–0.70; 2 = 66, P<0.005). This

represents the largest annual decrease in

invasive procedures during the 20-year study

period.

This change has important implications for

training in, and maintenance of, the

procedural skills of amniocentesis and CVS.

(Shah et al

2014)

Historical

control

III-3 500 Aim: To assess the impact of cfDNA testing

on choice of invasive procedures.


Population: Women with a positive first

trimester screening result.

Method: A retrospective chart review was

performed. Data were collected prior to

(2011) and after (2012) the introduction of

cfDNA.

Outcomes: gestational trimester at positive

screen, whether cfDNA screening was

requested or offered, and any additional

tests pursued

The percentage of participants who chose

not to pursue further testing after a positive

screen decreased significantly between

2011 and 2012, from 44% (110/250) to 32%

(79/250) (p=0.006). Of those participants

who chose to pursue additional testing in

2011, 47% (117/250) chose invasive testing

(either CVS or amniocentesis) and only 29%

chose invasive testing in 2012 (p<0.001).

68


(Tiller et al

2015)

Historical

control

III-3 200 Aim: To prospectively determine the impact

of cfDNA on invasive procedure utilization in

a managed care setting and to elucidate

women's views.

Setting: Southern California

Population: Pregnant women at 10-20

weeks' gestation with high-risk indications for

fetal aneuploidy

Methods: Enrolled patients received routine

prenatal counseling, completed a

questionnaire and were offered the option

of cfDNA by a genetic counselor.

Downstream data through 28weeks'

gestation were collected from the

electronic medical record (EMR). The EMR

was also used to identify a matched

historical cohort from 1 year prior to cfDNA

availability. Rates of invasive prenatal

procedures were compared using

McNemar's test.

Twenty-two subjects (11%) in the prospective

cohort underwent an invasive prenatal

procedure compared with 58 (29%) in the

historical cohort (p<0.0001). Safety and

accuracy were the most important factors

in considering cfDNA. At the time of survey,

only 12% of women indicated being very

comfortable with the possibility of

undergoing amniocentesis.

This prospective study demonstrates a 62%

reduction in invasive prenatal procedures

after cfDNA testing and finds safety,

accuracy, and personal beliefs key to

women's decision-making.

69


(Williams et

al 2015)

Historical

control

III-3 3,944 Aim: to understand the impact of cfDNA on

genetics counseling referrals, diagnostic

testing with CVS/amniocentesis, and

appropriate use of CFDNA TESTING.


Population: women referred for genetic

counseling and prenatal testing

Methods: Data from the 2 years preceding

the introduction of cfDNA (pre-cfDNA) and

2 years following (post-cfDNA) were

analysed.

Outcomes: The primary outcome was the

difference in the number of women referred

for genetic counseling and prenatal

diagnosis during the pre-cfDNA period

compared with the post-cfDNA period. The

secondary outcome was the difference in

the number of women referred who were

not considered candidates for cfDNA

between the two study periods.

There was a statistically significant reduction

(28.4%) in the number of referrals for genetic

counseling and diagnostic testing in the

post-cfDNA compared with the pre-cfDNA

period (2,824 vs 3,944, P=0.001).

During the post-cfDNA period there was a

significant reduction in referrals of women

who would not be candidates for cfDNA

(467 pre-cfDNA vs 285 post-cfDNA, P=0.043).

In women who had diagnostic testing with

CVS during the study period, 32.4% of the

aneuploidies identified would not have

been detected by cfDNA.

The data suggest that an increasing number

of potential patients are being offered

cfDNA screening instead of diagnostic

testing, including those at risk for fetal single

gene disorders and aneuploidies not

detectable by cfDNA, potentially leading to

misdiagnosis.

70

1.8 Factors affecting uptake of cell-free fetal DNA testing by women


(Chan et al

2015)

Historical

control

III-3 1,251 Aim: to evaluate the uptake of cfDNA

screening after a high-risk screening result

for trisomy 21

Setting: Hong Kong

Population: Chinese women who had a

high-risk (term risk >1:250) first-trimester or

second-trimester screening test at three

public hospitals.

Method: Association between maternal and

pregnancy characteristics on women's test

choice was assessed after adjusting for

confounding factors

Outcomes: rate of declining further testing

and obstetric and maternal factors

impacting on patient's selection of testing

options.

Nulliparous women with a spontaneous

[adjusted odds ratio (aOR)=2.18, 95%CI 1.63-

2.92] or assisted reproduction pregnancy

(aOR=3.95, 95% CI 1.6-9.32) were more likely

to choose cfDNA. Women with an adjusted

risk of '>1:10' (aOR=7.36, 95% CI 4.22-12.8)

and '1:10 to 1:50' (aOR=1.53, 95% CI 1.01-

2.32) were more likely to opt for chorionic villi

sampling or amniocentesis.

71


(Chetty et

al 2013)

Historical

control

III-3 1,036 Aim: to investigate how the introduction of

cfDNA testing impacted women's testing

choices following a positive prenatal

screening (PNS) result.


Population: Women with a positive prenatal

screening test result (first and/or trimester

serum analytes and nuchal translucency

ultrasound)

Method: Women were offered cfDNA or


Outcomes: Rates of invasive testing and

declining follow-up were compared with

testing decisions the prior year. Differences

were compared using t-test and chi-square.

Multivariable logistic regression was

performed to identify predictors of test

choice.

Race/ethnicity and timing of results (first

versus second trimester) were predictors of

testing choices; payer and maternal age

were not.

72


(Gil et al

2015a)

Cohort

study

III-2 6,651 Aim: to examine the factors affecting

patient decisions concerning their options.


Population: Women undergoing first

trimester combined screening for fetal

trisomies 21, 18 and 13

Methods: Women with a combined-test risk

of ≥1:100 (high risk) (n=260; 3.9%) were

offered the options of chorionic villus

sampling (CVS), cfDNA testing or no further

testing and those with a risk of 1:101 to

1:2500 (intermediate risk) (n=2,017; 30.3%)

were offered cfDNA or no further testing. Risk

was low in 4,374 (65.8%).

Outcomes: Logistic regression analysis was

used to determine which factors among

maternal characteristics, fetal nuchal

translucency thickness (NT) and risk for

trisomies were significant predictors of

opting for CVS in the high-risk group and

opting for cfDNA testing in the intermediate-

risk group.

In the high-risk group, 104 (40.0%) women

opted for CVS; predictors for CVS were

increasing fetal NT and increasing risk for

trisomies, while the predictor against CVS

was being of Afro-Caribbean racial origin (r

= 0.366).

In the intermediate-risk group, 1,850 (91.7%)

women opted for cfDNA testing; predictors

for cfDNA testing were increasing maternal

age, increasing risk for trisomies and

university education, while predictors

against cfDNA testing were being of Afro-

Caribbean racial origin, smoking and being

parous (r = 0.105).

73


(Han et al

2015)

Cohort

study

III-2 5,694 Aim: To determine the influence of free

invasive prenatal testing on the uptake of

cfDNA testing.

Setting: China

Population: women at risk of fetal trisomy

Method: women were given the option of

cfDNA or invasive prenatal testing. Invasive

prenatal testing was offered free of charge

to women with a local Hukou (household

registration); however, women without a

local Hukou were charged for invasive

prenatal testing. Both women with and

without a local Hukou were charged for

cfDNA.

Outcomes: Effect of cost on uptake

During the first year, 2,647 women with a

positive trisomy 21 screening test were

referred (474 with and 2,173 without a local

Hukou). Only 1.6% of the women with a local

Hukou underwent cfDNA, while this

proportion was 20.6% in the women without

a local Hukou.

During the second year, the price of cfDNA

was reduced. The total number of women

referred was 3,047 (502 women with and

2,545 women without a local Hukou). The

uptake of cfDNA in women without a local

Hukou doubled, but the uptake of cfDNA

remained stable in women with a local

Hukou.

74


(Maiz et al

2016)

Cohort

study

III-2 1,083 Aim: first to assess the uptake of cell free

DNA (cfDNA) testing after a combined test

and the maternal and fetal factors that

influenced this decision, and second, to

assess the uptake and factors that influence

the choice of invasive testing.

Setting: Spain


pregnancies who had a combined test for

screening for Down syndrome between

11 + 0 and 13 + 6 weeks.

Methods: maternal records were reviewed

retrospectively

Outcomes: Multivariate logistic regression

analysis was used to determine factors that

affected the uptake of cfDNA test and

invasive testing among risk for trisomies 21,

18, and 13, maternal characteristics and

fetal nuchal translucency (NT) thickness.

Two-hundred fifty-seven (23.7%) women had

a cfDNA test, 89 (8.2%) had an invasive test,

and 737 (68.1%) had no further test.

The uptake of cfDNA increased with the risk

for trisomies (p<0.001), maternal age

(p=0.013), and was higher in nulliparous

women (p=0.004).

The uptake of invasive testing increased with

the risk for trisomies (p<0.001) and NT

thickness (p<0.001).

75


(Poon et al

2015)

Historical

control

III-3 1,069 Aim: To investigate how the introduction of

cfDNA testing influenced women's testing

choices following a positive Down syndrome

screening.

Setting: Hong Kong

Population: Women (largely Chinese) with a

singleton pregnancy and a positive trisomy

21 screening (first trimester combined screen

or second trimester screening depending on

gestational age at presentation).

Methods: With the use of descriptive

statistics and a χ2 test, rates of women

choosing the invasive test and those who

declined further testing were compared

before and after the introduction of cfDNA.

We also compared demographic factors

with rates of different options including an

invasive test, cfDNA or ‘declined further

testing’. Predictors of accepting cfDNA and

an invasive test were analyzed with multiple

logistic regression. Conventional screening

was funded publicly, but cfDNA was not.

Outcomes: differences in the uptake rates of

invasive prenatal diagnosis (IPD) or no


cfDNA and factors affecting choices.

In multivariable analysis, first trimester

screening, nulliparity and working women

were significant predictors of accepting

cfDNA, while only nulliparity was a predictor

of declining IPD (OR = 0.61).

76


(Vahanian

et al 2014)

Cohort

study

III-2 235 Aim: To evaluate factors associated with

patient acceptance of noninvasive

prenatal testing for trisomy 21, 18 and 13 via

cfDNA.


Population: Women with advanced

maternal age, personal or family history of

chromosomal anomalies, fetal ultrasound

anomaly or positive maternal serum

screening test.

Method: Patients were identified

retrospectively through our perinatal

ultrasound database

Outcomes: demographic information,

testing indication and insurance coverage

were compared between patients who

accepted the test and those who declined.

Ninety-three patients (40%) accepted

testing and 142 (60%) declined. Women who

accepted cfDNA testing were more

commonly white, had private insurance and

had more than one testing indication. There

was no statistical difference in the number

or the type of testing indications.

Multivariable logistic regression analysis was

then used to assess individual variables.

After controlling for race, patients with

public insurance were 83% less likely to

accept cfDNA testing than those with

private insurance (3% vs. 97%, adjusted RR

0.17, 95% CI 0.05-0.62).

77

1.9 Cost-effectiveness of cell-free DNA testing

Australian studies

Study ref Design LoE N Aim, setting, population, method Results Comments

(Ayres et al

2014)

Cost-

effectiveness

analysis

— 300,000 Aim: To evaluate the cost-effectiveness of

different strategies of cfDNA for trisomy 21

screening in comparison with current

practice.

Setting: Australia

Population: A theoretical cohort of singleton

pregnancies

Methods: The strategies compared were the

following: current practice, cfDNA as a

second-tier investigation, cfDNA only in

women >35 years, cfDNA only in women >40

years and cfDNA for all women. The direct

costs (low and high estimates) were derived

using both health system costs and patient

out-of-pocket expenses. The number of

trisomy 21 cases detected and procedure-

related losses (PRL) were compared

between strategies. The incremental cost

per case detected was the primary

measure of cost-effectiveness.

Universal cfDNA costs an additional

$134,636,832 compared with current

practice, but detects 123 more trisomy 21

cases (at an incremental cost of $1,094,608

per case) and avoids 90 PRL.

cfDNA for women >40 years was the most

cost-effective strategy, costing an

incremental $81,199 per additional trisomy

21 case detected and avoiding 95 PRL.

The cost of cfDNA needs to decrease

significantly if it is to replace current practice

on a purely cost-effectiveness basis.

However, it may be beneficial to use cfDNA

as first-line screening in selected high-risk

patients. Further evaluation is needed to

consider the longer-term costs and benefits

of screening.

Study assumed a

sensitivity of 98%

and specificity

of 97% for cfDNA

testing. No

failure rate

assigned.

Estimates based

on costs of

$102.95 for cFTS,

$575 for cfDNA

testing and

$528.95 for

invasive testing.

78


(O'Leary et

al 2013)

Cohort study — 32,478 Aim: To analyse the cost-effectiveness and

performance of cfDNA testing for high-risk

pregnancies following first-trimester

screening compared with current practice.

Setting: Western Australia

Population: singleton pregnancies screened

between January 2005 and December 2006

Methods: A decision-tree analysis was used

to compare the costs and benefits of

current practice of first-trimester screening

with a testing pathway incorporating cfDNA.

We applied the model, adding Medicare

rebate data as a measure of public health

system costs. The analyses reflect the actual

uptake of screening and diagnostic testing

and pregnancy outcomes in this cohort.

If cfDNA testing was adopted by all women

identified as high risk by cFTS, up to 7 (2 per

10,000 women) additional trisomy 21 fetuses

could be confirmed.

The introduction of second-line cfDNA

testing would reduce the number of invasive

diagnostic procedures in high-risk women by

88%.

The cost per trisomy 21 case confirmed

including cfDNA was 9.7% higher ($56,360)

than the current prenatal testing strategy

($51,372) at a total cost of $3.91 million

compared with $3.57 million over 2 years in

Western Australia.

Analysis

assumed a cost

of $AU743 for

cfDNA testing.

Other costs were

based on

Medicare

rebates (85% of

schedule fee).

Downstream

costs such as

termination and

the lifetime cost

of care of an

individual with

trisomy 21 were

not included.

79

Overseas studies


(Benn et al

2015)

Cost-

effectiveness

analysis

— >4m Aim: To analyze the economic value of

replacing conventional fetal aneuploidy

screening approaches with cfDNA testing in

the general pregnancy population.


Population: annual US pregnancy

population

Methods: Sensitivity and specificity for fetal

aneuploidies, trisomy 21, trisomy 18, trisomy

13, and monosomy X, were estimated using

published data and modeling of both first-

and second trimester screening. Costs were

assigned for each prenatal test component

and for an affected birth. The overall cost to

the healthcare system considered screening

costs, the number of aneuploid cases

detected, invasive procedures performed,

procedure-related euploid losses, and

affected pregnancies averted. Sensitivity

analyses evaluated the effect of variation in

parameters. Costs were reported in 2014 US

Dollars.

Replacing conventional screening with

cfDNA would reduce healthcare costs if it

can be provided for $744 or less in the

general pregnancy population. The most

influential variables were timing of screening

entry, screening costs, and pregnancy

termination rates.

Of the 13,176 affected pregnancies

undergoing screening, cfDNA detected

96.5% (12,717/13,176) of cases, compared

with 85.9% (11,314/13,176) by conventional

approaches. cfDNA reduced invasive

procedures by 60.0%, with cfDNA and

conventional methods resulting in 24,596

and 61,430 invasive procedures,

respectively. The number of procedure-

related euploid fetal losses was reduced by

73.5% (194/264) in the general screening

population

80


(Beulen et

al 2014)

Cost-

effectiveness

analysis

— — Aim: to provide more information regarding

the consequences of implementing CFDNA

TESTING in a national programme for

prenatal screening.


Methods: A decision-analytic model was

developed to compare costs and outcomes

of current clinical practice in The

Netherlands using conventional screening

only, with two alternatives: implementing

cfDNA as an optional secondary screening

test for those pregnancies complicated by a

high risk for T21, and implementing cfDNA as

primary screening test, replacing

conventional screening. Probability

estimates were derived from a systematic

review of international literature. Costs were

determined from a health-care perspective.

Data were analysed to obtain outcomes,

total costs, relative costs and incremental

cost-effectiveness ratios (ICERs) for the

different strategies. Sensitivity analysis was

used to assess the impact of assumptions on

model results.

Implementing cfDNA as an optional

secondary, or as primary screening test will

increase T21 detection rate by 36% (from

46.8% to 63.5%) and 54% (from 46.8% to

72.0%), simultaneously decreasing the

average risk of procedure-related

miscarriage by 44% (from 0.0168% to

0.0094% per pregnant woman) and 62%

(from 0.0168% to 0.0064% per pregnant

woman), respectively.

None of the strategies clearly dominated:

current clinical practice is the least costly,

whereas implementing cfDNA will cause

total costs of the programme to increase by

21% (from 257.09 to 311.74 per pregnant

woman), leading to an ICER of k94 per

detected case of T21, when utilised as an

optional secondary screening test and by

157% (from 257.09 to 660.94 per pregnant

woman), leading to an ICER of k460 per

detected case of T21, when utilised as

primary screening test. However,

implementing cfDNA as triage test did result

in the lowest expected relative costs per

case of T21 diagnosed (k141).

cfDNA should be implemented in national

health care as an optional secondary

screening test for those pregnancies

complicated by a high risk for T21.

81


(Cuckle et

al 2013)

Cost-

effectiveness

analysis

— Aim: to determine the principal factors

contributing to the cost of avoiding a birth

with Down syndrome by using cell-free DNA

(cfDNA) to replace conventional screening.


Methods: A range of unit costs were

assigned to each item in the screening

process. Detection rates were estimated by

meta-analysis and modeling. The marginal

cost associated with the detection of

additional cases using cfDNA was estimated

from the difference in average costs divided

by the difference in detection.

The main factor was the unit cost of cfDNA

testing. For example, replacing a combined

test costing $150 with 3% false-positive rate

and invasive testing at $1000, by cfDNA tests

at $2000, $1500, $1000, and $500, the

marginal cost is $8.0, $5.8, $3.6, and $1.4m,

respectively. Costs were lower when

replacing a quadruple test and higher for a

5% false-positive rate, but the relative

importance of cfDNA unit cost was

unchanged. A contingent policy whereby

10% to 20% women were selected for cfDNA

testing by conventional screening was

considerably more cost-efficient. Costs were

sensitive to cfDNA uptake.

Potential conflict

of interest

82


(Evans et al

2015)

Cost-

effectiveness

analysis

— Aim: To determine whether implementation

of primary cell-free fetal DNA (cfDNA)

screening would be cost-effective in the

USA and to evaluate potential lower-cost

alternatives.


Methods: Three strategies to screen for

trisomy 21 were evaluated using decision

tree analysis: 1) a primary strategy in which

cfDNA screening was offered to all patients,

2) a contingent strategy in which cfDNA

screening was offered only to patients who

were high risk on traditional first-trimester

screening and 3) a hybrid strategy in which

cfDNA screening was offered to all patients

>35years of age and only to

patients<35years who were high risk after

first-trimester screening. Four traditional

screening protocols were evaluated, each

assessing nuchal translucency (NT) and

pregnancy-associated plasma protein-A

(PAPP-A) along with either free or total beta-

human chorionic gonadotropin (beta-hCG),

with or without nasal bone (NB) assessment.

Utilizing a primary cfDNA screening strategy,

the cost per patient was 1017 US$. With a

traditional screening protocol using free

beta-hCG, PAPP-A and NT assessment as

part of a hybrid screening strategy, a

contingent strategy with a 1/300 cut-off and

a contingent strategy with a 1/1000 cut-off,

the cost per patient was 474, 430 and 409

US$, respectively. Findings were similar using

the other traditional screening protocols.

Marginal cost per viable case detected for

the primary screening strategy as compared

to the other strategies was 3-16 times

greater than the cost of care for a missed

case.

Primary cfDNA screening is not currently a

cost-effective strategy. The contingent

strategy was the lowest-cost alternative,

especially with a risk cut-off of 1/1000. The

hybrid strategy, although less costly than

primary cfDNA screening, was more costly

than the contingent strategy.

83


(Fairbrother

et al 2016)

Cost-

effectiveness

analysis

— Aim: To estimate the cost-effectiveness of

fetal aneuploidy screening in the general

pregnancy population using cfDNA testing

as compared to first trimester combined

screening (FTS) with serum markers and NT

ultrasound.


Methods: Using a decision-analytic model,

we estimated the number of fetal T21, T18,

and T13 cases identified prenatally, the

number of invasive procedures performed,

corresponding normal fetus losses, and costs

of screening using FTS or cfDNA. Modelling

was based on a 4 million pregnant women

cohort, which represents annual births in the

United States.

For the general pregnancy population,

cfDNA testing identified 15% more trisomy

cases, reduced invasive procedures by 88%,

and reduced iatrogenic fetal loss by 94% as

compared to FTS. The cost per trisomy case

identified with FTS was 497 909. At a cfDNA

testing unit cost of 453 and below, there

were cost savings as compared to FTS.

Accounting for additional trisomy cases

identified by cfDNA testing, a cfDNA testing

unit cost of 665 provided the same per

trisomy cost as that of FTS.

Potential conflict

of interest (one

author an

industry

employee)

(Garfield &

Armstrong

2016)

Cost-

effectiveness

analysis

— 100,000 Aim: to evaluate the impact of

incorporating cfDNA testing into routine

high-risk maternal screening practice.


Methods: The multi-stage transition

probability model leveraged published cost

estimates from Medicare as well as practice

patterns and disease rates from published

literature.

The model demonstrates that inclusion of

the verifi™ prenatal test provides clear

clinical benefits. These include a 66 percent

reduction in invasive diagnostic induced

miscarriages and 38% more women

receiving a T21 diagnosis. Total costs for

prenatal screening and diagnosis for fetal

aneuploidies are reduced by 1% annually.

Industry-funded

research

84


(Neyt et al

2014)

Cost-

effectiveness

analysis

— Aim: to estimate the consequences of

introducing cfDNA testing for the detection

of T21.

Setting: Belgium

Methods: A cost-consequences analysis was

performed presenting the impact on

benefits, harms and costs. Context-specific

real-world information was available to set

up a model reflecting the current screening

situation in Belgium. This model was used to

construct the second and first line cfDNA

screening scenarios applying information

from the literature on cfDNA test accuracy.

Introducing cfDNA in the first or second line

reduces harm by decreasing the number of

procedure-related miscarriages after

invasive testing. In contrast with cfDNA in the

second line, offering cfDNA in the first line

additionally will miss fewer cases of T21 due

to fewer false-negative test results. The

introduction of cfDNA in the second line

results in cost savings, which is not true for

cfDNA at the current price in the first line. If

cfDNA is offered to all pregnant women, the

price should be lowered to about 150 to

keep the screening cost per T21 diagnosis

constant.

85


(Okun et al

2014)

Cost-

effectiveness

analysis

— Aim: To examine the cost and performance

implications of introducing cell-free fetal

DNA (cfDNA) testing within modeled

scenarios in a publicly funded Canadian

provincial Down syndrome (DS) prenatal

screening program.

Setting: Canada

Method: Two clinical algorithms were

created: the first to represent the current

screening program and the second to

represent one that incorporates cfDNA

testing. From these algorithms, eight distinct

scenarios were modeled to examine: (1) the

current program (no cfDNA), (2) the current

program with first trimester screening (FTS) as

the nuchal translucency-based primary

screen (no cfDNA), (3) a program

substituting current screening with primary

cfDNA, (4) contingent cfDNA with current

FTS performance, (5) contingent cfDNA at a

fixed price to result in overall cost

neutrality,(6) contingent cfDNA with an

improved detection rate (DR) of FTS, (7)

contingent cfDNA with higher uptake of FTS,

and (8) contingent cfDNA with optimized FTS

(higher uptake and improved DR).

This modeling study demonstrates that

introducing contingent cfDNA testing

improves performance by increasing the

number of cases of trisomy 21 detected

prenatally, and reducing the number of

amniocenteses performed and

concomitant iatrogenic pregnancy loss of

pregnancies not affected by trisomy 21.

Contingent models of cfDNA testing can

improve overall screening performance

while maintaining the provision of an 11- to

13-week scan. Costs are modestly

increased, but cost per prenatally detected

case of DS is decreased

86


(Walker et

al 2015)

Cost-

effectiveness

analysis

— Aim: to (1) determine the optimum maternal

serum screening risk cutoff for contingent

cfDNA testing and (2) compare the cost

effectiveness of optimized contingent

cfDNA testing to universal cfDNA testing and

conventional MSS.


Methods: Decision-analytic model using

micro-simulation and probabilistic sensitivity

analysis. We evaluated cost effectiveness

from three perspectives: societal,

governmental, and payer.

From a societal perspective, universal cfDNA

dominated both contingent cfDNA and

maternal serum screening. From a

government and payer perspective,

contingent cfDNA dominated maternal

serum screening. Compared to contingent

cfDNA, adopting a universal cfDNA would

cost $203,088 for each additional case

detected from a government perspective

and $263,922 for each additional case

detected from a payer perspective.

87

1.10 Guidelines and statements for research question 1

Guidelines and statements will inform revision of the narrative.

(ACOG 2015) Noninvasive prenatal screening that uses cell-free DNA from the plasma of pregnant women offers tremendous potential as a screening

method for fetal aneuploidy. A number of laboratories have validated different techniques for the use of cell-free DNA as a screening test for

fetal aneuploidy. All tests have a high sensitivity and specificity for trisomy 18 and trisomy 21, regardless of which molecular technique is used.

Women whose results are not reported, indeterminate, or uninterpretable (a "no call" test result) from cell-free DNA screening should receive

further genetic counseling and be offered comprehensive ultrasound evaluation and diagnostic testing because of an increased risk of

aneuploidy. Patients should be counseled that cell-free DNA screening does not replace the precision obtained with diagnostic tests, such as

chorionic villus sampling or amniocentesis and, therefore, is limited in its ability to identify all chromosome anomalies. Cell-free DNA screening

does not assess risk of fetal anomalies such as neural tube defects or ventral wall defects. Patients who are undergoing cell-free DNA

screening should be offered maternal serum alpha-fetoprotein screening or ultrasound evaluation for risk assessment. The cell-free DNA

screening test should not be considered in isolation from other clinical findings and test results. Management decisions, including termination

of the pregnancy, should not be based on the results of the cell-free DNA screening alone. Patients should be counseled that a negative cell-

free DNA test result does not ensure an unaffected pregnancy. Given the performance of conventional screening methods, the limitations of

cell-free DNA screening performance, and the limited data on cost-effectiveness in the low-risk obstetric population, conventional screening

methods remain the most appropriate choice for first-line screening for most women in the general obstetric population.

88

(Chitayat et al

2011)

1. All pregnant women in Canada, regardless of age, should be offered, through an informed counselling process, the option of a prenatal

screening test for the most common clinically significant fetal aneuploidies in addition to a second trimester ultrasound for dating, assessment

of fetal anatomy, and detection of multiples. (I-A) 2. Counselling must be non-directive and must respect a woman's right to accept or decline

any or all of the testing or options offered at any point in the process. (III-A) 3. Maternal age alone is a poor minimum standard for prenatal

screening for aneuploidy, and it should not be used a basis for recommending invasive testing when non-invasive prenatal screening for

aneuploidy is available. (II-2A) 4. Invasive prenatal diagnosis for cytogenetic analysis should not be performed without multiple marker

screening results except for women who are at increased risk of fetal aneuploidy (a) because of ultrasound findings, (b) because the

pregnancy was conceived by in vitro fertilization with intracytoplasmic sperm injection, or (c) because the woman or her partner has a history

of a previous child or fetus with a chromosomal anomaly or is a carrier of a chromosome rearrangement that increases the risk of having a

fetus with a chromosomal anomaly. (II-2E) 5. At minimum, any prenatal screen offered to Canadian women who present for care in the first

trimester should have a detection rate of 75% with no more than a 3% false-positive rate. The performance of the screen should be

substantiated by annual audit. (III-B) 6. The minimum standard for women presenting in the second trimester should be a screen that has a

detection rate of 75% with no more than a 5% false-positive rate. The performance of the screen should be substantiated by annual audit. (III-

B) 7. First trimester nuchal translucency should be interpreted for risk assessment only when measured by sonographers or sonologists trained

and accredited for this service and when there is ongoing quality assurance (II-2A), and it should not be offered as a screen without

biochemical markers in singleton pregnancies. (I-E) 8. Evaluation of the fetal nasal bone in the first trimester should not be incorporated as a

screen unless it is performed by sonographers or sonologists trained and accredited for this service and there is ongoing quality assurance. (II-

2E) 9. For women who undertake first trimester screening, second trimester serum alpha fetoprotein screening and/or ultrasound examination is

recommended to screen for open neural tube defects. (II-1A) 10. Timely referral and access is critical for women and should be facilitated to

ensure women are able to undergo the type of screening test they have chosen as first trimester screening. The first steps of integrated

screening (with or without nuchal translucency), contingent, or sequential screening are performed in an early and relatively narrow time

window. (II-1A) 11. Ultrasound dating should be performed if menstrual or conception dating is unreliable. For any abnormal serum screen

calculated on the basis of menstrual dating, an ultrasound should be done to confirm gestational age. (II-1A) 12. The presence or absence of

soft markers or anomalies in the 18- to 20-week ultrasound can be used to modify the a priori risk of aneuploidy established by age or prior

screening.

89

(Dondorp et al

2015)

This paper contains a joint ESHG/ASHG position document with recommendations regarding responsible innovation in prenatal screening with

cfDNA testing. By virtue of its greater accuracy and safety with respect to prenatal screening for common autosomal aneuploidies, cfDNA has

the potential of helping the practice better achieve its aim of facilitating autonomous reproductive choices, provided that balanced pretest

information and non-directive counseling are available as part of the screening offer. Depending on the health-care setting, different

scenarios for cfDNA-based screening for common autosomal aneuploidies are possible. The trade-offs involved in these scenarios should be

assessed in light of the aim of screening, the balance of benefits and burdens for pregnant women and their partners and considerations of

cost-effectiveness and justice. With improving screening technologies and decreasing costs of sequencing and analysis, it will become

possible in the near future to significantly expand the scope of prenatal screening beyond common autosomal aneuploidies. Commercial

providers have already begun expanding their tests to include sex-chromosomal anomalies and microdeletions. However, multiple false

positives may undermine the main achievement of cfDNA testing in the context of prenatal screening: the significant reduction of the invasive

testing rate. This document argues for a cautious expansion of the scope of prenatal screening to serious congenital and childhood disorders,

only following sound validation studies and a comprehensive evaluation of all relevant aspects. A further core message of this document is

that in countries where prenatal screening is offered as a public health programme, governments and public health authorities should adopt

an active role to ensure the responsible innovation of prenatal screening on the basis of ethical principles. Crucial elements are the quality of

the screening process as a whole (including non-laboratory aspects such as information and counseling), education of professionals,

systematic evaluation of all aspects of prenatal screening, development of better evaluation tools in the light of the aim of the practice,

accountability to all stakeholders including children born from screened pregnancies and persons living with the conditions targeted in

prenatal screening and promotion of equity of access.

(Gregg et al

2016)

The isolation of fetal DNA fragments from maternal circulation in sufficient quantity and sizes, together with proprietary bioinformatics tools,

now allows patients the option of noninvasive fetal aneuploidy screening. However, obstetric care providers must become famil iar with the

advantages and disadvantages of the utilization of this approach as analysis of cell-free fetal DNA moves into clinical practice. Once

informed, clinicians can provide efficient pretest and posttest counseling with the goal of avoiding patient harm. It is in the public's best

interest that test results contain key elements and that laboratories adhere to established quality control and proficiency testing standards. The

analysis of cell-free fetal DNA in maternal circulation for fetal aneuploidy screening is likely the first of major steps toward the eventual

application of whole fetal genome/whole fetal exome sequencing.

(Langlois &

Brook 2013)

Recommendations 1. Non-invasive prenatal testing using massive parallel sequencing of cell-free fetal DNA to test for trisomies 21, 18, and 13

should be an option available to women at increased risk in lieu of amniocentesis. Pretest counselling of these women should include a

discussion of the limitations of non-invasive prenatal testing. (II-2A) 2. No irrevocable obstetrical decision should be made in pregnancies with a

positive non-invasive prenatal testing result without confirmatory invasive diagnostic testing. (II-2A) 3. Although testing of cell-free fetal DNA in

maternal plasma appears very promising as a screening test for Down syndrome and other trisomies, studies in average-risk pregnancies and a

significant reduction in the cost of the technology are needed before this can replace the current maternal screening approach using

biochemical serum markers with or without fetal nuchal translucency ultrasound. (III-A).

90

(Michaelson-

Cohen et al

2014)

Prenatal testing of cell-free fetal DNA in maternal plasma is a novel approach, designed for detecting common aneuploidies in the fetus. The

Israeli Society of Medical Geneticists (ISMG) supports its use according to the guidelines stated herein. The clinical data collected thus far

indicate that cfDNA testing is highly sensitive in detecting trisomies 21 and 18, and fairly sensitive in detecting trisomy 13 and sex chromosome

aneuploidies. Because false-positive results may occur, an abnormal result must be validated by invasive prenatal testing. At this juncture,

cfDNA testing does not replace existing prenatal screening tests for Down syndrome, as these are relatively inexpensive and cost-effective.

Nonetheless, cfDNA testing may be offered to women considered to be at high risk for fetal chromosomal anomalies as early as 10 weeks of

gestation. The ISMG states that cfDNA testing should be an informed patient choice, and that pretest counseling regarding the limitations of

cfDNA testing is warranted. Women at high risk for genetic disorders not detected by cfDNA testing should be referred for genetic counseling.

A normal test result may be conveyed by a relevant healthcare provider, while an abnormal result should be discussed during a formal

genetic consultation session.

(RANZCOG

2015)

Cell-free DNA (cfDNA) screening using maternal plasma can be performed reliably from 10 weeks. This screening test became widely

available in Australia in 2013 and has the highest sensitivity and specificity of all the screening tests for Down syndrome. However, cfDNA

testing is currently more expensive than CFTS and must be self-funded (currently no Medicare or private insurance rebate). This direct cost

currently poses a significant barrier to accessibility and widespread clinical implementation.

Consensus-based recommendation:

• Accurate dating, confirmation of viability and determination of the number of embryos by ultrasound is recommended prior to cfDNA

testing.

• cfDNA based screening for fetal aneuploidy is not diagnostic. The chance of having an affected fetus following an abnormal/high risk

cfDNA result (ie the positive predictive value, PPV) may be < 50%, depending on the specific chromosome involved and the background

risk of the woman. Confirmatory diagnostic testing is strongly recommended after an abnormal cfDNA result.

• If a woman has received a normal/low risk result from a cfDNA testing test, an additional risk calculation for aneuploidy (e.g. by combined

first trimester or second trimester serum screening) is not recommended as this will increase the false positive rate without substantially

improving the detection rate.

• The presence of a fetal structural anomaly remains an important indication for invasive prenatal testing, even in the presence of a prior

normal/low risk cfDNA result.

• Pre-test counselling should include informed decision making regarding testing for fetal sex and sex chromosome aneuploidy. Women

should be given the choice to opt out of receiving this information.

(SMFM 2015b) Recent advances in technology have created exciting opportunities to expand and improve genetic testing options that are available to

women during pregnancy. However, the novelty and complexity of these technologies, combined with the commercial interest to implement

these tests rapidly into routine clinical care, have created challenges for physicians and patients and potentially will lead to misunderstanding,

misuse, and unintended consequences. The purpose of this document was to aid clinicians in their day-to-day practice of counseling patients

regarding prenatal aneuploidy testing options with cell-free DNA screening, which includes how it compares to current testing methods,

potential benefits and harms, and its limitations and caveats.

91

(SMFM 2015a) The purpose of this statement is to clarify that the Society for Maternal-Fetal Medicine (SMFM) does not recommend that cell-free DNA

aneuploidy screening be offered to all pregnant women, nor does it suggest a requirement for insurance coverage for cell-free DNA screening

in women at low risk of aneuploidy. However, SMFM believes, due to the ethics of patient autonomy, that the option should be available to

women who request additional testing beyond what is currently recommended by professional societies.

(Wilson et al

2013)

The BUN and FASTER studies, two prospective multicenter trials in the United States, validated the accuracy and detection rates of first and

second trimester screening previously reported abroad. These studies, coupled with the 2007 release of the American College of Obstetricians

and Gynecologists (ACOG) Practice Bulletin that endorsed first trimester screening as an alternative to traditional second trimester multiple

marker screening, led to an explosion of screening options available to pregnant women. ACOG also recommended that invasive diagnostic

testing for chromosome aneuploidy be made available to all women regardless of maternal age. More recently, another option known as

cfDNA testing became available to screen for chromosome aneuploidy. While screening and testing options may be limited due to a variety

of factors, healthcare providers need to be aware of the options in their area in order to provide their patients with accurate and reliable

information. If not presented clearly, patients may feel overwhelmed at the number of choices available. The following guideline includes

recommendations for healthcare providers regarding which screening or diagnostic test should be offered based on availability, insurance

coverage, and timing of a patient's entry into prenatal care, as well as a triage assessment so that a general process can be adapted to

unique situations.

1.11 Excluded studies for research question 1

Background papers

Background papers will inform revision of the narrative.

Health professional views

(Alexander et al

2015)

Genetic counsellors reported initially feeling cautious about offering the test, although they saw it as a positive advance for their patients at

genetic risk. Emphasis was placed on accuracy, adequate counselling provision and gatekeeping with concerns expressed about

broadening its use in the routine antenatal setting. Findings indicate the genetics model for offering prenatal testing to high risk patients can

incorporate cfDNA testing and the profession may have a role in informing its implementation in wider healthcare settings. In a wider context

this study highlights the challenges new technologies bring to genetic counsellors' practice and service structure.

(Benn et al 2014) In this study, 79.1% of participating Fellows of the American College of Obstetricians and Gynecologists supported the use of cfDNA testing as

a screen for Down syndrome for all women with 47.9% viewing cfDNA testing as a complete substitution for invasive testing. Most supported

expansion to other aneuploidies (97.5%) and severe early-onset Mendelian disorders (90.4%) but not for adult-onset disorders (29.8%) or

nonmedical sex identification (15.7%). A majority (73.2%) believed that cfDNA testing would increase pregnancy terminations for mild disease

states. Respondents favoured a role for professional societies in providing regulatory oversight.

92

(Buchanan et al

2014)

Respondents (genetic counsellors) indicated that a discussion about cfDNA testing with a patient should highlight that it is a screening test, the

detection rate is superior to that of maternal serum screening, it screens for specific conditions, and a positive cfDNA result should be

confirmed with a diagnostic test.

(Haymon et al

2014)

Assessment indicates cfDNA testing is being adopted by maternal fetal medicine specialists, largely in accord with recently published

American College of Obstetricians and Gynecologists and the Society for MFM guidelines. Cost and test performance remain factors for not

adopting cfDNA testing. Further research on clinical management based on cfDNA results and patient understanding of cfDNA results is

suggested.

(Horsting et al

2014)

Results indicate that genetic counselors value cfDNA testing as a screening option but are concerned regarding how some obstetricians and

patients make use of this testing.

(Hui et al 2015a) In a survey of members of the Australian Association of Obstetrical and Gynaecological Ultrasonologists (AAOGU) during the first year of local

availability of cell-free DNA-based prenatal testing for aneuploidy, we received 54 responses to the survey (39% response rate). Two thirds of

respondents were subspecialists in obstetric and gynaecological ultrasound or maternal fetal medicine. The majority of respondents had

already used cfDNA testing in their practice (94%). There was no significant difference in the proportion of respondents offering cfDNA to high-

risk women in private versus public practice (95 versus 82%, P = 0.14). However, inequity of access due to cost was the most common ethical

issue encountered. The vast majority continued to offer an 11–13 week ultrasound in addition to cfDNA. Almost all respondents (96%) were also

willing to offer cfDNA testing to low-risk women in December 2013 after appropriate genetic counselling.

(Hui et al 2015b) In a period of declining invasive prenatal testing, many Australian specialists are performing <25 procedures annually. Consideration of the

potential risks of bloodborne viruses is limited. Chromosomal microassays are rapidly being incorporated into clinical practice. These data

have implications for patient consent and safety, and workforce training and practice.

(Mayes et al

2016)

Overall, 85 obstetricians were surveyed. While all respondents indicated awareness of cfDNA in its traditional form, 75% (64/85) were aware of

the expanded testing option, and 14% (12/85) reported having ordered the expanded cfDNA option. A total of 91% (77/85) expressed that

practitioners need more information regarding the screening. Based on these findings and the fluid landscape of prenatal screening,

education, and reeducation of health care professionals is imperative to ensure responsible patient counseling, informed consent, and

appropriate posttest management.

(Musci et al

2013)

Of the 101 obstetricians (in the United States) that completed the survey (27% academic-based, 73% private practice), 97% offer screening to

high-risk patients and 91% offer screening to average-risk patients. With regard to current screening tests, the top three advantages were as

follows: recommendation by professional societies, no risk to the pregnancy, and long history/experience with the test, whereas the top three

limitations were as follows: patient anxiety, risks of follow-up invasive testing, and high false positives. cfDNA testing had been used by 32% of

respondents and 22% were familiar with cfDNA and the associated clinical data. The majority of physicians predicted that they would offer

cfDNA testing to high-risk women (86.1%) and average-risk women (76.2%) within 12months.

93

(Suskin et al

2016)

Results indicate substantial variation in practice regarding which patients are offered NIPS and how counselors have incorporated this

technology into existing screening routines. The majority of participants report offering NIPS in conjunction with another method of screening

for fetal aneuploidy, indicating that cfDNA testing is being used as an addition rather than as a replacement. These screening methods

primarily include nuchal translucency (NT) (45.1 %, n = 78) and first trimester serum screening, with or without an NT (19.7 %, n = 34). Furthermore,

the majority report that they would be concerned about losing the clinical value of an NT in a complete transition to cfDNA testing (85.4 %, n =

164). Counselors are evenly split on the merits of expanding the use of cfDNA testing to the general population (con: 55.3 %, n = 105; pro: 44.7

%, n = 85). The lack of consensus suggests that updated practice guidelines might benefit counselors. In addition, respondents emphasized the

need to better educate patients and providers about the risks, benefits, and limitations of the test.

(Swaney et al

2016)

Among maternal-fetal medicine fellows surveyed, >75 % reporting they are comfortable ordering cfDNA testing. Most (82 %) preferred that a

patient discuss options with a provider or genetic counselor. Three common methods used to learn about cfDNA testing were: formal

educational activities (n = 78, 69 %), self-review of the literature (n = 76, 67 %), and discussions with peers (n = 73, 65 %). On questions related to

trisomy 21, accuracy was >70 %. However, accuracy was lower regarding use in twin pregnancies (42 %) and monosomy X screening (50 %).

(Tamminga et al

2015)

Health professionals (in the Netherlands) favor offering cfDNA testing to all women; most want to maintain nuchal fold measurement. The

majority (92%) of health professionals thought cfDNA testing should include disorders characterized by neonatal death or death within the first

year of life; 52% favored testing for fetomaternal risk factors. Most health professionals thought that a broader range of disorders should be

offered as a 'fixed list of disorders' in contrast to pregnant women who mostly preferred to have a free choice.

(Yared et al

2016)

Obese women had a failure rate of 24.3% compared with 3.8% in nonobese women (P < .01). Gestational age was not associated with failure

rate (mean ± standard deviation, 13 ± 3 weeks for both screen failure and nonfailure; P = .76). The addition of a paternal cheek swab reduced

the failure rate from 10.2% in women with no swab to 3.8% in women with a swab (P < .01). In multivariable analysis, obesity and lack of a

paternal cheek swab were independent predictors of screen failure (odds ratio, 9.75; 95% confidence interval, 4.85-19.61; P < .01; and odds

ratio, 3.61; 95% confidence interval, 1.56-8.33; P < .01, respectively).

Women’s views

(Chan et al 2014) The majority of women can accept NIDT as an alternative to IPD provided that the test is 95% accurate in the diagnosis of Down syndrome.

Current evidence indicates that the detection rate of NIDT will be higher than this level.

(Farrell et al

2014b)

Women identified accuracy, early timing, testing ease, and determination of fetal sex as advantages of cfDNA testing over other screens, and

the noninvasive method of cfDNA testing as an advantage over diagnostic tests. False positive and false negative results, anxiety, cost and

insurance coverage were seen as disadvantages of cfDNA testing. Women who do not want fetal aneuploidy information most likely will not

undergo cfDNA testing, despite its advantages over other screening tests. However, given its advantages, the decision to have cfDNA testing

is straightforward for women who want genetic information about the fetus. Women emphasized the need to make autonomous, private, and

informed choices about cfDNA testing, as they would with any prenatal genetic testing option.

94

(Kellogg et al

2014)

Results suggest although mothers of children with Down syndrome believe new noninvasive testing will lead to an increase in termination of

pregnancies with Down syndrome, they do not think it is the MOST important factor. They also highlight the need to provide a diagnosis of

Down syndrome in a balanced and objective manner.

(Kooij et al 2009) Among women visiting for routine fetal anomaly ultrasound scan at 20 weeks' gestation and female medical master students, both groups

considered cfDNA testing an important asset in the reliable diagnosis of fetal aneuploidy and gender-determined genetic disorders, with the

exception of disorders manifesting themselves later in life. There was a negative response to its application for family balancing. 82% of the

pregnant women and 79% of the medical students responded positively to the question whether they consider cfDNA testing an important

asset in prenatal care. The statement that it is an asset because it enables pregnant women to bear an 'optimal child' was strongly rejected by

both groups.

(Lau et al 2012a) Over 95% of women (n=567) had complete or almost complete resolution of anxiety. Except for one, all were satisfied with the NIFTY test, and

all indicated that they would recommend the test to their friends. Conclusion: The NIFTY test was a highly specific test. Unnecessary invasive

tests and associated fetal losses could be avoided in almost all women who have a normal fetus.

(Lewis et al 2014) Respondents (women and partners in England) were overwhelmingly positive towards the introduction of cfDNA testing. Uptake is likely to be

high, and includes women who currently decline screening as well as those who will use the test for information only. Pre-test counselling to

ensure that women understand the implications of the test result is essential.

(Lewis et al

2016a)

Women were overwhelmingly positive about the opportunity to have a test that was procedurally safe, accurate, reduced the need for

invasive testing and identified cases of Down syndrome that might otherwise have been missed. Reassurance was identified as the main

motivator for accepting cfDNA testing, particularly amongst medium risk women, with high risk women inclined to accept cfDNA testing to

inform decisions around invasive testing. The current turnaround time for test result was identified as a key limitation. All the women interviewed

thought cfDNA testing should be adopted as part of NHS clinical practice, with the majority favouring cfDNA testing offered as a firstline test.

Our study highlights the potential that cfDNA testing has to positively impact women's experience of prenatal testing for aneuploidy.

(Sayres et al

2014)

Willingness to consider abortion of an affected pregnancy was the strongest correlate to interest in both cfDNA and first-trimester combined

screening, although markedly more respondents expressed an interest in some form of screening (69% and 71%, respectively) than would

consider termination. Greater educational attainment, higher income, and insurance coverage predicted interest in cfDNA screening;

stronger religious identification also corresponded to decreased interest. Prior experience with disability and genetic testing was associated

with increased interest in cfDNA screening. Several of these factors, in addition to advanced age and Asian race, were, in turn, predictive of

respondents' increased willingness to consider post-diagnosis termination of pregnancy.

(Steinbach et al

2016)

Regardless of opinion toward disability, the majority of respondents supported both the availability of screening and the decision to continue a

pregnancy positive for aneuploidy. Individuals rationalized their support with various conceptions of disability; complications of the expressivist

argument and other concerns from the disability literature were manifested in many responses analyzed.

95

(van Schendel et

al 2015)

Of the women (in the Netherlands), 51% expressed interest in having cfDNA testing, including 33% of women who had declined first-trimester

screening. The majority (73%) thought that the uptake of screening would increase with cfDNA testing. Most women agreed that testing for

life-threatening (89%), severe physical (79%), or severe mental (76%) disorders should be offered. A minority (29%) felt that prenatal screening

should also be offered for late-onset disorders. Most (41%) preferred to have a free choice from a list of disorders, 31% preferred a 'closed offer',

and 26% preferred choosing between packages of disorders. Although most women (76%) thought that screening for a broad range of

conditions would avoid much suffering, 39% feared that it would confront couples with choices, the implications of which would be difficult to

grasp.

(Verweij et al

2013b)

The pregnant women in our study (in the Netherlands) had a positive attitude regarding cfDNA testing for T21, and more than half of the

women who rejected prenatal screening would receive cfDNA testing if available. Due to the elimination of iatrogenic miscarriage, caregivers

should be aware that informed decision-making can change with respect to prenatal screening with the introduction of cfDNA testing.

(Yi et al 2013) cfDNA testing was regarded positively by women (in Hong Kong) who chose this method of screening over the routine, less expensive testing

options. Given its perceived utility, health providers need to consider whether cfDNA testing should be offered as part of universal routine care

to women at high-risk for fetal aneuploidy. If this is the case, then further development of guidelines and quality assurance will be needed to

provide a service suited to patients' needs.

Informed decision-making

(Agatisa et al

2015)

Participants voiced their desire to be informed of all conditions assessed by cfDNA testing prior to testing. They considered clinicians to be the

key provider of such information, although stated that patients have a responsibility to be knowledgeable prior to testing in order to support

informed decision-making. The use of cfDNA testing to identify sex chromosome aneuploidies and microdeletion syndromes will introduce new

challenges for clinicians to ensure pregnant women have the information and resources to make informed choices about cfDNA testing when

used for these conditions.

(Allyse et al 2014) There appears to be support for uptake of non-invasive prenatal tests. Clinical guidelines should therefore go forward in providing guidance on

how to integrate non-invasive methods into the current standard of care. However, our findings indicate that even when accuracy, which is

rated by patients as the most important aspect of prenatal testing, is significantly improved over existing screening methods and testing is

offered non-invasively, the number of individuals who reported that they would decline any testing remained the same. Attention should

therefore be directed at ensuring that the right of informed refusal of prenatal testing is not impacted by new, non-invasive methods.

(Farrell et al

2014a)

This study demonstrates that cfDNA testing will introduce new challenges for pregnant women and their health care practitioners who will be

charged with supporting informed decision-making about its use. It is critical that obstetric professionals are prepared to facilitate a patient-

centered decision-making process as its clinical application rapidly changes.

96

(Godino et al

2016)

The majority of women perceived as clear and helpful the information received at counselling, and only 12.7% had doubts left that, however,

often concerned non-pertinent issues. The impact of counselling on risk perception and decisions was limited: a minority stated their perceived

risk of foetal anomalies had either increased (6.8%) or reduced (3.6%), and only one eventually declined invasive test. The 52.6% of women

expressed a preference toward individual counselling, which also had a stronger impact on perceived risk reduction (P=0.003). Nevertheless,

group counselling had a more favourable impact on both clarity of understanding and helpfulness (P=0.0497 and P=0.035, respectively). The

idea that AMA represents an absolute indication for invasive tests appears deeply rooted; promotion of non-invasive techniques may require

extensive educational efforts targeted to both the general population and health professionals.

(Kou et al 2015) It is feasible to use a questionnaire based on the International Society for Prenatal Diagnosis 2011 statement on cfDNA testing to assess

women's knowledge of the test. The Chinese women who underwent cfDNA testing recognised the limitations, but did not understand the

complicated aspects. More information should be provided by health care professionals in order to facilitate an informed choice by patients.

More women preferred cfDNA testing as a contingent test than as a primary screening probably because of its high cost.

(Lau et al 2012b) Besides screening Down syndrome by NIFTY, most pregnant women would also like to be informed if there was suspicion of SCA. Those

screened positive should be counseled by those with experience in genetics to avoid unnecessary pregnancy termination.

(Lau et al 2016) A qualitative study was carried out using semi-structured interviews with 36 women who had undertaken cfDNA testing in Hong Kong. The

findings show that most Hong Kong Chinese women valued aspects of both relational and individual autonomy in decision-making for cfDNA

testing. Women expected support from doctors as experts on the topic and wanted to involve their husband in decision-making while

retaining control over the outcome. Somewhat surprisingly, the findings do not provide support for the involvement of family members in

decision-making for cfDNA testing. The adequacy of current interpretations of autonomy in prenatal testing policies as an individual approach

needs discussion, where policy developers need to find a balance between individual and relational approaches.

(Lewis et al 2013) The successful introduction of cfDNA testing into routine prenatal care will require guidelines and counselling strategies which ensure women

are offered this test in a way which safeguards informed consent.

(Lewis et al 2015) Health professionals should be aware that women may have incomplete information or misunderstandings about cfDNA testing. Pre-test

counselling to ensure informed decision-making is therefore important.

(Lewis et al

2016b)

Results indicate the vast majority of women (89%) made an informed choice; 95% were judged to have good knowledge, 88% had a positive

attitude and 92% had deliberated. Of the 11% judged to have made an uninformed choice, 55% had not deliberated, 41% had insufficient

knowledge, and 19% had a negative attitude. Ethnicity (OR=2.78, P=0.003) and accepting cfDNA testing (OR=16.05, P=0.021) were found to

be significant predictors of informed choice. The high rate of informed choice is likely to reflect the importance placed on the provision of pre-

test counselling in this study. It will be vital to ensure that this is maintained once cfDNA testing is offered in routine clinical practice.

(Piechan et al

2016)

Participants scored lowest on knowledge questions involving whether a negative cfDNA test result ensures a healthy baby or eliminates the

possibility of Down syndrome. Most perceived themselves to have a good basic understanding of cfDNA testing and two-thirds of the written

feedback proposed no changes to cfDNA testing administration. Overall, most patients appear satisfied with their understanding of cfDNA

testing and the testing process, yet they may not fully appreciate the limitations of this screening method.

97

(Silcock et al

2015)

Health professionals and pregnant women view the consenting process differently across antenatal test types. These differences suggest that

informed choice may be undermined with the introduction of cfDNA testing for DS into clinical practice. To maintain high standards of care,

effective professional training programmes and practice guidelines are needed which prioritize informed consent and take into account the

views and needs of service users.

(van den Heuvel

et al 2010)

This study provides the first empirical evidence to demonstrate that practitioners may view the consent process for cfDNA testing differently to

invasive testing. There is potential for the introduction of cfDNA testing to undermine women making informed choices in the context of

prenatal diagnostic testing for conditions like DS.

(van Schendel et

al 2014)

Participants (in the Netherland) felt that current prenatal screening has great disadvantages such as uncertain results and risk of miscarriage

from follow-up diagnostics. Characteristics of cfDNA testing (accurate, safe and early testing) could therefore diminish these disadvantages of

prenatal screening and help lower the barrier for participation. This suggests that cfDNA testing might allow couples to decide about prenatal

testing based mostly on their will to test or not, rather than largely based on fear of miscarriage risk or the uncertainty of results. The lower

barrier for participation was also seen as a downside that could lead to uncritical use or pressure to test. Widening the scope of prenatal

testing was seen as beneficial for severe disorders, although it was perceived difficult to determine where to draw the line. Participants argued

that there should be a limit to the scope of cfDNA testing, avoiding testing for minor anomalies. The findings suggest that cfDNA testing could

enable more meaningful decision-making for prenatal screening. However, to ensure voluntary participation, especially when testing for

multiple disorders, safeguards on the basis of informed decision-making will be of utmost importance.

Public attitudes

(Kelly &

Farrimond 2012)

In a survey of public attitudes, the majority (63%) of respondents described their first response as positive. However, respondents displayed

ambivalence, expressing positive views of individual/medical rationale for cfDNA testing and unease concerning public health rationale and

societal implications. Unease related to eugenic reasoning underlying existing prenatal testing, 'too much control' in reproduction, commercial

provision, information and support requirements for expanded testing, and limiting the use of testing.

(Lewis et al 2015) Positive reporting of cfDNA testing in the UK news media reflects the publics' broadly optimistic view towards genomic technology and

prenatal testing.

Implementation

(Hill et al 2012) Policies for implementing noninvasive prenatal diagnosis must consider the differences between womens and health professionals preferences

to ensure the needs of all stakeholders are met. Women’s strong preference for tests with no risk of miscarriage demonstrates that

consideration for safety of the fetus is paramount in decision-making. Effective pretest counseling is therefore essential to ensure women

understand the possible implications of results.

98

(Hill et al 2016) Differences in preferences were seen between women and health professionals within and between countries. Overall, women placed

greater emphasis on test safety and comprehensive information than health professionals, who emphasised accuracy and early testing.

Differences between women’s and health professionals’ preferences are marked between countries. Varied approaches to implementation

and service delivery are therefore needed and individual countries should develop guidelines appropriate for their own social and screening

contexts.

(Mackie 2016) Emerging evidence from the NIHR-funded RAPID study suggests that uptake will be high, both to help reassure more women that the baby

does not have Downs syndrome but also for women to prepare for the birth of a child with Down syndrome rather than to terminate an

affected pregnancy. There remain many questions, some of which will only be addressed when the test is used in a screening programme and

we can see what choices parents actually make and what information they need. One thing is clear though, we must distinguish this highly

accurate screening test for aneuploidy, which requires confirmation by invasive testing, from diagnostic testing, which does not require such

confirmation, in pregnancies at risk of monogenic disorders and RHD complications.

(Verweij et al

2013a)

The results suggest that implementing cfDNA testing (in the Netherlands) may be associated with an increased uptake of prenatal testing,

whereas the percentage of women who opt to terminate a pregnancy affected by trisomy 21 (T21) may likely decrease. cfDNA testing may

not lead to a vast reduction in live births of children with T21, but unlike the current situation, most will be born in families who accepted, with or

without testing, the chance of having and caring for a child with T21.

Information on the internet

(Mercer et al

2014)

Basic information about cfDNA testing use as a screening test was accurately described. Overall, sampled websites lacked balance and

comprehensive information about cfDNA testing and the complexity of decision-making involved in electing for its use. All websites were

written at reading levels higher than currently recommended levels for public health information.

(Skirton et al

2015)

The development of non-invasive prenatal testing has increased accessibility of fetal testing. Companies are now advertising prenatal testing

for aneuploidy via the Internet. While a number of websites provided balanced, accurate information, in the majority supporting evidence

was not provided to underpin the information and there was inadequate information on the need for an invasive test to definitely diagnose

aneuploidy.

Systematic reviews excluded due to low quality or overlap with high-quality systematic reviews

Study Reason for exclusion

Davis C, Cuckle H, Yaron Y (2014) Screening for Down syndrome--incidental diagnosis of

other aneuploidies. Prenat Diagn 34(11): 1044-8.

Of ten included studies, only two are specific to first trimester

screening.

Badeau, M., C. Lindsay, et al. (2015) Genomics-based non-invasive prenatal testing for

detection of fetal chromosomal aneuploidy in pregnant women. DOI:

10.1002/14651858.CD011767

Protocol

99


Gil, M. M., R. Akolekar, et al. (2014). "Analysis of cell-free DNA in maternal blood in screening

for aneuploidies: Meta-analysis." Fetal Diagnosis and Therapy 35(3): 156-173.

Updated in Gil et al 2015

Hayes and Inc (2013) Noninvasive Prenatal Testing (NIPT) for fetal aneuploidy. Does not meet criteria for grading (abstract only)

Kagan, K. O., M. Hoopmann, et al. (2016). "Discordance between ultrasound and cell free

DNA screening for monosomy X." Archives of Gynecology and Obstetrics: 1-6.

Includes seven studies all of which are included in high quality

SLRs included in this review

Mersy, E., L. J. M. Smits, et al. (2013). "Noninvasive detection of fetal trisomy 21: Systematic

review and report of outcome and quality." Prenatal Diagnosis 33: 73-74. ABSTRACT

Does not meet criteria for grading (abstract only)

Mersy, E., L. J. M. Smits, et al. (2013). "Noninvasive detection of fetal trisomy 21: Systematic

review and report of quality and outcomes of diagnostic accuracy studies performed

between 1997 and 2012." Human Reproduction Update 19(4): 318-329.

Included 16 studies of which 10 were included in high quality

SLRs. Of the included studies, 9 were considered too small to

give precise results and were not included in the discussion.

Verweij, E. J., J. M. van den Oever, et al. (2012). "Diagnostic accuracy of noninvasive

detection of fetal trisomy 21 in maternal blood: a systematic review." Fetal Diagnosis &

Therapy 31(2): 81-86.

Includes two studies, both of which are included in Gil et al 2015

and Taylor Philips et al 2016

Walsh, J. M. and J. D. Goldberg (2013). "Fetal aneuploidy detection by maternal plasma

DNA sequencing: a technology assessment." Prenatal Diagnosis 33(6): 514-520.

Identified eight studies, all of which are included in high quality

SLRs

Yang, H., H. B. Xu, et al. (2015). "Systematic review of noninvasive prenatal diagnosis for

abnormal chromosome genetic diseases using free fetal DNA in maternal plasma."

Genetics and Molecular Research 14(3): 10603-10608.

Includes four studies of which three are included in high quality

SLRs and one is an early report and a later report of the paper is

included in Gil et al 2015

Studies included in high-quality systematic reviews included in this review

Study Review

Alberti, A., L. J. Salomon, et al. (2015). "Non-invasive prenatal testing for trisomy 21 based on analysis of cell-free fetal DNA

circulating in the maternal plasma." Prenatal Diagnosis 35(5): 471-476.

Mackie et al 2016

Taylor-Philips et al 2016

Ashoor, G., A. Syngelaki, et al. (2012). "Chromosome-selective sequencing of maternal plasma cell-free DNA for first-

trimester detection of trisomy 21 and trisomy 18." American Journal of Obstetrics & Gynecology 206(4): 322.e321-325.

Gil et al 2015


Ashoor, G., A. Syngelaki, et al. (2013). "Trisomy 13 detection in the first trimester of pregnancy using a chromosome-

selective cell-free DNA analysis method." Ultrasound in Obstetrics & Gynecology 41(1): 21-25.

Gil et al 2015

100

Study Review

Beamon, C. J., E. E. Hardisty, et al. (2014). "A single center's experience with noninvasive prenatal testing." Genetics in

Medicine 16(9): 681-687.


Bevilacqua, E., M. M. Gil, et al. (2015). "Performance of screening for aneuploidies by cell-free DNA analysis of maternal

blood in twin pregnancies." Ultrasound in Obstetrics & Gynecology 45(1): 61-66.


Bianchi, D. W., R. Lamar Parker, et al. (2014). "DNA sequencing versus standard prenatal aneuploidy screening." New

England Journal of Medicine 370(9): 799-808.

Gil et al 2015

Mackie et al 2016


Bianchi, D. W., L. D. Platt, et al. (2012). "Genome-wide fetal aneuploidy detection by maternal plasma DNA sequencing."

Obstet Gynecol 119(5): 890-901.

Gil et al 2015


Bijok, J., K. Gorzelnik, et al. (2014). "[Non-invasive prenatal diagnosis of the most common aneuploidies with cell-free fetal

DNA in maternal serum--preliminary results]." Ginekologia Polska 85(3): 208-213.

Mackie et al 2016

Canick, J. A., E. M. Kloza, et al. (2012). "DNA sequencing of maternal plasma to identify Down syndrome and other

trisomies in multiple gestations." Prenatal Diagnosis 32(8): 730-734.

Gil et al 2015

Chen, E. Z., R. W. Chiu, et al. (2011). "Noninvasive prenatal diagnosis of fetal trisomy 18 and trisomy 13 by maternal plasma

DNA sequencing." PLoS ONE [Electronic Resource] 6(7): e21791.

Gil et al 2015


Chiu, R. W. K., R. Akolekar, et al. (2011). "Non-invasive prenatal assessment of trisomy 21 by multiplexed maternal plasma

DNA sequencing: Large scale validity study." BMJ 342(7790): 217.

Gil et al 2015


Comas, C., M. Echevarria, et al. (2015). "Initial experience with non-invasive prenatal testing of cell-free DNA for major

chromosomal anomalies in a clinical setting." Journal of Maternal-Fetal and Neonatal Medicine 28(10): 1196-1201.

Gil et al 2015


Dan, S., W. Wang, et al. (2012). "Clinical application of massively parallel sequencing-based prenatal noninvasive fetal

trisomy test for trisomies 21 and 18 in 11,105 pregnancies with mixed risk factors." Prenatal Diagnosis 32(13): 1225-1232.


Del Mar Gil, M., M. S. Quezada, et al. (2014). "Cell-free DNA analysis for trisomy risk assessment in first-trimester twin

pregnancies." Fetal Diagnosis and Therapy 35(3): 204-211.

Gil et al 2015


Ehrich, M., C. Deciu, et al. (2011). "Noninvasive detection of fetal trisomy 21 by sequencing of DNA in maternal blood: a

study in a clinical setting." American Journal of Obstetrics & Gynecology 204(3): 205.e201-211.

Gil et al 2015


101

Study Review

Fan, H. C., Y. J. Blumenfeld, et al. (2008). "Noninvasive diagnosis of fetal aneuploidy by shotgun sequencing DNA from

maternal blood." Proc Natl Acad Sci U S A 105(42): 16266-16271.

Mackie et al 2016

Ferres, M. A., L. Lichten, et al. (2013). "Early experience with noninvasive DNA testing for aneuploidy in prenatal care."

Prenatal Diagnosis 33: 73.

Mackie et al 2016

Ghanta, S., M. E. Mitchell, et al. (2010). "Non-invasive prenatal detection of trisomy 21 using tandem single nucleotide

polymorphisms." PLoS One 5(10): e13184.

Mackie et al 2016

Gorduza, E. V., R. Popescu, et al. (2013). "Prenatal diagnosis of 21 trisomy by quantification of methylated fetal DNA in

maternal blood: Study on 10 pregnancies." Romanian Review of Laboratory Medicine 21(3): 275-284.

Mackie et al 2016

Grömminger, S., E. Yagmur, et al. (2014). "Fetal aneuploidy detection by cell-free DNA sequencing for multiple pregnancies

and quality issues with vanishing twins." Journal of Clinical Medicine 3(3): 679-692.

Gil et al 2015

Guex, N., C. Iseli, et al. (2013). "A robust second-generation genome-wide test for fetal aneuploidy based on shotgun

sequencing cell-free DNA in maternal blood." Prenatal Diagnosis 33(7): 707-710.

Gil et al 2015

Hall, M. P., M. Hill, et al. (2014). "Non-invasive prenatal detection of trisomy 13 using a single nucleotide polymorphism- And

informatics-based approach." PLoS ONE 9(5).

Gil et al 2015


Hofmann, W., M. Entezami, et al. (2013). "Diagnostic accuracy for the noninvasive prenatal detection of common

autosomal aneuploidies." Prenatal Diagnosis 33: 75.

Mackie et al 2016

Hooks, J., A. J. Wolfberg, et al. (2014). "Non-invasive risk assessment of fetal sex chromosome aneuploidy through directed

analysis and incorporation of fetal fraction." Prenatal Diagnosis 34(5): 496-499.

Gil et al 2015

Huang, X., J. Zheng, et al. (2014). "Noninvasive prenatal testing of trisomies 21 and 18 by massively parallel sequencing of

maternal plasma DNA in twin pregnancies." Prenatal Diagnosis 34(4): 335-340.

Gil et al 2015


Jeon, Y. J., Y. Zhou, et al. (2014). "The feasibility study of non-invasive fetal trisomy 18 and 21 detection with semiconductor

sequencing platform." PLoS ONE [Electronic Resource] 9(10): e110240.


Jiang, F., J. Ren, et al. (2012). "Noninvasive Fetal Trisomy (NIFTY) test: an advanced noninvasive prenatal diagnosis

methodology for fetal autosomal and sex chromosomal aneuploidies." BMC Medical Genomics [Electronic Resource] 5:

57.

Gil et al 2015


Korostelev, S., G. Totchiev, et al. (2014). "Association of non-invasive prenatal testing and chromosomal microarray analysis

for prenatal diagnostics." Gynecological Endocrinology 30: 13-16.


102

Study Review

Lau, T. K., F. Chen, et al. (2012). "Noninvasive prenatal diagnosis of common fetal chromosomal aneuploidies by maternal

plasma DNA sequencing." Journal of Maternal-Fetal & Neonatal Medicine 25(8): 1370-1374.

Gil et al 2015

Mackie et al 2016


Lau, T. K., F. Jiang, et al. (2013). "Non-invasive prenatal screening of fetal Down syndrome by maternal plasma DNA

sequencing in twin pregnancies." Journal of Maternal-Fetal and Neonatal Medicine 26(4): 434-437.

Gil et al 2015

Li, P. Q., J. Zhang, et al. (2014). "Development of noninvasive prenatal diagnosis of trisomy 21 by RT-MLPA with a new set of

SNP markers." Arch Gynecol Obstet 289(1): 67-73.

Mackie et al 2016

Liang, D., W. Lv, et al. (2013). "Non-invasive prenatal testing of fetal whole chromosome aneuploidy by massively parallel

sequencing." Prenatal Diagnosis 33(5): 409-415.

Gil et al 2015


Liao, C., A. H. Yin, et al. (2014). "Noninvasive prenatal diagnosis of common aneuploidies by semiconductor sequencing."

Proc Natl Acad Sci U S A 111(20): 7415-7420.

Mackie et al 2016

Mazloom, A. R., Z. Dzakula, et al. (2013). "Noninvasive prenatal detection of sex chromosomal aneuploidies by sequencing

circulating cell-free DNA from maternal plasma." Prenatal Diagnosis 33(6): 591-597.

Gil et al 2015

Nicolaides, K. H., T. J. Musci, et al. (2014). "Assessment of fetal sex chromosome aneuploidy using directed cell-free DNA

analysis." Fetal Diagnosis & Therapy 35(1): 1-6.

Gil et al 2015

Nicolaides, K. H., A. Syngelaki, et al. (2012). "Noninvasive prenatal testing for fetal trisomies in a routinely screened first-

trimester population." American Journal of Obstetrics & Gynecology 207(5): 374.e371-376.

Gil et al 2015

Mackie et al 2016


Nicolaides, K. H., A. Syngelaki, et al. (2013). "Validation of targeted sequencing of single-nucleotide polymorphisms for non-

invasive prenatal detection of aneuploidy of chromosomes 13, 18, 21, X, and Y." Prenatal Diagnosis 33(6): 575-579.

Gil et al 2015

Mackie et al 2016


Norton, M. E., H. Brar, et al. (2012). "Non-Invasive Chromosomal Evaluation (NICE) Study: results of a multicenter prospective

cohort study for detection of fetal trisomy 21 and trisomy 18." American Journal of Obstetrics & Gynecology 207(2):

137.e131-138.

Gil et al 2015

Mackie et al 2016


Norton, M. E., B. Jacobsson, et al. (2015). "Cell-free DNA analysis for noninvasive examination of trisomy." New England

Journal of Medicine 372(17): 1589-1597 1589p.

Mackie et al 2016


103

Study Review

Palomaki, G. E., C. Deciu, et al. (2012). "DNA sequencing of maternal plasma reliably identifies trisomy 18 and trisomy 13 as

well as Down syndrome: an international collaborative study." Genetics in Medicine 14(3): 296-305.

Gil et al 2015

Palomaki, G. E., E. M. Kloza, et al. (2011). "DNA sequencing of maternal plasma to detect Down syndrome: an international

clinical validation study." Genetics in Medicine 13(11): 913-920.

Gil et al 201


Pergament, E., H. Cuckle, et al. (2014). "Single-nucleotide polymorphism-based noninvasive prenatal screening in a high-

risk and low-risk cohort." Obstetrics and Gynecology 124(2 PART1): 210-218.

Gil et al 2015

Mackie et al 2016


Porreco, R. P., T. J. Garite, et al. (2014). "Noninvasive prenatal screening for fetal trisomies 21, 18, 13 and the common sex

chromosome aneuploidies from maternal blood using massively parallel genomic sequencing of DNA." American Journal

of Obstetrics & Gynecology 211(4): 365.e361-365.e312 361p.

Gil et al 2015

Mackie et al 2016


Quezada, M. S., M. M. Gil, et al. (2015). "Screening for trisomies 21, 18 and 13 by cell-free DNA analysis of maternal blood at

10-11 weeks' gestation and the combined test at 11-13 weeks." Ultrasound in Obstetrics & Gynecology 45(1): 36-41.

Gil et al 2015

Mackie et al 2016


Sago, H., A. Sekizawa, et al. (2015). "Nationwide demonstration project of next-generation sequencing of cell-free DNA in

maternal plasma in Japan: 1-year experience." Prenatal Diagnosis 35(4): 331-336.


Samango-Sprouse, C., M. Banjevic, et al. (2013). "SNP-based non-invasive prenatal testing detects sex chromosome

aneuploidies with high accuracy." Prenatal Diagnosis 33(7): 643-649.

Gil et al 2015

Sehnert, A. J., B. Rhees, et al. (2011). "Optimal detection of fetal chromosomal abnormalities by massively parallel DNA

sequencing of cell-free fetal DNA from maternal blood." Clinical Chemistry 57(7): 1042-1049.

Gil et al 2015

Mackie et al 2016


Shaw, S. W. S., C. Y. Chen, et al. (2013). "Non-invasive prenatal testing for whole fetal chromosomal aneuploidies: A multi-

center prospective cohort trial in Taiwan." Prenatal Diagnosis 33: 81.

Mackie et al 2016

Shaw, S. W. S., C. H. Hsiao, et al. (2014). "Noninvasive prenatal testing for whole fetal chromosomal aneuploidies: A

multicenter prospective cohort trial in Taiwan." Fetal Diagnosis and Therapy 35(1): 13-17.

Gil et al 2015


Song, Y., S. Huang, et al. (2015). "Non-invasive prenatal testing for fetal aneuploidies in the first trimester of pregnancy."

Ultrasound in Obstetrics & Gynecology 45(1): 55-60.

Gil et al 2015


104

Study Review

Song, Y., C. Liu, et al. (2013). "Noninvasive prenatal testing of fetal aneuploidies by massively parallel sequencing in a

prospective Chinese population." Prenatal Diagnosis 33(7): 700-706.

Gil et al 2015

Mackie et al 2016


Sparks, A. B., C. A. Struble, et al. (2012). "Noninvasive prenatal detection and selective analysis of cell-free DNA obtained

from maternal blood: evaluation for trisomy 21 and trisomy 18." American Journal of Obstetrics & Gynecology 206(4):

319.e311-319.

Gil et al 2015

Mackie et al 2016


Stumm, M., M. Entezami, et al. (2014). "Diagnostic accuracy of random massively parallel sequencing for non-invasive

prenatal detection of common autosomal aneuploidies: a collaborative study in Europe." Prenatal Diagnosis 34(2): 185-

191.

Gil et al 2015

Mackie et al 2016


Tong, Y. K., S. Jin, et al. (2010). "Noninvasive prenatal detection of trisomy 21 by an epigenetic-genetic chromosome-

dosage approach." Clin Chem 56(1): 90-98.

Mackie et al 2016

van den Oever, J. M., S. Balkassmi, et al. (2013). "Successful noninvasive trisomy 18 detection using single molecule

sequencing." Clinical Chemistry 59(4): 705-709.

Mackie et al 2016

van den Oever, J. M., S. Balkassmi, et al. (2012). "Single molecule sequencing of free DNA from maternal plasma for

noninvasive trisomy 21 detection." Clinical Chemistry 58(4): 699-706.

Mackie et al 2016

Verweij, E. J., M. De Boer, et al. (2012). "Non-invasive prenatal diagnosis of trisomy 21: Replacing invasive testing or

replacing screening?" American Journal of Obstetrics and Gynecology 206(1): S313.

Mackie et al 2016

Verweij, E. J., B. Jacobsson, et al. (2013). "European non-invasive trisomy evaluation (EU-NITE) study: a multicenter

prospective cohort study for non-invasive fetal trisomy 21 testing." Prenatal Diagnosis 33(10): 996-1001.

Gil et al 2015


Wax, J. R., A. Cartin, et al. (2015). "Noninvasive prenatal testing: impact on genetic counseling, invasive prenatal diagnosis,

and trisomy 21 detection." Journal of Clinical Ultrasound 43(1): 1-6.


Zhang, H., Y. Gao, et al. (2015). "Non-invasive prenatal testing for trisomies 21, 18 and 13: clinical experience from 146,958

pregnancies.[Erratum appears in Ultrasound Obstet Gynecol. 2015 Jul;46(1):130; PMID: 26134734]." Ultrasound in Obstetrics

& Gynecology 45(5): 530-538.

Mackie et al 2016


Zhou, Q., L. Pan, et al. (2014). "Clinical application of noninvasive prenatal testing for the detection of trisomies 21, 18, and

13: a hospital experience." Prenatal Diagnosis 34(11): 1061-1065.


105

Study Review

Zimmermann, B., M. Hill, et al. (2012). "Noninvasive prenatal aneuploidy testing of chromosomes 13, 18, 21, X, and Y, using

targeted sequencing of polymorphic loci." Prenatal Diagnosis 32(13): 1233-1241.

Mackie et al 201


Level IV studies

Study

Dar, P., K. J. Curnow, et al. (2014). "Clinical experience and follow-up with large scale single-nucleotide polymorphism-based noninvasive prenatal aneuploidy

testing." American Journal of Obstetrics and Gynecology 211(5): 527.e521-527.e517.

Dobson LJ, Reiff ES, Little SE et al (2016) Patient choice and clinical outcomes following positive noninvasive prenatal screening for aneuploidy with cell-free DNA

(cfDNA). Prenat Diagn 36(5): 456-62.

Fairbrother, G., S. Johnson, et al. (2013). "Clinical experience of noninvasive prenatal testing with cell-free DNA for fetal trisomies 21, 18, and 13, in a general

screening population." Prenatal Diagnosis 33(6): 580-583.

Ke W-L, Zhao, W.-H., Wang, X.-Y., (2015) Detection of fetal cell-free DNA in maternal plasma for Down syndrome, Edward syndrome and Patau syndrome of high

risk fetus. Int J Clin Exp Med 8(6): 9525–30.

Lau, T. K., S. W. Cheung, et al. (2014). "Non-invasive prenatal testing for fetal chromosomal abnormalities by low-coverage whole-genome sequencing of

maternal plasma DNA: review of 1982 consecutive cases in a single center." Ultrasound in obstetrics & gynecology : the official journal of the International

Society of Ultrasound in Obstetrics and Gynecology 43(3): 254-264.

Lebo, R. V., R. W. Novak, et al. (2015). "Discordant circulating fetal DNA and subsequent cytogenetics reveal false negative, placental mosaic, and fetal mosaic

cfDNA genotypes." Journal of Translational Medicine 13(1).

Li, W. H., P. H. Wang, et al. (2015). "Noninvasive prenatal testing for fetal trisomy in a mixed risk factors pregnancy population." Taiwanese Journal of Obstetrics &

Gynecology 54(2): 122-125.

Oneda B, Steindl K, Masood R et al (2016) Noninvasive prenatal testing: more caution in counseling is needed in high risk pregnancies with ultrasound

abnormalities. Eur J Obstet Gynecol Reprod Biol 200: 72-5.

Persico N, Boito S, Ischia B et al (2016) Cell-free DNA testing in the maternal blood in high-risk pregnancies after first-trimester combined screening. Prenat Diagn

36(3): 232-6.

Radoi, V. E., C. L. Bohiltea, et al. (2015). "Cell free fetal DNA testing in maternal blood of Romanian pregnant women." Iranian Journal of Reproductive Medicine

13(10): 621-624.

106

Suzumori, N., T. Ebara, et al. (2014). "Non-specific psychological distress in women undergoing noninvasive prenatal testing because of advanced maternal

age." Prenatal Diagnosis 34(11): 1055-1060.

Taylor, J. B., V. Y. Chock, et al. (2014). "NIPT in a clinical setting: an analysis of uptake in the first months of clinical availability." Journal of Genetic Counseling

23(1): 72-78.

Wallerstein R, Jelks A, Garabedian MJ (2014) A new model for providing cell-free DNA and risk assessment for chromosome abnormalities in a public hospital

setting. J Pregnancy 2014: 962720.

Wang JC, Sahoo T, Schonberg S et al (2015a) Discordant noninvasive prenatal testing and cytogenetic results: a study of 109 consecutive cases. Genet Med

17(3): 234-6.

Wang L, Meng Q, Tang X et al (2015b) Maternal mosaicism of sex chromosome causes discordant sex chromosomal aneuploidies associated with noninvasive

prenatal testing. Taiwan J Obstet Gynecol 54(5): 527-31.

Yao, H., F. Jiang, et al. (2014). "Detection of fetal sex chromosome aneuploidy by massively parallel sequencing of maternal plasma DNA: initial experience in a

Chinese hospital." Ultrasound in Obstetrics & Gynecology 44(1): 17-24.

Zhang J & Zhang B (2016) Second-generation non-invasive high-throughput DNA sequencing technology in the screening of Down's syndrome in advanced

maternal age women. Biomed Rep 4(6): 715-18.

Other excluded studies


Akaishi, R., T. Yamada, et al. (2014). "Prenatal genetic counseling and diagnosis in our institute: 2007-2014." Prenatal Diagnosis

34: 72-73.

Does not meet criteria for

grading (abstract)

Alcaine, M. J., C. Aulesa, et al. (2015). "Present situation of prenatal screening of chromosomopathies in Spain: SEQC survey

results 2013." Revista del Laboratorio Clinico 8(3): 138-148.

Not in English

Allyse, M., L. C. Sayres, et al. (2012). "Anticipated uptake of non-invasive prenatal testing among U.S. adults." Prenatal

Diagnosis 32: 25.


grading (abstract)

Anselem, O., S. Keroui, et al. (2015). Journal de Gynecologie Obstetrique et Biologie de la Reproduction. Not In English

Audibert, F., A. Gagnon, et al. (2011). "Prenatal screening for and diagnosis of aneuploidy in twin pregnancies." Journal of

Obstetrics & Gynaecology Canada: JOGC 33(7): 754-767. Does not answer research

question

Ayres, A. C., J. A. Whitty, et al. (2015). "A cost-effectiveness analysis comparing different strategies to implement noninvasive

prenatal testing into a down syndrome screening program." Obstetrical and Gynecological Survey 70(2): 63-65.


grading (abstract)

107


Bayindir, B., L. Dehaspe, et al. (2015). "Noninvasive prenatal testing using a novel analysis pipeline to screen for all autosomal

fetal aneuploidies improves pregnancy management." European Journal of Human Genetics 23(10): 1286-1293.

Does not answer research

question

Beulen, L., J. P. C. Grutters, et al. (2013). "The implementation of noninvasive prenatal diagnosis in national health care: A

decision-analytic economic model." Prenatal Diagnosis 33: 69.


grading (abstract)

Beulen, L., J. P. C. Grutters, et al. (2015). "The consequences of implementing non-invasive prenatal testing in Dutch National

Health Care: A cost-effectiveness analysis: Editorial comment." Obstetrical and Gynecological Survey 70(3): 162-164

Editorial

Bianchi, D. W., S. Parsa, et al. (2015). "Fetal sex chromosome testing by maternal plasma DNA sequencing: Clinical laboratory

experience and biology." Obstetrics and Gynecology 125(2): 375-382.


question

Bianchi, D. W., T. Prosen, et al. (2013). "Massively parallel sequencing of maternal plasma DNA in 113 cases of fetal nuchal

cystic hygroma." Obstetrics & Gynecology 121(5): 1057-1062.


question

Cheung, S. W., A. Patel, et al. (2015). "Accurate description of DNA-based noninvasive prenatal screening." New England

Journal of Medicine 372(17): 1675-1677.

Letter

Chiu, R. W., K. C. Chan, et al. (2008). "Noninvasive prenatal diagnosis of fetal chromosomal aneuploidy by massively parallel

genomic sequencing of DNA in maternal plasma." Proceedings of the National Academy of Sciences of the United States of

America 105(51): 20458-20463.


question

Courtney, E. and M. Sinosich (2014). "Consumers' experiences of and attitudes towards noninvasive prenatal testing in

Australia: The good, the bad and the ugly." Prenatal Diagnosis 34: 74.


grading (abstract)

Crimmins, S., X. Liu, et al. (2016). "Universal QUAD screen versus universal cell free DNA testing for Down's syndrome screening:

Cost-effectiveness analysis." American Journal of Obstetrics and Gynecology 214(1): S381-S382.


grading (abstract)

Dall'Amico, D. and E. Viora (2011). "Guidelines for prenatal screening of Down syndrome." Biochimica Clinica 35(3): 229-241. Not in English

Davidson, T., E. Iwarsson, et al. (2015). "Costs and cost-effectiveness of non-invasive prenatal diagnosis (NIPT) for detection of

trisomy 21 in Sweden." Value in Health 18(7): A352.


grading (abstract)

Deng, Y. H., A. H. Yin, et al. (2011). "Non-invasive prenatal diagnosis of trisomy 21 by reverse transcriptase multiplex ligation-

dependent probe amplification." Clinical Chemistry & Laboratory Medicine 49(4): 641-646.


question (lab study)

Dondorp, W. J., G. M. W. R. De Wert, et al. (2015). "Non-invasive prenatal testing for aneuploidy and beyond: Challenges of

responsible innovation in prenatal screening-an ESHG/ASHG position statement." Human Reproduction 30: i107-i108. Does not meet criteria for

grading (abstract)

108


Durst, J., A. Sutton, et al. (2014). "A cost-effective analysis of non-invasive prenatal testing for trisomy 21 in low-risk women."

American Journal of Obstetrics and Gynecology 210(1): S219.


grading (abstract)

Farrell, R. M., P. Agatisa, et al. (2015). "Women's perspectives on noninvasive prenatal testing for detection of sex

chromosome abnormalities and microdeletions." Obstetrics and Gynecology 125: 92S.


grading (abstract)

Fumagalli, S., A. Locatelli, et al. (2012). "Perception of risk and access to invasive prenatal diagnosis in women aged >35

years." Prenatal Diagnosis 32: 74-75.


grading (abstract)

Futch, T., J. Spinosa, et al. (2013). "Initial clinical laboratory experience in noninvasive prenatal testing for fetal aneuploidy

from maternal plasma DNA samples." Prenatal Diagnosis 33(6): 569-574.

does not answer research question

(lab study)

Gitsels-van der Wal, J. T., J. Manniën, et al. (2014). "Prenatal screening for congenital anomalies: exploring midwives'

perceptions of counseling clients with religious backgrounds." BMC Pregnancy and Childbirth 14: 237.


question

Griffin, E., V. Lee, et al. (2015). "Cost effectiveness of first trimester aneuploidy screening in obese women of advanced

maternal age." American Journal of Obstetrics and Gynecology 212(1): S313-S314.


grading (abstract)

Hacker, F., E. Griffin, et al. (2015). "Role of genetic sonogram and NIPT after EIF detection: A cost-effectiveness analysis."

American Journal of Obstetrics and Gynecology 212(1): S171-S172.


grading (abstract)

Hernández-Gómez, M., E. Ramírez-Arroyo, et al. (2015). "Non invasive prenatal test (NIPT) in maternal blood by parallel

massive sequencing. initial experience in Mexican women and literature review." Ginecologia y Obstetricia de Mexico 83(5):

277-288.

Not in English

Higuchi, E. C., J. P. Sheldon, et al. (2016). "Non-invasive prenatal screening for trisomy 21: Consumers' perspectives." American

Journal of Medical Genetics, Part A 170(2): 375-385.


question

Hill, M., C. Compton, et al. (2014). "Client views and attitudes to non-invasive prenatal diagnosis for sickle cell disease,

thalassaemia and cystic fibrosis." Journal of Genetic Counseling 23(6): 1012-1021.


question

Hill, M., D. Wright, et al. (2014). "Evaluation of non-invasive prenatal testing (NIPT) for aneuploidy in an NHS setting: a reliable

accurate prenatal non-invasive diagnosis (RAPID) protocol." BMC Pregnancy & Childbirth 14: 229.


grading (protocol)

Hill, M., J. Fisher, et al. (2012). "Implementation of non-invasive prenatal diagnosis for Down's syndrome: What do women and

health professionals want?" Prenatal Diagnosis 32: 98.


grading (abstract)

Hill, M., J. Fisher, et al. (2013). "Women's and health professionals' preferences for prenatal tests for down syndrome: A discrete

choice experiment to contrast noninvasive prenatal diagnosis with current invasive tests." Obstetrical and Gynecological

Survey 68(3): 171-173.


grading (abstract and editorial)

109


Hill, M., J. Johnson, et al. (2014). "Preferences for prenatal tests for Down syndrome: Comparing women and health

professionals from nine countries." Prenatal Diagnosis 34: 2-3.


grading (abstract)

Hill, M., S. Taffinder, et al. (2011). "Incremental cost of non-invasive prenatal diagnosis versus invasive prenatal diagnosis of

fetal sex in England." Prenatal Diagnosis 31(3): 267-273.


question

Hui, L., M. Teoh, et al. (2014). "Clinical implementation of noninvasive prenatal testing for aneuploidy in Australia and New

Zealand." Prenatal Diagnosis 34: 56.


grading (abstract)

Hui, L., M. Teoh, et al. (2015). "Clinical implementation of noninvasive prenatal testing by Australian sonologists." BJOG: An

International Journal of Obstetrics and Gynaecology 122: 52.


grading (abstract)

Hulstaert, F., M. Neyt, et al. (2014) The non-invasive prenatal test (NIPT) for trisomy 21 ? health economic aspects. Does not meet criteria for

grading (abstract)

Jackson, J., B. Hamar, et al. (2014). "Nuchal translucency measurement plus non-invasive prenatal testing to screen for

aneuploidy in a community-based average-risk population." Ultrasound in Obstetrics & Gynecology 44(4): 491.

Letter

Jensen, T. J., T. Zwiefelhofer, et al. (2013). "High-throughput massively parallel sequencing for fetal aneuploidy detection from

maternal plasma." PLoS ONE [Electronic Resource] 8(3): e57381.


question

Jin, Y., Z. Miao, et al. (2014). "Prenatal diagnosis of fetal chromosome aneuploidy by massively parallel genomic sequencing."

National Medical Journal of China 94(23): 1788-1790.

Not in English

Johnson, J., M. Pastuck, et al. (2013). "First-trimester Down syndrome screening using additional serum markers with and

without nuchal translucency and cell-free DNA." Prenatal Diagnosis 33(11): 1044-1049.


question (no conclusions

relevant to current Australian

practice)

Kagan, K. O., D. Wright, et al. (2015). "First-trimester contingent screening for trisomies 21, 18 and 13 by fetal nuchal

translucency and ductus venosus flow and maternal blood cell-free DNA testing." Ultrasound in obstetrics & gynecology : the

official journal of the International Society of Ultrasound in Obstetrics and Gynecology 45(1): 42-47.




practice)

Kloza, E. M., P. K. Haddow, et al. (2015). "Evaluation of patient education materials: The example of circulating cell free DNA

testing for aneuploidy." Journal of Genetic Counseling 24(2): 259-266. Does not answer research

question

Larion, S., S. Warsof, et al. (2015). "Three year clinical experience with noninvasive prenatal testing in 3000 high risk cases in the

United States." Prenatal Diagnosis 35: 59.


grading (abstract)

110


Lefkowitz, R. B., J. A. Tynan, et al. (2016). "Clinical validation of a noninvasive prenatal test for genomewide detection of fetal

copy number variants." American Journal of Obstetrics and Gynecology.

Potential conflict of interest

(industry study)

Lemery, D., Y. Ville, et al. (2010). "The new policy for Down' syndrome Screening in France: the Order of June 23, 2009." Revue

de médecine périnatale: 1-10. Not in English

Lewis, C. (2015). "Clinical implementation of non-invasive prenatal testing worldwide-results from a global survey." Prenatal

Diagnosis 35: 59-60.


grading (abstract)

Lewis, C. (2015). "Offering non-invasive prenatal testing for Down syndrome in a public health service clinical setting-can we

ensure maintenance of informed choice?" Prenatal Diagnosis 35: 19-20.


grading (abstract)

Lewis, C., M. Hill, et al. (2013). "Noninvasive prenatal testing for aneuploidy-a survey of the UK public's views." Prenatal

Diagnosis 33: 70-71.


grading (abstract)

Lewis, C., M. Hill, et al. (2014). "Offering NIPT for Down syndrome in a national health service clinical setting: UK patient

experiences." Prenatal Diagnosis 34: 82.


grading (abstract)

Li SW, Barrett AN, Gole L et al (2015) The assessment of combined first trimester screening in women of advanced maternal

age in an Asian cohort. Singapore Medical Journal 56(01): 47-52.


question

Li, B., S. Pena, et al. (2014). "Trend of invasive procedure rates in women following positive first trimester combined screening

(FTCS) before and after the introduction of noninvasive prenatal testing (NIPT)." American Journal of Obstetrics and

Gynecology 210(1): S91-S92.


grading (abstract)

Li, G. and M. Allyse (2014). "Difference in attitudes on noninvasive prenatal testing in China and the United States." Prenatal

Diagnosis 34: 81.


grading (abstract)

Lim, J. H., S. Y. Kim, et al. (2011). "Non-invasive epigenetic detection of fetal trisomy 21 in first trimester maternal plasma." PLoS

ONE [Electronic Resource] 6(11): e27709.


question

Liu, J., H. Wang, et al. (2015). "Application of next-generation DNA sequencing for prenatal testing of fetal chromosomal

aneuploidies." Chinese Journal of Medical Genetics 32(4): 533-537.

Not in English

Ma, J., H. Pan, et al. (2015). "Perspective study of non-invasive prenatal testing using cell-free fetal DNA in high-risk

population." National Medical Journal of China 95(11): 849-852.

Not in English

Madankumar, R., K. Brown, et al. (2014). "Assessing obstetricians knowledge on non invasive prenatal screening."

Reproductive Sciences 21(3): 258A.


grading (abstract)

111


Maxwell, S. J., J. E. Dickinson, et al. (2015). "Knowledge of noninvasive prenatal testing among pregnant women." Medical

Journal of Australia 203(2): 76.

Letter

McCullough, R. M., E. A. Almasri, et al. (2014). "Non-invasive prenatal chromosomal aneuploidy testing - Clinical experience:

100,000 clinical samples." PLoS ONE 9(10).


question

Mundy, L. and J. E. Hiller (2008) Non-invasive prenatal diagnostic test for Down's Syndrome (Structured abstract). Does not meet criteria for

grading (abstract)

Mundy, L. and J. E. Hiller (2009) Non-invasive prenatal diagnostic test for trisomy-21 (Down's Syndrome) (Structured abstract). Does not meet criteria for

grading (abstract)

Nicolaides, K. H., A. Syngelaki, et al. (2013). "Noninvasive prenatal testing for fetal trisomies in a routinely screened first-

trimester population." Obstetrical and Gynecological Survey 68(3): 173-175.


grading (abstract)

Nicolaides, K. H., A. Syngelaki, et al. (2014). "First-trimester contingent screening for trisomies 21, 18 and 13 by biomarkers and

maternal blood cell-free DNA testing." Fetal Diagnosis & Therapy 35(3): 185-192.


question

Nicolaides, K. H., D. Wright, et al. (2013). "First-trimester contingent screening for trisomy 21 by biomarkers and maternal blood

cell-free DNA testing." Ultrasound in Obstetrics & Gynecology 42(1): 41-50.


question

Nicolaides, K. H., T. J. Musci, et al. (2014). "Assessment of fetal sex chromosome aneuploidy using directed cell-free DNA

analysis." Obstetrical and Gynecological Survey 69(5): 249-250.


grading (abstract)

Norton, M. E., B. Jacobsson, et al. (2015). "Cell-Free DNA Analysis for Noninvasive Examination of Trisomy." Obstetrical and

Gynecological Survey 70(8): 483-484.


grading (abstract)

Norton, M. E., L. L. Jelliffe-Pawlowski, et al. (2014). "Chromosome abnormalities detected by current prenatal screening and

noninvasive prenatal testing." Obstetrics & Gynecology 124(5): 979-986.


question

Odibo, A., A. Cahill, et al. (2013). "Introducing non-invasive prenatal testing (NIPT) into screening paradigms for trisomy 21

(T21): Is it cost-effective?" American Journal of Obstetrics and Gynecology 208(1): S242-S243.


grading (abstract)

Ohno M & Caughey A (2013) The role of noninvasive prenatal testing as a diagnostic versus a screening tool--a cost-

effectiveness analysis. Prenat Diagn 33(7): 630-5.


question

Ohno, M., A. Allen, et al. (2013). "A cost-effectiveness analysis of using non-invasive prenatal testing as a screening tool for

Down syndrome." American Journal of Obstetrics and Gynecology 208(1): S235.


grading (abstract)

112


Palomaki, G. E., E. E. Eklund, et al. (2015). "Evaluating first trimester maternal serum screening combinations for Down

syndrome suitable for use with reflexive secondary screening via sequencing of cell free DNA: High detection with low rates

of invasive procedures." Prenatal Diagnosis 35(8): 789-796.


question

Papageorgiou, E. A., A. Karagrigoriou, et al. (2011). "Fetal-specific DNA methylation ratio permits noninvasive prenatal

diagnosis of trisomy 21." Nature Medicine 17(4): 510-513.


question

Pérez-Pedregosa, J., B. Paredes Ros, et al. (2015). "Non-invasive prenatal screening for aneuploidy through analysis of cell-

free fetal DNA from maternal blood." Progresos de Obstetricia y Ginecologia 58(3): 113-117.

Not in English

Petersen, O. B., I. Vogel, et al. (2014). "Potential diagnostic consequences of applying noninvasive prenatal testing:

Population-based study from a country with existing first-trimester screening." Obstetrical and Gynecological Survey 69(6):

321-323.

Editorial

Polish Gynaecological, S. and S. Polish Human Genetics (2015). "[Cell-free fetal DNA testing in prenatal genetic screening.

Polish Gynaecological Society and Polish Human Genetics Society guidelines]." Ginekologia Polska 86(12): 966-969. Not in English

Reiff ES, Little SE, Dobson L et al (2016) What is the role of the 11- to 14-week ultrasound in women with negative cell-free DNA

screening for aneuploidy? Prenat Diagn 36(3): 260-5.


question

Rose, N. C., D. Lagrave, et al. (2013). "The impact of utilization of early aneuploidy screening on amniocenteses available for

training in obstetrics and fetal medicine." Prenatal Diagnosis 33(3): 242-244.


question

Ryan, A., N. Hunkapiller, et al. (2016). "Validation of an Enhanced Version of a Single-Nucleotide Polymorphism-Based

Noninvasive Prenatal Test for Detection of Fetal Aneuploidies." Fetal Diagnosis and Therapy.


(industry study)

Sánchez-Usabiaga, R. A., M. Aguinaga-Ríos, et al. (2015). "Clinical implementation of non-invasive prenatal study for

detecting aneuploidies by fetal DNA based on single nucleotide polymorphisms: Two years in Mexico." Ginecologia y

Obstetricia de Mexico 83(4): 220-231.

Not in English

Sayres, L. C., M. Allyse, et al. (2012). "Integrating stakeholder perspectives into the translation of cell-free fetal DNA testing for

aneuploidy." Genome Medicine 4(6).


question

Sbu (2014) Non-invasive prenatal test for Down's syndrome (Project record). Does not meet criteria for

grading (project record)

Sekhon, R., E. Lee, et al. (2015). "Non-invasive prenatal testing (NIPT): Evaluating patient preference of antenatal

investigations in high risk women." Journal of Medical Imaging and Radiation Oncology 59 (Suppl 1): 9.


grading (abstract)

113


Sharma, P., A. Metcalfe, et al. (2015). "Women's understanding of non-invasive prenatal testing based on cell free DNA versus

first trimester combined screening." Prenatal Diagnosis 35: 106.


grading (abstract)

Shengmou, L., C. Min, et al. (2014). "Effects, safety and cost-benefit analysis of Down syndrome screening in first trimester."

Zhonghua fu chan ke za zhi 49(5): 325-330.

Not in English

Silcock, C., L. S. Chitty, et al. (2012). "Will the introduction of non-invasive prenatal diagnosis for Down's syndrome influence

informed choice?" Prenatal Diagnosis 32: 25-26.


grading (abstract)

Sinkey, R. G. and A. O. Odibo (2016). "Cost-Effectiveness of Old and New Technologies for Aneuploidy Screening." Clinics in

Laboratory Medicine.

Narrative review

Song K, Musci TJ, Caughey AB (2013) Clinical utility and cost of non-invasive prenatal testing with cfDNA analysis in high-risk

women based on a US population. J Matern Fetal Neonatal Med 26(12): 1180-5.


(industry study)

Stokowski R, Wang E, White K et al (2015) Clinical performance of non-invasive prenatal testing (NIPT) using targeted cell-free

DNA analysis in maternal plasma with microarrays or next generation sequencing (NGS) is consistent across multiple

controlled clinical studies. Prenat Diagn 35(12): 1243-6.


(industry study)

Strah, D., P. Ovniek, et al. (2015). "Non-invasive prenatal cell-free fetal DNA testing for down syndrome and other

chromosomal abnormalities." Zdravniski Vestnik 84(11): 727-733.




practice)

Stumm, M., M. Entezami, et al. (2012). "Non-invasive prenatal detection of trisomy 21 using massively parallel sequencing: A

collaborative study in Europe." Prenatal Diagnosis 32: 63-64.


grading (abstract)

Stumm, M., M. Entezami, et al. (2012). "Noninvasive prenatal detection of chromosomal aneuploidies using different next

generation sequencing strategies and algorithms." Prenatal Diagnosis 32(6): 569-577.


question

Susman, M., J. L. Halliday, et al. (2011). "Understanding women's decisions about prenatal diagnosis for chromosome

abnormalities." Twin Research and Human Genetics 14(4): 378.


grading (abstract)

Sutton, A., J. Durst, et al. (2014). "Non-invasive prenatal testing for trisomy 21 in high-risk women: A cost-effectiveness analysis."

American Journal of Obstetrics and Gynecology 210(1): S67.


grading (abstract)

Swaney, P., E. Hardisty, et al. (2014). "Attitudes and knowledge of Maternal-Fetal Medicine fellows regarding noninvasive

prenatal testing (NIPT)." American Journal of Obstetrics and Gynecology 210(1): S254-S255.


grading (abstract)

114


Taneja, P. A., H. L. Snyder, et al. (2016). "Noninvasive prenatal testing in the general obstetric population: Clinical

performance and counseling considerations in over 85000 cases." Prenatal Diagnosis 36(3): 237-243.


(industry study)

Tonk, V. S. and G. N. Wilson (2016). "Inaccuracy of non-invasive prenatal screening demands cautious counsel and follow-

up." American Journal of Medical Genetics, Part A 170(4): 1086-1087.

Letter

Tynan, J. A., S. K. Kim, et al. (2016). "Application of risk score analysis to low-coverage whole genome sequencing data for

the noninvasive detection of trisomy 21, trisomy 18, and trisomy 13." Prenatal Diagnosis 36(1): 56-62.


(industry study)

Van Opstal D, Srebniak MI, Polak J et al (2016) False Negative NIPT Results: Risk Figures for Chromosomes 13, 18 and 21 Based

on Chorionic Villi Results in 5967 Cases and Literature Review. PLoS One 11(1): e0146794.


question

Van Schendel, R., L. Page-Christiaens, et al. (2015). "Experiences of high-risk pregnant women who were offered a choice

between non-invasive prenatal testing, invasive testing or no follow-up test." Prenatal Diagnosis 35: 18-19.


grading (abstract)

Van Wymersch, D. and G. Gilson (2015). "Introduction of noninvasive prenatal testing for fetal trisomies: preliminary results and

consequences on invasive samplings." Bulletin de la Societe des Sciences Medicales du Grand-Duche de Luxembourg(1): 65-

72.

Not in English

Verweij, E. J. J., D. Oepkes, et al. (2012). "Changed attitude towards termination of pregnancy for trisomy 21 with non-invasive

prenatal diagnosis." Prenatal Diagnosis 32: 26.


grading (abstract)

Verweij, E. J. J., D. Oepkes, et al. (2012). "Non-invasive prenatal detection of trisomy 21: What women want and what they

want to pay." Prenatal Diagnosis 32: 101.


grading (abstract)

Walker BS, Jackson BR, LaGrave D et al (2015a) A cost-effectiveness analysis of cell free DNA as a replacement for serum

screening for Down syndrome. Prenat Diagn 35(5): 440-6.


question (integrated screening)

Wang, S. J., Z. Y. Gao, et al. (2012). "[Value of detection of cell-free fetal DNA in maternal plasma in the prenatal diagnosis of

chromosomal abnormalities]." Zhonghua fu chan ke za zhi 47(11): 808-812.

Not in English

Wang, S., Z. Gao, et al. (2014). "Detection of fetal chromosomal aneuploidy in pregnant women at advanced maternal age

during the first trimester." Nan Fang Yi Ke Da Xue Xue Bao = Journal of Southern Medical University 34(5): 655-658.

Not in English

Wax, J. R., R. Chard, et al. (2015). "Noninvasive prenatal testing: the importance of pretest trisomy risk and posttest predictive

values." American Journal of Obstetrics & Gynecology 212(4): 548-549.

Letter

Wray, A., H. Landy, et al. (2015). "Physician utilization and interpretation of non-invasive prenatal screening (NIPS)." Prenatal

Diagnosis 35: 109.


grading (abstract)

115


Wright, D., A. Wright, et al. (2015). "A unified approach to risk assessment for fetal aneuploidies." Ultrasound in Obstetrics &

Gynecology 45(1): 48-54.


question

Yu, S. C., K. C. Chan, et al. (2014). "Size-based molecular diagnostics using plasma DNA for noninvasive prenatal testing."

Proceedings of the National Academy of Sciences of the United States of America 111(23): 8583-8588.


question

116

2. Are there specific issues for Aboriginal and Torres Strait Islander women and rural and

remote populations?

No studies identified

117

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