A comparison of fundal height and handheld ultrasound measured

abdominal circumference to screen for fetal growth abnormalities

Adriane Haragan, MDFaculty Mentor: Gene Chang, MD

Fetal Growth Abnormalities

• Common, complex in modern

obstetrics

– Difficult to prevent

– Consequences of missed diagnosis

– Consequences of false positive

screening

Background• Fetal Growth Restriction

• Various definitions

• EFW < 10%

• 1/2 cases undetected

• Macrosomia

• Various definitions

• EFW > 4000-4500 g

• Diagnosed at time of delivery

ACOG Practice Bulletin No. 12

Mattioli KP, Int J Gynaecol Obstet 2010

Chauhan SP, Am J Perinatol, 2013

Background: Screening

• Fundal height

– Pubic symphysis to top of fundus

– Measurement in cm correlates to GA +/- 2cm

– Screening modality used by majority

– Poor sensitivity

Persson, B. Br J Obstet Gynaecol 1986

Robert, PJ. Cochrane Data Syst Rev 2012

Background: Screening

• Ultrasound

– Fetal Biometry

• Measurement of:

– HC/BPD/AC/FL

– Costly and time intensive

– Needs further study

Zimmer, EZ. Clin Obstet Gynecol 1992Hadlock, FP. Am J Obstet Gynecol 1985

Background: Abdominal

Circumference

Kayem, G. Ultrasound Obstet Gynecol 2009

Smith, GC. Br J Obstet Gynaecol 1997

Background: Screening

• Handheld ultrasound (GE VScan)

– Introduced at MUSC 2011

– Quick assessment

• Presentation

• Fetal Heart Rate– Can measure radius of a circle

• 2πr

Hypothesis

We hypothesize that using a handheld

ultrasound to determine abdominal

circumference will be better for

detection of fetal growth abnormalities

than fundal height measurement.

Methods: Patient Population

• Prospective observational pilot study

• N = 251 patients

• Inclusion Criteria

– Singleton pregnancy undergoing growth scan

– 24-40 weeks

– Ultrasound <20w confirming EDC

• Exclusion Criteria

– Congenital anomaly

– Known aneuploidy

– Multiple gestation

– Poor dating

Methods

• Patients enrolled at time of growth scan

• Study personnel

– Measure fundal height in cm

– Measurement of AC with handheld ultrasound

– Record results from formal growth scan

– Record birth weights at time of delivery

Methods

• Demographics and birth outcomes

collected

• Statistical analysis

– SAS 9.3 statistical software

– Fisher’s exact test

– McNemar’s test

DemographicsDemographics Age 28.3 18 - 41 Gestational Age 31 6/7 weeks 24 0/7 Ğ 40 0/7 weeks Parity 1 0 - 4 BMI 33.9 18.1 - 71.6 EFW 1961.3 g 600 Ğ 4732 g Race:

Black 113 45% White 131 52% Other 7 3%

Prevalence of: Hypertension n = 65 25.9% Diabetes n = 52 20.7% Smoking n = 29 11.5%

Correlation

R = 0.939 (p<0.001)

Results - Fundal Results - Fundal HeightHeight

EFW < 10th percentile

Normal EFW EFW > 90th percentile

Totals

Size < Dates 3 (1.2%) 18 (7.17%) 0 21 (8.37%) Normal FH 4 (1.59%) 137 (54.58%) 2 (0.8%) 143 (56.97%) Size > Dates 0 82 (32.67%) 5 (1.99%) 87 (34.66%) Totals 7 (2.79%) 237 (94.42%) 7 (2.79%) 251 (100%)

BW < 10th percentile

Normal BW BW > 90th percentile

Totals

Size < Dates 10 (3.98%) 11 (4.38%) 0 21 (8.37%) Normal FH 13 (5.18%) 118 (47.01%) 12 (4.78%) 143 (56.97%) Size > Dates 4(1.59%) 71 (28.29%) 12 (4.78%) 87 (34.66%) Totals 27 (10.76%) 200 (79.68%) 24 (9.56%) 251 (100%)

57.8% of our population had BMI >

30

Results - HHACResults - HHAC EFW < 10th

percentile Normal EFW EFW > 90th

percentile Totals

HHAC < 5th percentile

7 (2.79%) 35 (13.94%) 1 (0.4%) 21 (8.37%)

Normal HHAC

0 167 (66.53%) 2 (0.8%) 143 (56.97%)

HHAC > 95th percentile

0 35 (13.94%) 4 (1.59%) 87 (34.66%)

Totals 7 (2.79%) 237 (94.42%) 7 (2.79%) 251 (100%)

BW < 10th percentile

Normal BW BW > 90th percentile

Totals

HHAC < 5th percentile

20 (7.97%) 22 (8.76%) 1 (0.4%) 43 (17.13%)

Normal HHAC

7 (2.79%) 155 (61.75%) 7 (2.79%) 169 (67.33%)

HHAC > 95th percentile

0 23 (9.16%) 16 (6.37%) 39 (15.54%)

Totals 27 (10.76%) 200 (79.68%) 24 (9.56%) 251 (100%)

Sn EFW = 25.9%

Sn EFW = 29.2%

Diagnostic Performance

Sensitivity (%) Specificity (%) PPV (%) NPV (%) EFW < 10th pecentile Fundal height (size<dates) HHAC < 5th percentile

42.86 100

92.62 85.24

14.29 16.28

98.26 100

EFW > 90th percentile Fundal height (size>dates) HHAC > 95th percentile

71.43 57.14

66.39 85.66

5.75 10.26

98.78 98.58

BW < 10th percentile Fundal height (size<dates) HHAC < 5th percentile

37.03 74.07

95.09 89.73

47.62 46.51

92.61 96.63

BW > 90th percentile Fundal height (size>dates) HHAC > 95th percentile

50

66.67

66.96 89.86

13.79 41.03

92.68 96.23

Limitations• Wide variety of gestational ages

• High risk population

• Prevalence of growth abnormalities low

– Inability to adequately compare sensitivity and

specificity between two screening modalities

– Statistical significance

Conclusions

• HHAC was a superior screening modality for prediction of:

• EFW < 10th percentile

• BW < 10th percentile

• BW > 90th percentile

• Fundal height was a superior screening modality for prediction of:

• EFW > 90th percentile

• HHAC could prove to be quick, effective bedside screening modality

• Further studies needed in a larger, low risk population

• Evaluation in obese population

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Hadlock FP, Harrist RB, Sharman RS, Deter RL, Park SK. Estimation of fetal weight with the use of head, body, and femur measurements—a prospective study. Am J Obstet Gynecol 1985; 151: 333-337

Mattioli KP, Sanderson M, Chauhan SP. Inadequate identification of small-for-gestational-age fetuses at an urban teaching hospital. Int J Gynaecol Obstet 2010; 109: 140-143

McIntire D. et al. Birth weight in relation to morbidity and mortality among newborn infants. N Engl J Med 1999;340:1234-1238.

Robert Peter J, Ho JJ, Valliapan J, Sivasangari S. Symphysial fundal height (SFH) measurement in pregnancy for detecting abnormal fetal growth. Cochrane Database of Systematic Reviews 2012, Issue 7. Art. No.: CD008136. DOI: 10.1002/14651858.CD008136.pub2.

Zimmer EZ, Divon MY. Sonographic diagnosis of IUGR-macrosomia. Clin Obstet Gynecol. 1992 Mar;35(1):172-84.

Thank you!• Drs. Chang, Hawk & Sullivan

• Keith Willan for ultrasound guidance

• Dr. Hulsey for statistical support

• Dr. Newman for editorial support