first trimester anatomy screening [read-only] · first trimester diagnosis spina bifida midsagittal...

First Trimester ScreeningFirst Trimester Screening

What Else Can We Learn?What Else Can We Learn?

John R. Allbert, MDJohn R. Allbert, MD

Presbyterian Maternal Fetal Presbyterian Maternal Fetal Presbyterian Maternal Fetal Presbyterian Maternal Fetal Medicine AssociatesMedicine Associates

11stst Trimester UltrasoundTrimester Ultrasound

�� ViabilityViability

�� Accurate gestational ageAccurate gestational age

�� Aneuploid screeningAneuploid screening

�� Detection of anomaliesDetection of anomalies

�� Identify fetuses at high risk of IUGR and PIHIdentify fetuses at high risk of IUGR and PIH

Nuchal Translucency Nuchal Translucency

(NT)(NT)

Nuchal translucency (NT)Nuchal translucency (NT)the most critical component of first the most critical component of first

trimester screeningtrimester screeningWhat is it?What is it?

A fluid collection behind the fetus’ neckA fluid collection behind the fetus’ neck

�� Measured by ultrasound between 10.3 and 14 Measured by ultrasound between 10.3 and 14 weeks’ gestationweeks’ gestation

�� Size of fetus is 39 to 84 mmSize of fetus is 39 to 84 mm�� Size of fetus is 39 to 84 mmSize of fetus is 39 to 84 mm

Excess fluid accumulation is an indication of an Excess fluid accumulation is an indication of an increased risk of fetal abnormalitiesincreased risk of fetal abnormalities

�� Trisomy 21, Trisomy 18, heart defects Trisomy 21, Trisomy 18, heart defects

�� More fluid indicates a greater risk of an More fluid indicates a greater risk of an abnormalityabnormality

• 10% of fetuses with NT of 3mm have major abnormalities

• 90% of fetuses with NT of 6mm have major abnormalities

Measurement Criteria

Margins of NT edges clear

Fetus in mid-sagittal plane

Fetus occupies majority of imageFetus occupies majority of image

Fetal head in neutral position

Fetus observed away from amnion

(+) calipers usedHorizontal crossbars placed correctly

Calipers placed ⊥ to long axis of fetus

Measurement at widest NT space

Caliper Placement

X X XX X X

Adjusted risk T21: 1:3700 Adjusted risk of T21: 1:100

Increased Nuchal TranslucencyIncreased Nuchal Translucency

Increased RisksIncreased Risks

�� AneuploidyAneuploidy

�� AnomaliesAnomalies

�� Genetic syndromesGenetic syndromes

�� MiscarriageMiscarriage

�� Perinatal deathPerinatal death

Ancillary first trimester screening for Ancillary first trimester screening for

Down SyndomeDown Syndome

Absent nasal boneAbsent nasal bone

Tip of Nose

Skin of Nasal Bridge

Nasal Bone

“= Sign”

Screening for Down SyndromeScreening for Down Syndrome

�� FIRST TRIMESTER FIRST TRIMESTER MARKERSMARKERS

�� Advanced maternal ageAdvanced maternal age

�� Excess Nuchal translucencyExcess Nuchal translucency

�� Low PAPPLow PAPP--AA

�� Elevated hCGElevated hCG

Evolution of Down Syndrome Detection

Maternal age alone 20%

Second TM Maternal age and biochemistry 75%

First TM Maternal age, biochemistry and ultrasound 84%

Integrated (MA, US, 1st and 2nd TM Biochemistry 92%

Sequential Screen 90% (3.7% screen + rate)

First Trimester UltrasoundFirst Trimester Ultrasound

Beyond AneuploidyBeyond Aneuploidy

�� Cardiac defectsCardiac defects

�� Genetic syndromesGenetic syndromes

�� Other anomaliesOther anomalies

*Direct visualization*Direct visualization*Direct visualization*Direct visualization

*Indirect visualization: spina bifida, facial*Indirect visualization: spina bifida, facial

clefting, & facial profile dysmorphiaclefting, & facial profile dysmorphia

�� Risk for perinatal M&M: preeclampsia & Risk for perinatal M&M: preeclampsia & IUGRIUGR

NTNT

PathophysiologyPathophysiology

�� Cardiac dysfunctionCardiac dysfunction

�� Altered composition of the extracellular Altered composition of the extracellular matrixmatrix

�� Failure of lymphatic drainageFailure of lymphatic drainage�� Failure of lymphatic drainageFailure of lymphatic drainage

�� Fetal anemiaFetal anemia

�� HypoproteinemiaHypoproteinemia

�� Congenital infectionCongenital infection

Increased NTIncreased NT

NTNT AneuploidyAneuploidy Fetal DeathFetal Death AnomaliesAnomalies Alive & WellAlive & Well

<95<95thth%% 0.2%0.2% 1.3%1.3% 1.6%1.6% 97%97%

9595--99%99% 3.7%3.7% 1.3%1.3% 2.5%2.5% 93%93%

3.53.5--4.4mm4.4mm 21.2%21.2% 2.7%2.7% 10.0%10.0% 70%70%

4.54.5--5.4mm5.4mm 33.3%33.3% 3.4%3.4% 18.5%18.5% 50%50%

5.55.5--6.4mm6.4mm 50.5%50.5% 10.1%10.1% 24.2%24.2% 30%30%

>>6.5mm6.5mm 64.5%64.5% 19.0%19.0% 46.2%46.2% 15%15%

Soulka AJOG 2005 192:1005

Increased NT 5.5 mmIncreased NT 5.5 mm

13+4/7 Week 4 CH View13+4/7 Week 4 CH View

Red Up

13+4/7 Week ROFT13+4/7 Week ROFT

Blue Down

13+4/7 weeks LOFT13+4/7 weeks LOFT

Red Up

Isolated Severe Increased NT

Cardiac Defects

N=16,383, 0.3/1000

Sensitivity %Sensitivity % FPR %FPR %

NT NT >> 95%95% 7/52 (13.5)7/52 (13.5) 2.6, 427/163312.6, 427/16331NT NT >> 95%95% 7/52 (13.5)7/52 (13.5) 2.6, 427/163312.6, 427/16331

> 3.0mm> 3.0mm 5/52 (9.6)5/52 (9.6) 0.8 131/163310.8 131/16331

> 3.5mm> 3.5mm 3/52 (5.8)3/52 (5.8) 0.3 49/163310.3 49/16331

Westin M Ultrasound Obstet Gynecol 2006; 27:632

Increased NT Cardiac Defects

>> 95%95% >> 99% (99% (>> 3.5 mm)3.5 mm)

SensitivitySensitivity 56%56% 40.0%40.0%

SpecificitySpecificity 93.8%93.8% 99.0%99.0%SpecificitySpecificity 93.8%93.8% 99.0%99.0%

PPVPPV 1.5%1.5% 6.3%6.3%

NPVNPV 99.1%99.1% 99.9%99.9%

Hyett JA Br Med J 1999

Increased NT >95%Increased NT >95%

Cardiac DefectsCardiac Defects

�� Left sided defects highest sensitivityLeft sided defects highest sensitivity

�� HLHS 67%HLHS 67%

�� TGV 50%TGV 50%

�� Coarcation 100%Coarcation 100%

�� VSD 50%VSD 50%

�� TOF 22%TOF 22%

Hyett JA, BMJ 1999;318:81



Literature ReviewLiterature Review�� N=3448N=3448

�� 2.52.5--3.4, 17/10003.4, 17/1000

�� >3.5, 78.4/1000>3.5, 78.4/1000�� >3.5, 78.4/1000>3.5, 78.4/1000

�� FPR (NT cutoff 2.5FPR (NT cutoff 2.5--3.0), 4.9%3.0), 4.9%

�� Detection Rate 37.5%Detection Rate 37.5%

Souka AP, AJOG 2005;192:1005



ProtocolProtocol

�� Transvaginal ultrasound at 14Transvaginal ultrasound at 14--15 weeks15 weeks

�� Targeted ultrasound at 18 weeksTargeted ultrasound at 18 weeks�� Targeted ultrasound at 18 weeksTargeted ultrasound at 18 weeks

�� Echocardiogram at 22Echocardiogram at 22--26 weeks26 weeks

Conditions Associated with Conditions Associated with

Increased NTIncreased NT�� Cardiac defectsCardiac defects

�� CDHCDH

�� OmphaloceleOmphalocele

�� AchondroplasiaAchondroplasia

�� Asphyxiatingthoracic dystrophyAsphyxiatingthoracic dystrophy�� Asphyxiatingthoracic dystrophyAsphyxiatingthoracic dystrophy

�� Blomstrand OsteochondrodysplasiaBlomstrand Osteochondrodysplasia

�� Body Stalk AnomalyBody Stalk Anomaly

�� Campomelic DysplasiaCampomelic Dysplasia

�� Fetal Akinesia Deformation SequenceFetal Akinesia Deformation Sequence

�� Fryn SyndromeFryn Syndrome

�� Hydrolethalus SyndromeHydrolethalus Syndrome

�� Jarco Levin SyndromeJarco Levin Syndrome

Conditions Associated with Conditions Associated with

Increased NTIncreased NT�� Jourbert SyndromeJourbert Syndrome�� MeckelMeckel--Gruber SyndromeGruber Syndrome�� NanceNance--Sweeny SyndromeSweeny Syndrome�� Noonan SyndromeNoonan Syndrome�� Perlman SyndromePerlman Syndrome

Smith Lemli Opitz SyndromeSmith Lemli Opitz SyndromeSmith Lemli Opitz SyndromeSmith Lemli Opitz Syndrome�� Spinal Muscular Atrophy Type ISpinal Muscular Atrophy Type I�� Osteogenesis ImperfectaOsteogenesis Imperfecta�� Thanatophoric DysplasiaThanatophoric Dysplasia�� Short Rib Polydactyly SyndromeShort Rib Polydactyly Syndrome�� Trigonocephaly “C” SyndromeTrigonocephaly “C” Syndrome�� VACTERLVACTERL�� Zellweger SyndromeZellweger Syndrome


Diaphragmatic HerniaDiaphragmatic Hernia�� 1/40001/4000

�� Aneuploidy and other anomalies 50%Aneuploidy and other anomalies 50%

�� Venous congestion probable cause of Venous congestion probable cause of nuchal edemanuchal edemanuchal edemanuchal edema

�� 37% of all cases of CDH37% of all cases of CDH

�� 83% of those with NND secondary to 83% of those with NND secondary to pulmonary hypoplasiapulmonary hypoplasia

�� 22% of survivors22% of survivors

Anatomy ScreenAnatomy Screen

First TrimesterFirst Trimester

�� SkullSkull

�� Cerebral midline echoCerebral midline echo

�� OrbitsOrbits

�� Facial profileFacial profile

�� Anterior abd wallAnterior abd wall

�� KidneysKidneys

�� Bladder Bladder

�� Upper and lower limbsUpper and lower limbs�� Facial profileFacial profile

�� SpineSpine

�� HeartHeart

�� StomachStomach

�� Upper and lower limbsUpper and lower limbs

�� Hands and fingersHands and fingers

�� Feet and ToesFeet and Toes

1313--14 Week Fetal Anatomy Scan14 Week Fetal Anatomy Scan

�� 5 year prospective study5 year prospective study

�� N=2876N=2876

�� Transabdominal and transvaginal if neededTransabdominal and transvaginal if needed

�� TV superior with cranium, spine, stomach, TV superior with cranium, spine, stomach, �� TV superior with cranium, spine, stomach, TV superior with cranium, spine, stomach, kidneys and upper and lower limbskidneys and upper and lower limbs

�� TA complete scan in 64%TA complete scan in 64%

�� TA & TV complete scan in 82%TA & TV complete scan in 82%

�� Heart not adequately seen in 42%Heart not adequately seen in 42%

Ebrashy A, UOG 2010;35:292

First Trimester Anomalies DetectedFirst Trimester Anomalies Detected1313--14 weeks14 weeks 1616--20 weeks20 weeks

AnencephalyAnencephaly 33 00

CardiacCardiac 11 33

OmphaloceleOmphalocele 11 11

GastroschisisGastroschisis 22 22GastroschisisGastroschisis 22 22

MegacystisMegacystis 22 22

Skeletal Skeletal

dysplasiadysplasia

11 22

HoloprosencephalyHoloprosencephaly 11 00

Bilateral TalipesBilateral Talipes 11 11Ebrashy 2010Ebrashy 2010

Sensitivity of Major AnomaliesSensitivity of Major Anomalies

1313--14 week Ultrasound14 week Ultrasound

AuthorAuthor YearYear NumberNumber Sensitivity %Sensitivity %

EconomidiesEconomidies 19981998 16321632 5454

CarvalhoCarvalho 20022002 28532853 3838

TaipaleTaipale 20042004 45134513 1818

Chen Chen 20042004 16091609 5454

SoulkaSoulka 20062006 11481148 5050

EbrashyEbrashy 20102010 28762876 6868

View of Arm @ 12w2dView of Arm @ 12w2d

Fetal Hand 12w2dFetal Hand 12w2d

EncephaloceleEncephalocele

CephaloceleCephalocele


Normal Choroid PlexusNormal Choroid Plexus

Butterfly

HoloprosencephalyHoloprosencephaly

Sepulva JUM 2004; 23:761

HoloprosencephalyHoloprosencephaly

Sepulva JUM 2004:23:761

First Trimester BladderFirst Trimester Bladder

First Trimester MegacystisFirst Trimester Megacystis

First Trimester U/SFirst Trimester U/S

MegacystisMegacystis


8 mm



�� >/= 7 mm longitudinal >/= 7 mm longitudinal

diameterdiameter

�� Trisomy 13 & 18 in Trisomy 13 & 18 in

23.623.6--31.4%31.4%23.623.6--31.4%31.4%

�� Euploidy Euploidy

spontaneously spontaneously

resolves in 90%resolves in 90%

�� >15 mm indicates >15 mm indicates

obstructive uropathyobstructive uropathy

Kagan KO Ultrasound Obstet Gyn 2010;35:10

OmphaloceleOmphalocele

OmphaloceleOmphalocele

Risk of aneuploidyRisk of aneuploidy

�� 88--10 weeks all fetuses have midgut herniation10 weeks all fetuses have midgut herniation

�� By 11 5/7 weeks the midgut heniation has By 11 5/7 weeks the midgut heniation has

retractedretracted

�� Neonate with omphalocele risk of aneuploidy 15%Neonate with omphalocele risk of aneuploidy 15%�� Neonate with omphalocele risk of aneuploidy 15%Neonate with omphalocele risk of aneuploidy 15%

�� Second trimester risk is 30%Second trimester risk is 30%

�� 11 4/711 4/7--13 6/7 risk is 5513 6/7 risk is 55--61%61%

�� NT > 2.5, risk is 85%NT > 2.5, risk is 85%

�� NT < 2.5, risk is 4%NT < 2.5, risk is 4%

Snijders, Ultrasound Obstet Gynec 1995;6:250


Diaphragmatic HerniaDiaphragmatic Hernia�� 1/40001/4000

�� Aneuploidy and other anomalies 50%Aneuploidy and other anomalies 50%

�� Venous congestion probable cause of Venous congestion probable cause of nuchal edemanuchal edemanuchal edemanuchal edema

�� 37% of all cases of CDH37% of all cases of CDH

�� 83% of those with NND secondary to 83% of those with NND secondary to pulmonary hypoplasiapulmonary hypoplasia

�� 22% of survivors22% of survivors

Increased NT Increased NT

Orofacial CleftsOrofacial Clefts

�� N=8638N=8638

�� NT increased in 714 (8.6%), NT increased in 714 (8.6%),

513, (5.9%) euploid513, (5.9%) euploid

�� CL and or CL&CP in 18, rate 2.2/1000CL and or CL&CP in 18, rate 2.2/1000

�� Increased NT risk 19.5/1000Increased NT risk 19.5/1000

�� NT < 95% risk 1/1000, (same as general NT < 95% risk 1/1000, (same as general population)population)

Ultrasound Obstet Gynec 2010;36:427


Cleft PalateCleft Palate

�� Retronasal triangle: 3 echogenic lines Retronasal triangle: 3 echogenic lines formed by 2 processes of the maxilla and formed by 2 processes of the maxilla and palate, in the coronal section of the fetal palate, in the coronal section of the fetal face posterior to the nose face posterior to the nose face posterior to the nose face posterior to the nose

�� Fetuses with cleft palate will have an Fetuses with cleft palate will have an abnormally shaped retronasal triangleabnormally shaped retronasal triangle

Sepulveda W, UOG 2010;25:7

Normal Retronasal TriangleNormal Retronasal Triangle

Retronasal

Triangle

Retronasal TriangleRetronasal Triangle

Holoprosencephaly and Cleft PalateHoloprosencephaly and Cleft Palate

Bilateral Cleft LipBilateral Cleft Lip

Facial Profile DysmorphismFacial Profile Dysmorphism

�� Agnathia (Otocephaly): rare anomaly Agnathia (Otocephaly): rare anomaly complete or severe hypoplasia of the complete or severe hypoplasia of the mandiblemandible

�� Micrognathia: small mandibleMicrognathia: small mandible�� Micrognathia: small mandibleMicrognathia: small mandible

�� Retrognathia: posterior displacementRetrognathia: posterior displacement

�� Mandible can be seen as early as 10 weeksMandible can be seen as early as 10 weeks


Micrognathia/RetrognathiaMicrognathia/Retrognathia

�� Important phenotype of many syndromesImportant phenotype of many syndromes

�� The mandible requires several elements The mandible requires several elements from different embryonic components to from different embryonic components to interact and fuseinteract and fuseinteract and fuseinteract and fuse

�� Susceptible to a series of molecular and Susceptible to a series of molecular and genetic insultsgenetic insults

MicrognathiaMicrognathia

Fetal akinesia

deformation sequenceOrofacialdigital syndrome

Paladini D, UOG;2010:35:377

deformation sequence

Acrofacial dysostosis


SyndromesSyndromes

�� Acrofacial dystosis ADAcrofacial dystosis AD

�� Treacher Collins ARTreacher Collins AR

�� BranchioBranchio--oculofacial ADoculofacial AD

�� Cerebrocostomandibular AD, ARCerebrocostomandibular AD, AR

�� Orofaciodigital Orofaciodigital

�� Robin Sequence ADRobin Sequence AD


AneuploidyAneuploidy

�� Trisomy 13, 18, 8, 9Trisomy 13, 18, 8, 9

�� Deletion 3p, 4p, 5pDeletion 3p, 4p, 5p

�� PallisterPallister--KillianKillian

�� Monosomy XMonosomy X

�� Deletion 22q 11.2, 13q, 11q, 9qDeletion 22q 11.2, 13q, 11q, 9q

�� TriploidyTriploidy


DiagnosisDiagnosis

�� Subjective: small or receding chin with Subjective: small or receding chin with prominent upper lipprominent upper lip

�� Objective: small AObjective: small A--P measurement between P measurement between the two rami (Jaw Index) and decrease in the two rami (Jaw Index) and decrease in the two rami (Jaw Index) and decrease in the two rami (Jaw Index) and decrease in the inferior facial angle (IFA) the inferior facial angle (IFA)

�� Midfacial Hypoplasia: increased Midfacial Hypoplasia: increased frontomaxillary facial angle, (FMF)frontomaxillary facial angle, (FMF)

�� Retrognathia: Decrease in the Inferior facial Retrognathia: Decrease in the Inferior facial angle, (IFA)angle, (IFA)

Frontomaxillary Facial Angle (FFA)Frontomaxillary Facial Angle (FFA)

Facial Profile DysmorphiaFacial Profile Dysmorphia

Mandible IFA

Borenstein M. UOG 2007;30:928

Micrognathia Micrognathia


Maxilla

Mandible

Paladini, D UOG 2010;35:377

Facial Profile DysmorphiaFacial Profile Dysmorphia

11stst Trimester Trimester

Normal Trisomy 18

Borenstein M. UOG 2007;30:928


�� Check for other anomaliesCheck for other anomalies

�� Determine karyotype (44Determine karyotype (44--65% aneuploid)65% aneuploid)

�� Consider Robin SequenceConsider Robin Sequence

�� Risk of recurrence: most are AD and ARRisk of recurrence: most are AD and AR

First Trimester U/SFirst Trimester U/S

Spina BifidaSpina Bifida

�� Screening with MSAFPScreening with MSAFP

�� Ultrasound second trimesterUltrasound second trimester

*Spine*Spine

*Scalloping of the frontal bones*Scalloping of the frontal bones

*Caudal displacement of the cerebellum *Caudal displacement of the cerebellum

Intracranial TranslucencyIntracranial Translucency

Chaoui R, OUG 2009;34:249

First Trimester DiagnosisFirst Trimester Diagnosis


�� Midsagittal view of the fetal faceMidsagittal view of the fetal face

�� 44thth ventricle is between the brainstem and ventricle is between the brainstem and the choroid plexusthe choroid plexus

�� In spina bifida the 4In spina bifida the 4thth ventricle is ventricle is �� In spina bifida the 4In spina bifida the 4thth ventricle is ventricle is compressed by the caudally displaced compressed by the caudally displaced hindbrain and cannot be visualizedhindbrain and cannot be visualized

Chaoui, R UOG 2009;34:249


Chaoui UOG 2010;35:133


Chaoui R, OUG 2009;34:249

Intracranial TranslucenyIntracranial Transluceny


Compression of the 4th ventricleChaoui 2009

First Trimester Markers for First Trimester Markers for

Poor Pregnancy OutcomePoor Pregnancy Outcome

Low PAPPLow PAPP--A <0.45 MoMA <0.45 MoM

IUGRIUGR

Extreme preterm deliveryExtreme preterm delivery

PreeclampsiaPreeclampsia

StillbirthStillbirth

FASTER Trial AJOG 2004;191:1446

First Trimester Markers First Trimester Markers

PreeclampsiaPreeclampsia

�� 11+0 and 13 6/7 weeks11+0 and 13 6/7 weeks

�� 210 controls 210 controls

�� 42 with PIH and 14 with early preeclampsia42 with PIH and 14 with early preeclampsia

�� Serum PP13Serum PP13

�� Uterine artery mean PIUterine artery mean PI

�� PWA: Pulse wave analysis (peripheral PWA: Pulse wave analysis (peripheral arterial pulse waveform)arterial pulse waveform)

Khalil A, UOG 2010;35:671

First Trimester Markers First Trimester Markers

Early PreeclampsiaEarly Preeclampsia

TestsTests Sensitivity with FPR 10%Sensitivity with FPR 10%

PP13PP13 64.3% (35.164.3% (35.1--87.2)87.2)

PP13+PIPP13+PI 78.6% (49.278.6% (49.2--95.3)95.3)

PP13+PI+AlxPP13+PI+Alx--7575 92.9% (66.192.9% (66.1--99.9)99.9)

Khalil UOG 2010


Beyond AneuploidyBeyond Aneuploidy

�� Cardiac defectsCardiac defects

�� Genetic SyndromesGenetic Syndromes

�� Other anomaliesOther anomalies

*Direct visualization: polydactyly, cephalocele*Direct visualization: polydactyly, cephalocele*Direct visualization: polydactyly, cephalocele*Direct visualization: polydactyly, cephalocele

*Indirect visualization: spina bifida, facial*Indirect visualization: spina bifida, facial

clefting, & facial profile dysmorphiaclefting, & facial profile dysmorphia

�� Risk for perinatal M&M: preeclampsia & IUGRRisk for perinatal M&M: preeclampsia & IUGR


ConclusionConclusion

�� Vast majority of major fetal abnormalities Vast majority of major fetal abnormalities can be diagnosed in the first trimestercan be diagnosed in the first trimester

�� Women prefer first trimester detection over Women prefer first trimester detection over the second trimesterthe second trimesterthe second trimesterthe second trimester

�� Diagnosis often requires identifying easily Diagnosis often requires identifying easily recognizable markersrecognizable markers

Evaluation for Bladder ExtrophyEvaluation for Bladder Extrophy

Evaluation for Bladder ExtrophyEvaluation for Bladder Extrophy

Genital

Tubercle

Cord

Insertion

Tubercle

Prospective study outcomesProspective study outcomesFirst trimester DR at 5% FPRFirst trimester DR at 5% FPR

StudyStudy PatientsPatients Down S. Down S.

casescases

Detection Detection

raterate

BUNBUN 85148514 48 of 6148 of 61 78.7%78.7%

FASTERFASTER 38,16738,167 100 of 117100 of 117 86%86%

SURUSSSURUSS 47,05347,053 84 of 10184 of 101 83%83%

TOTALTOTAL 93,73493,734 232 of 276232 of 276 84%84%

Nuchal Nuchal translucency translucency

(mm)(mm)

TotalTotal Termination Termination (abnormal)(abnormal)

Prenatal Prenatal DeathDeath

Postnatal Postnatal DeathDeath

Alive (%)Alive (%)

9595thth –– 3.43.4 34233423 49 (36)49 (36) 4747 2929 3298 3298 (96.3)(96.3)

3.53.5--4.44.4 448448 23 (14)23 (14) 99 44 412 (92)412 (92)

4.54.5--5.45.4 4848 13 (7)13 (7) 44 00 31 (64.6)31 (64.6)4.54.5--5.45.4 4848 13 (7)13 (7) 44 00 31 (64.6)31 (64.6)

5.55.5--6.46.4 5959 21 (12)21 (12) 1010 22 26 (44.4)26 (44.4)

>6.5>6.5

TotalTotal 41164116 119 (77)119 (77) 7474 3838 3885 3885 (94.4)(94.4)

Souka AP Ultrasound OB/Gyn 1998;11:391



�� >/= 7 mm longitudinal diameter>/= 7 mm longitudinal diameter

�� Trisomy 13 & 18, 23.6%Trisomy 13 & 18, 23.6%

�� Euploidy spontaneously resolves in 905Euploidy spontaneously resolves in 905

�� >15 mm indicates obstructive uropathy>15 mm indicates obstructive uropathy

�� Increased NT in 75% of aneuploidy and Increased NT in 75% of aneuploidy and 30% of euploid fetuses30% of euploid fetuses

Human Chorionic Gonadotropin Human Chorionic Gonadotropin

(hCG)(hCG)

�� Glycoprotein made by the Glycoprotein made by the placentaplacenta

�� Made up of two subunitsMade up of two subunits

betaalpha

�� Made up of two subunitsMade up of two subunits

beta

alpha

�� In maternal blood hCG In maternal blood hCG degrades into free subunitsdegrades into free subunits

–– Alpha and betaAlpha and beta

first trimester anatomy screening [read-only] · first trimester diagnosis spina bifida midsagittal...

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