Andersons pediatric cardiology 212
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Abstract
Thischapterdescribesthecurrentmodalitiesforimagingthefetalheart,the
timingoffetalechocardiography,andperinatalmanagementstrategiesfor
differenttypesofcongenitalheartdisease.
KeyWords
Fetalechocardiography;Doppler;colorDoppler
Introduction
Malformationoftheheartandarterialtrunksisthemostcommonformof
congenitalanomalyfoundinhumans.Theyoccurinapproximately6ofevery
1000livebirthsandin8to10ofevery1000pregnancies.Fetal
echocardiography,ortheuseofultrasonictechnologiestoevaluatethefetal
cardiovascularsystem,enablesthediagnosisofstructuralheartdefectsand
offersawaytoobservecomplexphysiologicprocessespriortobirth.The
primarybenefitsoffetalechocardiographyincludetheabilitytocounselparents
priortobirthastotheexpectationsforachildbornwithacongenitally
malformedheartandtheabilitytoimplementappropriatepostnatalmanagement
strategiesinananticipatoryfashionsoastomaximizeoutcomeandtoidentify
andtreatcardiovasculardiseasespriortobirth.
ScreeningWithFetalEchocardiography
Asimagingtechnologiesandtheskillsofoperatorscontinuetoimprove,a
higherpercentageofcongenitalcardiacmalformationscanbedetected
accuratelybeforebirth.Analysisoflargeregistrieshasshownthatratesof
detectioncanvaryfrom15%to25%.1–5Manystudieshavedocumentedthe
utilityofthefour-chamberviewoftheheartinidentifyingthemalformations
duringfetallife.5–11Inthesestudies,ratesofdetectionusingthisviewalone
rangedfrom4.5%to81%.5–11Malformationsoftheoutflowtracts,however,and
discordantventriculoarterialconnections,mayfrequentlybemissedwhenthis
viewisusedinisolation.Whenviewsshowingtherightandleftventricular
outflowtractsareincludedintheobstetricscreen,thereporteddetectionrate
increasestobetween43.8%and85.5%.8,12,13Incontrast,iffetal
echocardiography—definedasadetailed,focusedassessmentofthefetal
cardiovascularsystem—isperformed,ratesofdetectionaresignificantlyhigher
anddiagnosticaccuracyratesmayexceed85%to90%.12,14Giventhedisparity
inratesofdetectionbetweenthosespecializinginfetalechocardiographyand
routineobstetricscreening,thequestionofwhoshouldbereferredforfetal
echocardiographyremainsanimportantconsideration.
CurrentlytheAmericanSocietyofEchocardiographyrecommendsfetal
echocardiographyforfetal,maternal,andfamilialindications(Box8.1).15Inthe
past,manywomenwerereferredforfetalechocardiographyduetoafamily
historyofcongenitalcardiacdisease,anumbilicalcordcontainingtwovessels,
maternaldiabetes,ormaternalexposuretoteratogens.Patternsofreferral,
however,havechangedbecauseofimprovedtechniquesforimaginghave
becomeavailable.Referralsforfetalechocardiographyproducingahighyield
nowincludeanabnormalobstetricultrasoundevaluation,inwhichuptotwothirdsofreferralshavecongenitalcardiacmalformations,andachromosomal
anomaly,withhalfofsuchreferralsprovingtohavecongenitalcardiaclesions.
Referralswithalowyieldincludethepresenceofasingleumbilicalarteryor
exposuretoteratogens,withcongenitalcardiaclesionsdetectedinfrequentlyin
mothersreferredwiththeseindications.Afamilyhistoryofcongenitalcardiac
diseaseaccountsforbetweenone-quarterandone-thirdofallreferralsforfetal
echocardiographybutlessthanone-twentiethofcaseswithdetected
malformations.16,17Increasednuchaltranslucencynotedonscreeningduringthe
