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The origins of fetal cardiology were in the novel and still relevant
fetal lamb investigations of Rudolph and Heymann.1-3 From
these early studies we began to understand normal fetal cardiovascular
physiology and developed hypotheses regarding the evolution of congenital
heart disease (CHD) in utero and its influence on fetal circulation.4 With
advances in ultrasound technology in the late 1970s and 1980s, it
became possible to demonstrate normal fetal cardiac anatomy and
document growth of the cardiac chambers and great arteries.5-9 Doppler
investigations in the 1980s and 1990s added insight into developmental
changes in normal human fetal circulation and cardiovascular function.10-13 Initial
reports describing prenatal detection of fetal CHD documented a
more severe spectrum of disease than that encountered after birth.14-16 This
was at least in part a consequence of the ease with which the more
severe pathology, including fetal hydrops, was recognized at routine
ultrasound assessment.
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Advances in ultrasound technology over the past 20 years have
led to monumental improvements in our ability to define fetal cardiovascular
anatomy and to evaluate normal and altered myocardial function in
greater detail.To date, most forms of CHD, both major and minor,
have been detected prenatally. It has even become possible to define
fetal cardiovascular anatomy and function and to detect abnormalities
of cardiovascular structure, function, and rhythm as early as 10
to 14 weeks of gestation, only a short time after completion of
cardiac morphogenesis. With rapid advances in technology, fetal
cardiology has evolved as its own subspecialty that merges maternal-fetal
medicine and pediatric cardiology. This chapter reviews unique aspects
of this field and its role in the management of neonates with significant
structural and functional CHD.
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Pregnancies at increased risk for fetal congenital heart disease
(CHD), whether structural, functional, or rhythm related, are evaluated
by the fetal echocardiogram. Indications for fetal echocardiography
include maternal diseases associated with fetal CHD (eg, maternal
diabetes, phenylketonuria, and autoimmune pathology), maternal infection, and
maternal exposure to medications known to be teratogenic for the
developing fetal heart. Fetal indications include a suspected cardiac
abnormality at routine ultrasound; a suspected extracardiac abnormality
in the fetus, including a chromosomal abnormality known to be associated
with CHD; an abnormal fetal rhythm; and conditions associated with
altered fetal heart function (eg, twin-twin transfusion syndrome,
acardiac twins, anemia). A family history of CHD (mother, father,
or sibling) or of a syndrome associated with CHD are also indications.
Although many pregnancies are referred as a consequence of maternal
disease or a family history of CHD, the majority of positive referrals (pregnancies
with fetal CHD) come from the low-risk population and are referred
because of a suspicion of CHD during routine ultrasound assessment.17-18 Recognition
of this has prompted educational initiatives to train obstetrical
ultrasound personnel for better screening of the heart at the time
of routine obstetrical scanning.
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Pregnancies at risk for fetal CHD as a consequence of a known
family history and maternal disease are ...