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486 D. Maulik
Table 33.2. Approximate risk of cardiac anomalies for selected
high risk conditions
Anomaly Risk (%)
Isolated cardiac anomalies (multifactorial)
Overall 3±5
Mother 10
Father 3±5
Sibling 3
Left heart anomalies 10±15
Environmental
Maternal rubella infection 35
Pregestational diabetes 3±5
Phenylketonuria (phenylalanine > 16 mg/dl) 18
Alcohol consumption 25±30
Trimethadone 15±30
Retinoic acid 4
Genetic
Overall 25
Marfan syndrome 60±80
Holt-Oram syndrome 100
Chromosomal
Overall 25
Trisomy 21 50
Trisomy 18 100
Data are derived from the literature.
nostic procedures should be offered to the mother.
Recently, increased nuchal translucency at 10±14
weeks of gestation in chromosomally normal fetuses
has emerged as an indication because of its association
with cardiac malformations. The extent of this
association varies between 7% and 9% [3, 4]. Controversy,
however, exists on whether polymorphisms of
5,10-methylenetetrahydrofolate reductase (MTHFR)
lead to a higher risk of congenital cardiac defect [5,
6], and it therefore remains uncertain whether this
abnormality should indicate fetal cardiac evaluation.
Although a precise measure of the increased risk is
not available for all the conditions listed in Table
33.1, a summary of risk quantification for selected
conditions is presented in Table 33.2. Such information
should be an essential part of informed counseling
of patients. More detailed information may be obtained
from the standard texts on pediatric cardiology.
Fetal echocardiography is indicated whenever a
higher probability of fetal cardiac malformation exists.
It is also indicated for the precise diagnosis and
follow-up of fetal cardiac arrhythmias and fetal heart
failure. Furthermore, a suspicious fetal cardiac image
during general obstetrical ultrasonography mandates
more focused assessment. In many centers, a non-reassuring
fetal cardiac image is the most common reason
for echocardiographic referral. Frequency of
these indications varies from center to center. Common
indications for fetal echocardiography are listed
in Table 33.3.
Table 33.3. Indications for fetal echocardiographic assessment
n Non-reassuring fetal cardiac image during obstetrical
sonography
n Extracardiac malformations
n Fetal cardiac arrhythmia
n Increased nuchal translucency
n Insulin-dependent diabetes mellitus in pregnancy
n History of congenital cardiac disease
n Teratogenic exposure
n Maternal viral infection
n Nonimmune hydrops
n Nonlethal aneuploidy
Benefits of Fetal Echocardiographic
Assessment
Fetal echocardiographic examination allows prenatal
diagnosis of congenital heart disease so that appropriate
perinatal management can be planned and implemented.
An accurate diagnosis of the cardiac lesion
will obviously lead to more reliable prognostication
and informed management choices. The process
involves participation by a multidisciplinary perinatal
cardiology team which should include primary obstetricians,
maternal-fetal medicine specialists, neonatologists,
pediatric cardiologists, cardiac surgeons,
and other relevant support personnel. In addition,
the parents must be an integral part of this process
so that they are appropriately counseled regarding the
fetal condition and prognosis, and are able to participate
in the decision-making process. In early gestation,
severe cardiac anomalies with poor prognosis
may prompt the parents to opt for a termination of
pregnancy. If this is not an option, a multidisciplinary
medical team can develop optimal plans for surveillance,
delivery, and perinatal intervention. Table
33.4 summarizes the prognostic factors for survival.
Depending on the complexity of the fetal cardiac
problem, the site for delivery and neonatal management
can be carefully selected. This is particularly
important as not all medical centers may have adequate
medical or surgical resources to deal effectively
with the complexities of congenital heart disease. In
this context, one should also note that recent progress
in surgical management of certain malformations has
improved the chances of survival in cases previously
considered hopeless [7]. The reported mortality rate
following pediatric cardiac surgery in one of the
prominent centers is given in Table 33.5. As noted
during the 32nd Bethesda Conference, ªCare Of The
Adult With Congenital Heart Diseaseº, the survival
rate has continued to improve over the last few decades
and the estimated cumulative survivors of con-