Congenital malformations - Edocr

160 PART IV RESPIRATORY MALFORMATIONS
A 7% fetal aneuploidy rate, without associated
structural anomalies, has been reported in a
number of studies. 1,4,5 In a large study by Waller
et al, 246 cases of congenital pleural effusions
were evaluated and the prevalence of chromosomal
abnormalities was 35.4%; the aneuploidy
rate was 63% among the first trimester cases in
this study. 6
CLINICAL PRESENTATION
Prenatally, the fetus will be noted to have pleural
effusions and often polyhydramnios on ultrasound.
Depending on the severity and duration
of the hydrothorax, hydrops fetalis with skin
edema, scalp edema, and ascites may be present.
After delivery, clinical presentation can vary
from an asymptomatic infant in the presence of
small effusion to a critically ill infant with large
effusions presenting with cyanosis and respiratory
distress requiring mechanical ventilation. If
there was progression to hydrops in utero, postnatal
physical examination will also reveal generalized
body edema.
ASSOCIATED MALFORMATIONS
AND SYNDROMES
Primary hydrothorax often occurs as an isolated
finding. Secondary hydrothorax is more likely
to be associated with malformations or multiple
congenital anomalies. Associated malformations
include: cardiac defects, renal anomalies, and
omphalocele. 6 Syndromes frequently associated
with hydrothorax include Noonan syndrome,
Turner syndrome, Down syndrome, and Edwards
syndrome. The important clinical features
associated with these syndromes and other syndromes
presenting with hydrothorax in the perinatal
period are summarized in Table 25-1.
EVALUATION
Carroll was the first to describe the sonographic
diagnosis of fetal hydrothorax in 1977. 7 Serial
ultrasounds may demonstrate spontaneous regression
of the effusion in utero, or development
of polyhydramnios, hydrops, and fetal
demise; therefore, it is crucial to monitor affected
fetuses on a regular basis. Prenatal diagnostic
evaluation should include ultrasound
to evaluate for multiple gestations. Referral to
a high-risk obstetrics group is recommended.
A level II ultrasound to document presence of
other anatomic abnormalities as well as a fetal
echocardiogram to evaluate for congenital heart
defects are both essential. Maternal laboratory
evaluation for blood type, Rh, antibody screen,
Kleinhauer-Betke stain, as well as, serology for
parvo virus infection should be considered. Additional
evaluation should include cordocentesis
to evaluate for fetal anemia and an amniocentesis
for karyotyping. Figure 25-1 offers a suggested
algorithm for evaluation of a fetus with
congenital hydrothorax.
After delivery, a careful examination to evaluate
for dysmorphic features is important. However,
this may be difficult to assess in the presence of
significant body edema in some cases. Maternal
Kleinhauer-Betke stain may be helpful if the infant
presents with significant anemia. Maternal
TORCH (toxoplasmosis, rubella, cytomegalovirus
[CMV], herpes, varicella, syphilis) titers, serology
for parvo virus should be considered. A chest
and abdominal x-ray should be performed to
evaluate for the extent of the effusions and ascites.
An echocardiogram is necessary to evaluate
for congenital heart defects and to exclude
associated pericardial effusion. Renal ultrasound
to evaluate for renal anomalies and chromosomal
analysis are also useful in establishing the
diagnosis. If sufficient pleural fluid is drained,
this fluid should be sent for analysis and may
help differentiate chylous from nonchylous effusion.
Chylothorax is suggested by the predominance
of lymphocytes (>70–90%), high triglyceride
count, elevated protein, and albumin concentrations.
However, analysis of pleural fluid may be
unreliable in infants who are not being fed or
have never been fed enterally, in these patients
a diagnosis of chylothorax is suggested by detecting
a high lymphocyte count in the pleural