Etiology and outcome of second trimester non-immunologic fetal hydrops

Background. This investigation was undertaken to study the conditions resul ting in midtrimester fetal hydrops and to evaluate its overall prognosis as regards counseling purposes. Material and methods. The etiology of midtrimester non-immune fetal hydrops was retrospectively evaluated as regards cases detected in singleton pregn ancies (n=58) from January 1987 through December 1996. The condition was di agnosed by way of routine biochemical and ultrasonographic screening of a p regnant population. Results. The rate of diagnosed midtrimester fetal hydrops was 1 in 1700 pre gnancies and the overall survival rate in this usually unexpected condition was less than 10%. Various chromosomal and fetal structural abnormalities dominated as a cause of fetal hydrops, representing 44.8% and 43.1% of the cases, respectively. Infection caused only 6.9%. The underlying etiology re mained unknown in only three cases. However, in 78% the diagnosis was alrea dy known prenatally. Discussion. Although the overall prognosis is poor, knowledge of the primar y etiology is important to determine a rational therapeutic strategy. If th e results of routine investigations rule out malformation and abnormal chro mosomes, follow-up serial ultrasonographic assessment may indicate that the hydropic state is transient, carrying a somewhat better prognosis.