Etiology and prognosis of fetal ascites

Objective: To examine the prenatal course and outcomes of neonates with isolated fetal ascites.

Methods: A retrospective analysis (from 1990 through 2000) was performed on 26 consecutive cases presenting with fetal ascites. A systematic diagnostic protocol which included fetal blood sampling for karyotyping, serology and serial ultrasound examinations to determine etiology was followed in all cases after diagnosis. Pregnancy outcome was assessed by a chart report or autopsy reports.

Results: The majority of cases were associated with fetal malformations (n = 11). Five fetuses had malformations with associated syndromes. Less commonly associated were intrauterine infections (n = 3), intestinal perforation (n = 2), genetic disorders (n = 2), neoplasm (n = 1) and growth retardation (n = 1). In only 1 case (4%) was the etiology idiopathic. Secondary generalized hydrops occurred only in 4 of 26 cases. Only 13 of 16 liveborn infants survived past the neonatal period and only 4 cases are doing well at childhood age without any sequelae.

Conclusion: A wide range of etiologies were associated with isolated fetal ascites. Those with malformations had the worst pregnancy outcome. Prenatal diagnosis was made in 92% utilizing a systematic diagnostic workup. The diagnosis of idiopathic ascites has become rare due to the improvement in prenatal diagnosis.