Sonographically documented disappearance of fetal ascites.

Two patients with sonographically documented fetal ascites are described. Workup for immunologic or nonimmunologic causes was negative. Subsequent sonar examinations demonstrated disappearance of fetal ascites. At delivery, previous abdominal distention was apparent. Fetal ascites of unknown etiology in the late second trimester does not necessarily have a poor prognosis. Serial sonographic examinations are indicated for follow-up of fetal ascites.