Prenatal sonographic diagnosis of a vesico‐allantoic abdominal wall defect.

The differential diagnosis of fetal ventral wall defects includes omphalocele, gastroschisis, body stalk anom ~ aly, omphalomesenteric duct cyst, and extrophy of the bladder or cloaca. These have all been identified antenatally.•-t Whereas allantoic cyst remnants confined to the umbilical cord have also been prenatally diag ~ nosed,5•6 prenatal detection of a vesica-allantoic abdom· ina) wall defect, is not a common occurence. Of particular importance in this case is that the vesico ~ allantoic cyst prolapsed inward on itself late in gestation and would have been misdiagnosed as a simple umbilical hernia at birth had it not been for early ultrasound evaluation.