The route of delivery for the fetus with an abdominal wall defect is controversial. This investigation proposed two null hypotheses: 1) The prognosis for the fetus with an abdominal wall defect is not affected by the timing of the diagnosis (antenatal or postnatal); and 2) the route of delivery does not affect fetal outcome. Sixty-one pregnancies complicated by either fetal gastroschisis (33) or omphalocele (28) delivered between December 1979 and January 1989 were reviewed. Seventy-one percent of the fetuses with gastroschisis and 59% with omphalocele were born vaginally. Gestational age at delivery, incidence of meconium staining, days to first neonatal oral feeding, percentage of neonates with one-stage closure of their defect, and percent of neonates with a birth weight less than the tenth percentile for gestational age were similar in fetuses with gastroschisis and with omphalocele, whether diagnosed antenatally or at birth. Significantly lower birth weights and longer neonatal hospitalizations were noted in the infants with omphalocele diagnosed antenatally compared with those diagnosed at birth (P less than .03), but no such differences were seen with gastroschisis. The route of delivery did not affect outcome for either defect. All fetuses born with gastroschisis and 87% with omphalocele free of associated lethal abnormalities were discharged alive. We conclude that the antenatal diagnosis of gastroschisis is not associated with either worse disease or a poorer outcome, though this may not be true for omphalocele. The good outcome with a high vaginal delivery rate suggests the need for a randomized trial of vaginal and cesarean delivery for fetal gastroschisis and omphalocele.