Distinguishing omphalocele from pseudo-omphalocele, highlighting the ultrasonography pitfall: a case report.

Background: Omphalocele is a congenital anomaly where abdominal contents herniate through a defect in the fetal abdominal wall, covered by peritoneum and amnion. It is associated with high mortality and other anomalies. Pseudo-omphalocele is a potential pitfall in antenatal ultrasonography, where a transient bulge of abdominal contents may appear owing to factors such as a contracted uterus, placenta, or excessive transducer pressure.

Case report: This report presents two cases: one of true omphalocele in a twin pregnancy and another of pseudo-omphalocele, underscoring the importance of careful assessment. The first case involves a twin pregnancy at 12 weeks' gestation, conceived through assisted reproductive technique in a 38-year-old Nepali woman of Indo-Aryan ethnicity. During a routine check-up, one twin was diagnosed with omphalocele. Trans-abdominal fetal reduction of the anomalous twin was performed. The other twin progressed to term and was delivered via cesarean section at 39 weeks. The second case involved pseudo-omphalocele, observed at 15 weeks' 3 days of gestation in a 32-year-old Nepali woman of Tibeto-Burmese ethnicity. Initially, the fetal abdomen appeared to herniate, mimicking omphalocele. However, a repeat examination after 30 min showed no herniation or defect. Retrospective analysis revealed that the misdiagnosis occurred because the fetal abdomen was compressed between the contracted myometrium and placenta.

Conclusion: Accurate diagnosis of omphalocele is crucial to prevent unnecessary abortions and potential professional repercussions. We recommend repeat examination after 30 min in all cases of omphalocele to prevent misdiagnosis.