OEIS Complex: A Rare Fetal Autopsy Case Series with its Embryological Annotations

Background: OEIS Complex is a rare form of ventral body wall defect affecting 1 in 200,000–400,000 pregnancies and consists of a cluster of multiple congenital anomalies such as omphalocele, exstrophy of cloaca/bladder, imperforate anus, and spinal defects. It results from the defect of mesodermal migration during the primitive streak period leading to failure of ventral body wall closure. Aims and Objectives: In the present study, we aimed to study autopsy findings of cases, exhibiting varying spectrum of OEIS complex. Materials and Methods: The study was conducted on cases of foetal autopsies, referred from the department of Obstetrics and Gynaecology, to the department of Anatomy. Anthropometric measurements were done to assess the gestational age. The foetuses were then examined and dissected for findings related to OEIS complex. Results: On autopsy, three cases were observed with OEIS complex with cloacal exstrophy while one case with bladder exstrophy. All the cases of OEIS were associated with undifferentiated gonads and the absence of external genitalia. The other defects observed were great toe brachymetatarsia, serinomelia, and diaphragmatic defect. Conclusion: The fetal autopsy delineating detailed knowledge of all the OEIS components and associated other congenital defects can play a significant role in better understanding of the defect in diagnosis, prognosis evaluation, and management.