Anencephaly in a discordant twin pregnancy: a case report of a rare neural tube defect from rural Ethiopia

Discordant twin pregnancies, where one fetus is structurally normal and the co-twin has a congenital anomaly, are rare and pose complex clinical challenges, especially in low-resource settings. Anencephaly is a lethal neural tube defect (NTD) associated with significant morbidity and mortality. We report a rare case of a twin pregnancy discordant for anencephaly managed at a rural health center in Ethiopia. A 35-year-old multiparous woman presented in the active stage of labor at 40 weeks of gestation and subsequently delivered vaginally. Post-delivery examination revealed marked birth-weight discordance between the twins, with the anencephalic twin weighing 56.8% more than the healthy co-twin. Notably, despite being the smaller twin, the structurally normal neonate survived, whereas the larger twin affected by anencephaly died shortly after delivery. This unusual combination of severe birth-weight discordance, survival of the smaller twin, and successful vaginal delivery in a resource-limited setting makes this case rare and unusual. This case demonstrates an extreme instance of birth weight discordance in a twin pregnancy, where the anencephalic twin was paradoxically larger than the healthy co-twin—a rare clinical finding. This report underscores significant gaps in the utilization of antenatal care, consistent folic acid supplementation, and access to routine prenatal anomaly screening. To reduce the incidence of preventable neural tube defects and optimize maternal–neonatal outcomes in similar resource-limited settings, it is essential to strengthen ANC services, promote comprehensive preconception care, and ensure the availability of early prenatal diagnostic imaging.