Intestinal atresia of co-twin after spontaneous cessation of blood flow through an acardiac twin.

A 33-year-old woman was diagnosed at 15 weeks gestation with a twin pregnancy complicated by an acardiac acephalic foetus. The patient opted for expectant management with close foetal surveillance. Serial ultrasonography showed polyhydramnios at 22 weeks gestation. However, subsequent scans over the next two weeks showed cessation of blood flow in the acardiac foetus, decreasing size of the foetal mass, as well as gradual resolution of the polyhydramnios. Subsequent follow-up was rather uneventful and she underwent an uncomplicated elective caesarean section at 35 weeks, resulting in a healthy 2,820 g girl. The baby was found to have intestinal atresia at birth. She underwent surgery successfully and was well when discharged. The possible causes and pathophysiology of intestinal atresia are discussed.