Exposure of the fetus to indomethacin by administration of the drug to the mother may cause many side effects, including premature closure of the ductus arteriosus. Hypoxia is a predisposing factor for premature ductal closure and often occurs after maternal indomethacin therapy. We present two sets of monozygotic twins with twin-to-twin transfusion, where in utero ductal closure occurred in the donor twin while the recipient twin appeared unaffected. This selective closure of the ductus arteriosus suggests that the affected twin was predisposed to hypoxia and thus was more susceptible to ductal closure in response to indomethacin exposure.

Congenital diaphragmatic hernia (CDH) is a defect seen in approximately 1 in 3500 live births. A complication of CDH is the herniation of abdominal contents into the chest cavity through the defect, which may prevent normal intrauterine development of the lungs. The resultant pulmonary hypoplasia and pulmonary hypertension causes respiratory distress in the newborn, usually requiring some form of intervention before the defect is surgically corrected (Embryology for Surgeons. Baltimore, MD: Williams & Wilkins; 1994:491-539). Extracorporeal membrane oxygenation, which involves cannulation of the superior vena cava (SVC), is often used to manage these infants. However, the mediastinal shift that often occurs with CDH can cause an abnormal acute angulation of the SVC, which during cannulation can result in trauma and possible perforation of the SVC. We present 2 autopsy cases where the infants accidentally died as a result of extracorporeal membrane oxygenation cannulation.