Aorto-pulmonary window with absent ductus arteriosus-A case report.

Aorto-pulmonary window (APW) is a rare congenital heart defect characterized by the connection between the ascending aorta and the pulmonary trunk before its bifurcation, just above the semilunar valves, due to the abnormal development of spiral septum. The short-axis echocardiographic view of the right ventricular outflow track, the three-vessel-view, and the three-vessel-trachea view are the key planes for prenatal diagnosis. We report a case of APW with absent ductus arteriosus in a monochorionic twin, detected by prenatal echocardiography.