Ultrasound images prenatally and postnatally. (a) Fetal scan at the 12th week of pregnancy demonstrating moderate nuchal edema and cystic hygroma. (b) Pathological flow of the venous duct at the 20th week. During atrial contractions, a reverse flow is noticeable. (c) Two-dimensional echocardiogram of a newborn with absent SVC. The azygos and the hemiazygos veins have fused, and the venous duct formed is draining into the IVC.
