The fetuses of 352 patients at between 16 and 38 weeks of gestation were studied by using two-dimensional Doppler echocardiography (2-DDE). In 32 fetuses, structural and/or functional abnormalities were detected. The advantages of 2-DDE are, in particular, rapid screening for flow abnormalities and, thus, shortening of the Doppler examination time. Further benefits include a rapid diagnosis of valvular regurgitation, valvular stenosis, and abnormal shunting of blood across the cardiac septa. The diagnosis of complex heart defects is facilitated by and, in certain cases, only possible at all using 2-DDE.