Prenatal diagnosis of right pulmonary artery to left atrium communication.

We report a case of right pulmonary artery to left atrium communication in a fetus at 24 weeks' gestation. Fetal echocardiography showed dilatation of the left atrium and main and right pulmonary arteries. The right pulmonary artery was seen to communicate with the left atrium. Color Doppler velocimetry demonstrated high-velocity flow through the communication. The pregnancy was terminated and findings were confirmed at autopsy. The embryological and postnatal aspects of right pulmonary artery to left atrium communication are discussed.