Fetal Doppler echocardiography in pulmonary atresia.

The prenatal diagnosis of pulmonary atresia is of particular importance because the affected neonate may be dependent on ductal blood flow to the lung, requiring urgent administration of prostaglandins. We review eight cases studied by ultrasonography in utero. Severe tricuspid regurgitation was present in six fetuses. Right ventricular size varied among cases. Right atrial enlargement was present in seven, usually with tricuspid regurgitation. Failure to identify the main pulmonary artery or valve on a single examination was not specific. Doppler flow studies were most reliable for the diagnosis by establishing the existence of retrograde flow in the ductus arteriosus from the aorta.