Prenatal diagnosis of primary pulmonary hypoplasia in fraternal twins.

Primary pulmonary hypoplasia is a rare, usually lethal, condition presenting only after birth without other congenital abnormalities. We describe the first case of fraternal twins diagnosed prenatally with primary pulmonary hypoplasia. Both had diffuse hypoplasia of the pulmonary arteries initially identified by fetal echocardiography and confirmed at autopsy following termination. These cases permit examination of the histopathology of this disease in the fetal stage of development.