The pathological diagnosis of pulmonary atresia with abnormal ventriculoarterial connections in the fetus

Pulmonary atresia with abnormal ventriculoarterial connections in the presence of an intact ventricular septum is rare even in postnatal life. Two cases are described in which this combination of lesions was diagnosed in previable fetuses at autopsy. Both pregnancies were terminated for gross structural abnormalities discovered on antenatal ultrasound scans. In the first case, the pulmonary atresia was associated with intact ventricular septum, a double outlet left ventricle and hypoplasia of the tricuspid valve, right ventricle and arterial duct, a combination of lesions that would appear to be unique. In the second case, there was complete transposition and a hypoplastic left ventricle. The severity of the cardiac lesions in both fetuses was such that it is unlikely that either would have survived to term. In the first case no other malformation was present, but in the second there was also a large encephalocoele secondary to early amnion rupture, and a single umbilical artery. The association of the cardiac lesion with early amnion rupture in this second fetus would appear to be a chance event.