Congenital absence of portal vein in the fetus: a case report.

Congenital absence of portal vein (CAPV) is a rare abnormality, which may be associated with other abnormalities. We report a case of prenatal diagnosis of absent portal vein confirmed on postnatal ultrasonography and computed tomography scan. The ultrasound features of CAPV include dilated intra-abdominal segment of umbilical vein, dilated inferior vena cava and the presence of hyperechogenic areas in the liver. Blood coming from the umbilical vein directly drains into the inferior vena cava. The dilated intra-abdominal segment of the umbilical vein shows high velocity pulsatile flow, resembling that of ductus venosus. These findings should prompt a careful search for the portal vein and any associated anomalies.