Agenesis of the Ductus Venosus and its Correlation to Hydrops Fetalis and the Fetal Hepatic Circulation: Case Reports and Review of the Literature

Abstract

Under normal conditions about 50% of the placental venous return bypasses the liver through the ductus venosus. This blood flow is preferentially directed toward the foramen ovale and provides optimum oxygenation to the fetal heart and brain. Absence of the ductus venosus is a rare vascular anomaly, the significance of which has been disputed. We distinguish the pattern in which the liver is entirely bypassed, a manifestation of a fundamental malformation in the umbilical venous system, from the pattern in which the ductus venosus is absent despite a normal course of the umbilical vein. We review the literature regarding the latter and report eight new cases. Three of the four previously reported cases showed associated malformations and two of them suffered from portal congestion and hydrops. Among our eight cases three showed severe malformations in the cardiovascular system. Three cases presented themselves with hydrops fetalis and disturbance in the portal circulation, and two cases expressed signs of intrauterine asphyxia. The absence of the ductus venosus might be a minor vascular maldevelopment resulting in an early disturbance in the portal circulation. Our findings suggest that this anomaly might induce hydrops fetalis.

Key Words:

• ductus venosus
• hydrops fetalis
• malformation
• portal hypertension