[Congenital absence of the ductus venosus associated with severe congenital heart malformation--case report and review of the literature].

Congenital absence of the ductus venosus is a rare anomaly. The authors have found 57 cases in the literature. Their case was associated with a complex congenital heart disease, what occurs only in 10% of absent ductus venosus cases. In cases, where the umbilical vein connects directly to the right atrium, the volume overloading causes dilatation of the right atrium and ventricle, development of polyhydramnios and fetal hydrops. The diagnosed an umbilical vein directly connected to the right atrium, extreme systemic congestion, but no hydrops. In some fetuses this condition did not result hydrops, because there is compensation by the rich compliance of intrahepatic vascular beds. This case is an illustration that mild sonographic signs such a transient bradycardia in the early second trimester could be a sign of a heart malformation and can draw attention of the sonographer to other associated severe congenital heart disease.