In utero ultrasonographic diagnosis of an aberrant umbilical vein associated with fetal hepatic hyperechogenicity.

Intra-hepatic abnormalities of the fetal umbilical venous system are poorly documented and clinically not well understood. A case of routine ultrasound examination at 23 weeks' gestation demonstrating foci of hepatic hyperechogenicity and cardiomegaly is presented. Colour Doppler detected absence of flow in the ductus venosus and markedly increased blood flow through an aberrant channel connecting the umbilical vein with the right atrium. The pregnancy was terminated and anomalous venous drainage of the umbilical vein into an enlarged hepatic vein was found, as well as hepatic congestion and focal hepatic necrosis and calcifications. Incidental findings of fetal hepatic hyperechogenicities require colour Doppler investigation of the intra- and extra-hepatic venous systems. We propose that a thrombo-embolic mechanism may be involved in the pathogenesis of these lesions.