PERSISTENT INTRAHEPATIC RIGHT UMBILICAL VEIN - A PRENATAL SONOGRAPHICSERIES WITHOUT SIGNIFICANT ANOMALIES

Umbilical venous anatomy variation is considered extremely rare. The i ntrahepatic persistent right umbilical vein represents one version in the spectrum of umbilical vein variations. Prior reports of a prenatal ly diagnosed persistent right umbilical vein suggest it is strongly as sociated with severe fetal anomalies including congenital heart diseas e and gastrointestinal malformations. Our experience contrasts with th ese findings. Nine cases of intrahepatic persistent right umbilical ve in were identified via prenatal sonography between July 1992 and Janua ry 1994. The gestational ages of the fetuses ranged from 20 to 36 week s. Targeted fetal surveys were performed in all nine fetuses and forma l fetal echocardiograms were obtained in six. All nine infants have be en delivered. In nine cases, the intrahepatic persistent right umbilic al vein was an isolated observation with no abnormalities identified p re- or postnatally except one case of hypospadias. Formal fetal echoca rdiography was normal in all six of the fetuses studied. Given previou s reports describing a high risk of congenital malformations in associ ation with the presence of a persistent right umbilical vein, the sono graphic finding of this anomaly should still prompt targeted fetal son ography and fetal echocardiography. However, our series indicates that this vascular variant may occur as an isolated abnormality and may no t necessarily represent the ominous finding suggested previously.