P106Persistent right umbilical vein: incidence and significance in a low risk population

Objectives Our purpose was to conduct the first prospective evaluation of the incidence and neonatal outcome of fetuses with persistent right umbilical vein (PRUV). This condition had traditionally been considered to be extremely rare and to forebode grave consequences for the babies, but later evidence raised some doubt upon the veracity of these contentions. Methods Between August 1995 and November 1998, 8950 low-risk patients were prospectively evaluated at two medical centers. The ultrasonographic diagnosis of a persistent right umbilical vein was made in a transverse section of the fetal abdomen when the portal vein was curved toward the stomach and the fetal gallbladder was located medially to the umbilical vein. Results Seventeen cases of fetuses with PRUV were detected during the study period among the 8950 study participants. Four of them had additional malformations of which three had been detected antenatally. Conclusions We established that the incidence of PRUV in a low risk population is 1:526. We believe that the sonographic finding of this anomaly is an indication for conducting targeted fetal sonography and fetal echocardiography. When the PRUV is connected to the portal system and after other anomalies are ruled out, the prognosis can generally be expected to be favorable.