Prenatal diagnosis of persistent right umbilical vein.

A persistent right umbilical vein is thought to be a rare anomaly, frequently associated with other life-threatening malformations. Eight cases of prenatal diagnosis of persistent right umbilical vein are presented. All cases were discovered on a routine second-trimester sonogram in an unselected population. Of the seven babies who were delivered, one had a dextrocardia and right-sided descending aorta, but none had other associated major malformations. The outcome was favorable in all cases and all seven infants are well and thriving with up to a year and a half of follow-up. Our findings suggest that persistent right umbilical vein might not be as rare as the paucity of reports in the literature implies. Provided that no other malformations are present, this anomaly is probably of little prognostic significance, requiring no further evaluation or follow-up.