Isolated fetal intra-abdominal umbilical vein varix: clinical importance and recommendations.

This series describes a single center's experience in follow-up and management of fetuses with an isolated fetal intra-abdominal umbilical vein varix. All cases with a fetal intra-abdominal umbilical vein varix that were diagnosed or referred to our medical center over 15 years were followed and managed. The definition of a fetal intra-abdominal umbilical vein varix used was a segment dilated to 9 mm or greater or at least 50% wider than the diameter of the adjacent umbilical vein. Over the 15-year period, our center had approximately 65,000 births with 28 cases of isolated fetal intra-abdominal umbilical vein varices: a prevalence rate of 1 case per 2300 births. Three of the 28 cases (10.7%) had intrauterine growth restriction. Five of 30 fetuses (17%) showed turbulent flow in the varix. We had no cases of intrauterine fetal death, and 27 of the 28 neonates had good outcomes. In contrary to earlier reports, we found that when a fetal intra-abdominal umbilical vein varix is isolated, a good fetal outcome is expected. On the basis of our experience, we have changed our policy and do not recommend inducing preterm labor. Nevertheless, close fetal surveillance until delivery is warranted.