Perinatal outcomes of fetal intra-abdominal umbilical vein varix: a multicenter cohort study.

To investigate the perinatal outcomes of fetuses with antenatal diagnoses of intra-abdominal umbilical vein varix (UVV). A multicenter retrospective study was conducted in four countries on fetuses diagnosed with intra-abdominal UVV between 2012 and 2019. Collected data included gestational age (GA), UVV maximum diameter at diagnosis and delivery, associated anatomical and chromosomal anomalies, birth weight, and neonatal outcomes. Twenty fetuses were identified, of which 20% had associated chromosomal and/or anatomical abnormalities, most resulting in poor outcomes (either intrauterine fetal death or pregnancy termination). Mean maternal age was 34.1 ± 7.0 years, UVV was diagnosed at 26.5 ± 4.5 weeks of GA on average with a maximum diameter of 12.0 ± 4.0 mm. Mean GA at delivery was 35.4 ± 5.6 weeks. Survival rate was 85%. Our study shows a satisfactory outcome when intra-abdominal UVV is an isolated finding, with minimal obstetrical and perinatal consequences. The prognosis is worse when UVV is associated with other anomalies.