Progressive Umbilical Vein Varix Enlargement Preceding Fetal Growth Restriction: A Longitudinal Ultrasonographic Case Report

Background: Umbilical vein varix (UVV) is a rare umbilical cord abnormality associated with adverse perinatal outcomes, including fetal growth restriction (FGR), although its clinical significance remains unclear.
Case Presentation A 31-year-old gravida 2 woman was diagnosed with intra-abdominal UVV at 20 weeks of gestation. Serial ultrasonography demonstrated progressive enlargement of the varix from 8.4 mm to 15.3 mm at 26 weeks, followed by stabilization. Fetal growth progressively declined, and FGR was diagnosed at 26 weeks of gestation when the estimated fetal weight fell to the 2nd percentile, despite preserved conventional Doppler findings. Serial evaluation suggested a visual inverse temporal relationship between varix size and fetal growth percentile. The pregnancy was closely monitored, and a healthy female infant weighing 2349 g was delivered at 37 weeks without immediate neonatal complications.
Conclusion: Progressive enlargement of umbilical vein varix may be associated with the subsequent development of fetal growth restriction, even in the presence of preserved conventional Doppler parameters, and could represent a potential early imaging marker requiring close surveillance. These findings underscore the potential value of serial ultrasonographic monitoring of varix size, flow characteristics, and fetal growth for individualized antenatal management in pregnancies complicated by UVV.

Keywords: Umbilical vein varix, Fetal growth restriction, Doppler ultrasound, Prenatal diagnosis, Fetoplacental circulation