Fetal intra-abdominal umbilical vein varix: a case report

The incidence of the fetal intra-abdominal umbilical vein varix condition is very rare. Its significance in pregnancy is still unknown, but it has been associated with fetal hydrops, IUGR and still birth. However, in most isolated cases, the outcome is good. A 31-year-old primigravida was referred to the antenatal clinic at 28 weeks of gestation as her uterus was measuring small for gestational age. Her anomaly scan at 20 weeks was normal. The scan at 28 weeks showed growth below the lower 10th centile with normal liquor volume and umbilical Doppler wave velocity. However, an intra-abdominal ovoid structure measuring 28mm x 10mm was seen superior to the fetal bladder. Color flow Doppler revealed venous flow in continuity with the umbilical vein. A diagnosis of umbilical varix was made. The venous flow was present throughout the lesion, suggesting the absence of thrombi. There was no evidence of fetal hydrops. Subsequent scans at 32, 34 and 36 weeks showed no increase in size of the umbilical varix and progressive fetal growth, although growth remained below the lower 10th centile with normal Doppler results and liquor volume. The patient had an uneventful emergency cesarean section at 37 weeks for failed induction of labor and reduced fetal movements. Postnatal assessment and a follow-up neonatal cardiac echo scan were normal. Our case supports the new emerging evidence that pregnancy outcome in cases of isolated fetal umbilical vein varix is generally good. Caution must be exercised against unnecessary early induction and costly preterm births.