Clinical characteristics and outcomes of antenatal fetal intra-abdominal umbilical vein varix detection

OBJECTIVE: This study reviewed clinical characteristics of fetal intra-abdominal umbilical vein (FIUV) varices that were detected during antenatal ultrasound examinations. METHODS: Between January 2006 and January 2012, 121 cases of FIUV varices were detected and 7 cases were lost to follow-up. We retrospectively reviewed the medical records of 114 patients and neonates. RESULTS: From a total 96,553 ultrasound examinations in 43,995 pregnancies, 121 cases of FIUV varices were identified (2.8 per 1,000 pregnancies). Gestational age at diagnosis was 32.0 ± 2.9 weeks (range, 20.1-36.3 weeks), the mean diameter of the FIUV varix was 12.6 ± 2.1 mm (range, 8.0-21.0 mm) at initial diagnosis and the mean maximal diameter was 13.1 ± 2.3 mm (range, 8.0-21.0 mm) during follow-up. The most severe pregnancy complications included one case of intrauterine fetal death and another case of fetal hydrops. Associated fetal anomalies (n = 11, 9.6%) detected by ultrasonography included bilateral renal pelvis dilatation, ventriculomegaly, cryptorchidism, incomplete renal duplication and pulmonary sequestration. A total of 104 cases (91.2%) were delivered at term and 10 cases (8.8%) were preterm deliveries before 37 weeks of gestation. CONCLUSION: FIUV varices that are not associated with fetal anomalies based on ultrasound examination during prenatal care have favorable pregnancy outcomes. Nevertheless, close fetal monitoring is recommended to decrease perinatal complications.