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.