Fetal intra-abdominal umbilical vein varix: retrospective cohort study and systematic review and meta-analysis.

OBJECTIVE: To investigate the ultrasound characteristics and outcome of pregnancies with fetal intra-abdominal umbilical vein varix (FIUVV).

METHODS: Cases of FIUVV managed at our tertiary university hospital over an 8-year period were reviewed. Information retrieved included gestational age and diameter of the umbilical varix at diagnosis, increase in varix diameter, associated ultrasound or chromosomal anomalies and pregnancy outcome. Furthermore, a systematic review and meta-analysis of series of FIUVV in the literature was performed to assess the incidence of chromosomal anomalies, small-for-gestational age infants and intrauterine fetal demise (IUFD), and to pool odds ratio (OR) estimates on the relationship between the incidence of these outcomes and the presence of additional associated ultrasound anomalies.

RESULTS: Thirteen cases of FIUVV were included in the cohort study. Additional ultrasound anomalies were found in two (15.4%) of 13 cases. One case of IUFD was observed and no case of chromosomal anomaly or thrombosis of varix was recorded. A total of five studies comprising 254 cases met the inclusion criteria of the systematic review. FIUVV was associated with additional ultrasound anomalies (non-isolated FIUVV) in 19% (95% CI, 10.9-29.1%) of cases. No case of chromosomal abnormality or IUFD was reported in fetuses with isolated FIUVV. In contrast, in the group of non-isolated FIUVV, the incidence of chromosomal anomalies was 19.6% and that of IUFD was 7.3%, with ORs of 14.8 (95% CI, 2.9-73.0) and 8.2 (95% CI, 1.05-63.1), respectively, when compared with the group of isolated FIUVV.

CONCLUSION: When isolated, the outcome of cases affected by FIUVV is usually favorable. In about 20% of cases, additional ultrasound anomalies are found, which are associated with an increased risk for chromosomal abnormalities and IUFD. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.