The Clinical Significance of Fetal Intra-Abdominal Umbilical Vein Varix A Comparative Study: A Comparative Study.

Objectives: To clarify the clinical significance and optimal management of fetal intra-abdominal umbilical vein varix (FIUVV).

Methods: A retrospective study comparing composite asphyxia-related adverse outcomes including stillbirth, cesarean delivery due to non-reassuring fetal heart rate (CD NRFHR), Apgar <7, Cord pH <7, neonatal intensive care unit admission, mechanical ventilation, seizures, asphyxia, and hypoxic ischemic encephalopathy, as well as rates of small for gestational age (SGA) and congenital anomalies, between FIUVV singletons and the general population born at a single center. A subgroup analysis included FIUVV singletons and controls delivering ≥39 weeks.

Results: Compared to controls (99,715), FIUVV subjects (142) had more congenital anomalies (15.5% versus 0.84%, P < .01) and SGA (9.9% versus 5.4%, P = .02). There were no stillbirths among FIUVV. There were similar rates of CD NRFHR and asphyxia-related composite adverse outcomes between the study and control groups (4.2% versus 4.4%, P = .9; 7.7% versus 8.7%, P = .7) including the subgroup delivering ≥39 weeks (12.5% versus 4.6%, P = .06; 12.5% versus 5.7%, P = .09).

Conclusions: FIUVV does not appear to increase asphyxia-related adverse outcomes. Targeted anomaly scan and growth assessment are recommended. There is no evidence to support labor induction before 39 weeks.