Outcomes of Isolated Fetal Ventriculomegaly That Resolve In Utero

Objective Isolated fetal ventriculomegaly is often an incidental finding on antenatal ultrasound. It is benign in up to 90% of cases, although it can be associated with genetic, structural, and neurocognitive disorders. The literature suggests that over 40% of isolated mild ventriculomegaly will resolve in utero, but it is unclear if resolution decreases the associated risks. The aim of this study is to compare the fetal and neonatal genetic outcomes of ventriculomegaly that persists or resolves on subsequent ultrasound. Study Design This is a retrospective cohort study of women diagnosed with isolated ventriculomegaly via fetal ultrasound at a tertiary referral center between 2011 and 2019. Patients were excluded if other structural anomalies were identified on ultrasound. Results A total of 49 patients were included in the study, 19 in the resolved ventriculomegaly group and 30 in the persistent ventriculomegaly group. Women in the resolved ventriculomegaly group were more likely to be diagnosed earlier (24 vs. 28 weeks,p = 0.007). Additionally, they were more likely to have mild ventriculomegaly (63 vs. 84%,p = 0.15), and less likely to have structural neurological abnormalities diagnosed on postnatal imaging (5 vs. 17%,p = 0.384), although these were not statistically significant. Aneuploidy risk for resolved compared with persistent ventriculomegaly was similar (5 vs. 7%,p = 0.999). Conclusion This study suggests that resolution of isolated ventriculomegaly in utero may not eliminate the risk of genetic or chromosomal abnormalities in this population and may warrant inclusion as part of the counselling of these at-risk patients. Larger prospective studies are needed to confirm these findings.