Cortical folding and thickness characteristics of gray matter in fetuses with non-severe ventriculomegaly

Ventriculomegaly (VM) is a common fetal brain anomaly. While non-severe VM is often not associated with other anatomical abnormalities during the fetal period, some affected fetuses remain at risk of neurodevelopmental impairment. Characterizing whole-brain cortical morphological changes in fetal gray matter associated with VM may help identify biomarkers predictive of adverse neurodevelopmental outcomes. We aimed to determine whether and how VM is associated with cortical morphological characteristics of fetal gray matter regions in fetuses with mild or moderate VM, compared with normally developing controls. Cortical thickness and folding measures (including convexity, curvature, and sulcal depth) were quantified across 80 gray matter regions in normally developing fetuses and in fetuses with mild or moderate VM. Associations between lateral ventricular dilation and cortical characteristics were examined, and group differences in VM-associated cortical characteristics were compared. Postnatal follow-up assessments were also conducted. VM was associated with alterations in hippocampal convexity and thickness; convexity in the calcarine gyrus and inferior temporal gyrus; lingual gyrus curvature; and sulcal depth in the opercular part of the inferior frontal and rectus gyrus. Distinct degrees of ventricular dilation were associated with differential cortical morphological feature changes. Postnatal follow-up revealed postpartum developmental deviation rates of 23.33% and 38.10% in fetuses with mild and moderate VM, respectively. Our findings indicate that VM is associated with gray matter morphological changes in fetuses, particularly in periventricular, vision-related, and frontal regions. Distinct brain morphological changes characterize mild versus moderate VM, and greater prenatal ventricular dilatation is associated with an increased risk of adverse postnatal neurodevelopmental outcomes.