Quantitative MRI Assessment of Gyrification and Brain Volume in Congenital Cytomegalovirus Fetuses and Postnatal Outcome

Objective: Quantitative assessment of the impact of cytomegalovirus (CMV) infection on fetal brain development beyond conventional imaging remains limited. We aimed to quantify cortical gyrification and brain volumes in CMV-exposed fetuses, compare groups with varying severities of conventional MRI findings, and evaluate postnatal outcomes. Method: This retrospective study included 82 singleton pregnancies following maternal CMV infection. Fetuses were grouped by CMV infection status and conventional MRI findings. Automated tools quantified cerebral gyrification and supratentorial, infratentorial and lateral ventricle volumes. Postnatal hearing and neurodevelopmental outcomes were assessed at follow-up. Results: CMV-infected fetuses (n = 67) showed reduced cerebral gyrification compared with uninfected controls (n = 15). This reduction was observed across fetuses with gross (n = 10), subtle (n = 19), and even normal (n = 38) MRI findings. Infected fetuses with gross abnormalities also showed reduced infratentorial volume compared with infected fetuses with normal MRI and controls. Follow-up was available in 42 cases and indicated that most children developed normally. However, eight children developed mild-to-moderate neurodevelopmental difficulties, four of whom also had sensorineural hearing loss, including cases with normal or subtle prenatal imaging. Conclusion: Quantitative analysis of routine fetal MRI reveals alterations in brain development in CMV-infected fetuses, including those with normal conventional imaging, and may improve the identification of fetuses at risk for adverse outcomes.