Serial prenatal MRI evaluation of valacyclovir-treated vs untreated fetuses with congenital cytomegalovirus (cCMV) infection.

Maternal valacyclovir therapy was associated with a significantly higher likelihood of persistently normal prenatal MRI findings and absence of early minor brain lesions, suggesting a protective effect on fetal brain involvement in cCMV.

KEY POINTS: Question Minor temporal pole lesions are common early MRI findings in cCMV. Findings Valacyclovir-treated fetuses showed fewer and later-onset minor lesions.

Clinical relevance Serial fetal MRI may serve as an imaging surrogate marker of treatment response.