Cerebral Lateral Ventricular Asymmetry: Normal Variant or an Indicator of Underlying Pathology

Introduction: Isolated lateral ventricular asymmetry has been associated with a favorable prognosis; however, prenatal evaluations in existing studies have been conducted using ultrasonography (US). This study aimed to describe the magnetic resonance imaging (MRI) findings, progression of ventricular asymmetry, and perinatal outcomes in fetuses prenatally diagnosed with isolated ventricular asymmetry.

Methods: This retrospective study included patients who underwent MRI for isolated fetal ventricular asymmetry at a tertiary center between January 2012 and January 2020. Information, including pregnancy history, US, MRI findings, and perinatal outcomes, was obtained from medical records.

Results: The study cohort included 17 women with fetal ventricular asymmetry but without ventriculomegaly at the time of index US. Mild ventriculomegaly subsequently developed in 13 patients; 12 of them showed spontaneous resolution before delivery. MRI identified low-grade intraventricular hemorrhage (IVH) in 13 fetuses. Postnatally, 12 newborns underwent neonatal cranial US where two of them showed evidence of germinal matrix hemorrhage. Both newborns appeared normal at birth without neonatal complications.

Conclusion: MRI identified low-grade IVH in most fetuses with isolated ventricular asymmetry. These fetuses were also likely to develop mild ventriculomegaly with spontaneous resolution. Although perinatal outcomes appeared good, careful follow-up in both prenatal and postnatal periods is warranted.