Objectives-Fetal brain non-dilated ventricular asymmetry (NDVA) is a common finding
on prenatal ultrasound exams. However, the optimal prenatal management in these cases
remains unknown. We aimed to evaluate the benefit of prenatal genetic and magnetic
resonance imaging (MRI) exams performed in cases of fetal NDVA detected on ultrasound.
Methods-A historical cohort study from a tertiary medical center. Singleton pregnancies
with fetal brain NDVA diagnosed on ultrasound were included. We defined ventricular
asymmetry as a difference of >= 2.0 mm between the lateral ventricles and ventricular
dilation as ventricular width of >10.0 mm. Outcomes were evaluated with genetic exams
(karyotype and chromosomal microarray analysis [CMA]) and fetal brain MRI. Results-During
the study period, there were 145 cases diagnosed with NDVA on ultrasound that comprised
the cohort study. The rate of abnormal karyotype was 1.8% (1/56) and of abnormal CMA
was 10% (3/30). The rate of minor additional CNS findings did not differ between ultrasound
and MRI (3.4 versus 2.8%, respectively, p = .74). No major additional fetal brain
findings were detected on MRI performed after ultrasound. Conclusions-In cases diagnosed
with NDVA on ultrasound, no significant additional anomalies were detected on fetal
brain MRI. The rate of abnormal genetic tests was relatively high and warrants further
studies.
