Mild fetal cerebral ventriculomegaly: prevalence, characteristics, and utility of ancillary testing in cases presenting to a tertiary referral center.

OBJECTIVE: Ventriculomegaly is the most common fetal brain anomaly identified during prenatal anatomy ultrasound. The aim of our study was to characterize cases of mild ventriculomegaly and investigate the utility of ancillary tests.
METHOD: We reviewed 121 cases of mild ventriculomegaly, defined as lateral ventricle diameter of 10 to 15 mm. Characteristics of the ventricular dilation as well as each pregnancy were investigated. Ancillary tests performed included follow-up magnetic resonance imaging (MRI), chromosomal abnormality testing, and maternal serologic infection screening. The utility of each test was analyzed.
RESULTS: We identified 56 cases of isolated and 65 cases of complex ventriculomegaly. Seventy-two (59.5%) were unilateral, and 49 (40.5%) were bilateral, with a mean gestational age at diagnosis of 24.5 weeks. MRI provided additional information in 3/24 (12.5%) cases of isolated ventriculomegaly compared with 18/23 (78.2%) cases of complex ventriculomegaly. Chromosomal abnormality testing identified 4/9 (44.4%) genetic abnormalities compared with 8/30 (26.7%) in cases of isolated and complex mild ventriculomegaly, respectively. Finally, maternal serology infection screening was negative in all cases.
CONCLUSION: Ancillary testing is useful in isolated mild ventriculomegaly. Follow-up MRI and chromosome abnormality testing specifically provided clinically useful information. Although there were no cases of maternal infection, screening may be an important component in management.