Outcome of fetuses with isolated borderline unilateral ventriculomegaly diagnosed at mid-gestation

Objective To evaluate the outcome of fetuses with isolated borderline, unilateral ventriculomegaly. Design A retrospective survey was conducted at four perinatal centers in Israel. Subjects and methods Only fetuses with one ventricular width of greater than or equal to 11 mm and the other < 10 mm were included in the study. In all cases, the difference of the ventricular width between the two ventricles was > 2.4 mm (two standard deviations). Fetuses with other malformations, chromosomal abnormalities, or those with evidence of in utero infection, were not included in the study. Results Unilateral ventriculomegaly was found in 27 subjects (after excluding one case with unilateral ventriculomegaly and Down's syndrome). The mean width of the enlarged ventricle was 11.7 +/- 0.9 mm, while the other normal ventricle was 7.2 +/- 0.9 mm. The mean gestational age at diagnosis of the unilateral ventriculomegaly was 23.6 +/- 2.7 weeks. In one case, pregnancy was terminated, and pathological examination of the fetal brain failed to detect any structural abnormality. Twenty-five patients delivered at term and only one at 34 weeks' gestation. The neurological development in all 25 fetuses was normal, and one fetus had petit mal seizures. Conclusion Fetuses with isolated, borderline unilateral ventriculomegaly, but without other abnormalities, have a good neurological outcome.