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 > or = 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.