Antenatal diagnosis of partial agenesis of the corpus callosum: a benign cause of ventriculomegaly.

Dilation of the posterior horns of the cerebral ventricles may be an early finding of fetal hydrocephalus, but it is also the hallmark of partial agenesis of the corpus callosum. Reported is the first precise prenatal diagnosis of posterior agenesis of the corpus callosum. Accurate diagnosis allows for appropriate obstetric management.