Based on a structured questionnaire and medical records, the authors found that 12 of 25 mothers with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) with the R133CNOTCH3 mutation had had neurologic symptoms in 17 of their 43 pregnancies, most commonly hemiparesthesia (76%), hemiparesis (36%), aphasia (65%), and visual disorders (47%).