The long-term effects on cognitive functioning of school-aged children exposed to antiepileptic drugs (AEDs) in utero were investigated at Alder Hay Hospital and Walton Centre for Neurology and Neurosurgery, Liverpool, UK. Neuropsychological tests (WISCIII) were performed on 249 children, ages 6-16, of women with epilepsy recruited from epilepsy and obstetric clinics in the region. Children with prenatal exposure to sodium valproate (VPA) showed a significantly lower verbal IQ when compared to other AEDs or no drug exposure; their IQ was more likely to be <69, and memory was more often impaired. Patients taking VPA and other AEDs showed no significant differences between maternal IQ and socioeconomic status. In addition to VPA exposure, low maternal IQ and tonic-clonic seizures during pregnancy were risk factors for impaired verbal IQ in the child. Two thirds of children exposed to VPA had a verbal IQ below average and one fifth had a learning disability with a verbal IQ <69. Five or more tonic-clonic seizures during pregnancy were associated with impaired verbal IQ. 
COMMENT. In this retrospective study controlled for maternal IQ, prenatal exposure to VPA and maternal seizures increased the risk of impairment of verbal intelligence and memory functioning in the child.