Abstracts

Rationale: The cognitive abilities of children following fetal exposure to antiepileptic drugs are still being debated. There is evidence from retrospective and a small number of prospective studies that children exposed to sodium valproate in utero are at an increased risk of poorer cognitive functioning in childhood. Methods: A prospective investigation into the development of the offspring of 593 women with epilepsy commenced in 2000. To date 369 children have been assessed at 6 years of age by an assessor blinded to their exposure type. Here preliminary results regarding the children exposed to sodium valproate and those exposed to carbamazepine, in comparison to control children are presented. Results: When adjusted for maternal IQ, the children exposed to sodium valproate (n=43) in utero differed significantly in comparison to control children (n=177) on their full scale IQ abilities (p=0.002), their memory abilities (p<0.001) and their naming abilities (p=0.001). Significant differences were also found in comparison to control children for auditory attention tasks (p=0.003) but not visual attention tasks (p=0.059). The variance explained by exposure to sodium valproate remained significant once the effects of maternal IQ, maternal age, presence of epilepsy in the mother, exposure to seizures and the child’s gestational age were controlled for, for full scale IQ (p=0.006), for memory (p=0.001), for naming abilities (p=0.008) and for auditory attention (p=0.025). A significant proportion (47%) of children exposed to sodium valproate required speech therapy intervention in comparison to only 6% of control children. Children exposed to carbamazepine (n=45) in utero differed significantly in comparison to control children following an adjustment for maternal IQ for visual attention (p=0.016) but not for full scale IQ (P=0.887), memory abilities (p=0.126), naming abilities (p=0.350) or auditory attention (p=0.457). Once the effects of maternal IQ, maternal age, presence of epilepsy in the mother, exposure to seizures and the child’s gestational age were controlled for, exposure to CBZ was not a significant predictor for visual attention (p=0.061). The need for speech therapy in children exposed to carbamazepine was 9%. Conclusions: Preliminary findings indicate that children exposed to sodium valproate in utero are at an increased risk of poorer abilities for language, IQ, memory and auditory attention. Nearly half of the children exposed to sodium valproate required intervention for poor language development. These differences represent a clinical problem. Children exposed to carbamazepine in utero were not found to differ significantly in their cognitive abilities in comparison to control children. Women with epilepsy should be informed of a possible cognitive risk to their child prior to conception to allow for an informed decision over treatment to be made.