The Neurodevelopmental Effects of Antiepileptic Drugs (NEAD) Study was a prospective observational multicenter study in the USA and UK, which enrolled pregnant women with epilepsy on antiepileptic drug (AED) monotherapy from 1999 to 2004. The study aimed to determine if differential long-term neurodevelopmental effects exist across four commonly used AEDs (carbamazepine, lamotrigine, phenytoin, and valproate).
This report examines fetal AED exposure effects on learning and memory functions in 221 six-year-old children (including four sets of twins) whose mothers took one of these AEDs during pregnancy. Their performance was compared with that of a national sample of normally developing six year olds from the standardization sample of the Children’s Memory Scale (CMS).
The major results of this study indicate that the mean performance levels of children exposed to valproate were significantly below that of the children in the normal comparison group across all seven of the CMS Indexes. However, once the information was learned and stored, the valproate-exposed children appeared to be able to retrieve the information they did learn at normal levels.
Additional research employing larger prospective studies will be required to confirm the long-term cognitive and behavioral risks to children of mothers who are prescribed these four AEDs during pregnancy as well as to delineate any potential risks of newer AEDs and to understand the underlying mechanisms of adverse AED effects on the immature brain.