The neurodevelopmental risks of fetal exposure to many antiseizure medications are unknown. A prospective, observational study was conducted to compare pregnancy outcomes in women with epilepsy and their children. Researchers compared children at two years of age who had been born to women who had epilepsy with children born to healthy women, examining the association between fetal exposure to antiseizure medications and neurodevelopment.

Inclusion criteria for pregnant women with epilepsy included the following: 14 to 45 years of age, gestational age of 20 weeks or less, and use of an antiseizure medication. Most of the women were taking lamotrigine, levetiracetam, or a combination of the two. Cognitive outcomes for the 292 children of women with epilepsy and 90 children of healthy women were assessed using the Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III), which scores performance in five domains: language, motor, cognitive, social emotional, and general adaptive.

No significant differences were found between the two groups of children for the BSID-III primary outcome of language domain, nor for any of the four other domains. In adjusted analyses, higher maximum blood levels of antiseizure medication in the third trimester were associated with significantly lower scores for the motor domain and lower scores for the general adaptive domain.

One limitation of the study was that cognitive and behavioral assessments performed at two years of age don't yield associations as strong as those resulting from assessments of older children. Also, the prescribing patterns in the study population may not reflect those of the general population. The authors advise that studies in older children and other cohorts are needed to fully understand the effect of exposure to antiseizure medications on the immature brain.