Antiepileptic drug intake during pregnancy and malformed offspring.

Possible associations between the presence of malformations in the offspring and various factors related to epilepsy were studied in 134 pregnancies in 105 epileptic women who had plasma antiepileptic drug concentrations measured on multiple occasions during pregnancy. No statistically significant associations could be detected between the malformations and maternal age, the number of the pregnancy, the type, duration or activity of the maternal seizure disorder, and the nature, dose or maximum recorded plasma concentration of the antiepileptic drugs used in the first 16 weeks of pregnancy. However, there was a statistically significant association between the malformations and maternal intake of antiepileptic drugs in combination. No particular combination of agents could be shown responsible for the association, which has been noted previously in the literature. It seems that a much larger study will be needed to clarify the matter.