Teratogenicity of antiepileptic drugs: is the prevention possible?

To assess the relative contribution of antiepileptic drugs (AEDs) toward the occurrence of congenital malformation, two prospective studies (previous and present) were compared. In the present subjects of 145 cases, the total daily dose of AEDs (drug score) in each case was decreased as much as possible, and polypharmacy was changed to monopharmacy before conception where it was possible. The incidence of malformations significantly decreased from 13.5% to 6.2% (p = 0.031) by the change in drug regimen. The drug score, number of AEDs, maternal age at delivery, seizure type, and etiology of epilepsy were statistically different between the two study groups. Even after the correction of the data by the last three factors, the difference in the incidence of malformation did not disappear, while it disappeared if data were corrected either by the drug score or number of AEDs. These results suggest that the possibility of prevention of AED related malformations is possible by an improvement in AED therapy.