Teratogenicity of the newer antiepileptic drugs - the Australian experience

Data on the use in pregnancy of the new antiepileptic drugs (AED) are limited. We analysed data collected by the Australian Pregnancy Register to provide information on their relative teratogenicity. The database containing pregnancy outcomes from 1317 women with epilepsy (WWE) was examined for three widely used new AED in monotherapy in the first trimester - lamotrigine, levetiracetam and topiramate. This was compared with outcomes of pregnant WWE on monotherapy with three traditional AED, and with untreated women. The incidence of malformations associated with lamotrigine monotherapy was 12/231 (5.2%), with topiramate 1/31 (3.2%) and with levetiracetam 0/22 (0%). This compares with rates of 1/35 (2.9%) for phenytoin, 35/215 (16.3%) for valproate (VPA), 19/301 (6.3%) for carbamazepine and 6/116 (5.2%) for untreated women. There was no evidence of dose-dependent risks of foetal malformation, except with VPA monotherapy. We conclude that the new AED appear no more teratogenic than traditional drugs in monotherapy.