Trends in use of antiseizure medication and treatment pattern during the first trimester in the German Embryotox cohort

Because of their developmental toxicity, some antiseizure medication (ASM) should be avoided during pregnancy. This may lead to discontinuation or switching of ASM after recognition of pregnancy, but some of these changes may be suboptimal. Trends in ASM use at conception were analyzed in 3,763 pregnancies prospectively ascertained by a teratology information service in Germany between 2000 and 2018. Focusing on women with epilepsy (n = 2,395), changes of treatment pattern during the 1st trimester were evaluated. There was an increase in women using ASMs for non-epilepsy indications from 19% in 2000 to 39% in 2018. Although a shift from non-recommended teratogenic ASMs to recommended ASMs was observed, 13% of women were still receiving non-recommended ASMs in early pregnancy at the end of the study period. Among women with epilepsy, ASM regimen remained unchanged during the 1st trimester in 90%, 6% switched to other ASMs, and only 4% discontinued. Valproate, oxcarbazepine, and topiramate were more likely to be discontinued or switched than other ASMs. This first analysis of treatment pattern in ASM exposed pregnancies in Germany confirms the general trend towards less teratogenic and newer ASMs. However, it remains questionable whether women still using non-recommended ASMs are refractory to lower-risk ASMs or disregard treatment guidelines and risk minimization measures.