Antiseizure medications (ASMs) are increasingly used by pregnant women worldwide, not only for the treatment of epilepsy but also for mood disorders, migraine, and pain. Some ASMs, such as valproate and phenobarbital, clearly negatively affect the child’s developing brain.1 However, evidence of cognitive risks of in utero exposure remains limited for most ASMs.1 Healthcare professionals and pregnant women in need of ASM must balance the risks and benefits of different treatment options for the mother and her unborn child, which, in the absence of robust safety data, is a challenging endeavor. Thus, quality data are urgently needed about the safety of ASMs used in pregnancy. However, since randomized clinical trials (providing Class I–II evidence)2 cannot be conducted for ASMs in pregnant women to assess teratogenicity, such evidence in humans must be obtained from observational studies such as large-scale population-based cohort studies with ample follow-up.