Exposure in the womb to antiseizure medications and their potential impact on the brain of the developing child has long been researched. Despite this long period of interest, this review highlights that above the well-known risks associated with valproate exposure, there are more data required for conclusions regarding all other antiseizure medications. Limited experience with phenytoin and phenobarbital in monotherapy makes clearly defining the risk to later child postnatal functioning difficult, although the evidence of an impact is stronger for phenobarbital than for phenytoin. The widely prescribed lamotrigine is limited in its investigation in comparison to unexposed control children, and whilst it has been demonstrated to carry a lower risk than valproate for certain outcomes, whether it is associated with a more moderate impact on wider aspects of neurodevelopmental functioning is still to be understood. Data for levetiracetam, topiramate and oxcarbazepine are too limited to confidently draw conclusions for most neurodevelopmental outcomes. This slow accumulation of evidence impacts on the safest use of medications in pregnancy and makes counseling women regarding the risks and benefits of specific antiseizure medications difficult. Improved focus, funding, and research methodologies are urgently needed.