Deleterious effects of drugs on the developing nervous system

In the past two decades, several categories of drugs have emerged as serious neuroteratogens. These include vitamin A congeners, isotretinoin and etretinate, certain antiepileptic drugs, especially trimethadione, and valproic acid. Other antiepileptic drugs have low teratogenic potential and variably affect the developing CNS. When multiple antiepileptics are administered during pregnancy, however, the risk to the fetus increases considerably.