Antiepileptic drugs during pregnancy: pharmacokinetics and transplacental transfer.

Epilepsy represents the most common maternal neurological disorder requiring continuous treatment during pregnancy. Maintaining optimum seizure control is an important objective in pregnancy, and the majority of women with epilepsy will need to continue antiepileptic drugs (AEDs). AEDs are frequently used to treat several other conditions, such as headaches and mood disorders. They have been associated with an increased risk of congenital malformations, minor anomalies, congenital syndrome and development disorders. This risk seems to be higher among women using polypharmacy and valproic acid. Neural tube defects are associated with valproic acid and carbamazepine exposure. New AEDs seem to have a less teratogenic effect, but human experience is still limited. The purpose of this review is to provide an update on AED exposure in pregnancy, focusing on pharmacokinetics and transplacental transport.