Drugs in pregnancy: anticonvulsants

Although 90% of patients using anticonvulsant drugs can expect a favorable pregnancy result, this outcome can be maximized by careful preconceptional, antepartum, and postpartum management. There is no clearcut agreement that any one of the four major drugs used for the treatment of seizure disorders (phenytoin, phenobarbital, valproic acid, and carbamazepine) is more teratogenic than others. Patients should be counseled that the risk of adverse maternal and neonatal outcomes from recurrent seizures during pregnancy is greater than the risk of teratogenicity with anticonvulsant drugs. The lowest possible dose of one of the four front-line agents is recommended for seizure control in pregnancy. The interaction of epilepsy and pregnancy, as well as the possible mechanisms of anticonvulsant teratogenesis, are reviewed. The use and toxicity of individual, commonly used, anticonvulsant drugs are described. Detailed consensus recommendations for preconceptional, antenatal, intrapartum, and postpartum management of patients using anticonvulsant drugs are discussed.