The importance of monotherapy in pregnancy.

The great majority of women with epilepsy who become pregnant have normal pregnancies and healthy infants. However, in utero exposure to antiepileptic drugs (AEDs) can put infants of women with epilepsy at increased risk for a variety of abnormalities, including intrauterine growth retardation, minor anomalies, major congenital malformations, microcephaly, and cognitive dysfunction. Various combinations of these findings can occur in an individual infant and are referred to as the fetal anticonvulsant syndrome (FAS). The most common major malformations are cleft lip/palate, heart defects, neural tube defects, and urogenital defects. Although AEDs have teratogenic risks, withdrawal of all AEDs before pregnancy is not a realistic option for many women with epilepsy. The results of several studies indicate that AED monotherapy reduces the risk for development of FAS compared with polytherapy exposure in utero. Current treatment guidelines advise use of AED monotherapy when possible and folate supplementation beginning before and continuing throughout pregnancy. Prenatal screening for major malformations should be offered. Careful planning and management of any pregnancy in women with epilepsy is essential to increase the likelihood of a healthy outcome for mother and infant.