Maternal use of antiepileptic drugs during pregnancy has been associated with an increased risk of major congenital abnormalities in the fetus. Carbamazepine (CBZ) is an antiepileptic drug that was developed and marketed mainly for the treatment of epileptic seizures. Some investigators described an increased rate of major congenital anomalies following treatment with CBZ during pregnancy while others found no such increase. In order to quantify better the risks of exposure to CBZ during pregnancy, we pooled data from prospective studies known to us. We found in prospective studies involving 1255 cases of exposure that CBZ therapy increased the rate of congenital anomalies, mainly neural tube defects, cardiovascular and urinary tract anomalies, and cleft palate. CBZ may also induce a pattern of minor congenital anomalies and developmental retardation, but our study did not address these endpoints. CBZ also appears to reduce gestational age at delivery. A combination of CBZ with other antiepileptic drugs is more teratogenic than CBZ monotherapy. Children born to untreated epileptic women do not appear to have an increased rate of major birth defects. In light of these results, we recommend performing a level 2 ultrasound and fetal echocardiography in women treated with CBZ during pregnancy.