In the United States, the Food and Drug Administration (FDA) assigns each medication to a Pregnancy Category according to whether it has been proven to be harmful in pregnancy. Carbamazepine, the medicine in Tegretol-XR, is listed in Pregnancy Category D. This means that there is a risk to the baby, but the benefits may outweigh the risk for some women.

In fact, a large majority of women who use Tegretol-XR during pregnancy have normal, healthy babies. Certain types of defects are increased (especially if Tegretol-XR is taken during the first 3 months of pregnancy) but they are still relatively uncommon. The risk of defects is higher for women who take more than one seizure medicine. Women with a family history of birth defects also have a higher risk.

All women who are capable of becoming pregnant should take 0.4 mg (400 mcg) of the vitamin called folic acid every day because it helps to prevent one type of birth defect. (The most well-known of these is spina bifida, in which the spinal cord is not completely enclosed.) These defects are more common in the babies of women who take Tegretol-XR during the first 4 to 6 weeks of pregnancy. If the doctor thinks a woman is at especially high risk, a much larger dose of folic acid—4 mg (4000 mcg) per day—will be recommended.

Women with epilepsy who are pregnant or thinking about becoming pregnant should talk to their doctor about their seizure medicines. Taking more than one seizure medicine may increase the risk of birth defects, so doctors sometimes gradually reduce the number or amount of seizure medicines taken by women planning for pregnancy.

This is not done routinely, however, because it increases the risk of seizures. Some kinds of seizures can injure the baby, so do not stop using seizure medicines or reduce the amount without the doctor’s OK.