The U.S. Food and Drug Administration (FDA) lists Gabapentin in Pregnancy Category C. This indicates that caution is advised, but the benefits of the medication may outweigh the potential risks. There have been no good scientific studies in women, but studies in animals have shown some harm to the fetus.

In general, the risk of defects is higher for women who take more than one AED and for women with a family history of birth defects. Whether this applies to Gabapentin is not yet known.

Women who are capable of becoming pregnant should take at least 400 mcg (0.4 mg) of folic acid (folate) daily to help prevent a type of birth defect called a neural tube defect. (The best-known of these is spina bifida, in which the spinal cord is not completely enclosed.) Women at high risk, such as those with a history of this kind of defect in a previous pregnancy, should take 4000 mcg (4 mg) daily, beginning before they become pregnant.

About 20% to 35% of women have seizures more often during pregnancy because of changes in hormones or changes in how their seizure medicine is handled by the body. Even though this may not apply to Gabapentin, the doctor may recommend checking the level of medication in the blood regularly during pregnancy so that the dosage can be adjusted as needed.

Breast-feeding by mothers taking Gabapentin should be safe for healthy, full-term newborns. A small amount of the medication will appear in the milk; one estimate is that the baby may receive up to about 1 mg/kg per day in the milk. The effect of this amount on an infant is unknown.