Divalproex and carbamazepine have been associated with a variety of problems and birth defects, including nerve conditions and developmental delays. Children exposed to these anticonvulsant mood stabilizers in the womb may display low sugar levels in the blood (hypoglycemia) and liver dysfunction, among other problems. These two medications pass into breast milk and some adverse effects may occur. Therefore, women who are breastfeeding and using divalproex or carbamazepine must be monitored closely through blood tests. The safety of oxcarbazepine, a derivative of carbamazepine, requires further study.

Recent studies suggest that lamotrigine may increase the risk of cleft lip or palate when taken during the first trimester of pregnancy. In addition, the drug is excreted in breast milk and levels in infants can be high.

Topiramate appears to be safe to use during pregnancy and breastfeeding. No problems in infants exposed to this medication in the womb or through breast milk have been discovered.