Animal studies have revealed evidence of developmental toxicity, including teratogenic effects, an increased incidence of malformations (cleft palate), embryofetal death, decreased fetal body weights, increased incidences of fetal anatomic variations, neurobehavioral (convulsions, neuromotor impairment, learning deficits), and neurohistopathological (brain vacuolation, decreased myelination, and retinal dysplasia) abnormalities. A limited amount of data from spontaneous reports of exposed human pregnancies have shown congenital anomalies or spontaneous abortion in the offspring of mothers taking this drug; however, definite conclusions cannot be drawn due to inherent limitations of such data (e.g., concomitant use of other antiepileptic drugs). There are no controlled data in human pregnancy.

To provide information regarding the effects of in utero exposure to this drug, physicians are advised to recommend that pregnant patients enroll in the North American Antiepileptic Drug (NAAED) Pregnancy Registry. This can be done by calling the toll free number 1-888-233-2334, and must be done by patients themselves. Information on the registry can also be found at the website http://www.aedpregnancyregistry.org/.

AU TGA pregnancy category D: Drugs which have caused, are suspected to have caused or may be expected to cause, an increased incidence of human fetal malformations or irreversible damage. These drugs may also have adverse pharmacological effects. Accompanying texts should be consulted for further details.

US FDA pregnancy category C: Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.

This drug should be used during pregnancy only if the benefit outweighs the risk.

AU TGA pregnancy category: D
US FDA pregnancy category: C

Comments:
-Specialist advice should be provided to all women of childbearing potential.
-The need of antiepileptic treatment should be reevaluated when a patient plans a pregnancy.
-It is recommended that antiepileptic drugs should be continued during pregnancy, if possible as monotherapy and at the lowest effective dose; women should be apprised of the potential hazards to the fetus.
-Women should take folic acid 5 mg daily starting 4 weeks before conception and during the first 12 weeks of pregnancy, and be offered specialist antenatal screening including ultrasound scanning.

See references

A decision should be made to discontinue breastfeeding or discontinue the drug, taking into account the importance of the drug to the mother.

Excreted into human milk: Yes (in low concentrations)

Comments:
-The effects in the nursing infant are unknown.

Limited information indicates that maternal doses of this drug up to 2000 mg daily produce low levels in milk and would not be expected to cause any adverse effects in breastfed infants, especially if the infant is older than 2 months. Until more data are available, this drug should only be used with careful monitoring during breastfeeding.

See references