Animal studies have shown teratogenicity at doses in excess of 10 times the recommended dose in humans. There is no evidence of a direct association between this drug and birth defects during human pregnancy. In the Collaborative Perinatal Project (CCP), a retrospective study that evaluated 50,282 mother-child pairs, 12 had first trimester exposure to this drug with no anomalies observed. A total of 1024 anytime exposures were reported and the number of infants with malformations was less than expected (18 vs 18.06). There are no adequate and well-controlled studies in pregnancy women.

Physicians are encouraged to register patients before fetal outcome is known (e.g., ultrasound, results of amniocentesis, etc) into the Antiepileptic Drug (AED) Pregnancy Registry at 1-888-233-2334 (-888-AED-AED4) or www.aedpregnancyregistry.org. This is an ongoing study at the Massachusetts General Hospital/Harvard Medical School. This study is designed to monitor the outcomes of pregnant women exposed to antiepileptic drugs in order to determine which therapies are associated with increased risk.

AU TGA pregnancy category B3: Drugs which have been taken by only a limited number of pregnant women and women of childbearing age, without an increase in the frequency of malformation or other direct or indirect harmful effects on the human fetus having been observed. Studies in animals have shown evidence of an increased occurrence of fetal damage, the significance of which is considered uncertain in humans.

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.

Benefit should outweigh risk

AU TGA pregnancy category: B3
US FDA pregnancy category: C

See references

Benefit should outweigh risk

Excreted into human milk: Yes

Based on single case reports, low levels of this drug are expected in human milk. The infants estimated dose from a maternal dose of 1000 mg a day (sustained-release product) is less than 0.7% of the maternal weight-adjusted dose. Some authorities believe this drug is compatible with breastfeeding when used to treat glaucoma. However, product manufacturers advise against, or advise use with extreme caution while breastfeeding due to the potential for serious adverse effects in nursing infants.

See references