High dose reproductive studies in animals have demonstrated teratogenic effects (craniofacial, appendicular, and visceral malformations), maternal toxicity (transient weight loss or reduced maternal weight gain during gestation), as well as adverse fetal outcome when the drug is administered during late gestation and throughout parturition (increase in stillbirths and decrease in postnatal offspring viability). No adverse fetal or maternal effects were observed with doses equivalent to three times the maximum recommended human dose on a mg/m2 basis. There are no controlled data in human pregnancy.

Patients should be encouraged to enroll in the North American Antiepileptic Drug (NAAED) Pregnancy Registry if they become pregnant. This registry is collecting information about the safety of antiepileptic drugs during pregnancy. To enroll, patients can call the toll free number 1-888-233-2334. Information on the registry can also be found at the website http://www.aedpregnancyregistry.org/.

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.

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

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

Comments:
-The risk of having an abnormal child as a result of antiepileptic medication is far outweighed by the dangers to the mother and fetus of uncontrolled epilepsy.
-Women on antiepileptic drugs (AEDs) should receive prepregnancy counseling about the risk of potential fetal abnormalities.
-AEDs should be continued during pregnancy and monotherapy should be used if possible at the lowest effective dose because risk of abnormality is greater in women taking combined medication.
-Folic acid supplementation (5 mg) should be started 4 weeks prior to and continue for 12 weeks after conception.
-Specialist prenatal diagnosis including detailed mid-trimester ultrasound should be offered.

See references

Monitor the infant for drowsiness, adequate weight gain, and developmental milestones, especially in younger, exclusively breastfed infants and when using combinations of anticonvulsant or psychotropic drugs. Because there is very limited published experience with this drug during breastfeeding, other agents may be preferred, especially while nursing a newborn or preterm infant.

Benefit should outweigh risk.

Excreted into human milk: Unknown
Excreted into animal milk: Yes

See references