Animal studies have revealed evidence of fetotoxicity involving delayed ossification in several bones of the skull, vertebrae, forelimbs, and hindlimbs.
Hydroureter and hydronephrosis have also been reported in animal studies. 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 B1: 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 not shown evidence of an increased occurrence of fetal damage.
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: B1
US FDA pregnancy category: C
Comments:
-Women on antiepileptic drugs (AEDs) should receive prepregnancy counseling with regard to the risk of fetal abnormalities.
-AEDs should be continued during pregnancy and monotherapy should be used if possible at the lowest effective dose as the risk of abnormality is greater in women taking combined medication.
-Folic acid supplementation (5 mg) should be started 4 weeks prior to and continued for 12 weeks after conception.
-Specialized prenatal diagnosis including detailed mid-trimester ultrasound should be offered.
-The risk of having a child with a congenital defect as a result of antiepileptic medication is far outweighed by the dangers to the mother and fetus of uncontrolled epilepsy.