Study Reveals Birth Defects Increased with Four Common Epilepsy Drugs 06/07/2011 Study Reveals Birth Defects Increased with Four Common Epilepsy Drugs
June 7, 2011
A total of 230 pregnancies associated with major birth defects were identified by the end of the first year after birth. An increase in the rate of birth defects was noted with increasing dose for all drugs. The rate was lowest for low doses of the drugs lamotrigine (less than 300 mg per day) and carbamazepine (less than 400 mg per day).
The highest doses of valproic acid (1500 mg per day or greater) and phenobarbital (150 mg per day or day or greater) posed the highest risk to the fetus, with particularly high rates of birth defects recorded in pregnancies exposed to valproic acid 1500 mg per day or greater.
The authors caution: “It should be emphasised, however, that, irrespective of which of the four investigated drugs was prescribed, the vast majority of women gave birth to perfectly healthy children.”*
Additionally, the risk of defects was four times greater for offspring with a parental history of major congenital malformations (birth defects).
The authors say: “Our results show that dose selection is as crucial as the choice of drug…[and] gives the prescriber the possibility of assessing how teratogenic [ability to cause birth defects] risks at that dose compare with the risk associated with alternative treatments at various doses.”
Page B. Pennell, Chair of the Professional Advisory Board of the Epilepsy Foundation, from Harvard Medical School and Brigham and Women’s Hospital, Boston, Mass. said, “This study pooling observational data from numerous countries provides critical new information that gets us even closer to our goal of healthy pregnancy outcomes for women with epilepsy. Health care providers can continue to minimize the risk for birth defects by adjusting the type of AED prescribed AND the dosage of the AED going into the first trimester of pregnancy.
Epilepsy Foundation Executive Vice President Alexandra Finucane added, "In general, these studies confirm recent research that newer AEDs are safer in pregnancy than older ones."