Epilepsy Drugs May Lead To Birth Defects

Epileptic pregnant women are at greater risk when taking epileptic drugs

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Women with epilepsy comprise one half of a percent of all pregnancies in America. It is necessary for these women to remain on their anti-convulsant drugs during pregnancy as uncontrolled seizures are risky for both the mother and her unborn child.

Four of the most commonly prescribed drugs treating epilepsy, if taken during the beginning of pregnancy, may increase the risk of major birth defects. This research study indicates that the degree of risk is dose dependent.

"Pregnant women with epilepsy should consult their obstetrician regarding every medication."

Torbjörn Tomson from the Karolinska Institute, Stockholm, Sweden explains that present recommendations regarding epileptic drugs used during pregnancy only caution on the use of valproic acid.  However, little to no guidance on alternative options for women whose seizures aren't controllable by other drugs.

The authors of this study comment that their results indicate how crucial the dose given a patient is and gives physicians treating these women dose selection options regarding each drug available to treat epilepsy in pregnant women.  Drugs with the potential to cause birth defects risks are dose dependent for each drug. 

For this worldwide case review study which included 3,909 pregnancies of epileptic women, the researchers investigated the association between the use of carbamazepine (Tegretol, Epitol), lamotrigine (Lamictal), valproic acid (Depakote), and phenobarbital at different doses and the risk of major birth defects detected up to one year after birth. 

Of the 3,909 pregnancies reviewed, 230 pregnancies, or almost 6 percent, resulted in children with major birth defects. These major birth defects were associated with large doses of all the drugs. The rate of birth defects was lowest for low doses of the drugs Lamictal (less than 300 mg per day), Tegretol and Epitol (less than 400 mg per day).

The highest doses of Depakote (1500 mg per day or greater) and phenobarbital (150 mg per day or day or greater) pose the highest risk of birth defects, with particularly high rates of birth defects recorded in pregnancies exposed to valproic acid 1500 mg per day or greater. The authors declare that a large majority of women on the four studied drugs gave birth to healthy children.

If a parent history of major birth defects is in place in addition to taking these epilepsy drugs, the risk of birth defects was four times greater.

Reviewed by: 
Review Date: 
June 7, 2011
Last Updated:
June 8, 2011