April 16, 2009

Epilepsy Med Lower Child’s IQ If Taken While Pregnant

According to a new study, children of mothers who took the epilepsy drug valproate during pregnancy had lower IQs than children of mothers who used other anti-seizure medications.

Valproate affected children had IQ scores up to nine points lower by age 3, Dr. Kimford Meador, the study's lead author, told the Associated Press.

Women who could potentially bear children have long been advised to avoid valproate, also sold under the brand name Depakote, because it has previously been linked to other birth defects, including spina bifida.

"We've known this drug is a bad actor for a long time," said Dr. Lewis Holmes, director of the North American Antiepileptic Disease Pregnancy Registry.

The new study, which appears in the New England Journal of Medicine, is the largest to show a link between valproate and lower IQ.

The study's appearance in the popular medical journal should alert many physicians who may have ignored the drug's potential harm.

To gather data, researchers followed pregnant women in the U.S. and United Kingdom between 1999 and 2004. The results were based on 260 of their children.

On average, toddlers of women who had taken valproate had IQs of 92, while IQ scores for children of women who took lamotrigine, phenytoin, and carbamazepine to treat epilepsy, ranged from 98 to 101. 

A child of average intelligence should score 100.

Researchers also found that children of women who took large doses of valproate had the lowest IQs. 

Dosage levels had little to no effect for other epilepsy drugs.

The numbers could potentially be flawed due to the small number of children involved in the study.

Researchers did take into account differences in age and IQs of mothers, the type of epilepsy a mother suffered from, and other factors.

According to Holmes, who was not involved in the research, the study did not include children whose mothers abstained from epileptic medication during pregnancy which is a major drawback.

It's possible that all four epilepsy medications had some effect on mental development, he added.

Valproate continues to be used to treat migraine headaches, mood disorders, and epilepsy because of its success rate.

Many doctors recommend that epileptic women continue taking their medications during pregnancy to prevent seizures which can lead to injuries.

According to Swedish researcher Dr. Torbjorn Tomson, women taking valproate should consult their doctors, and carefully plan their pregnancies.

Changing medications or stopping treatment during pregnancy may endanger the mother and the fetus, Tomson added.

Each year, roughly 25,000 children are born in the U.S. to women who have epilepsy.


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