Valproate, marketed as Depakote by Abbott Labs is the second-most-popular anti-seizure medication used for epilepsy. Previous studies have shown that using it during pregnancy also increases the risk of developmental delays and major malfunctions. Yet it is still widely prescribed for epilepsy, migraines, bipolar disorder and other conditions, mostly by general practitioners who have not heard of its dangers.

 

For the current study, Kimford J. Meador, MD, of Emory University in Atlanta and colleagues investigated pregnant women with epilepsy at 25 centers in the US and England.

 

All of the women were taking a single anti-seizure drug: either valproate, or one of the following: lamotrigine, phenytoin or carbamazepine. Women taking other drugs than the ones above were excluded because of insufficient numbers.

 

The researchers analyzed 309 kids at age 3: 99 of them were exposed to lamotrigine, 92 to carbamazepine, 52 to phenytoin and 60 to valproate.

 

The researchers found that children born to mothers who took valproate had the lowest average IQ even after adjusting for other factors that might influence IQ, such as mothers’ IQ, her age at delivery, or the type of epilepsy.

 

More exactly, the researchers found the following average IQs: 101 for children whose mothers took lamotrigine, 99 for children whose mothers took phenytoin, 98 for children whose mothers took carbamazepine and 92 for children whose mothers took valproate.

 

“This finding supports a recommendation that valproate not be used as a first-choice drug in women of childbearing potential,” Meador said.

 

When the researchers examined the quantities of valproate the children were exposed to during pregnancy, they also discovered that those exposed to high doses had an average IQ of 87 and those exposed to lower doses had an average IQ of 97. “An average IQ is 100 and below 70 is mentally retarded,” Meador said.

 

According to the Epilepsy Foundation of America, about 3 million people in the US have some form of epilepsy and experience seizures, defined as brief disturbances of electrical activity in the brain. About 25,000 children in the United States are born to mothers with epilepsy each year.

 

In a statement issued after reviewing the study, drugmaker Abbot said: “For many women, Depakote may be the only effective medicine to control their seizures, but it is important that physicians and patients have a candid conversation about the risks of treatment versus the benefits of treatment.”