Epilepsy Drug Linked to Autism Risk

Dec. 2, 2008— -- While a new study that suggests pregnant women who take the epilepsy drug Depakote may increase their babies' risk of developing autism, experts say the usefulness of the drug and the high risk of seizures during pregnancy may outweigh the threat of autism.

Some neurologists believe the finding may one day prove more intriguing for autism research.

The study, published in the journal Neurology, followed 632 children from womb to birth and into childhood between 2000 and 2006. Nearly half the children were exposed to various epilepsy drugs in the womb, while the other half were not.

Statistically, researchers estimate that children who were exposed to the drug sodium valproate were seven times more likely to later develop autism than the children who were not exposed to any epilepsy drug.

Despite the strong finding, the study is actually small: Only nine of the 632 children ended up with an autism diagnosis.

"These findings are only preliminary. More research is needed in this area and into the more general area of autism itself," said Rebecca Bromley, a co-author of the study and an assistant psychologist at the Liverpool and Manchester Neurodevelopment Group at the University of Liverpool in England.

Women who have epilepsy have always faced a special challenge with pregnancy. Neurologists in the United States say that the study raises questions for both parents in the epilepsy community and autism researchers.

"For one, it's a very good drug," said Dr. Michael Goldstein, a vice president of the American Academy of Neurology.

Sodium valproate goes by several names -- valproic acid, depakene and Depakote -- and is commonly used to treat generalized epilepsy and its potentially life-threatening convulsion seizures.

"Prolonged seizure could cause blood flow problems to the baby, which could cause injury," said Goldstein, who is also in practice with Western Neurological Associates in Salt Lake City.

Goldstein said anticonvulsants, especially valproic acid and carbamazepine, have been known to cause "teratogenic malformation," meaning visible birth defects in the limbs.