Researchers have found that pregnant women who take the drug valproate (for epilepsy) could be at an increased risk of giving birth to a child with autism, according to a new study published in the journal JAMA.

Valproate is also prescribed for migraine, panic attack, anorexia nervosa, anxiety disorder, posttraumatic stress disorder, bipolar disorder, as well as some other psychiatric conditions.

The background information of the article said: "Anti-epileptic drug exposure during pregnancy has been associated with an increased risk for congenital malformations and delayed cognitive development in the offspring, but little is known about the risk of other serious neuropsychiatric disorders."

The U.S. Food and Drug Administration has already issued a warning concerning the risks of taking valproate while pregnant. They stated that there are already studies that have found that children of mothers who took valproate sodium while pregnant have a higher risk of lower cognitive test scores compared to those whose were exposed to different anti-seizure medications.

In this study the researchers conducted a population based study to see whether the maternal use of the drug valproate during pregnancy had any association with an increased risk of autism in the offspring. Jakob Christensen, Ph.D., of Aarhus University Hospital, Aarhus, Denmark, led a team which analyzed Danish children born between 1996 and 2006.

They gathered data from national registers to see how many children were exposed to the drug valproate as well as how many were diagnosed with an autism-spectrum disorder.

A total of 655,615 children born from 1996 through 2006 were included in the study, of whom 5,437 were diagnosed with an autism spectrum disorder.

The children were followed until the day they were diagnosed with autism, death or December 31, 2010. They adjusted the data for factors that could influence outcomes (such as maternal age at conception and prevalence of mental illness in the family).

Of the 2,644 children who were found to be exposed to antiepileptic drugs during pregnancy 508 were specifically exposed to the drug valproate.

They found that the children exposed to valproate were at a 4.42 percent risk of an autism spectrum disorder as well as a 2.50 percent risk of childhood autism.

Although valproate is a very effective drug, prescribing it to pregnant women should be minimized. Instead, doctors should offer alternative therapies. If no alternative therapies work, then only the lowest effective dose of valproate should be prescribed. Those who have to take it should be fully aware of the risks involved of taking the medication.

The American Academy of Neurology and the American Epilepsy Society have both said that while it's safe for women with epilepsy to become pregnant, particular caution must be taken with valproate. The authors of the study concluded:

"In this population-based cohort study, children of women who used valproate during pregnancy had a higher risk of autism spectrum disorder and childhood autism compared with children of women who did not use valproate. Their risks were also higher than those for children of women who were previous users of valproate but who stopped before their pregnancy.

Because autism spectrum disorders are serious conditions with lifelong implications for affected children and their families, even a moderate increase in risk may have major health importance. Still, the absolute risk of autism spectrum disorder was less than 5 percent, which is important to take into account when counseling women about the use of valproate in pregnancy."
Written by Joseph Nordqvist