Use of anti-epileptic drug during pregnancy associated with increased risk of autism

Maternal use of valproate (a drug used for the treatment of epilepsy and other neuropsychological disorders) during pregnancy was associated with a significantly increased risk of autism in offspring, according to a study in the April 24 issue of JAMA. The authors caution that these findings must be balanced against the treatment benefits for women who require valproate for epilepsy control.

"Anti-epileptic 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 ," according to background information in the article.

Jakob Christensen, Ph.D., of Aarhus University Hospital, Aarhus, Denmark, and colleagues evaluated the association between maternal use of valproate during pregnancy and the risk of autism spectrum disorder and childhood autism in offspring. The population-based study included all born alive in Denmark from 1996 to 2006. National registers were used to identify children exposed to valproate during pregnancy and diagnosed with autism spectrum disorders (childhood autism [autistic disorder], Asperger syndrome, atypical autism, and other or unspecified pervasive developmental disorders). Data were analyzed and adjusted for potential confounders (factors that can influence outcomes) such as at conception, paternal age at conception, parental psychiatric history, , birth weight, sex, congenital malformations, and parity. Children were followed up from birth until the day of autism spectrum disorder diagnosis, death, emigration, or December 31, 2010, whichever came first.

The analysis included 655,615 children born from 1996 through 2006. The average age of the children at end of follow-up was 8.8 years. During the study period, 5,437 children were diagnosed with autism spectrum disorder, including 2,067 with childhood autism. The researchers identified 2,644 children exposed to antiepileptic drugs during pregnancy, including 508 exposed to valproate. The authors found that use of valproate during pregnancy was associated with an absolute risk of 4.42 percent for autism spectrum disorder and an absolute risk of 2.50 percent for childhood autism.

"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," the researchers write.

"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 was less than 5 percent, which is important to take into account when counseling women about the use of valproate in pregnancy."

Kimford J. Meador, M.D., and David W. Loring, Ph.D., of Emory University, Atlanta, write in an accompanying editorial that "women of childbearing potential should be informed of the potential risks of fetal valproate exposure before valproate is prescribed."

"Despite the established risks of fetal valproate exposure, valproate continues to be a common treatment in women of childbearing age. Valproate is an effective drug, but it appears that it is being prescribed for women of child-bearing potential at a rate that does not fully consider the ratio of benefits to risks. This raises concern as to whether these women are receiving adequate information for informed consent based on a full understanding of the treatment risks and alternative therapies. Given the accumulating evidence linking fetal valproate exposure to , cognitive impairments, and autism, the use of valproate in of childbearing potential should be minimized. Alternative medications should be sought. If no alternative effective medications can be found, the lowest effective dose of valproate should be used. Because approximately half of the pregnancies in the United States are unplanned, delaying discussions of treatment risks until a is considered will leave a substantial number of children at unnecessary risk."

More information: JAMA. 2013;309(16):1696-1703
JAMA. 2013;309(16):1730-1731

Related Stories

Epilepsy drug may increase risk of autism in children

Dec 01, 2008

A new study shows that women who take the epilepsy drug valproate while pregnant may significantly increase their child's risk of developing autism. The preliminary research is published in the December 2, 2008, print issue ...

Exposure to antiepileptic drug in womb linked to autism risk

Jan 30, 2013

Children whose mothers take the antiepileptic drug sodium valproate while pregnant are at significantly increased risk of autism and other neurodevelopmental disorders, suggests a small study published online in the Journal of ...

Lower IQ found in children of women who took epilepsy drug

May 03, 2007

Children of women who took the epilepsy drug valproate during pregnancy appear to be at a greater risk for lower IQ, according to research presented at the American Academy of Neurology's 59th Annual Meeting in Boston, April ...

Recommended for you

A tool enhances social inclusion for people with autism

Oct 15, 2014

The University of Alicante has developed, together with centres in the UK, Spain and Bulgaria, a tool designed to assist people with autism spectrum disorders by adapting written documents into a format that ...

User comments