WASHINGTON — Pregnant women who took the antiseizure drug valproate during pregnancy increased the odds that their baby would have autism and were roughly twice as likely to give birth to a child who would go on to be diagnosed with an autism spectrum disorder, according to a large study that captured 10 years of births in Denmark.
Valproate, often known by its commercial name, Depakote, is widely prescribed in the treatment of epilepsy and a wide range of psychiatric conditions. It is one of a class of drugs that has been linked to a child's delayed cognitive development and to some congenital malformations. But the latest study, published Tuesday in the Journal of the American Medical Association, appears to be the first to explore its link to autism.
Researchers tracked 665,615 Danish babies born between 1996 and 2006 for an average of eight years and looked at whether their mothers used valproate before they were pregnant or during pregnancy.
Though past use of valproate did not raise a child's risk of being diagnosed with autism spectrum disorder, its use by a woman during pregnancy resulted in an absolute risk of 4.42 percent that the child would receive such a diagnosis at some point in his or her early years. The absolute risk of having a childhood autism diagnosis — generally a more disabling condition — was 2.4 percent when the child's mother took valproate during pregnancy.
Among women who did not take the antiseizure drug, the likelihood of giving birth to a child who would receive an autism spectrum diagnosis was 2.44 percent, while 1.2 percent of such babies would have the more serious childhood autism diagnosis.
In an editorial published with the study, Dr. Kimford J. Meador and David W. Loring of Emory University warned that physicians should minimize the use of valproate in women of childbearing age and seek alternatives or use the lowest effective dose for those who must take antiseizure drugs.