In utero sodium valproate exposure linked to higher risk of autism.(News)

Exposure to sodium valproate early in pregnancy may increase a child's risk for developing an autism spectrum disorder, judging by preliminary results from an ongoing study on the effects of in utero exposure to antiepileptic drugs.

In the study, those children exposed to valproate early in pregnancy were at a sevenfold greater risk of developing autism spectrum disorder (ASD), compared with children whose mothers did not have epilepsy, reported investigators from the Liverpool and Manchester Neurodevelopment Study Group, England (Neurology 2008; 71: 1923-4).

"The potential risk for autism in this study was substantial for children whose mothers took valproate while pregnant, but more research needs to be done since these are early findings," one of the authors, Gus Baker, Ph.D., of the University of Liverpool (England) said in a statement issued by the American Academy of Neurology, which publishes Neurology. "However, women who take valproate while pregnant should be informed of the possible risks of autism and are encouraged to discuss them with their doctor[s]. Those who are taking valproate should not stop their treatment without speaking to their doctor[s] first."

The study enrolled 620 women in Liverpool and Manchester between 2000 and 2006 and has collected information on 632 live births. Of these births, 296 of the babies were born to women with epilepsy, including 249 who were taking antiepileptic drugs (AEDs) at the beginning of their pregnancies (64 were exposed to valproate, 44 to lamotrigine, 76 to carbamazepine, 14 to other monotherapy treatments, and 51 to poly-therapy). The remaining 47 babies were born to mothers with epilepsy who were not taking medication.

Neuropsychological tests were done at ages 1, 3, and 6 years; at the end of the study, most--68%--of the children were aged 6 years and older, about 4% were under age 3 years and about 28% were aged 4-5 years).

Of the 632 children, 9 met the DSM-IV criteria for autism spectrum disorders, the authors reported. Another child with a lack of attention, social difficulties, and other ASD features was included in the analyses as a case of ASD. ...