A recent study showed that women who took sodium valproate during pregnancy were six times more likely to have children with neurological or developmental disorders, especially autism.
If the women took sodium valproate and other epilepsy medications while pregnant, their children were ten times more likely to have a neurodevelopmental disorder.
The researchers concluded that women should be informed of this increased autism risk for their child if they might take sodium valproate while pregnant.
"Discuss medications during pregnancy with your OB or midwife."
The study, led by Rebecca Louise Bromley, of the Department of Molecular and Clinical Pharmacology at the University of Liverpool in the United Kingdom, looked at the rate of neurodevelopmental disorders among children who were exposed to anti-epilectic medications.
Neurodevelopmental disorders are those that involve the nervous system, the brain and a child's overall development, such as autism spectrum disorder. Anti-epileptic medications are those given to people to control seizures, epilepsy or some psychiatric conditions, such as bipolar disorder.
The researchers followed 415 children from birth until they were 6 years old. About half the children's mothers did not take any anti-epileptic medications.
The mothers of the other half had epilepsy, and most were taking at least one of several anti-epileptic drugs to treat it while they were pregnant.
Among the mothers who had epilepsy, 70 were taking a medication with sodium valproate (the main active ingredient in Depakote), 50 were taking carbamazepine (Tegretol), and 30 were taking lamotrigine (Lamictal).
The researchers assessed the children's physical and intellectual development when the children were 1, 3 and 6 years old. A total of 19 children were diagnosed with a neurodevelopmental disorder, and 12 of these were autism spectrum disorder.
The researchers found that a higher percentage of children whose mothers took sodium valproate had neurodevelopmental disorders than the children of the other mothers, whether the other mothers took another anti-epileptic medication or not.
Of the 50 women taking only sodium valproate, 6 of them had children with a neurodevelopmental disorder, for a rate of 12 percent. Among the 20 women taking multiple drugs that included sodium valproate, 3 of their children (15 percent) had a disorder.
Meanwhile, only one of the mothers taking carbamazepine (2 percent), two of the mothers taking lamotrigine (6.7 percent) and four of the 214 mothers not taking anti-epileptics (1.9 percent) had children with neurodevelopmental disorders.
The most common neurodevelopmental disorder diagnosed in the children of women who took sodium valproate was autism spectrum disorder.
The researchers noted that past research has also found evidence for a link between sodium valproate and neurodevelopmental disorders. They recommended that women who might take sodium valproate for any reason during pregnancy be made aware of its link to autism and related disorders.
The study was published January 31 in the The Journal of Neurology, Neurosurgery and Psychiatry. The research was funded by Epilepsy Research UK, Sanofi Aventis pharmaceutical company and indirectly by the National Institutes of Health.
Five authors had financial links to pharmaceutical companies in the form of receiving travel funds, speaking fees, grant money or honoraria. Four authors have previously testified in court regarding the effects of anti-epileptic drugs during pregnancy on children.