The drug valproate is already at the center of a British court action after claims from nearly 140 British families that it has harmed children, many of whom are suffering from fetal anti-convulsant syndrome.
The children born with this syndrome tend to suffer from neural, behavioral and physical disorders such as cleft palate and spina bifida, learning difficulties, behavioral problems and abnormalities in movement, speech, vision and hearing.
According to the Guardian, most of the mothers involved in the study were prescribed the brand Epilim, made by Sanofi-Synthelabo, the only company involved in the court action, with a trial date set for October 2008.
The study report, presented Wednesday at the annual meeting of the American Academy of Neurology in Boston, was the latest to document the potential dangers of valproate to the unborn.
Kimford Meador, of the University of Florida in Gainesville, tracked the IQ results of 187 children born to mothers who had taken the epilepsy drugs carbamazepine, lamotrigine, phenytoin, or valproate during pregnancy.
It was found that nearly 24 percent of the children of mothers who took valproate had an IQ low enough to be defined as mentally retarded, compared to 12 percent for carbamazepine, 9 percent for lamotrigine, and 12 percent for phenytoin.
"Our findings are consistent with other studies, which have shown valproate poses an increased risk for fetal death and birth defects," said Dr. Meador.
Experts have now urged doctors to inform their patients about the risks associated with valproate as the drug is not recommended for use for women of child bearing potential. It was also noted that the women with epilepsy should consult their doctors before conceiving and if the drug is to be given, its dosage should be limited.
