Exposure to valproate in utero linked to low IQ

A recent study reporting a link between exposure to valproate in utero and impaired cognitive development provides further evidence that the drug should not be prescribed in pregnant women or women of child bearing age. The Neurodevelopmental Effects of Antiepileptic Drugs study found that the children of mothers who took valproate during pregnancy had significantly lower IQ scores than those exposed to other antiepileptics. At 3 years of age their mean IQ was 92, significantly lower than the mean scores of 101 for lamotrigine exposure (p = 0.009), 99 for phenytoin (p = 0.04), and 98 for carbamazepine (p = 0.04). Maternal IQ was strongly related to child IQ except for mothers who took sodium valproate during pregnancy, the authors reported. "Most major congenital malformations can be detected with the use of prenatal screening, and many can be successfully treated surgically after birth, but cognitive impairment cannot," a related editorial noted. Because of the risks associated with a loss of seizure control during pregnancy, changes from valproate to another antiepileptic drug should be made and evaluated before conception, the editorialist noted. “By the time a woman realizes that she is pregnant, switching drugs is unlikely to reduce the risk of birth defects.” “A reduced dose of valproate to below 800 mg/d may be an option, but only after careful assessment by the physician, given that the risks of uncontrolled seizures must be balanced against the risks of valproate use,” the editorial concluded. N Engl J Med 2009;360:1597-1605,1667-1669....