Women who took valproate during pregnancy had children with lower IQ scores than those who used a different antiseizure medication, according to scientists at Emory University.
Valproate, available generically or under the brand name Depakote, is the second-most-popular drug for the treatment of epilepsy.
Earlier studies had shown it to cause developmental delays and malformations in the offspring of pregnant women.
To reach these conclusions, Kimford Meador and colleagues recruited 303 pregnant women that took drugs to control epilepsy from 25 medical centers in the US and the UK between 1999 and 2004.
They performed cognitive assessments on 258 2- and 3-year-olds born to these mothers, 53 of which had taken valproate.
They found that kids whose moms had taken valproate while pregnant had a mean IQ of 92. Kids that had been exposed to lamotrigine, phenytoin and carbamazepine in utero had mean IQs of 101, 99 and 98, respectively.
Overall, there was a strong correlation between the IQs of kids and their mothers, but this relation was not present in the offspring of mothers taking valproate.
The write-up appears in the New England Journal of Medicine.
Valproate is also widely prescribed for migraines, pain and psychiatric disorders although people taking the drug for these indications were not enrolled in the study.
The study authors warned against using valproate as first-line therapy for seizure control in women of childbearing age.
“If I (use another drug) and the patient has a breakthrough seizures, I can switch the patient to valproate,” said Meador reasoned for the New York Times. But “If I put the patient on valproate as a first choice and the baby has cognitive impairment or a malformation, I can’t repair that.”