Press reports of association between valproate use during pregnancy and children with lower IQ
There have been several reports in the press that women who take valproate during pregnancy are at a greater risk of having children with a lower IQ (The Guardian and NetDoctor, 4th May 2007).
These reports are based on research presented at the American Academy of Neurology's annual meeting. Investigators looked at IQ results of 187 children born to mothers who had taken carbamazepine, lamotrigine, phenytoin, or valproate during pregnancy. A total of 24% of the children of mothers who took valproate had an IQ low enough to be defined as mentally retarded, compared to 12% for carbamazepine, 9% for lamotrigine, and 12% for phenytoin. The average IQ scores were 84, 93, 96 and 93, respectively. No further details of the study, including potential confounders and details of the use of other medications, were presented in the articles.
The lead researcher commented that "valproate should not be used as the drug of first choice for women of child bearing potential, and when used, its dosage should be limited if possible." A representative of the British Epilepsy Association, Ms Burns, agreed that women with epilepsy should be counselled before embarking on a pregnancy, but said that "we believe there should be a balance struck between the potential effects of seizures on the developing brain of foetuses and the effects of valproate. While this is very concerning, it has to be said that valproate is a highly effective anti-epileptic drug…..what we don't want is to scare people to stop people taking this drug suddenly because that can result in seizures and, potentially, deaths."
[Editor's comment: this report appears to relate to an ongoing prospective study called NEAD (Neurodevelopmental Effects of Antiepileptic Drugs), having the same lead researcher. Data from this study was also presented at another conference in December 2006 - this only included 166 children, of whom 28 were born to mothers taking valproate.]
The Guardian's report is available here; and the NetDoctor report here;
there is information from the December 2006 presentation on Medscape (free registration required)
and there is a NEAD website giving much more information about the study