Wednesday, June 18, 2008

For women with epilepsy--get the facts straight before you worry

Here's an interesting abstract. I post it partly for the important medical information it provides but also to comment on the interesting editorial twist that may affect how readers interpret the information.

The subjects: women with epilepsy and the children they bore.
The question: whether epilepsy affects the development of those children. (As quoted by the authors of the study, "We aimed to ascertain the prevalence of cardiac malformation (CM) and its association with antenatal exposure to an antiepileptic drug (AED) in infants of mothers with epilepsy.")

At 3 months of age, 462 babies born to mothers with epilepsy were examined by a cardiologist to see if they had at least one of several heart defects: atrial septal defect, tetrology of Fallot, patent ductus arteriosus, pulmonic stenosis, ventricular septal defect, tricuspid regurgitation, and transposition of great arteries. Possible correlations between the existence of these defects and any of the following were evaluated: mother's epilepsy history, use of antiepileptic medications in the first trimester of pregnancy, mother's age, seizure frequency during pregnancy, and folate supplementation.

There were a few significant relationships. Prematurely born children were more likely to have heart defects. Use of more than one medication was also a significant contributing factor. And there was a trend, though not significant, for children whose mothers who had used valproic acid (Depakote) to have heart defects. No relationships to mother's age, epilepsy history, seizure frequency, or folate usage were noted.

So even though there were only three identified contributing factors, two of which involved antiepileptic medications, the authors were allowed to title their publication in a way that somewhat masked this relationship. It also, for someone skimming research abstracts, could lead to an impression that epilepsy itself, and not the way in which epilepsy is treated, is the problem.

I am a diligent scientist and try to get the facts straight before I put anything on this blog, or in anything I write. But anyone reading this blog knows that all you have to do is turn on the evening news and see how vague headlines become top news stories and "facts" are generated without any meat behind them.

It's simply not fair to generalize to all mothers with epilepsy. There were an awful lot of babies in this study who did not have heart defects, 426 to be exact. That's a lot of unnecessary fear to be putting out there for women with epilepsy. Of course, the take home message is that women of childbearing age may not be the most appropriate candidates for valproic acid, but somehow that got lost in the analysis.

Thomas SV, Ajaykumar B, Sindhu K, Francis E, Namboodiri N, Sivasankaran S, Tharakan JA, Sarma PS. Cardiac malformations are increased in infants of mothers with epilepsy. Pediatr Cardiol. 2008 May;29(3):604-8.

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