Lead investigator, Dr. Nina Oyen, M.D., examined the I.Q. levels of sons born to mothers with and without epilepsy, and found an association between intelligence and the illness.
Relying on extensive data on maternal epilepsy reported to the Medical Birth Registry of Norway and adult I.Q. scores and anthropometric measures taken later in life, the study monitored male children until the age of nineteen, providing a long-term look at the possible effects of maternal epilepsy on foetal brain development.
The assessment showed that almost twenty years after birth, the sons of mothers who suffered from epilepsy before or during pregnancy displayed reduced I.Q. scores when compared to men whose mothers did not have epilepsy.
Dr. Oyen and colleagues also found that a history of maternal epilepsy was linked with shorter height as well.
"Our results underline the need for population-based registries with complete long-term follow-up of infants with prenatal exposure to phenobarbital and phenytoin, drugs that are still widely used in many countries," Oyen said.
She also drew attention to the need for studying the effects of exposure to newer medications. "It remains to be seen whether the newer antiepileptic drugs are safer to offspring exposed during fetal life," she said.
The study is published in Vol. 48 Issue 9 (September 2007) of Epilepsia.