ERUK study shows promising results for two antiepileptic drugs in pregnancy
An Epilepsy Research UK-funded study has shown that taking the antiepileptic drugs (AEDs) levetiracetam or topiramate during pregnancy may not have a negative impact on the baby’s IQ and thinking skills. The research, which also confirms the risks associated with valproate (another AED), is published in Neurology® online.
There is accumulating evidence that exposure to valproate before birth is linked to a significantly increased chance of birth defects, developmental problems and lower IQ, especially at higher dosages. However, valproate is an effective and widely-prescribed AED, so it is important to establish what the alternatives are for women with epilepsy during pregnancy (they need to be effective at controlling seizures and safe for the baby). Levetiracetam and topiramate are newer drugs, and to date few studies have looked at their effects on child development and thinking.
Lead Researcher, Dr Rebecca Bromley, at the University of Manchester, comments: “As doctors move away from prescribing valproate, we need to know about the alternatives for pregnant women with epilepsy. Lower IQs early on can harm a child’s educational success for years to come and so it is important that we gain a full understanding about any impact on development these medications may have.”
During the study, the researchers used data from the UK Epilepsy and Pregnancy Register to identify 171 women with epilepsy who had a child between the ages of five and nine years. Forty-two of the women had taken levetiracetam during pregnancy; 27 had taken topiramate; and 47 had taken valproate. A control group of 55 women who did not take AEDs during pregnancy was also included. The team carried out assessments of the children to measure their IQ, verbal and non-verbal comprehension, and the speed at which they could process visual information.
The results showed that the children of women who took levetiracetam or topiramate did not have reduced IQs, or other thinking skills, compared to the control group, regardless of the dosage of medication their mother took. Children whose mothers had taken valproate were found to have the lowest IQs; scoring an average of 11 points lower on the IQ test (which has an average of 100 points). Nine of the 47 children whose mothers took valproate (19%) were shown to be below the average range on the IQ score, compared to three of the 55 children whose mothers did not take any epilepsy drugs during pregnancy ((6%).
These findings are encouraging; however Dr Bromley adds a note of caution: “While our findings represent a promising start, larger studies need to be done ensure that these drugs will not change the thinking abilities of children.”
She notes that one limitation of the study is that the pregnancy registry represents only a small proportion of women with epilepsy, and that therefore the results may not be representative of all women with epilepsy. She also observes that topiramate has been associated with an increased risk of birth defects such as cleft lip and palate. Due to the fact that few children exposed to topiramate were included in the study, the results should be interpreted carefully.
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