By Jean Balchin 29/03/2018

According to a study published recently in the Journal of Neurology Neurosurgery & Psychiatry, exposure to epilepsy drugs in the womb is linked to significantly poorer school test results among 7 year olds. Evidently, prospective mothers need to be fully informed of the risks of treatment. However these risks need to be weighed against the need for effective seizure control during pregnancy.

Currently, women with epilepsy who need drugs to control their seizures are advised to continue taking them during pregnancy, as convulsions can harm both mother and the unborn child. While several studies have indicated a link between epilepsy drugs, particularly sodium valproate, taken during pregnanchy and neurodevelopmental disorders, few of these studies have been based on real life circumstances (ie population data).

Thus to address this, the researchers employed routinely collected healthcare information from the Secure Anonymous Information Linkage (SAIL) databank and national school test (key stage 1) data in order to compare the academic performance of 7 year olds in Wales born to mothers with epilepsy.

The SAIL databank comprises the anonymised primary care health records of 80 percent of Welsh family doctors, roughly about 77 percent of the Welsh population (2.3 million people). In the Key Stage 1 test, 7 year old children have their maths, language (English & Welsh), and science skills tested, and are scored from levels 1 to 3. The researchers were granted access to 440 children’s test results, whose mothers had been diagnosed with epilepsy before their pregnancy for 2003 through to 2008.

The mother’s prescription patterns were divided into five categories:

  1. Treatment with one drug – carbamazepine,
  2. Lamotrigine
  3. Or sodium valproate
  4. A combination of several drugs
  5. And no drug treatment.

Twenty (54%) of the 39 mums prescribed several drugs were taking sodium valproate, but there were 15 different drug combinations in all.

The test results indicated that children born to mothers who had been taking carbamazepine or lamotrigine, or nothing, performed just as well as those born to mums of the same age and deprivation level, but without epilepsy (comparison group).

However, children whose mothers had been prescribed sodium valproate during their pregnancy performed 10.5 to just under 13 per cent less well on all KSI tests than those in the comparison group. Moreover, children whose mothers had been prescribed a cocktail of epilepsy drugs achieved even worse results still, with scores being 19-22 percent lower.

When the researchers excluded children with epilepsy and mothers who smoked during the analysis, the results did not materially change. However, researchers were not able to account for various potentially influential factors, such as the doses of the epilepsy drugs prescribed, the mother’s IQ, weight and alcohol consumption and intake of folic acid around conception. Nevertheless, this study’s findings do echo those of other independent studies, and should be considered very carefully.

According to the researchers: “While this study highlights the risk of cognitive effects in the children of mothers prescribed sodium valproate or multiple [anti-epilepsy drugs], it is important to acknowledge that some epilepsies are difficult to treat without these treatment regimens.”

“Women with epilepsy should be informed of this risk and alternative treatment regimens should be discussed before their pregnancy with a physician that specialises in epilepsy.”

According to Dr Richard Chin of the University of Edinburgh’s Muir Maxwell Epilepsy Centre, because this study is based on population data, it can be used to inform preventive and interventional strategies, as well as helping women better understand the implications of epilepsy treatment while pregnant.

“By providing ‘functional’ outcome data from their study, the authors have now provided information that prospective parents may find readily tangible: it should be included in information given to women with epilepsy prior to pregnancy,” he said.

You can read this study here.