pregnancy and epilepsy

Epilepsy drug exposure in womb linked to significantly poorer school test results

Epilepsy research conducted by Arron Lacey at Swansea University Medical School found exposure to epilepsy drugs in the womb is linked to significantly poorer school test results among seven year olds.

Arron is part of the Prudent Healthcare Research Team and the Swansea Neurology Research Group that includes SAIL analysts, clinicians and academics. They conduct research using the SAIL Databank as well as analysing unstructured text in medical records. Having already published several population based studies exploring the effects of epilepsy on social deprivation, the effects of epilepsy drugs, as well as prescribing trends in epilepsy, they are using natural language processing (NLP) to extract clinical data from clinic letters for epilepsy research.

As part of a study published online in the BMJ Journal of Neurology, Neurosurgery and Psychiatry, the team studied mothers that had epilepsy, recorded the type of epilepsy drug that they were prescribed during pregnancy and analysed their children’s school test results, comparing them with a matched control group.

The study

Several previous studies have shown that epilepsy drugs, particularly sodium valproate, when taken during pregnancy, are associated with neurodevelopmental disorders, but few of these studies have been based on population data.

Arron and the team used routinely collected healthcare information from SAIL Databank and national school test data at Key Stage 1 to compare the academic performance of seven year olds in Wales born to mothers with epilepsy to the matched control group.

Prescription patterns were divided into five categories: treatment with one drug (carbamazepine, lamotrigine or sodium valproate); a combination of epilepsy drugs; and no drug treatment.

Research findings

The results showed that children born to mums prescribed sodium valproate during their pregnancy performed 10.5 to just under 13 per cent less well on all Key Stage 1 tests than those in the control group.

Children born to mums who had been prescribed epilepsy drugs in combination achieved worse results still, where scores were 19­–22 percent lower than the control group.

Children born to mums who had been prescribed carbamazepine or lamotrigine, or nothing, performed just as well as those born to mums in the control group.

The research team acknowledge that they weren’t able to account for certain potentially influential factors, such as the mothers’ IQ, weight or alcohol consumption; the doses of epilepsy drugs prescribed; or intake of folic acid around conception.

SAIL epilepsy research Arron Lacey

Co-author and clinical neurologist Dr Owen Pickrell suggested it’s possible that the mum’s epilepsy severity may affect their child’s school performance.

“This might be due to a more severe underlying brain pathology, which is partly genetic and may be passed on to the child.”

Dr Pickrell also pointed out that it’s generally women with more severe epilepsy who are receiving polytherapy during pregnancy.

Key outcomes

Arron states in the research paper:

“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 who need drugs to control their seizures are currently advised to continue taking them during pregnancy because convulsions can harm both mother and unborn child.”

“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.”

In a linked commentary, Dr Richard Chin of the University of Edinburgh’s Muir Maxwell Epilepsy Centre, emphasises the importance of a study that is based on population data as this can be used to inform preventive/interventional strategies and help women to 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.”