Epileptic mothers in the dark about pregnancy risk?

By Sally Robertson, B.Sc.Oct 30 2014

A new study has highlighted the need for more research into the safety of using anti-epileptic drugs during pregnancy.

The authors of the study say evidence on the safety of these drugs is currently limited and women need to be better informed when facing treatment decisions if they become pregnant.

Many women with epilepsy currently rely on these drugs to prevent seizures during pregnancy, yet increasing evidence suggests they may pose a risk to a baby’s development in the womb.

For the study, the researchers analysed data drawn from 28 studies and examined children’s cognitive ability across three groups of women – those who took an anti-epileptic during pregnancy, those who took no such medication and women without epilepsy. Cognitive ability was assessed using the intelligence quotient (IQ) for school-aged children and the development quotient (DQ) for younger children.

The findings, published in The Cochrane Library, showed that children born to women who took sodium valproate during pregnancy displayed lower IQ and DQ scores than children born to women from the other groups. The observed effects on cognitive ability were dose-dependent, with higher doses of valproate linked to more significant drops in cognitive scores. Carbamazepine, on the other hand, showed no significant between-group differences in its effect on IQ or DQ.

When the effects on cognitive ability were compared for different drugs, lower IQs were observed among children exposed to valproate than among those exposed to carbamazepine, lamotrigine or phenytoin. However, no differences in IQ were observed between the children exposed to carbamazepine, lamotrigine or phenytoin.

The study also revealed a lack of available data for all of the anti-epileptic drugs currently in use today, with the data on newer anti-epileptic drugs being particularly scarce.

"This makes it difficult for women and their doctors to know which medications are safe to use during childbearing years,” says lead author Rebecca Bromley (Institute of Human Development, University of Manchester, UK).

Future research needs to be carried out in a timelier manner to ensure that when prescribing decisions are being made, the risks are already established.

However, Bromley adds that women should not stop taking or alter their medication without consulting their doctor first.