Experts have warned that pregnant women or women planning to get pregnant who have epilepsy should not take the drug, sodium valproate, due to a reported risk of malformations and cognitive difficulties in children whose mothers take it.

The warning has come from Sinead Murphy, a registered nurse who runs a
specialist epilepsy clinic and from the Irish College of General Practitioners (ICGP).

The European Medicines Agency in 2014 advised doctors not to prescribe valproate for epilepsy or bipolar disorder in pregnant women, and in women who can become pregnant, unless other treatments are ineffective or not tolerated.

It said where this drug is considered the only option for these conditions, women should be advised on the use of effective contraception.

Ms Murphy, in an article in the ICGP journal, Forum, pointed to previous research which linked valproate use with an increased risk of congenital malformations in babies born to mothers with epilepsy

She said the rate of malformations appears to be related to the dose of drug taken in pregnancy. In addition, Ms Murphy said there have been reports of cognitive difficulties in children born to mothers who took valproate during their pregnancy.

She reported on a 34-year old pregnant woman who attended her epilepsy clinic who had been taking valproate for her epilepsy for many years. The patient said her three children all had a variety of developmental delays and was told that valproate was known to increase the risk of developmental delay.

The patient said this was the first time she had heard about these risks. The woman was switched to another epilepsy medication, which is regarded as a safer one for women with epilepsy planning a family.

According to the ICGP, recent studies have shown a risk of developmental problems of up to 30-40% in pre-school children exposed to valproate in the womb.

In addition, data shows that children exposed to valproate in the womb are at an approximately 11% risk of major malformations at birth compared to 2-3% risk for children of the general population, it noted.

The European directive states that valproate should not be used to treat epilepsy or bipolar disorders in women who are pregnant or can become pregnant unless other treatments are ineffective or not tolerated. Women for whom valproate is the only option should use effective contraception.

Doctors who prescribe valproate, including doctors who issue repeat scripts for women who are already on valproate, should provide full information to their patients about these new study findings to ensure they have full understanding of the risks.

Ms Murphy advised that women with epilepsy of childbearing age should ideally be on a single tolerated anti-epileptic drug at the lowest effective dose to control seizures.

She said that valproate should generally be avoided where possible among any women with childbearing potential.

In a recent statement on this issue, the ICGP said that GPs should seek to review all women in their practice being prescribed valproate, to inform them of the risks associated with pregnancy, to offer adequate contraception, and to refer them to a specialist clinic to discuss their options if they are considering a pregnancy.

According to Ms Murphy, pre-conceptual counselling is key for women with epilepsy and contraception education is a must.

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