The bigger picture

According to the charity Epilepsy Action, high dose sodium valproate (above 1,000mg) is the anticonvulsant that most increases the risk of major congenital malformations such as spina bifida, hole in the heart and cleft palate. However, the risk is similar for women taking valproate plus any other AED, with high dose lamotrigine monotherapy, lower dose valproate and any anti-epilepsy combination that does not include valproate also posing a significantly higher risk. The risk of major congenital malformations with carbamazepine or lower dose lamotrigine is around the same as women with epilepsy who take no anticonvulsants at all, though clearly if a woman has a seizure while pregnant, she and her unborn child may be in danger.

The usual recommendation of 400mcg folic acid each day for women trying to conceive and during the first trimester of pregnancy is upped in women on epilepsy medication to 5mg per day during the entire time that there is any chance of conception and during the first three months of pregnancy. This is a prescription only dose and cannot be purchased over the counter.

It is worth noting that folic acid can alter the effectiveness of the anticonvulsants phenytoin, phenobarbital and primidone, which in turn increases the risk of seizures. All women with epilepsy who are thinking about having a baby should speak to a specialist medical professional so that a personal risk assessment can be conducted and options discussed.