Epilepsy medicines in pregnancy

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Although your baby has a very good chance of not having any birth problems, epilepsy medicines can sometimes cause some specific problems. These are:

  • Neurodevelopmental problems 
  • Minor congenital abnormalities
  • Major congenital abnormalities

Neurodevelopmental problems

Neurodevelopment describes how a child develops skills such as speaking, understanding and behaving. If you take sodium valproate (Epilim) during pregnancy, your child has a higher risk of neurodevelopmental problems than other children. Neurodevelopmental problems have been found to affect between 30 to 40 in 100 babies born to mothers who have been taking sodium valproate (Epilim) during pregnancy. Neurodevelopmental problems become more obvious over time, so you may not know about these problems until your child is a few years old.

Minor congenital abnormalities

Minor congenital abnormalities are birth problems that do not usually need any treatment. They include minor abnormalities of the fingers, toes or limbs. They also include specific facial features. Any woman can have a baby with minor congenital abnormalities, but taking epilepsy medicines means your baby may be at a slightly higher risk.

Major congenital abnormalities

Major congenital abnormalities are birth problems that need treatment, usually with surgery. They include things like spina bifida, a hole in the heart, or a cleft palate (where the roof of the mouth is not correctly joined).

In women who don’t have epilepsy, around 1 or 2 babies in every 100 will have a major congenital abnormality. In women who have epilepsy, but don’t take epilepsy medicines, around 2 babies in every 100 born will have a major congenital abnormality. If you take epilepsy medicines, your risks are higher, depending on which medication you take. See table below for approximate level of risk of major congenital abnormalities for women with epilepsy taking an AED. The highest risks are associated with sodium valproate (Epilim) - see our section here on minimising risks associated with Epilim.

The risk of epilepsy medicines causing your unborn baby to have a major congenital abnormality seems to be greatest during the first 3 months of pregnancy (data below from the Irish Epilepsy & Pregnancy Register).

If you take just one epilepsy medicine

If you take Sodium Valproate with another epilepsy medicine