Always get medical advice before making any changes to your epilepsy medicine.
Although your baby has a very good chance of not having any birth problems, epilepsy medicines can sometimes cause some specific problems. These are:
• Minor congenital abnormalities
• Major congenital abnormalities
• Neurodevelopmental problems
These are explained below.
What are minor congenital abnormalities?
Minor congenital abnormalities are birth problems that don’t 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 risk is higher.
What are major congenital abnormalities?
Major congenital abnormalities are birth problems that usually need treating. 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.
UK Epilepsy and Pregnancy Register
The UK Epilepsy and Pregnancy Register was set up to find out more about having epilepsy and taking epilepsy medicines during pregnancy.
The information in the table below is from the register’s findings between 1996 and 2012. It doesn’t have information about every epilepsy medicine available because, at the moment, there isn’t enough information available.
The risk of epilepsy medicines causing your unborn baby to have a major congenital abnormality seems to be greatest during the first 3months of pregnancy.
If you take just one epilepsy medicine
2 to 3 in 100
2 to 3 in100
2 - 3
2 in 100
sodium valproate (see note)
below 1,000 mg
6 in 100
sodium valproate (see note)
above 1,000 mg
10 in 100
4 - 5 in 100
4 - 5
If you take more than one epilepsy medicine
Epilepsy medicine combination
sodium valproate with any other epilepsy medicine
9 in 100
any combination without sodium valproate
4 in 100
What are neurodevelopmental problems?
Neurodevelopment describes how a child develops skills such as speaking, understanding and behaving. If you take sodium valproate 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 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.
Sodium valproate is associated with an increased risk of harm to babies if taken during pregnancy. If you are a woman capable of becoming pregnant, sodium valproate should only be prescribed if no other epilepsy medicine suits you.
If you are pregnant or planning a pregnancy and you take sodium valproate, seek advice from your doctor and do not stop taking your medication.
If you would like to see this information with references, visit the Advice and Information references section of our website. If you are unable to access the internet, please contact our Epilepsy Action Helpline freephone on 0808 800 5050.
Epilepsy Action would like to thank Beth Irwin, epilepsy nurse/midwife, The Royal Hospital, Belfast, for her contribution to this information.
Beth Irwin has no conflict of interest to declare.
This information has been produced under the terms of Epilepsy Action's information quality standards.
- Updated March 2016To be reviewed March 2019