Are there risks to my baby

Most women with epilepsy will have a normal pregnancy and labour. However, women with epilepsy have a slightly higher chance of having a baby with a birth abnormality due to genetic conditions, injury during seizures and anti-seizure medications (ASMs). Talk to your neurologist about how you can reduce the risk to your unborn baby.

Physical birth abnormalities

For any woman there is a small (‘background’) risk that her baby may be born with a birth abnormality or malformation. Physical birth abnormalities are problems that happen when the development of a baby is affected while it is in the womb. There are different types of birth abnormality, which can affect different organs in the body, and can happen for different reasons. Birth abnormalities can be classed as ‘minor’ and ‘major’.

Minor malformations are those that do not need surgery, for example small fingers and toes, and eyes set wide apart.

Major malformations are those that need surgery to correct them. These include a hole in the heart, problems with the kidneys or genitals, cleft lip, and cleft palate (where the roof of the mouth is not correctly joined). They also include problems with the development of the spine and nervous system (neural tube defects), such as spina bifida (where part of the spinal cord is exposed). 

Sometimes the child’s arms or legs, or the way their face looks, may also be affected.

If you are pregnant, avoiding the following will all help reduce the risk of birth abnormalities: alcohol, smoking, unprescribed medication, and illegal drugs. This is because all these substances can be passed through your bloodstream to your baby and so may affect your baby’s development. 

Women with epilepsy have a higher chance of having a baby with a birth abnormality than women who don’t have epilepsy. This may be due to an underlying genetic condition which also caused the epilepsy. 
Or risks can be due to injury to your unborn baby if you have seizures during pregnancy, or from taking some types of ASM.

Can ASM affect an unborn baby? 

For a woman with epilepsy who takes ASM during pregnancy, her baby will be exposed to ASM in the womb. While she is pregnant, a mother’s bloodstream is kept separate from her unborn baby’s. However, some substances can pass from her blood into her baby’s blood via the placenta. These substances include nutrients, oxygen, alcohol, and medication including ASM. 

Some ASMs can affect how the baby grows and develops inside the womb, particularly in the first 12 weeks of pregnancy when the  main organs and skeleton are developing.

ASMs and birth abnormalities

Different ASMs vary in the risk they pose, and the risk of birth abnormalities rises with higher doses of the drug, and if you already have a child with a birth abnormality. Taking more than one ASM increases the risks, especially if this includes sodium valproate (see below).

• 2 – 3 women in every 100 (2 – 3%) in the general population will have a baby with a major malformation (the 'background risk').
• 3 women in every 100 (3%) who have epilepsy and don’t take ASMs will have a baby with a major malformation.
• 4 – 10 women in every 100 (4 – 10%) who have epilepsy and do take an ASM will have a baby with a major malformation.
• Recent studies carried out by the Commission on Human Medicines (CHM), looking at the risks associated with commonly prescribed ASMs shows that lamotrigine (Lamictal) and levetiracetam (Keppra) are safer to use during pregnancy than other ASMs, having low rates of physical birth abnormalities, in line with the background risk (2 - 3%). Again, for each drug the risks increase with higher doses. The Medicines and Healthcare Products Regulatory Agency (MHRA) has produced more guidance on the risks for ASMs in pregnancy. A further study into Pregabalin was published in April 2022.

Sodium valproate – an important case

Sodium valproate (brand names include Epilim, Episenta, Epival and Dyzantil) has greater risks in pregnancy than other ASMs, with 7 women in 100 (7%) having a baby with a major abnormality, rising to 1 in 10 women (10%) if they take more than 1000mg (1g) per day.

Also, up to 4 children in 10 (up to 40%) whose mothers took sodium valproate have problems with development and learning.

There is also evolving information about potential risks in men.

The (MHRA) states that sodium valproate should not be prescribed to anyone under the age of 55, unless it is the only effective drug for them, and if they are a woman, they are on a pregnancy prevention programme (see below). They also recommend that treatment with sodium valproate should only be started by a doctor experienced in managing epilepsy. 

Sodium valproate is an effective drug for epilepsy and, for some people, it is the best or only drug that controls their seizures. 

Whichever ASM you are taking, do not suddenly stop taking it, but talk to your doctor or epilepsy specialist nurse (ESN) about any specific risks, and the best options, for you individually.

Pregnancy prevention programme (PPP)

Current MHRA advice states that sodium valproate must not be prescribed for any woman or girl under the age of 55, unless she has a pregnancy prevention programme (PPP sometimes called PREVENT) in place.

• Your specialist will discuss the risks of taking sodium valproate with you, and whether or not you are planning to become pregnant. This will help to decide if the PPP is right for you.
• They will explain the risks to an unborn child if the mother takes sodium valproate during pregnancy. (See above for risks of taking sodium valproate during pregnancy).
• Before you start to take sodium valproate, you will need to have pregnancy tests. 
• Your specialist will explain the options for highly effective contraception.
• Your specialist will carry out reviews of your treatment at least annually. You and your specialist will complete an annual risk acknowledgement form at each review. This confirms that you have been given appropriate advice, which you have understood.

Fetal anti-convulsant syndrome

Some ASMs are thought to affect a child’s development after they are born. This is called Fetal anti-convulsant syndrome (FACS). The risk of this happening appears to be higher with sodium valproate than with other ASMs. 

Problems with the child's development and learning can include: delayed walking and talking, poor speech and language, and problems with memory, attention, lower intelligence and behaviour. Often these effects are not seen until the child starts to get older, for example when they start nursery or school. 

Children exposed to sodium valproate in the womb may also be more likely to have on the autism spectrum. There are organisations which provide information and support to families affected by Fetal anti-convulsant syndrome:

FACS Association
INFACT
OACS

What do these risks mean for me

Most women with epilepsy have over a 90% chance of having a healthy baby. Any individual risks for you will depend on many factors, including your type of epilepsy, the ASMs and dose you take, and any other medical conditions.  

If you stop taking your ASMs, your seizures may increase, or become more severe. Seizures may cause more harm for you and your baby than any risks associated with the ASMs themselves.

You and your specialist can discuss any specific risks, and the best options, for you individually.

Further information

National Institute for Health and Care Excellence.
nice.org.uk/guidance/ng217 
Guidance on the diagnosis and treatment of epilepsy.

Epilepsy Society is grateful to Dr F J Rugg-Gunn, Consultant Neurologist & Honorary Associate Professor Clinical Lead, Chalfont Centre for Epilepsy, who reviewed this information.

Information updated: September 2023