Epilepsy medicines and pregnancy

Most women with epilepsy have healthy pregnancies and give birth to healthy babies. But, some epilepsy medicines can be harmful if taken during pregnancy.

It’s important to be aware of the risks for your medicine, and to get advice from your healthcare team about your options as early as possible.

Will taking epilepsy medicines affect my unborn baby?

Taking certain epilepsy medicines during pregnancy increases the risk of your baby being born with a with a physical birth defect. Some epilepsy medicines can also harm the baby’s growth or development. The highest risk is thought to be between weeks 1 and 13 of your pregnancy.

Some epilepsy medicines have a higher risk of harming a baby during pregnancy than others. Taking a higher dose or more than one epilepsy medicine at the same time may also increase the risk of harm. For information about the risk of individual medicines, see our list below.

Most women with epilepsy have healthy pregnancies and give birth to healthy babies. But, it is important that you get the right information and support about which medicines to take.

What effects can taking epilepsy medicine during pregnancy cause?

Research into epilepsy medicines in pregnancy has focused on 3 areas: birth defects, effects on learning and thinking ability and growth in the womb.

 

Birth defects

These are problems that happen when the baby doesn’t develop properly in the womb. They include:

  • Spina bifida (where the bones of the spine do no develop properly)
  • The face or skull not forming properly (including cleft lip and palate, where the upper lip or facial bones are split)
  • Problems with the formation of the limbs, heart, kidney, urinary tract and sexual organs

 

Effects on learning and thinking ability

Some medicines may affect a child’s learning and development. Possible effects include:

  • Walking and talking later than other children of the same age
  • Poor speech and language skills
  • Memory problems
  • Lower intelligence than other children of the same age
  • Autism spectrum disorder or attention deficit hyperactivity disorder (ADHD)

 

Growth in the womb

Some medicines increase the risk of a baby being born smaller than expected.

Which epilepsy medicine should I take?

This depends on the type of epilepsy and seizures you have, as well as your age.

To have the best chance of having a healthy pregnancy, medical professionals advise you have pre-conception counselling before you become pregnant. Having pre-conception counselling before you start trying for a baby gives you the time to make changes to your epilepsy medicines, should you need to. It also gives you time to have your questions answered by a doctor or nurse who knows about pregnancy and epilepsy. Being more informed about epilepsy and epilepsy medicines means you are better prepared for pregnancy and making decisions about your treatment.

If you are already pregnant, don’t stop taking your epilepsy medicine. This could cause you to have more seizures or seizures that are more severe. This could be harmful for you and your baby. Instead, speak to your GP urgently, so they can get you the help and advice you need.

For some women, a medicine that may be less safe for their baby is still the best at controlling their seizures. If this is the case for you, you and your doctor will need to balance the benefit of controlling your seizures against the risk of harm to your baby from the medicine.

What are the risks for different epilepsy medicines?

In 2021 the Medicines and Healthcare products Regulatory Agency (MHRA) published a report about the safety of epilepsy medicines during pregnancy. This looked at all the available safety data. We explain the main findings below for the medicines that are most often prescribed in the UK. We have used the generic name and the most common brand name for each one. To see more brand names, visit our webpage epilepsy medicines available in the UK.

We updated this page in 2022 with new information about pregabalin and cenobamate.

We have updated this page in June 2024 with new information about topiramate.

  • Carbamazepine (brand name Tegretol)

    Carbamazepine use during pregnancy increases the risk of physical birth defects. If 100 women take carbamazepine during their pregnancy, 4 to 5 of the babies will be born with physical birth defects. This compares with 2 to 3 out of 100 in the general population.

    The available information does not suggest an increased risk of learning and thinking difficulties in children whose mothers took carbamazepine during pregnancy.

    It is not possible to confirm or rule out whether carbamazepine affects the growth of the baby in the womb. This is because the available evidence is inconsistent.

  • Clobazam (brand name Frisium)

    Some research suggests that clobazam may slightly increase the risk of a baby being born with physical birth defects.

    However, the research that is available does not allow firm conclusions to be reached. So, the risk of harming a baby cannot be confirmed or ruled out.

  • Gabapentin (brand name Neurontin)

    The risks of taking gabapentin during pregnancy are not yet fully understood. The MHRA was not able to make any firm conclusions about its safety in pregnancy.

  • Lamotrigine (brand name Lamictal)

    Lamotrigine is one of the safer medicines to use during pregnancy. Research suggests that it does not increase the risk of physical birth defects compared with the general population.

    There is less information about whether taking lamotrigine in pregnancy causes learning or thinking difficulties in children. The limited information available does not suggest an increased risk compared to the general population, but the possibility of an increased risk cannot be ruled out.

    Information suggests that using lamotrigine during pregnancy does not affect a baby’s growth in the womb.

  • Levetiracetam (brand name Keppra)

    Levetiracetam is one of the safer medicines to use during pregnancy. Research suggests that it does not increase the risk of physical birth defects compared with the general population.

    There is less information about whether taking levetiracetam in pregnancy causes learning or thinking difficulties in children. The limited information available does not suggest an increased risk compared to the general population, but the possibility of an increased risk cannot be ruled out.

    Information suggests that using levetiracetam during pregnancy does not affect a baby’s growth in the womb.

  • Oxcarbazepine (brand name Trileptal)

    There is only limited information about the risk of birth defects with this medicine. This means an increased risk of birth defects cannot be ruled out.

    The MHRA was also not able to make any firm conclusions about whether this medicine may increase the risk of learning and thinking difficulties, or affect growth in the womb.

  • Phenobarbital

    Phenobarbital use during pregnancy increases the risk of physical birth defects. If 100 women take phenobarbital during their pregnancy, 6 to 7 of the babies will be born with physical birth defects. This compares with 2 to 3 out of 100 in the general population.

    Phenobarbital taken during pregnancy also increases the risk the child may have difficulties with learning and thinking ability. Although the exact risk is not known, it is not as high as for valproate, which causes difficulties in 30 to 40 out of 100 children.

    Taking this medicine during pregnancy also increases the risk of the baby being born smaller than expected compared with the general population.

  • Phenytoin (brand name Epanutin)

    Phenytoin use during pregnancy increases the risk of physical birth defects. If 100 women take phenytoin during their pregnancy, 6 of the babies will be born with physical birth defects. This compares with 2 to 3 out of 100 in the general population.

    Phenytoin taken during pregnancy also increases the risk the child may have difficulties with learning and thinking ability. Although the exact risk is not known, it is not as high as for valproate, which causes difficulties in 30 to 40 out of 100 children.

    It is not possible to confirm or rule out whether phenytoin affects the growth of the baby in the womb. This is because the available evidence is inconsistent.

  • Pregabalin (brand name Lyrica)

    In April 2022 the MHRA published a drug safety update for pregabalin. A study of more than 2,700 pregnancies suggests that taking pregabalin during pregnancy may slightly increase the risk of a baby being born with birth defects.

    The MHRA says that people should use effective contraception when taking pregabalin, and avoid taking it during pregnancy unless the benefits outweigh the risks.

  • Topiramate (brand name Topamax)

    The MHRA introduced new rules in June 2024 about taking topiramate. This is after an evidence review of the risks of taking topiramate in pregnancy for an unborn baby.

    The rules have been introduced to make sure more people understand the risks of taking topiramate in pregnancy.

    You can find out more on our page about topiramate and risks in pregnancy.

  • Valproate (sodium valproate, brand name Epilim)

    Medicines containing valproate (sodium valproate and valproic acid) can seriously harm the unborn baby if taken during pregnancy. If 100 women take valproate medicines during their pregnancy, about 10 of the babies will be born with physical birth defects. This compares with 2 to 3 out of 100 in the general population.

    About 30 to 40 of the 100 children will go on to have lifelong difficulties with learning and thinking abilities, including autism (also called neurodevelopmental disorders).

    For up-to-date information about valproate for women who could become pregnant, visit our webpage or call the Epilepsy Action Helpline on 0808 800 5050.

  • Zonisamide (brand name Zonegran)

    More research is needed to understand if zonisamide use during pregnancy increases the risk of birth defects.

    More research is needed to understand if zonisamide use during pregnancy increases the risk of a child having thinking or learning difficulties.

    Zonisamide use during pregnancy increases the risk of the baby being born smaller than expected compared with the general population.

  • Other epilepsy medicines

    The medicines listed below are less commonly prescribed in the UK. The MHRA found there is not enough information on their use in pregnancy to make any conclusions about their safety when used during pregnancy. This means the risk of harming a baby cannot be confirmed or ruled out.

    • Brivaracetam (Briviact)
    • Clonazepam
    • Eslicarbazepine (Zebinix)
    • Ethosuximide
    • Lacosamide (Vimpat)
    • Perampanel (Fycompa)
    • Primidone
    • Rufinamide (Inovelon)
    • Tiagabine (Gabitril)
    • Vigabatrin (Sabril)

    Cenobamate

    Cenobamate is a new epilepsy medicine and was not included in the MHRA’s review. There is not enough information about cenobamate use in pregnant humans, but research in animals suggests it could cause problems if taken during pregnancy. The makers of cenobamate say it should not be used in pregnancy, unless the benefits outweigh the risks.

Which epilepsy medicines are safest to use in pregnancy?

The MHRA report found that lamotrigine and levetiracetam are safer to use in pregnancy than other epilepsy medicines.

This is because they are not linked with an increased risk of birth defects compared with the general population.

Which epilepsy medicines increase the risk of birth defects?

The MHRA found there was enough evidence to say that carbamazepine, phenobarbital, phenytoin, topiramate and valproate increase the risk of a baby being born with birth defects. A new drug safety alert also says that pregabalin may slightly increase the risk of birth defects.

The table below shows the risk for the general population, and for each medicine.

 

 General population  2 to 3 out of 100 babies
 Carbamazepine  4 to 5 out of 100 babies
 Phenobarbital  6 to 7 out of 100 babies
 Phenytoin  about 6 out of 100 babies
 Pregabalin  exact risk unclear
 Topiramate  4 to 5 out of 100 babies
 Valproate  about 10 out of 100 babies

 

I think my child has been affected by epilepsy medicine I took while I was pregnant. What should I do?

If you are concerned that your child has been affected by use of epilepsy medicine during pregnancy, you can discuss this with your family doctor. The doctor may refer your child to see a specialist in children’s medicine if they think this is needed.

You could also contact a support network such as:

Organisation for Anti-convulsant Syndrome (OACS)
OACS support all families touched by Fetal Anti-Convulsant Syndromes
Tel: 07904200364
Email: oacscharity.org@gmail.com

Valproate Victims
This charity represents some of the people and families who have been affected by sodium valproate taken in pregnancy.

INFACT
INFACT provides information, advice and support to anyone that has taken anti-seizure medications (ASMs) in pregnancy and are concerned it may have affected the foetus during pregnancy.

A mother working on a laptop at home whilst holding their baby

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. If you have epilepsy and are pregnant, the register would be delighted to hear from you.

Website: epilepsyandpregnancy.co.uk
Tel: 0800 389 1248

Published: July 2022
Last modified: September 2024
To be reviewed: July 2024
Tracking: L020.12 (previously F044)
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