Epilepsy medicines and pregnancy

Always get medical advice before making any changes to your epilepsy medicine.

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 preconception 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.

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)

Some research suggests that pregabalin 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.

Topiramate (brand name Topamax)

Topiramate use during pregnancy increases the risk of physical birth defects. If 100 women take topiramate 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.

More information is needed to understand if taking topiramate during pregnancy increases the risk of having a child with thinking and learning difficulties.

Taking topiramate during pregnancy increases the risk of the baby being born smaller than expected.

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)
 

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.

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
 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)
Tel: 07904 200364
Email: oacscharity.org@gmail.com

Fetal Anti-convulsant Syndrome Association (FACSA)
Tel: 01253 799161

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

If you would like to know where our information is from, download a copy of this information with references.

Code: 
F044.08

Epilepsy Action would like to thank Dr Janine Winterbottom, advanced nurse specialist in epilepsy at the Walton Centre NHS Foundation Trust, and Dr Rebecca Bromley, research fellow at the University of Manchester, for their contributions to this information.

  • Updated July 2021
    To be reviewed July 2024

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