(Date: September 2022. Version: 4)

This factsheet has been written for members of the public by the UK Teratology Information Service (UKTIS). UKTIS is a not-for-profit organisation funded by the UK Health Security Agency (UKHSA) on behalf of UK Health Departments. UKTIS has been providing scientific information to health care providers since 1983 on the effects that medicines, recreational drugs and chemicals may have on the developing baby during pregnancy.

Quick read

Topiramate use in pregnancy has been linked to birth defects and altered neurodevelopment in the baby.

Topiramate is occasionally used in pregnancy if no other medicine will work to treat epilepsy.

What is it?

Topiramate (Topamax®) is used to treat epilepsy and to prevent migraine.

What are the benefits of taking topiramate in pregnancy?

Topiramate prevents seizures in women with epilepsy, which can be dangerous or even life-threatening and can also lead to pregnancy complications.

Topiramate is not usually used to prevent migraine attacks during pregnancy as there are alternatives that are considered to be safer for the baby.

Are there any risks of taking topiramate during pregnancy?

Some studies have suggested that there is an increased chance of cleft lip and palate in the baby following use of topiramate in early pregnancy. Overall, it is very clear that most babies exposed to topiramate in the womb do not have cleft lip and palate.

Studies have also shown that children who were exposed to topiramate in the womb have a higher chance of autism spectrum disorder (ASD) or intellectual disability. In the background population, around one in every 100 children is diagnosed with ASD. More research is required, but early data suggests that around 3 in every 100 children exposed in the womb to topiramate will be diagnosed with ASD.

Some drugs used to treat epilepsy can affect folic acid levels. UK guidelines state that women taking topiramate while trying to conceive and during pregnancy should be prescribed a high dose folic acid supplement (5 mg/day).

Are there any alternatives to taking topiramate?

Topiramate is generally only prescribed in pregnancy when epilepsy cannot be controlled with a different drug. In these cases, a specialist will help the pregnant woman to weigh up the risk from uncontrolled seizures to both woman and baby compared to the risk from drug exposure.

Women planning a pregnancy should be offered a medication review with their epilepsy specialist, to determine whether topiramate is still the most suitable medicine. Women with an unplanned pregnancy while taking topiramate should be reviewed as soon as possible by their GP or specialist.

What if I prefer not to take medicines during pregnancy?

It is very important to take any medicines prescribed to treat epilepsy. Uncontrolled seizures can be serious and can lead to pregnancy complications.

Doctors will only prescribe medicines when absolutely necessary and will be happy to talk about any concerns that a woman might have.

Pregnant women should not stop or reduce the dose of topiramate unless this has been advised by their GP or specialist.

Will my baby need extra monitoring?

All pregnant women in the UK will be offered a very detailed anomaly scan at around 20 weeks of pregnancy as part of their routine antenatal care. No extra monitoring for major birth defects is required following topiramate use in pregnancy.

Are there any risks to my baby if the father has taken topiramate?

We would not expect any increased risk to the baby if the father takes, or has taken, topiramate.

Who can I talk to if I have questions?

If you have any questions regarding the information in this leaflet please discuss them with your health care provider. They can access more detailed medical and scientific information from

How can I help to improve drug safety information for pregnant women in the future?

Our online reporting system allows women with a current or previous pregnancy to create a digitally secure ‘my bumps record’. You will be asked to enter information about your health, whether or not you take any medicines, and your pregnancy outcome. You can update your details at any time during pregnancy or afterwards. This information will help us better understand how medicines affect the health of pregnant women and their babies. Please visit to register.

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General information 

Up to 1 out of every 5 pregnancies ends in a miscarriage, and 1 in 40 babies are born with a birth defect. These are referred to as the background population risks.  They describe the chance of these events happening for any pregnancy before taking factors such as the mother’s health during pregnancy, her lifestyle, medicines she takes and the genetic make up of her and the baby’s father into account.

Medicines use in pregnancy

Most medicines used by the mother will cross the placenta and reach the baby. Sometimes this may have beneficial effects for the baby.  There are, however, some medicines that can harm a baby’s normal development.  How a medicine affects a baby may depend on the stage of pregnancy when the medicine is taken. If you are on regular medication you should discuss these effects with your doctor/health care team before becoming pregnant.

If a new medicine is suggested for you during pregnancy, please ensure the doctor or health care professional treating you is aware of your pregnancy.

When deciding whether or not to use a medicine in pregnancy you need to weigh up how the medicine might improve your and/or your unborn baby’s health against any possible problems that the drug may cause. Our bumps leaflets are written to provide you with a summary of what is known about use of a specific medicine in pregnancy so that you can decide together with your health care provider what is best for you and your baby.   

Every pregnancy is unique. The decision to start, stop, continue or change a prescribed medicine before or during pregnancy should be made in consultation with your health care provider. It is very helpful if you can record all your medication taken in pregnancy in your hand held maternity records.

Disclaimer: This information is not intended to replace the individual care and advice of your health care provider. New information is continually becoming available. Whilst every effort will be made to ensure that this information is accurate and up to date at the time of publication, we cannot cover every eventuality and the information providers cannot be held responsible for any adverse outcomes following decisions made on the basis of this information. We strongly advise that printouts should NOT be kept for any length of time, or for “future reference” as they can rapidly become out of date.

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