(Date: September 2019. Version: 3)

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 Public Health England 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.

What is it?

Topiramate (Topamax®) is used to treat epilepsy, sometimes in combination with other epilepsy medicines. Topiramate is also sometimes used to prevent migraine in recurrent sufferers. In the USA, topiramate is used to help with weight loss.
When deciding whether to use topiramate during pregnancy it is important to weigh up the potential benefits to your health and wellbeing against any possible risks to you or your baby, some of which may depend on how many weeks pregnant you are. Use of topiramate in pregnancy may sometimes be considered necessary to control epilepsy. Your doctor or specialist will help you make decisions about your treatment.

It is recommended that all women taking anti-epileptic medicines also take high dose folic acid (5mg/day) whilst trying to conceive and during the first trimester of pregnancy. High dose folic acid has to be prescribed by a doctor. For more information please see the folic acid bump leaflet.

What if I have already taken topiramate during pregnancy?

If you have taken or are taking any medicines it is always a good idea to let your doctor know that you are pregnant so that you can decide together whether you still need the medicines that you are on and to make sure that you are taking the lowest dose that works and only for as long as you need to.

If you have epilepsy it is very important that you do not suddenly stop taking topiramate as this could be dangerous. Do not make any changes to your medication without first talking to your doctor.

Because of the normal bodily changes associated with a progressing pregnancy, the dose of topiramate may need to be adjusted to ensure that symptoms remain well-controlled. Your doctor may offer ongoing monitoring to determine whether dose changes are required.

Can taking topiramate in pregnancy cause birth defects in the baby?

A baby’s body and most internal organs are formed during the first 12 weeks of pregnancy. It is mainly during this time that some medicines are known to cause birth defects.

Topiramate use in pregnancy has been linked to cleft lip and palate in the baby. However, studies indicate that this is quite rare. In the background population, around one in every 1,000 babies is born with a cleft lip and/or palate. This increases to around seven in every 1,000 babies born to pregnant women taking topiramate (therefore 993 out of every 1,000 topiramate-exposed babies will be unaffected).

Can taking topiramate in pregnancy cause miscarriage or stillbirth?

There are currently no concerns that topiramate use in pregnancy causes miscarriage or stillbirth. However, only very small numbers of women have been studied with respect to these pregnancy outcomes, therefore more research is required.

Can taking topiramate in pregnancy cause preterm birth or my baby to be small at birth (low birth weight)?

There is no scientific evidence to link taking topiramate in pregnancy with preterm birth.

A side effect of topiramate in non-pregnant users is weight loss. Some studies have shown that babies exposed to topiramate in the womb are more likely to have a low birth weight (<2500 g) or to be smaller than expected for the stage of pregnancy.

Can taking topiramate in pregnancy cause other health problems in the child?

Withdrawal symptoms at birth (neonatal withdrawal)
Withdrawal symptoms are thought to occur when a newborn baby’s body has to adapt to no longer getting certain types of medicines through the placenta.

Topiramate works in a similar way to other medicines that are known to cause neonatal withdrawal, therefore close monitoring of your baby for a few days after birth may be advised if you have taken topiramate regularly in the weeks before delivery. Monitoring of your baby may be particularly important if you have taken topiramate in combination with other anti-epileptic medicines or medicines that act on the brain.

Bleeding problems in the newborn baby
Topiramate belongs to a group of medicines that can reduce the capacity of blood to clot normally. Although studies do not show that bleeding problems are any more common in babies whose mothers took topiramate in pregnancy, because of the possible (theoretical) risk of bleeding problems, it is currently recommended that all babies born to women who took topiramate in pregnancy receive an injection of vitamin K at birth to help to protect against blood clotting problems.

Learning and behavioural problems
A baby’s brain continues to develop right up until the end of pregnancy. It is therefore possible that taking certain medicines at any stage of pregnancy could have a lasting effect on a child’s learning or behaviour. Because topiramate acts upon the brain there have been concerns that its use in pregnancy may affect a baby’s brain development.

Two studies have assessed whether exposure to topiramate in the womb can affect a child’s learning and development. One did not report any problems, while the second, much smaller study, found that topiramate exposure might be linked to problems with learning and motor skills. However, larger numbers of children need to be studied before we can say for sure whether topiramate use in pregnancy can cause changes in learning and behaviour in exposed children.

Will my baby need extra monitoring?

As part of their routine antenatal care most women will be offered a scan at around 20 weeks of pregnancy to look for birth defects and to check the baby’s growth.

Because there is a possibility that topiramate taken in the first trimester increases the chance of cleft lip and/or palate in the baby, your doctor may offer you more detailed anomaly scans.

Pregnant women taking topiramate in pregnancy may receive additional monitoring of their weight and of their baby’s growth, as topiramate use can cause weight loss and has been linked to reduced fetal growth. In general, women with epilepsy may be more closely monitored during pregnancy to ensure that they remain well throughout and that their baby is growing and developing as expected. 

If you have taken topiramate around the time of delivery your baby may require extra monitoring after birth because of the risk of neonatal withdrawal.

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

We would not expect any increased risk to your baby if the father took topiramate before or around the time you became pregnant.

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  

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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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