(Date: December 2014. Version: 2.1)

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.

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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.

Is it safe to take topiramate in pregnancy?

There is no yes or no answer to this question. When deciding whether or not to take topiramate during pregnancy it is important to weigh up how necessary topiramate is to your health against the possible risks to you or your baby, some of which will depend on how many weeks pregnant you are. Remaining well is particularly important during pregnancy and whilst caring for a baby. It is vital that epilepsy is well-controlled during pregnancy as seizures can harm both the mother and unborn child. For some pregnant women treatment with topiramate may be necessary. 

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 bumps leaflet.

This leaflet summarises the scientific studies relating to the effects of topiramate on a baby in the womb. It is advisable to consider this information if you are taking topiramate and are pregnant or could become pregnant in the future.

Your doctor is the best person to help you decide what is right for you and your baby.

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, if so, to make sure that you are taking the lowest dose that works and only for as long as you need to.

It is very important that you do not suddenly stop taking topiramate as this could be dangerous to you, and also to your baby if you are already pregnant. Do not make any changes to your medication without first talking to your doctor.

Because of the normal bodily changes that occur as pregnancy progresses your doctor may advise closer monitoring of your health to assess whether your topiramate dose needs to be adjusted during your pregnancy for it to remain effective. You should not change the dose of any prescribed medicine without medical supervision.

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.

Cleft lip and/or palate
Topiramate use in pregnancy may be linked to an increased risk of cleft lip and palate (a split in the top lip and/or roof of the mouth) in the baby. Seven studies have investigated this, with five of these studies showing a possible link between topiramate use in pregnancy and cleft lip and/or palate in the baby. However, even in the study that showed the strongest link between use of topiramate in pregnancy and cleft lip and palate in the baby, the vast majority (around 98 out of every 100) of the babies born to pregnant women who had taken topiramate did not have cleft lip and/or palate.

It is unclear whether male babies born to women who took topiramate in pregnancy may be at increased risk of hypospadias (where the opening of the penis is on the underside rather than the tip). Of the three studies that have investigated this two showed a possible link, while the remaining study did not agree with this finding. More information therefore needs to be collected to accurately assess whether there is a link between topiramate use in pregnancy and hypospadias.  

Topiramate in combination with other anti-epileptic medicines
Topiramate is sometimes taken in combination with other medicines to treat epilepsy. Some studies have suggested that women taking combinations of anti-epileptic medicines may be more likely to have a baby with a birth defect than women taking a single anti-epileptic medicine. However, it is now thought that this finding may be due to the fact that many of the women in these studies were taking combinations of anti-epileptics that included sodium valproate (Epilim®), an antiepileptic medicine which is known to cause birth defects.

There is some weak evidence to suggest that women taking topiramate in combination with other anti-epileptic medicines, regardless of whether sodium valproate is included, may be at an increased risk of having a baby with a birth defect compared to women who just take topiramate. However, much more research into this subject is required to confirm this.

If you are taking more than one medicine to control epilepsy you should discuss any concerns that you may have with your doctor. Do not stop or alter the dose of any medicine you are taking without first speaking to your doctor. Making changes to your medicine yourself may be more harmful to both you and your baby than continuing to take that medicine.

Can taking topiramate in pregnancy cause miscarriage or stillbirth?

There is currently no convincing scientific evidence to link topiramate use in pregnancy with miscarriage or stillbirth. However, only very small numbers of women have been studied with respect to these pregnancy outcomes, therefore more thorough research is required before any links can be ruled out.

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

There is currently no strong scientific evidence to link taking topiramate in pregnancy with preterm birth. However, this has been studied in only a very small number of women, therefore more research is required before an increase in risk can be ruled out.

A side effect of topiramate in non-pregnant users is weight loss. Two studies have shown that babies exposed to topiramate in the womb are more likely to have a low birth weight (<2500g) or to be smaller than expected for the stage of pregnancy. Being small at birth may be associated with certain health problems later on in life.

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 serious 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.

Only one very small study of nine children aged between around three and seven has investigated this possibility. In this study, children who had been exposed to topiramate in the womb were more likely to have certain problems with learning and behaviour compared to children of a similar age whose mothers did not have epilepsy and who were therefore not exposed to topiramate in the womb. However, six of the mothers of children exposed to topiramate had epileptic seizures whilst pregnant. Seizures in pregnancy can temporarily reduce the amount of oxygen available to the baby, which could then affect brain development. It is therefore not possible to say whether the differences observed in this study were due to exposure to topiramate or to other factors.

Larger numbers of children therefore need to be studied before we can say 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 the option of having more detailed anomaly scans to look for this from as early as around 12 weeks of pregnancy. It is, however, harder to see birth defects at this stage of pregnancy, which is why the main scan for birth defects is generally offered at around 20 weeks of pregnancy.

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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