(Date: December 2014. Version: 2)

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?

Lamotrigine (Lamictal®) is used to treat epilepsy, sometimes in combination with other medicines. Lamotrigine is also occasionally used in the treatment of bipolar disorder.

Is it safe to take lamotrigine in pregnancy?

There is no yes or no answer to this question. When deciding whether or not to take lamotrigine during pregnancy it is important to weigh up how necessary lamotrigine 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 mother and unborn child. For some women treatment with lamotrigine in pregnancy may be necessary.

This leaflet summarises the scientific studies relating to the effects of lamotrigine on a baby in the womb. It is advisable to consider this information if you are taking lamotrigine 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.

Why do UK guidelines recommended that pregnant women or women planning a pregnancy who take lamotrigine also take high dose folic acid?

Lamotrigine can affect the amount of folic acid in the body. Folic acid is necessary for a baby’s growth and development in the womb. It is therefore recommended that all women taking lamotrigine (or any other antiepileptic medicine) also take high dose folic acid (5mg/day) instead of the standard dose of 400mcg whilst trying to conceive and during the first trimester of pregnancy. High dose folic acid has to be prescribed by a doctor. There is currently no scientific evidence to show whether high dose folic acid is any better than the standard dose, however, until more scientific information is available high dose folic acid is advised in pregnant women who are taking these medicines. For more information please see the folic acid bumps leaflet.

What if I have already taken lamotrigine 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 lamotrigine as this could be dangerous to you, and also to your baby if you are already pregnant. Do not make any change 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 lamotrigine 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 lamotrigine 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.

Around 7,500 babies born to women who took lamotrigine during pregnancy have been studied in total. These babies do not appear to be any more likely to have a birth defect than babies born to women who didn’t take lamotrigine. In studies of specific birth defects, although one study suggested a possible link between lamotrigine use in early pregnancy and cleft lip and/or palate in the baby, three further studies have not agreed with this finding.

Lamotrigine is sometimes taken in combination with other medicines to treat epilepsy. Some studies have shown that women taking combinations of antiepileptic medicines may be more likely to have a baby with a birth defect than women taking a single antiepileptic 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 antiepileptics that included a medicine called sodium valproate (Epilim®) which can cause birth defects. All three studies which investigated this have shown that women taking lamotrigine in combination with antiepileptics other than sodium valproate were not at higher risk of having a baby with a birth defect than women who took only lamotrigine. 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 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 it.

Can taking lamotrigine in pregnancy cause miscarriage, stillbirth, or preterm birth?

No links between lamotrigine use in pregnancy and miscarriage, stillbirth, or preterm birth are known about, although no scientific studies have been carried out that have specifically investigated these pregnancy outcomes.

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

No link between taking lamotrigine in pregnancy and an increased risk of low birth weight in the baby was identified in one study of around 1,000 women.

Because these results are from just one study more research is required to confirm these findings.

Can taking lamotrigine 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.

Lamotrigine 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 lamotrigine regularly in the weeks before delivery. Monitoring of your baby may be particularly important if you have taken lamotrigine in combination with other antiepileptic medicines or medicines that act on the brain.

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.

Antiepileptic medicines act upon the brain, and children who were exposed in the womb to the antiepileptic sodium valproate have been shown to be more likely to have problems with learning and behaviour. A small number of studies have therefore been carried out to look at whether there is an increased risk of learning and behavioural problems in children who were exposed to lamotrigine while in the womb. These studies are summarised below: 

• Autism spectrum disorder (ASD) - Two studies have investigated whether taking lamotrigine during pregnancy is linked to having a child with ASD. One of these studies showed that three year olds who had been exposed to lamotrigine in the womb may be more likely to show autistic traits. However, this was not confirmed in the other study which showed that children exposed to lamotrigine in the womb were no more likely to have ASD than those not exposed to lamotrigine. Larger numbers of children exposed to lamotrigine in the womb need to be studied before we can say whether there is any link with ASD.

• Attention deficit hyperactivity disorder (ADHD) - None of three studies have shown a link between use of lamotrigine in pregnancy and ADHD in the child.

• Learning and thinking skills - Four studies compared different learning and thinking abilities of children who were exposed to lamotrigine in the womb with children not exposed to lamotrigine. Overall, these studies provide no strong evidence of any major differences in IQ, communication and memory. However, these types of studies are very difficult to carry out and may not produce reliable results if too few children are studied. More research is needed before we can say for certain that exposure to lamotrigine in the womb is not linked with problems with learning and thinking skills.

• Movement skills - Three studies have investigated whether children who were exposed to lamotrigine in the womb have poorer motor skills such as sitting, walking, jumping. None of these studies showed any effects of lamotrigine exposure on motor development of children. 

Although these results are generally reassuring, because only small numbers of children have been studied, much more research is required before we can say whether lamotrigine use in pregnancy can cause changes in co-ordination, movement, learning  and behaviour in exposed children.

Will my baby need extra monitoring?

Most women will be offered a scan at around 20 weeks of pregnancy to look for birth defects as part of their routine antenatal care. Taking lamotrigine in pregnancy is not expected to cause problems that would require extra monitoring of your baby. However, 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 lamotrigine 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 lamotrigine?

We would not expect any increased risk to your baby if the father took lamotrigine 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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