(Date: October 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

Baclofen use may occasionally be advised in pregnancy if it is needed to control severe muscle spasms.

What is it?

Baclofen (Lyflex®, Lioresal®) is a medicine used to treat severe muscle tightness and muscle spasms caused by an underlying brain condition. Baclofen can be given by mouth or intrathecally (into the fluid-filled space around the spinal cord).

What are the benefits of taking baclofen in pregnancy?

Baclofen use may be advised to control pain and improve problems with mobility and day-to-day function that are caused by severe muscle spasms. In these cases, the benefits to both woman and baby of ensuring the woman remains well are likely to outweigh any possible risks.

Are there any risks of taking baclofen during pregnancy?

Baclofen use in pregnancy has been studied in only around 150 women. Although the available information does not suggest it harms the baby in the womb, much more information needs to be collected to confirm this.

Baclofen given intrathecally is thought to reach the baby in very small amounts that are unlikely to cause harm.

Baclofen taken by mouth can potentially cause short-term withdrawal symptoms in the newborn baby if taken in the weeks before delivery. For this reason, a baby may be monitored for some time after birth to check for symptoms such as jitteriness, difficulty sleeping and breathing problems.

Are there any alternatives to taking baclofen?

Possibly. There may be other medications that can be used depending on the specific circumstances. When a particular medicine is being offered, a doctor will be able to explain why it is the best choice.

What if I prefer not to take baclofen during pregnancy?

Reduced mobility and chronic pain can greatly affect quality of life. Baclofen will only be offered in pregnancy if the benefits of use outweigh the possible risks. A doctor or specialist will be happy to discuss this.

Will my baby need extra monitoring?

In the UK, all women will be offered a very detailed scan at around 20 weeks of pregnancy as part of their routine antenatal care. No additional monitoring of the baby is required due to use of baclofen. However, closer monitoring may be offered to women with some of the underlying health conditions that baclofen is used to treat.

Are there any risks to my baby if the father takes baclofen?

We would not expect any increased risk to the baby if the father took baclofen around the time of conception.

Who can I talk to if I have questions?

If you have any questions about 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.

Feedback request 

WE NEED YOUR HELP! Do you have 3 minutes to complete a short, quick and simple 12 question user feedback form about our bumps information leaflets? To have your say on how we can improve our website and the information we provide please visit here.

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.

My bump’s record

Create your own ‘My bump’s record’.

Provide information about your pregnancy to help women in the future.

Login to my bumps

Join my bumps