Interferon beta

(Date: September 2021. 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.

What is it?

Interferon beta is mainly used to treat multiple sclerosis (MS).

What are the benefits of using interferon beta in pregnancy?

Interferon beta is an effective treatment for many people with MS. It reduces the inflammation that damages nerves. The symptoms of MS can be extremely difficult, sometimes affecting your ability to cope with daily living. It is therefore important that MS is as well-controlled as possible during pregnancy and whilst looking after a baby.

What are the risks of using interferon beta in pregnancy?

There are currently no concerns that interferon beta use in early pregnancy causes birth defects, miscarriage, or low infant birth weight. Some studies have shown that women taking interferon beta might be more likely to have a preterm delivery. However, this is thought to be due to women with MS opting to have their baby delivered early, rather than a direct effect of interferon beta.

Are there any alternatives to using interferon beta in pregnancy?

Some women with MS find that their symptoms improve when they are pregnant. If this occurs, your specialist may advise that your medicine(s) can be altered. You should not, however, make changes to your treatment without speaking to your doctor first.

What if I prefer not to take medicines to treat multiple sclerosis?

Your doctor will only prescribe medicines when necessary and will be happy to talk to you about any concerns. It is important to take any medicines prescribed for MS during pregnancy to avoid a flare-up of symptoms and to help prevent damage to the nerves. You can feel reassured that interferon beta is often used in pregnancy with no known effects on the unborn baby.

Will my baby need extra monitoring?

As part of routine antenatal care, most women will be offered a scan at around 20 weeks of pregnancy to check the baby’s wellbeing. Use of interferon beta is not expected to cause problems that would require specialist scans, although extra growth scans may be needed in women with MS.

Are there any risks to my baby if the father has used interferon beta?

A small number of pregnancies in which the father used interferon beta around the time of conception have been studied. There is currently no evidence that interferon beta used by the father can harm the baby through effects on the sperm, and most experts agree that this is unlikely.

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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