Interferon beta

Date: May 2025, Version 5

Quick read

Interferon beta can be used during pregnancy if recommended by a specialist.

What is it?

Interferon beta (Avonex®, Rebif®, Betaferon®) is mainly used to treat multiple sclerosis (MS).

Benefits

What are the benefits of using interferon beta in pregnancy?

Interferon beta reduces the symptoms of MS, allowing you to stay healthy and carry on your daily life during pregnancy and while looking after your baby. Interferon beta can also help slow down the nerve damage caused by MS.

Risks

What are the risks of using interferon beta in pregnancy?

Interferon beta is used by many women during pregnancy and there are no concerns that it can harm your baby. Taking interferon beta in pregnancy has been linked to a higher chance of preterm delivery. This is not thought to be a direct effect of interferon beta and is because women with MS are more likely to opt for their baby to be delivered earlier.

Alternatives

Are there any alternatives to using interferon beta in pregnancy?

Possibly. Other medicines can be used for MS. You might find that your MS symptoms improve during pregnancy. If this occurs, your specialist may advise that your medicine can be altered. You should not make changes to your treatment without speaking to your doctor first.

No treatment

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.

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 no evidence that interferon beta 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 www.uktis.org.

How can I help to improve drug safety information for pregnant women in the future?

Our online reporting system (MyBump Portal) allows women who are currently pregnant to create a secure record of their pregnancy, collected through a series of questionnaires. You will be asked to enter information about your health, whether or not you take any medicines, your pregnancy outcome and your child's development. 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 the MyBump Portal to register.

General information
Sadly, miscarriage and birth defects can occur in any pregnancy.

Miscarriage occurs in about 1 in every 5 pregnancies, and 1 in every 40 babies are born with a birth defect. This is called the ‘background risk’ and happens whether medication is taken or not.

Most medicines cross the placenta and reach the baby. For many medications this is not a problem. However, some medicines can affect a baby’s growth and development.

If you take regular medication and are planning to conceive, you should discuss whether your medicine is safe to continue with your doctor/health care team before becoming pregnant. If you have an unplanned pregnancy while taking a medicine, you should tell your doctor as soon as possible.

If a new medicine is suggested for you during pregnancy, please make sure that the person prescribing it knows that you are pregnant. If you have any concerns about a medicine, you can check with your doctor, midwife or pharmacist.

Our Bumps information leaflets provide information about the effects of medicines in pregnancy so that you can decide, together with your healthcare provider, what is best for you and your baby.