Date: September 2020, Version 3

What is it?

Sulfasalazine is a medicine that dampens the immune response. It used to treat ulcerative colitis, Crohn’s disease, and rheumatoid arthritis.


What are the benefits of taking sulfasalazine in pregnancy?

Sulfasalazine reduces ongoing tissue damage caused by ulcerative colitis, Crohn’s disease, and rheumatoid arthritis. It also controls unpleasant symptoms that can affect quality of life, and can help to prevent the pregnancy complications that have been associated with these illnesses.


Are there any risks of taking sulfasalazine during pregnancy?

There are no concerns that taking sulfasalazine in pregnancy causes problems in the baby and it is routinely prescribed for pregnant women with ulcerative colitis, Crohn’s disease, and rheumatoid arthritis.

Because sulfasalazine can potentially affect folic acid levels, women taking it while trying to conceive and during pregnancy should be prescribed a high dose folic acid supplement.


Are there any alternatives to taking sulfasalazine?

Possibly. Other medicines can be used to treat ulcerative colitis, Crohn’s disease, and rheumatoid arthritis. However, where a woman’s illness is well-controlled with sulfasalazine, staying on it may be the best option.

Ideally, women planning a pregnancy should speak to their specialist to determine whether sulfasalazine is still the most appropriate medicine for them. If you have an unplanned pregnancy while taking it, you should be reviewed at the earliest opportunity by your specialist. For many, ongoing use of sulfasalazine in pregnancy will be considered appropriate.

No treatment

What if I prefer not to take medicines during pregnancy?

It is very important to take any medicines prescribed to treat ulcerative colitis, Crohn’s disease, and rheumatoid arthritis. Left untreated these can be serious and can also lead to pregnancy complications.

Your doctor will only prescribe medicines when absolutely necessary and will be happy to talk to you about any concerns that you might have.

Do not stop sulfasalazine without speaking to your midwife, GP, or specialist.

Will my baby need extra monitoring?

All pregnant women in the UK should be offered a detailed anomaly scan at around 20 weeks of pregnancy as part of their routine antenatal care. No extra monitoring for major birth defects is required following sulfasalazine use in pregnancy.

Are there any risks to my baby if the father has taken sulfasalazine?

We would not expect any increased risk to your baby if the father takes sulfasalazine.

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

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.