Ustekinumab

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Date: March 2025, Version 3.0

Quick take

Ustekinumab can be used in pregnancy if advised by a specialist. Babies exposed in the womb after the first trimester might be offered some of their vaccinations later than usual.

What is it?

Ustekinumab (Pyzchiva®, Stelara®, Steqeyma®, Uzpruvo®, Wezenla®) is an antibody therapy used to treat inflammatory illnesses, including psoriasis, psoriatic arthritis, and inflammatory bowel disease.

Benefits

What are the benefits of using ustekinumab in pregnancy?

Ustekinumab reduces inflammation by stopping your immune system from attacking your body’s tissues. This is important to reduce unpleasant symptoms and prevent long-term damage. It may also lower the chance of some pregnancy problems linked to uncontrolled inflammatory bowel disease, including miscarriage and lower infant birth weight.

Risks

What are the risks of using ustekinumab in pregnancy?

Ustekinumab does not cross the placenta in the first trimester so will not directly affect your baby’s development. Only around 200 women using ustekinumab in later pregnancy have been studied. No problems were identified but further research is ideally required.

Antibody treatments given in the second and third trimesters can affect your baby’s immune system after birth. Babies exposed to ustekinumab in later pregnancy are not usually given live vaccines (such as the BCG vaccine against tuberculosis [TB]) until they are around one year old, to reduce the risk of vaccine complications.

Alternatives

Are there any alternatives to using ustekinumab in pregnancy?

Possibly. Other medicines can be used to treat inflammatory conditions during pregnancy, although these may not work as well as ustekinumab. If ustekinumab is working well to control your illness, staying on it during pregnancy may be the best option.
  
If you are planning a pregnancy, speak to your specialist to determine which medicine is best. This can be arranged through your GP or specialist clinic.
 
If you become pregnant while taking ustekinumab, you should be reviewed by your doctor as soon as possible.

No treatment

What if I prefer not to take ustekinumab during pregnancy?

It is important that inflammatory conditions are well-treated during pregnancy to avoid a flare-up of symptoms and reduce the chance of certain pregnancy complications. A doctor will be happy to discuss any concerns.

Will I or my baby need extra monitoring?

As part of routine antenatal care in the UK, women are invited for a very detailed scan at around 20 weeks of pregnancy to check the baby’s development. No further scans to check for birth defects will be required, although extra growth scans may be offered.

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

There is currently no evidence that ustekinumab used by the father can harm the baby through effects on the sperm.

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.

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