Eculizumab

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Date: March 2026, Version 2.0

Quick take

Eculizumab can be used in pregnancy. 

What is it?

Eculizumab (Bekemv®, Epysqli®, Soliris®) is an antibody therapy used to treat myasthenia gravis, paroxysmal nocturnal haemoglobinuria (PNH), and atypical haemolytic-uraemic syndrome (aHUS).

Benefits

What are the benefits of using eculizumab in pregnancy?

Eculizumab works by stopping your immune system from attacking your body’s tissues. Studies have shown that continuing eculizumab during pregnancy keeps you well, reducing the chance of pregnancy complications.

Risks

What are the risks of using eculizumab in pregnancy?

Eculizumab does not cross the placenta in the first trimester so will not directly affect your baby’s development.

There is little information on eculizumab use in pregnancy. Preterm birth and lower birth weights have been reported in babies exposed to eculizumab. However, the medical conditions that eculizumab is used to treat have been linked to these outcomes and can be much more serious if left untreated.

Antibody treatments in later pregnancy can affect a baby’s immune system after birth. Babies may be at higher risk of infection for the first two weeks. You will be advised about symptoms to be alert for in your baby, and what to do if they seem unwell. Babies exposed to eculizumab can receive all their normal infant vaccinations.

Alternatives

Are there any alternatives to using eculizumab in pregnancy?

Possibly. Other medicines can sometimes be used, although these may not work as well as eculizumab. If eculizumab is working for you, staying on it during pregnancy is likely to be your best option.
  
If you are planning a pregnancy, speak to your specialist about eculizumab treatment. This can be arranged through contacting your doctor, or their secretary/specialist nurse.
 
If you become pregnant whilst receiving eculizumab treatment, you should be reviewed by your doctor as soon as possible.

No treatment

What if I prefer not to take eculizumab during pregnancy?

It is important that autoimmune disease is well-treated during pregnancy to avoid a flare-up and to reduce the chance of pregnancy complications. In many cases, ongoing eculizumab treatment is essential. Your 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 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 are likely to be offered.

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

There is currently no evidence that eculizumab 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.