This sheet talks about exposure to mepolizumab in a pregnancy or while breastfeeding. This information should not take the place of medical care and advice from your healthcare provider.
What is mepolizumab?
Mepolizumab is a prescription medication used with other medicines to treat a severe type of asthma called eosinophilic asthma, and to treat eosinophilic granulomatosis with polyangiitis (Churg-Strauss Syndrome). Eosinophils are a type of white blood cell. In eosinophilic diseases, the number of these cells increases in the body. Mepolizumab is thought to reduce the number of eosinophils. Mepolizumab is given in a healthcare provider’s office by an injection (a shot just under the skin) every 4 weeks. It is sold under the brand name Nucala®.
I take mepolizumab. Can it make it harder for me to get pregnant?
Based on the available data, it is not known if mepolizumab can make it harder to get pregnant.
I am taking mepolizumab, but I would like to stop taking it before getting pregnant? How long does the drug stay in my body?
Individuals eliminate medication at different rates. On average, it takes about 4 months for mepolizumab to leave your body. Talk to your healthcare provider before you stop taking this medication. It is important to consider the benefits of controlling your disease during pregnancy.
Untreated or poorly controlled asthma increases the risk for complications for both the mother and the baby. For more information about asthma in pregnancy, please see the MotherToBaby fact sheet on Asthma at https://mothertobaby.org/fact-sheets/asthma-and-pregnancy/pdf/.
Does taking mepolizumab increase the chance for a miscarriage?
Miscarriage can occur in any pregnancy. Based on the data available, it is not known if mepolizumab increases the chance for miscarriage.
Does taking mepolizumab while pregnant cause birth defects?
Every pregnancy starts out with a 3-5% chance of having a baby with a birth defect. This is called the background risk. It is not known if mepolizumab can cause birth defects. Animal studies done by the manufacturer have not shown an increase in the chance for birth defects. While this is reassuring, there are no well-controlled human studies looking at exposure to mepolizumab during pregnancy.
Could taking mepolizumab cause other pregnancy complications?
No studies have been done looking to see if exposure to mepolizumab would cause other pregnancy complications.
Does taking mepolizumab in pregnancy cause long-term problems in behavior or learning for the baby?
Based on the data available, it is not known if mepolizumab can cause behavior or learning issues.
Can I breastfeed while taking mepolizumab?
Mepolizumab has not been studied for use during breastfeeding. Because it is a very large protein, it is not likely that very much of the medication would be able to pass into breast milk. Also mepolizumab is not thought to be well absorbed in the stomach, so any of the medication that gets into breastmilk would be unlikely to enter the baby’s system from the stomach. Premature babies (born before 37 weeks of pregnancy) have digestive systems that may not be fully developed. This could allow more of the medication to be absorbed from the breast milk. Be sure to talk to your healthcare provider about all of your breastfeeding questions.
I take mepolizumab. Can it make it harder for me to get my partner pregnant or increase the chance of birth defects?
Based on the data available, it is not known if mepolizumab can make it harder for you to get your partner pregnant or increase the chance of birth defects. In general, exposures that fathers or sperm donors have are unlikely to increase risks to a pregnancy. For more information, please see the MotherToBaby fact sheet on Paternal Exposures at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/.
MotherToBaby is currently conducting a study looking at mepolizumab and other medications used to treat asthma in pregnancy. If you are interested in taking part in this study, please call 1-877-311-8972 or sign up at https://mothertobaby.org/join-study/.
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OTIS/MotherToBaby recognizes that not all people identify as “men” or “women.” When using the term “mother,” we mean the source of the egg and/or uterus and by “father,” we mean the source of the sperm, regardless of the person’s gender identity.
