This sheet is about exposure to guselkumab in pregnancy and while breastfeeding. This information should not take the place of medical care and advice from your healthcare provider.
What is guselkumab?
Guselkumab is a medication used to treat adults with moderate to severe plaque psoriasis and psoriatic arthritis. It is taken by an injection under the skin and is sold under the brand name Tremfya®. For more information about psoriasis, please see the MotherToBaby fact sheet on psoriasis in pregnancy at https://mothertobaby.org/fact-sheets/psoriasis-and-pregnancy/.
I take guselkumab. Can it make it harder for me to get pregnant?
It is not known if guselkumab can make it harder to become pregnant.
I just found out I am pregnant. Should I stop taking guselkumab?
Talk with your healthcare providers before making any changes to how you take your medication(s). They can go over your options, weighing the risks and benefits of treating or not treating your condition.
How long does guselkumab stay in my body?
People eliminate medications from their bodies at different rates. Guselkumab can remain in the body for up to three months after the last dose.
Does taking guselkumab increase the chance for miscarriage?
Miscarriage can occur in any pregnancy. It is not known if guselkumab increases the chance for miscarriage.
Does taking guselkumab increase the chance of birth defects?
Every pregnancy starts out with a 3-5% chance of having a birth defect. This is called the background risk. Based on the available data, it is not known if taking guselkumab increases the chance of birth defects. Because guselkumab is an antibody, transfer of the medication to the developing baby might be low in early pregnancy, when many of the organs are forming.
Could taking guselkumab cause other pregnancy complications?
It is not known if guselkumab can cause other pregnancy complications.
Does taking guselkumab in pregnancy cause long-term problems in behavior or learning for the baby?
It is not known if guselkumab can cause behavior or learning issues.
Can I breastfeed while taking guselkumab?
Guselkumab has not been well-studied in breastfeeding. It is a very large protein, so not very much is expected to pass into breast milk. Guselkumab is not well absorbed from the gut, so any medication that gets into breast milk would be unlikely to enter the baby’s system. Babies born before 37 weeks of pregnancy (preterm delivery) and newborns have digestive systems that are not fully developed, which 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 guselkumab. Can it make it harder for me to get my partner pregnant or increase the chance of birth defects?
It is not known if there are possible risks to a pregnancy when a father or sperm donor takes guselkumab. In general, exposures that fathers and sperm donors have are unlikely to increase risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/pdf/.
MotherToBaby is currently conducting a study looking at guselkumab and other medications used to treat psoriasis in pregnancy. If you are interested in taking part in this study, please call 1-877-311-8972 or or sign up at https://mothertobaby.org/join-study/.
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OTIS/MotherToBaby encourages inclusive and person-centered language. While our name still contains a reference to mothers, we are updating our resources with more inclusive terms. Use of the term mother or maternal refers to a person who is pregnant. Use of the term father or paternal refers to a person who contributes sperm.