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 that has been used to treat moderate to severe plaque psoriasis and psoriatic arthritis in adults. It is given by injection under the skin and is sold under the brand name Tremfya®. For more information about psoriasis, please see the MotherToBaby fact sheet at https://mothertobaby.org/fact-sheets/psoriasis-and-pregnancy/.
Sometimes when people find out they are pregnant, they think about changing how they take their medication, or stopping their medication altogether. However, it is important to talk with your healthcare providers before making any changes to how you take this medication. Your healthcare providers can talk with you about the benefits of treating your condition and the risks of untreated illness during pregnancy.
I am taking guselkumab, but I would like to stop taking it before getting pregnant. How long does the drug stay in my body?
People eliminate medication at different rates. In healthy adults, it takes up to three months, on average, for most of the guselkumab to be gone from the body.
I take guselkumab. Can it make it harder for me to get pregnant?
It is not known if guselkumab can make it harder to get pregnant.
Does taking guselkumab increase the chance for miscarriage?
Miscarriage is common and can occur in any pregnancy for many different reasons. Studies have not been done to see 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. Studies have not been done to see if guselkumab increases the chance of birth defects.
Very little guselkumab is expected to cross the placenta and reach the developing pregnancy during the first trimester (when many of the fetal organs and body structures are forming). More of the medication can cross the placenta starting in the second trimester.
Does taking guselkumab in pregnancy increase the chance of other pregnancy-related problems?
Studies have not been done to see if guselkumab increases the chance for other pregnancy-related problems such as preterm delivery (birth before week 37) or low birth weight (weighing less than 5 pounds, 8 ounces [2500 grams] at birth).
Does taking guselkumab in pregnancy affect future behavior or learning for the child?
Studies have not been done to see if guselkumab can cause behavior or learning issues for the child.
Breastfeeding while taking guselkumab:
Guselkumab is a large protein, so very little of the medication is expected to get into breast milk. Also, guselkumab is not well absorbed when swallowed, so any medication that the baby swallows in the breast milk is unlikely to enter their bloodstream. If you suspect the baby has any symptoms (such as fever or frequent infections), contact the child’s healthcare provider. Be sure to talk to your healthcare provider about all of your breastfeeding questions.
If a male takes guselkumab, could it affect fertility (ability to get partner pregnant) or increase the chance of birth defects?
Studies have not been done to see if guselkumab could affect male fertility or increase the chance of birth defects above the background risk. 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/.
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/.
Please click here for references.
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.
