This sheet talks about exposure to abatacept in a pregnancy and while breastfeeding. This information should not take the place of medical care and advice from your healthcare provider.

What is abatacept?

Abatacept is a prescription medication used to treat rheumatoid arthritis (RA; https://mothertobaby.org/fact-sheets/rheumatoid-arthritis/pdf/), juvenile rheumatoid arthritis (JRA), and psoriatic arthritis (https://mothertobaby.org/fact-sheets/psoriasis-and-pregnancy/pdf/). Abatacept is a protein that suppresses overly active T cells (part of the body’s immune system) to help reduce inflammation. It can be given in a healthcare provider’s office by intravenous infusion (through a vein in the arm) every 4 weeks, or once a week at home with a shot under the skin. It is sold under the brand name Orencia®.

I take abatacept. Can it make it harder for me to become pregnant?

At this time, it is not known if taking abatacept would make it more difficult for a woman to get pregnant. Animal studies done by the manufacturer did not find that fertility was lowered with the use of abatacept in pregnancy. There have been no studies done in humans to see if abatacept has any effect on human fertility.

I just found out I am pregnant. Should I stop taking abatacept?

Talk with your healthcare providers before making any changes to this medication. The benefits of taking abatacept and treating your autoimmune condition during pregnancy need to be weighed against any possible risks of continuing the medication during pregnancy.

I am taking abatacept, but I would like to stop taking it before becoming pregnant. How long does the drug stay in my body?

People eliminate medications at different rates. In healthy adults, it takes up to 10 weeks, on average, for most of the abatacept to be gone from the body.

Does taking abatacept increase the chance of miscarriage?

Miscarriage can occur in any pregnancy. The manufacturer did not find a greater chance for miscarriage among 151 women who used abatacept in pregnancy.

Does taking abatacept in the first trimester increase the chance of birth defects?

In every pregnancy, a woman starts out with a 3-5% chance of having a baby with a birth defect. This is called her background risk.  Animal studies done by the manufacturer did not show an increased chance for birth defects when abatacept was used in pregnancy. There is a small report from the manufacturer on 151 human pregnancies. This reported did not find a pattern of birth defects to be associated with abatacept use in pregnancy. There is also a case report of a woman with active rheumatoid arthritis who became pregnant while using abatacept, with her last dose just after the fourth week of pregnancy. She delivered a healthy infant that was also reported to be doing well at a 3.5-year follow-up visit.

Could taking abatacept in the second or third trimester cause other pregnancy complications?

At this time, it is not known if there is an increased chance of pregnancy complications when a woman takes abatacept in the second or third trimester.

Does taking abatacept in pregnancy cause long-term problems in behavior or learning for the baby?

At this time there are no studies on the possible long-term effects of abatacept on the baby. It is not known if there is or is not an increased chance of long-term problems in behavior or learning by taking abatacept during pregnancy.

Can I breastfeed while taking abatacept?

There have been no studies looking at the use of abatacept during breastfeeding. Abatacept is poorly absorbed from the gut, so it is unlikely that if any of the medication gets into breast milk that it would enter the baby’s system. It is possible that babies born before 37 weeks of pregnancy (premature) with digestive systems that are not fully developed would be able to absorb more of the medication in breast milk. Be sure to talk to your healthcare provider about all of your breastfeeding questions.

If a man takes abatacept, could it affect his fertility (ability to get partner pregnant) or increase the chance of birth defects? 

The manufacturer had information on 10 men who were taking abatacept when their partners became pregnant, and did not find a greater chance for birth defects. There are no other studies looking at possible risks to a pregnancy when the father takes abatacept. In general, exposures that fathers have are unlikely to increase risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures and Pregnancy (https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/pdf/).

MotherToBaby is currently conducting a study looking at abatacept and other medications used to treat autoimmune diseases 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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