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. This sheet talks about whether exposure to abatacept may increase the risk for birth defects over that background risk. This information should not take the place of medical care and advice from your health care 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 health care 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®.

How long does abatacept stay in the body? Should I stop taking it before I try to get pregnant?

Individuals break down medicines at different rates. The average time it takes for this medication to leave the body is about 10 weeks (or 2 and ½ months) after taking the last dose of abatacept.

However, you should not stop taking any medication without first talking with your healthcare provider. The benefits of taking abatacept and treating your autoimmune condition during pregnancy need to be weighed against any possible risks of continuing the medication.

Can taking abatacept make it more difficult for me to become 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. At this time, it is not known if taking abatacept would make it more difficult for a woman to get pregnant.

Can taking abatacept during my pregnancy increase the chance of miscarriage?

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

Can taking abatacept during my pregnancy cause birth defects?

Probably not. 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 pregnancies, which 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 fourth week of pregnancy. She delivered a healthy infant that was also reported to be fine at a 3.5-year follow-up visit.

Can I take abatacept while breastfeeding?

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 premature babies (born before 37 weeks gestation) 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 health care provider about all of your breastfeeding questions.

What if the father of the baby takes abatacept?

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/.

Selected References:

  • Kumar M, et al. 2015. Pregnancy outcomes following exposure to abatacept during pregnancy. Semin Arthritis Rheum. 45(3):351-6.
  • Makol A, et al. 2011. Rheumatoid arthritis and pregnancy: safety considerations in pharmacological management. Drugs. 22;71(15):1973-87.
  • Ojeda-Uribe M, et al. 2013. Exposure to abatacept or rituximab in the first trimester of pregnancy in three women with autoimmune diseases. Clin Rheumatol. 32(5): 695-700.
  • Orencia Prescribing Information. Available online at http://packageinserts.bms.com/pi/pi_orencia.pdf. Accessed 27 Jul 2012.
  • Ostensen M and Förger F. 2011. Treatment with biologics of pregnant patients with rheumatic diseases. Curr Opin Rheumatol. 23(3):293-8.
  • Partlett R and Roussou E. 2011. The treatment of rheumatoid arthritis during pregnancy. Rheumatol Int. 31(4):445-9.
  • Pham T., et al. 2012. Abatacept therapy and safety management. Joint Bone Spine 79 Suppl 1:3-84.