This sheet is about having ankylosing spondylitis in a pregnancy or while breastfeeding. This information is based on available published literature. It should not take the place of medical care and advice from your healthcare provider.
What is ankylosing spondylitis?
Ankylosing spondylitis (AS) is an inflammatory disease with symptoms that can include swelling, stiffness, pain, and fatigue (feeling extremely tired). AS is a type of arthritis (swelling and tenderness of one or more joints). Sometimes, severe AS can lead to the formation of new bone that causes the spine to become fused or stuck in one position.
I am taking medication for ankylosing spondylitis. Can I take my medication during pregnancy?
Since people with AS can take medication to control inflammation and prevent or reduce joint damage, it is important to talk with your healthcare providers about your medications and the best treatment options before trying to get pregnant. For information on specific medications, see our fact sheets at https://mothertobaby.org/fact-sheets/ or speak with a MotherToBaby specialist.
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 your medication. Your healthcare providers can talk with you about the benefits of treating your condition and the risks of untreated illness during pregnancy.
I have ankylosing spondylitis. Can it make it harder for me to get pregnant?
It is not known if having AS can make it harder to get pregnant. There is no evidence to suggest AS could cause problems getting pregnant.
Will pregnancy affect my AS symptoms?
It is hard to predict if or how AS symptoms might change during pregnancy. Some studies suggest that symptoms stay about the same during pregnancy and others suggest symptoms can get better. However, some people report an increase in symptoms, especially as the pregnancy gets further along. Pregnancy does not appear to reduce the chance of AS flare-ups like it might for some other autoimmune conditions. An increase in symptoms is common in the first few months after delivery. This does not mean that the symptoms will continue long-term.
Does having ankylosing spondylitis increase the chance for miscarriage?
Miscarriage is common and can occur in any pregnancy for many different reasons. It is not known if having AS could increase the chance for miscarriage.
Does having ankylosing spondylitis increase the chance of birth defects?
Every pregnancy starts with a 3-5% chance of having a birth defect. This is called the background risk. It is not known if AS increases the chance for birth defects above the background risk. One small study found that the thymus (part of the body’s immune system) was smaller in babies born to people with rheumatic disease, including AS. However, this study did not find differences in health outcomes among this group.
Would having ankylosing spondylitis increase the chance of other pregnancy-related problems?
Several studies have not found an increased chance for pregnancy complications in people with AS. However, a few studies have reported that having AS might increase the chance for preterm delivery (birth before week 37) and lower birth weights in babies. There may also be an increased need for the baby to be in the neonatal intensive care unit (NICU) after delivery. The chance for these complications may be higher in those with more AS symptoms, in those who also have other medical conditions, or in people who develop preeclampsia (high blood pressure and problems with organs, such as the kidneys) in their pregnancy.
Does having ankylosing spondylitis in pregnancy affect future behavior or learning for the child?
Studies have not been done to see if AS can cause behavior or learning issues for the child.
Breastfeeding while I have ankylosing spondylitis:
AS does not appear to affect the ability to breastfeed. If you are having trouble with breastfeeding, contact your healthcare provider or a lactation specialist.
Can I take my medication for ankylosing spondylitis while breastfeeding?
Many medications for AS can be used while breastfeeding. Some medications may increase risks to a nursing child. For information on specific medications, see our fact sheets or contact MotherToBaby to speak with a specialist. Be sure to talk to your healthcare provider about all of your breastfeeding questions.
If a male has ankylosing spondylitis, can it make it harder to get a partner pregnant or increase the chance of birth defects?
AS might affect male fertility (ability to get partner pregnant). No increased chance of birth defects was reported in a study looking at pregnancy outcomes in partners of males who were treated for AS. In general, exposures that fathers or sperm donors have are unlikely to increase the 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 studies looking at medications used to treat ankylosing spondylitis (AS) in pregnancy. If you are interested learning more about these studies, please call 1-877-311-8972 or visit 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.
