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How Does AS Affect Women?

While ankylosing spondylitis (AS) can develop in both genders, there are some differences between men and women with the disease and some special considerations for women, such as how AS might affect (or be affected by) pregnancy.

Incidence of AS

AS occurs more often in men than women. Earlier estimates suggested AS occurred in 3 men for every 1 woman, but more recent estimates suggest it occurs in 2-3 men for every woman with AS. Historically, AS was considered a “man’s disease,” and this bias may lead to women being underdiagnosed. Women typically have different symptoms than men with AS, and this may also lead to a lengthy process before being diagnosed.1-3

Symptoms of AS in women

In both men and women, AS typically begins in teens or younger adults, under the age of 45. However, while in men the symptoms of AS typically occur in the spine, women are more likely to experience AS in the peripheral joints, those located in the arms and legs. For example, approximately 30 percent of people with AS experience hip or shoulder involvement, and about 30 percent experience AS in their heels. Women with AS can also have pain and stiffness in their spine that is usually worse at night or in the morning and improves with activity.1,2 It’s important to note that there is wide variability between different individuals with AS, both in the severity of symptoms and the progression of the disease.

AS causes chronic inflammation of the affected joints and where the ligaments and tendons attach to the bone, called enthesitis. Enthesitis can cause tenderness or pain and may be called “hot spots.” The chronic inflammation at the joints can lead to the development of bone being formed between the joint, called ankylosis or bony fusion. This can cause stiffness and a loss of mobility.4,5 As AS worsens and the spine becomes more immobilized by the formation of bone in the joints, the spine can take on the appearance of bamboo on x-rays and is referred to as “bamboo spine.” The presence of bamboo spine increases the risk of fractures in the vertebrae.6

Research has found that women with AS report higher levels of pain and issues with day-to-day functioning than men with AS. However, x-rays show men with AS have more erosive damage to the joints than women with AS.7-9

AS and pregnancy

Because AS can affect women during their reproductive years, some women with AS may question how their condition may affect their ability to get pregnant, the health of their pregnancy, or how pregnancy may affect the severity of their AS. The research to date has not found a link between AS and infertility. Women with AS generally have a similar chance of getting pregnant as women who do not have AS. There is no consensus among researchers on whether AS affects the outcome of the pregnancy. Most studies have not found an association between AS and early-term birth or other complications, although one study did find that AS may increase the risk of premature birth, low birth weight, or delivery by Cesarean section (C-section).10,11

A review of the research found that pregnancy is not associated with a reduction in the disease activity of AS.11 One study found that although women had a slight increase in disease activity during the second trimester, overall disease activity was relatively low during the pregnancy.12

Treatment of AS in women

Treatment for AS usually involves a combination of approaches, including medications, physical therapy, and exercise. Medications used to treat AS include11,12:

  • Non-steroidal anti-inflammatory drugs (NSAIDs)
  • Pain relievers (analgesics), including acetaminophen and opioid pain medications
  • Corticosteroids (glucocorticoids), which are generally used for short-term therapy
  • Slow-acting anti-rheumatic drugs (SAARDs)
  • TNF inhibitors

Women who are pregnant, planning to become pregnant, breastfeeding or planning to breastfeed should talk to their doctor before beginning any medications. Some medications may be harmful to an unborn baby or may pass through breastmilk. In March of 2018, Cimzia® (certolizumab) became the first biologic to add to their label that the medication has “minimal transfer” to breast milk and very little transfer through the placenta which may provide women with an option to manage their condition while pregnant and breastfeeding.12-13 Furthermore, it has not been shown to be associated with any birth defects.

Written by: Emily Downward | Last reviewed: February 2019
  1. Ankylosing spondylitis in women vs. men. Face Your Back Pain, AbbVie. Available at https://www.faceyourbackpain.com/understanding-ankylosing-spondylitis/women-vs-men. Accessed 1/14/19.
  2. Overview of ankylosing spondylitis. Spondylitis Association of America. Available at https://www.spondylitis.org/Ankylosing-Spondylitis. Accessed 1/14/19.
  3. Haroon MM, Sayed S, Gheita T. Gender differences in ankylosing spondylitis patients: Relation to clinical characteristics, functional status and disease activity. International Journal of Clinical Rheumatology. 2018;13(4):258-262.
  4. https://www.openaccessjournals.com/articles/gender-differences-in-ankylosing-spondylitis-patients-relation-to-clinical-characteristics-functional-status-and-disease.pdf. Accessed 1/14/19.
  5. Ankylosing spondylitis. Columbia University Department of Neurological Surgery. Available at https://www.columbiaspine.org/condition/ankylosing-spondylitis-2/. Accessed 1/14/19.
  6. How is a person affected? Spondylitis Association of America. Available at https://www.spondylitis.org/Possible-Complications. Accessed 1/14/19.
  7. Babu V and Gaillard F. Bamboo spine. Radiopaedia. Available at https://radiopaedia.org/articles/bamboo-spine. Accessed 1/14/19.
  8. Lee W, Reveille JD, Davis JC, Learch TJ, Ward MM, Weisman MH. Are there gender differences in severity of ankylosing spondylitis? Results from the PSOAS cohort. Ann Rheum Dis. 2006;66(5):633-8.
  9. Holliman K. Sex differences in ankylosing spondylitis. Spondylitis Association of America. Available at https://www.spondylitis.org/About-SAA/Updates/sex-differences-in-ankylosing-spondylitis. Accessed 1/14/19.
  10. Gracey E, Yao Y, Green B, et al. Sexual dimorphism in the Th17 signature of ankylosing spondylitis. Arthritis Rheumatol. 2016 Mar;68(3):679-689.
  11. Ankylosing spondylitis, fact sheet. Mother to Baby. Available at https://mothertobaby.org/fact-sheets/ankylosing-spondylitis/pdf/. Accessed 1/14/19.
  12. Giovannopoulou E, Gkasdaris G, Kapetanakis S, Kontomanolis E. Ankylosing spondylitis and pregnancy: a literature review. Curr Rheumatol Rev. 2017;13(3):162-169. doi: 10.2174/1573397113666170317114857. Abstract.
  13. Disease activity during and after pregnancy in women with axial spondyloarthritis. Spondylitis Association of America. Available at https://www.spondylitis.org/About-SAA/Updates/disease-activity-during-and-after-pregnancy-in-women-with-axial-spondyloarthritis. Accessed 1/14/19.