Infertility Linked to Higher Risk of Autoimmune Diseases Post-Childbirth

Women who experience infertility but do not undergo fertility treatments may face a heightened risk of developing systemic autoimmune rheumatic diseases (SARD) within nine years of giving birth, according to new research published in Human Reproduction. These findings persist even when accounting for pregnancy complications such as preeclampsia, preterm birth, and stillbirth, which are often associated with infertility.

New Insights Into the Infertility-SARD Connection

The study, conducted by researchers from the University of Toronto Scarborough, analyzed health data from 465,078 women who gave birth to 568,053 singletons in Ontario, Canada, between 2012 and 2021. Women with infertility who did not use fertility treatments had a 25% higher risk of developing SARD compared to women without infertility issues. This equates to about 13 new cases of SARD per 10,000 women annually in the infertility group, compared to nine cases per 10,000 women annually in the reference group.

Interestingly, women who used fertility treatments—whether non-invasive methods like ovulation-inducing medications or invasive techniques such as in vitro fertilization (IVF)—did not exhibit the same increased risk. Their rates of SARD were comparable to those of women without infertility, at approximately 11 new cases per 10,000 women annually.

The study’s lead author, Dr. Natalie V. Scime, noted that this disparity could be partially explained by the "healthy patient effect," where women who undergo fertility treatments may have better access to healthcare and a generally healthier baseline.

Why These Findings Matter

Systemic autoimmune rheumatic diseases, which include conditions such as lupus, Sjögren’s syndrome, and inflammatory myopathy, are rare but can significantly impact quality of life. These conditions disproportionately affect women, particularly during their reproductive years.

The study highlights infertility as a potential risk marker for SARD, underscoring the need for vigilant screening and early diagnosis. Infertility care presents an opportunity for doctors to screen for rheumatic symptoms, such as unexplained fatigue or joint pain, and initiate referrals to specialists when necessary, Dr. Scime explained. Early detection is critical, as SARD often goes undiagnosed for years, potentially leading to organ damage and poorer outcomes.

Although the study shows a clear association, it does not establish causation. The researchers point out that infertility may have various underlying causes, such as endometriosis or advanced maternal age, that could influence the observed link with SARD. Future research is needed to explore the biological pathways connecting infertility and autoimmune diseases, as well as to examine whether specific infertility causes carry a higher SARD risk.

For clinicians, this study serves as a reminder to monitor women with a history of infertility for symptoms of autoimmune diseases, even years after childbirth, to improve patient outcomes and quality of life.