Structural reproductive problems and risk of endometriosis: A population-based cohort study

To examine the association between structural reproductive anomalies and the risk of endometriosis.

This study used data from the Genetic variants, Early Life exposures, and Longitudinal Endometriosis symptoms Study (GELLES), a sub-study of the Australian Longitudinal Study on Women's Health (ALSWH). We included 8563 women from two population-based cohorts (born 1989-95 and 1973-78). Poisson regression with robust error variance was used to estimate relative risks (RRs) and 95% confidence intervals (CIs), adjusting for sociodemographic, lifestyle, and reproductive or health-related factors.

Endometriosis was identified using self-reported data from the GELLES survey and validated against linked health records.

In both cohorts, structural reproductive anomalies were associated with an increased risk of endometriosis. In the 1973-78 cohort, women with structural anomalies were more likely to have endometriosis, with adjusted RR = 1.88 (95% CI 1.53, 2.30); similar findings were observed in the 1989-95 cohort, 1.63 (1.25, 2.13). In site-specific analyses of the 1973-78 cohort, uterine 1.86 (1.48, 2.35), cervical 1.77 (1.20, 2.62), and vaginal 3.23 (1.39, 7.55) anomalies were each independently associated with a higher risk. Both congenital uterine anomalies 2.48 (1.72, 3.59) and uterine positional variants, such as a retroverted uterus 1.66 (1.25-2.20), were linked with endometriosis. Associations remained consistent, though slightly attenuated, after excluding women with corrective surgery.

Structural reproductive anomalies are independently associated with a higher risk of endometriosis. Greater clinical awareness and targeted monitoring of reproductive tract anomalies may support earlier recognition and management, potentially reducing disease burden.