Examining the co-occurrence of endometriosis and polycystic ovarian syndrome

Authors: Schliep KC, Ghabayen L, Shaaban M, Hughes FR, Pollack AZ, Stanford JB, Brady KA, Kiser A, Peterson CM.

Publication: AJOG Global Reports. 2023 Aug 1;3(3):100259.


Endometriosis and polycystic ovarian syndrome (PCOS) are two common gynecological conditions affecting 11% and 6-15% of people assigned female at birth, respectively. While it is well known that some women suffer with both endometriosis and PCOS, the prevalence of co-occurrence of these conditions is unknown. Therefore, the authors of this study investigated how common it is for patients to have both endometriosis and PCOS at the same time.

In this study, a total of 600 women were enrolled. The first group (operative cohort) included 473 women between the ages 18-44 who underwent either laparoscopy or laparotomy in 2007-2009 in the USA. The second group was composed of 127 persons who were not actively seeking gynecologic care (a population cohort) and were matched to the operative cohort by age and residency. People diagnosed with endometriosis prior to this study were excluded. A history of PCOS, subfertility, and pelvic pain was assessed in each study participant during an interview. Subfertility was defined as unsuccessful fertility lasting less than 12 months in individuals younger than 35 years old or less than 6 months if older than 35 old.

Key findings:

Take home message:

Endometriosis and PCOS occur together in approximately 5% of women undergoing gynecologic surgery. In contrast, endometriosis and PCOS occur together in only 2% of the population seeking general gynecology care. Difficulty conceiving was more common in women with both endometriosis and PCOS than when either condition was present alone. Therefore, the potential co-occurrence of endometriosis and PCOS should be considered in women with either condition seeking fertility care. The authors highlight the urgent need for less invasive endometriosis diagnosis methods that will enable tailoring more informed fertility treatment plans.


This study is based on data collected 14-16 years ago. Diagnostic criteria for PCOS diagnosis as well as endometriosis diagnosis techniques have evolved since the data underpinning this study was collected and thus prevalence and co-occurrence rates may have shifted in recent years.