Endometriosis affects 10 -15% of reproductive age women. ¹ It occurs when endometrial- like tissue is found in areas outside of the uterine cavity, often in the pelvis, but they can be found just about anywhere. There is neither a universal screening tool nor non-surgical diagnostic instrument in use; with the exception of endometriomas on ultrasound, only surgically obtained pathology can confirm endometriosis. Most women suffer without a diagnosis for between 4 – 11 years and see numerous physicians before finally being given some answers. ²

A good history though may provide several clues to help determine which patients are likely to have endometriosis. The key presentation of pelvic pain and extreme, often disabling menstrual cramping should trigger the RRM clinician to consider endometriosis. This Clinical CHARRM Pearl looks at studies that have identified cycle abnormalities and their relationship to endometriosis. RRM uses fertility or cycle charting as a key instrument in guiding our diagnoses and treatment so it seems reasonable to understand what the non-RRM research has found and apply it to our work.

Information from the patient’s cycle charting may provide additional evidence supporting the diagnosis of endometriosis, although these are non-RRM studies, they apply well to our field and may give further confirmation of what most of us see in our patient’s charting.

Epidemiologic studies have identified that patients with endometriosis often having shorter cycles than most women. ^{3, 4}  A 2014 study by Heitman ⁵identified 2 or greater days of premenstrual spotting as having 90% specificity and 76% sensitivity and a positive predictive value of 96%. Further work in 2017 involving over 48 thousand women completing a cross-sectional survey identified the following as being associated with findings of endometriosis – heavy menstrual bleeding (OR 1.5 95% CI of 1.3 -1.7), excessive or irregular bleeding (OR 2.1 95% CI 1.8 – 2.4), passing clots (OR 1.8 95% CI, 1.6–2.0), and irregular menstruation either timing or duration (OR, 1.5 95% CI, 1.3–1.7). ⁶

If a patient presents with a history of pelvic pain and these charting abnormalities, consider endometriosis. Further research is needed to refine and identify specifics seen in cycle charts used in RRM, but based on the above studies this RRM approach may prove particularly beneficial in helping diagnose patients with this difficult condition.