Decrease of dysmenorrhoea with hormonal treatment is a marker of endometriosis severity.

RESEARCH QUESTION: Is a decrease in dysmenorrhoea after suppressive hormonal therapy a marker of the endometriosis phenotype and of greater disease severity? DESIGN: Retrospective observational cohort study conducted in a French university hospital, between January 2004 and December 2019. Non-pregnant women aged younger than 42 years, who tested for dysmenorrhoea relief after suppressive hormonal therapy before surgery, and who had histological confirmation of endometriosis, were included. The comparisons were carried out according to the results of the suppressive hormonal test. RESULTS: Of the 578 histologically proven endometriosis patients with preoperative pain symptoms, the rate of dysmenorrhoea decrease after suppressive hormonal therapy was 88.2% (n = 510). These patients had a higher incidence of deep infiltrating endometriosis (DIE) intestinal lesions (45.7% [233/510] versus 30.8% [21/68], P = 0.01) and an increased rate of multiple DIE lesions (two or more) (72.8% [287/394] versus 56.4% [22/39], P = 0.02). After multivariate analysis, decrease of dysmenorrhoea after suppressive hormonal therapy remained significantly associated with the severe DIE phenotype (adjusted OR 3.9, 95% CI 2.0 to 7.6, P < 0.001). CONCLUSION: In women with endometriosis, a decrease of dysmenorrhoea after suppressive hormonal therapy is associated with the DIE phenotype and is a marker of greater severity.