Design: Prospectively collected data were analysed. Data were collected at three timepoints: pre-appointment patient questionnaire, initial appointment, and surgery. Surgery was done by gynecologists specializing in endometriosis.

Setting: Tertiary referral centre for pelvic pain and endometriosis.

Patients or Participants: Participants included were aged 18 to 50, pre-menopausal, diagnosed with endometriosis via specified criteria, and underwent surgery at our centre. A total of 358 participants referred to our centre between January 2018 and December 2019 completed the study. The median follow-up (duration between pre-appointment questionnaire and surgery) was 6 months, range 0-28 months.

Interventions: Participants who reported that orgasm worsened their pelvic or lower abdominal pain were compared to those who did not.

Measurements and Main Results: Among 358 participants, 14% (n=49) reported pelvic pain worsened by orgasm. Pain with orgasm was significantly associated with pelvic floor myalgia (p = 0.01), higher scores on the Central Sensitization Inventory (p < 0.001), Patient Health Quality-9 (p < 0.001), and Generalized Anxiety Disorder-7 (p = 0.002). For surgical findings, there was no difference between the two groups for revised American Society for Reproductive Medicine scores (p=0.07). There was a trend towards ovarian endometriosis more commonly seen in participants without orgasm-associated pain (p=0.049). However, the prevalence of superficial peritoneal endometriosis, deep infiltrating endometriosis, and cul-de-sac obliteration were similar between the two groups.

Conclusion: Pelvic pain worsened by orgasm in people with endometriosis may be associated with concurrent pelvic floor myalgia and central sensitization. Interventions targeting these factors may alleviate the symptom. There were no associations with more anatomically severe endometriosis found at surgery. Further research is needed to identify effective treatments.