Pain after oocyte retrieval in women with endometriosis undergoing fertility preservation or IVF

Research question: Do women with endometriosis undergoing oocyte retrieval for fertility preservation experience the same level of pain as women undergoing oocyte retrieval for IVF? Design: This retrospective cohort study included 796 cycles in women with endometriosis undergoing oocyte retrieval for fertility preservation ( n = 401) or IVF ( n = 395) between January 2020 and October 2022. Post-operative pain assessments were compared between the two groups using a numeric rating scale (NRS). Results: Women in the fertility preservation group were younger (32.1 +/- 4.2 years versus 35.1 +/- 4.1 years; P < 0.001), had a lower body mass index (22.8 +/- 3.9 kg/m 2 versus 24.6 +/- 4.4 kg/m(2) ; P < 0.001) and had a lower concentration of anti-Mu <euro> llerian hormone (1.8 +/- 1.5 ng/ml versus 2.15 +/- 2.11 ng/ml; P = 0.026) in comparison with women in the IVF group. The oestrogen concentration on the day of ovulation trigger was higher in women in the fertility preservation group (2188 +/- 1152 pg/ml versus 2081 +/- 995 pg/ml; P = 0.004), and the prevalence rates of adenomyosis and digestive endometrial lesions were lower in women in the fertility preservation group (14% versus 29%, P < 0.001; 16% versus 25%, P = 0.003, respectively) compared with women in the IVF group. After oocyte puncture, more women in the fertility preservation group had an NRS pain score > 3 (moderate to severe pain) compared with women in the IVF group (20% versus 14%; P = 0.018). The progestin-primed ovarian stimulation (PPOS) protocol was identi fi ed as an independent predictive factor of greater post-operative pain (adjusted OR 2.30, 95% CI 1.06- 5.15; P = 0.039). Conclusion: Women with endometriosis undergoing fertility preservation reported more intense post-operative pain in the recovery room than women undergoing IVF. The PPOS protocol was an independent risk factor of intense pain (NRS pain score > 3) in women with endometriosis, but further studies are needed to confirm this result.