P-321 Does the oocyte quality influence the assisted reproductive technology treatment outcomes in women with advanced endometriosis: ? a cohort study

Abstract Study question Is the cumulative live birth rate (LBR) lower in women with diminished ovarian reserve (DOR) and advanced endometriosis versus women without endometriosis but have DOR? Summary answer The cumulative LBR was significantly higher in women with DOR and advanced endometriosis versus those women with DOR who did not have endometriosis. What is known already Earlier studies have shown that surgery for endometriosis negatively influences assisted reproductive technology (ART) outcomes because of its effect on ovarian reserve. On the other hand, it has been suggested that altered oocyte quality and reduced endometrial receptivity are the main causes of reduced success following ART in women with endometriosis. However, it is still unclear how endometriosis affects ART outcomes. We wanted to explore whether excisional surgery and consequent lower oocyte yield during ART in women with endometriosis is the main factor influencing treatment outcomes or whether altered oocyte quality or reduced endometrial receptivity plays an important role. Study design, size, duration The current study is a retrospective cohort study that included women under 41 who underwent their first ART cycle at a tertiary-level academic department between January 2011 and December 2023. After screening a total of 4376 ART cycles, 259 eligible ART cycles were included in the study. We included one ART cycle per woman only. Participants/materials, setting, methods The study population was women with DOR based on POSEIDON groups 3 and 4 who were divided into two groups. The first group included women with endometriosis and DOR who had previously undergone surgery for endometrioma while the second group included women with DOR who did not have endometriosis. The primary outcome was cumulative LBR while secondary outcomes included clinical pregnancy and implantation rates. We performed a 1:2 propensity matching and a logistic regression. Main results and the role of chance There was no significant difference between the live birth per fresh cycle (32.7% vs. 19.1%; P 0.06) and frozen cycles (66.7% vs. 41.7%; P 0.32) in women with endometriosis versus those without endometriosis. The live birth per completed cycle did not differ significantly between women with endometriosis versus no endometriosis (30.4% vs. 17.9%; P 0.18). The cumulative LBR (32.1% vs, 19.6%; odds ratio, OR, 0.52, confidence interval, CI, 0.24 -1.10; P 0.08) also did not differ significantly between the two groups. However, after adjusting for stage and type of embryo transfer as well as the number of embryos transferred, the adjusted odds ratio (aOR) for cumulative LBR was significantly higher in the women with endometriosis and DOR (aOR, 0.39, CI 0.17- 0.89; P 0.025) versus those without endometriosis. Limitations, reasons for caution The retrospective design with its inherent bias along with the small sample size are the main limitations of the current study. Wider implications of the findings In a homogenous cohort of women at risk of poor response, the ART outcomes in women with advanced endometriosis were not inferior to those without endometriosis, implying minimal role of oocyte quality or endometrial receptivity on treatment outcomes. The focus should be on maximizing the oocyte yield in advanced endometriosis. Trial registration number No