P-338 Impact of Endometriosis on IVF Outcomes: A Comprehensive Review of Ovarian Stimulation, Pre-treatment Strategies, and Adjunctive Therapies

Abstract Study question How does endometriosis affect IVF outcomes, and can novel approaches like Elagolix improve key fertility parameters and cumulative live birth rates Summary answer Endometriosis variably affects IVF success, with Elagolix and progestin-primed protocols enhancing fertilization and oocyte yields, though pregnancy and live birth rates remain inconsistent across studies. What is known already Endometriosis is a significant cause of infertility, impairing oocyte quality, fertilization rates, and cumulative live birth rates (CLBR), particularly in advanced stages. Traditional IVF approaches, including GnRH agonists and injectable GnRH antagonists, have yielded inconsistent improvements in clinical pregnancy rates. Recent advancements, such as Elagolix, an oral GnRH antagonist, have shown promise with comparable ovulation suppression, improved biochemical pregnancy rates, and reduced patient burden. Progestin-primed ovarian stimulation (PPOS) protocols have demonstrated improved oocyte yields and effective LH suppression. However, the overall impact on key IVF outcomes remains unclear, necessitating a comprehensive review of evidence to guide future treatment strategies. Study design, size, duration This study is a comprehensive review of 13 randomized controlled trials (RCTs) examining impact of endometriosis on IVF outcomes. It includes a total of 3,260 patients, with study sizes ranging from 36 to 786 and an average of 218 patients per study. The review focuses on ovarian stimulation protocols, pre-treatment strategies, and adjunctive therapies. Key outcomes analyzed include fertilization rates, implantation rates, clinical pregnancy rates, and cumulative live birth rates (CLBR), using extracted statistical data. Participants/materials, setting, methods We analyzed 3,260 patients from 13 RCTs focusing on IVF outcomes in women with endometriosis. Various protocols were examined, including ovarian stimulation methods, pre-treatment strategies such as oral Elagolix, and adjunctive therapies. Fertilization rates, implantation rates, clinical pregnancy rates, and cumulative live birth rates (CLBR) were key outcomes. The studies were conducted in different clinical and research environments, with statistical data extracted to evaluate the effectiveness and impact of these treatment approaches. Main results and the role of chance 13 studies evaluated the impact of endometriosis on IVF outcomes, involving 3,260 patients. 4 studies reported improvements in specific IVF outcomes, such as fertilization rates and serum markers, 9 found no significant effect on key outcomes like pregnancy rates. The number of patients varied from 36 to 786, with average 218 patients per study. Correlation analysis revealed a moderate positive relationship (r = 0.56, p = 0.049) between study size and positive outcomes. Elagolix was evaluated in 342 patients (10.4% of the total). It demonstrated comparable efficacy to GnRH antagonists for ovulation suppression, with similar fertilization rates (79.7% vs. 84.6%, p = 0.18). However, it showed superior biochemical pregnancy rates in frozen embryo transfers (74.5% vs. 55.9%, p < 0.05) and reduced patient burden by requiring 4.2 fewer injections per cycle. Progestin-primed ovarian stimulation (PPOS) protocols improved oocyte yields (9.3 vs. 7.8, p = 0.021) and effectively suppressed LH surges. Prolonged GnRH agonist therapy reduced cytokine levels in follicular fluid and improved fertilization rates (72.7% vs. 61.7%, p < 0.05), though clinical pregnancy rates remained unaffected. ICSI achieved higher fertilization rates than conventional IVF (73.3% vs. 54.7%, p = 0.003). Adjunctive therapies, including Dienogest and lipiodol, showed mixed results Limitations, reasons for caution The review is limited by the variability in study designs, sample sizes, and outcome measures across the 13 RCTs. Additionally, inconsistent reporting of key IVF outcomes, lack of long-term follow-up data, and potential publication bias may affect the reliability of findings. Further large-scale, well-controlled studies are needed for stronger conclusions. Wider implications of the findings Endometriosis impacts IVF outcomes variably. While some treatments, such as Elagolix and progestin-primed protocols, improved fertilization and oocyte yields, most studies found no significant effect on pregnancy rates. Larger studies reported more positive outcomes (r = 0.56, p = 0.049). ICSI and adjunctive therapies demonstrated selective benefits but require investigation Trial registration number No