JBRA Assisted Reproduction 2025;29(Suppl.2 SBRA 2025):11
Oral Presentation
29^th Annual Congress of the SBRA. São Paulo/SP - Brazil, 2025
doi: 10.5935/1518-0557.20263527

O-11. Progestin-Primed Ovarian Stimulation and GnRH Antagonist Protocol yield comparable embryological and clinical outcomes: a large retrospective cohort study

Eduarda Nabinger¹, Priscila Scalco¹, Mariana Lopes¹, Gabriella Mamede Andrade¹, Nilo Frantz¹, Marcos Iuri Roos Kulmann¹

¹Nilo Frantz Medicina Reprodutiva - Porto Alegre - RS - Brasil

Objective: Progestin-primed ovarian stimulation (PPOS) has emerged as a patient-friendly alternative to GnRH antagonist regimens for the prevention of premature LH surges during controlled ovarian stimulation (COS). Its oral administration and cycle scheduling flexibility offer practical advantages for both patients and clinicians. Despite these benefits, robust comparative evidence on the live birth rate (LBR) remains limited. This study aimed to compare PPOS and GnRH antagonist protocols regarding embryological and clinical outcomes in PGT-A cycles, with a particular focus on the LBR.
Methods: This retrospective cohort study included 860 patients undergoing COS for IVF at a single reproductive center (January 2022–December 2023). Patients were allocated to PPOS (n = 315) or GnRH antagonist (n = 545) protocols based on the physician preference. The primary outcome was LBR per transfer. Secondary outcomes included β-hCG positivity, clinical pregnancy rate (CPR), miscarriage rate (MR) and key embryological parameters. Blastocyst quality was assessed using the Gardner grading system, with top-quality embryos defined as having inner cell mass and trophectoderm grades of AA, AB, BA, or BB. Continuous variables were compared using Mann–Whitney U tests; categorical variables via Chi-square or Fisher’s exact test.
Results: Baseline characteristics were comparable between the PPOS and antagonist groups, with mean oocyte age of 33.7±5.7 vs. 33.1±5.2years (p=0.116). Groups exhibited similar yield of metaphase II (MII) oocytes (14.4±9.6 vs. 13.7±8.9, p=0.709), fertilization rates after ICSI (80.6% vs. 81.2%, p=0.406) and embryo development outcomes, with blastocyst formation rates of 66.3% vs. 63.8% (p=0.218) and top-quality blastocyst rates of 77.5% vs. 81.3% (p=0.766) for PPOS and antagonist cycles, respectively. Clinical outcomes further confirmed the parallel performance of the two protocols. Positive β-hCG rates were 69.8% vs. 66.2% (p=0.290), CPR reached 63.2% vs. 60.0% (p=0.383) and MR were comparable at 8.9% vs. 12.7% (p=0.094). Notably, the LBR per tranfer was similar between PPOS and antagonist protocols (53.0% vs. 47.0%, p=0.089).
Conclusion: PPOS and GnRH antagonist protocols yield comparable embryological and clinical outcomes. This large, real-world dataset supports the use of PPOS as a viable and patient-friendly alternative to GnRH antagonists, potentially enhancing patient comfort without compromising results. Future randomized controlled trials are warranted to confirm these findings and to identify specific patient subgroups that may derive additional benefit.