JBRA Assisted Reproduction 2025;29(Suppl.2 SBRA 2025):60
Poster Presentation
29^th Annual Congress of the SBRA. São Paulo/SP - Brazil, 2025
doi: 10.5935/1518-0557.20263599

P-48. Comparison of Progestin-Primed Ovarian Stimulation Using Dydrogesterone Versus GnRH Antagonist Protocol on Laboratory and Clinical Outcomes of In Vitro Fertilization

Kazue Harada Ribeiro¹, Mila Harada Ribeiro Cerqueira¹, Gustavo Cerqueira Silva¹, Roberta Marcolino Tesch¹, Vanessa Nayane Pino Perez¹

¹ CLINIFERT - Florianópolis - SC - Brasil

Objective: To compare the effects of progestin-primed ovarian stimulation using dydrogesterone (DYD) and a gonadotropin-releasing hormone antagonist protocol (GnRH) during in vitro fertilization (IVF) cycles, evaluating fertilization, cleavage, blastocyst formation, embryo euploidy, number of injected oocytes, and clinical outcomes after embryo transfer.
Methods: Retrospective cohort study including patients who underwent IVF cycles between 2024 and 2025. Patients were divided into two groups based on the protocol used: DYD group (n=136) and GnRH group (n=208). We compared mean patient age, number of injected oocytes, fertilization rate, cleavage, blastocyst formation, and euploidy (in cases with preimplantation genetic testing – PGT-A), as well as clinical outcomes after embryo transfer (positive or negative β-hCG and miscarriage). Data were analyzed using the chi-square test for categorical variables and the Mann-Whitney test for numerical variables. A p-value <0.05 was considered statistically significant.
Results: Mean age was similar between groups: 35.2 years in the DYD group and 36.2 years in the GnRH group (p=0.072). The DYD group had a significantly higher mean number of injected oocytes (10.6) compared to the GnRH group (7.3) (p<0.0001). The mean fertilization rate was significantly lower in the DYD group (84.5%) than in the GnRH group (89.72%) (p=0.0005). Similarly, the blastocyst formation rate was lower in the DYD group (46.28%) compared to the GnRH group (54.60%) (p=0.020). However, the cleavage rate did not differ significantly: 90% in the DYD group and 88.5% in the GnRH group (p=0.46). Among patients who underwent PGT-A (n=85 in the DYD group and n=63 in the GnRH group), euploidy rates were 44.5% and 40%, respectively, with no statistical difference (p=0.445). A total of 102 embryo transfers were performed in the DYD group and 174 in the GnRH group. There were no significant differences in clinical outcomes (positive β-hCG, negative, or miscarriage) between groups (p=0.543).
Conclusion: Although the DYD group had a higher mean number of injected oocytes, it showed significantly lower fertilization and blastocyst formation rates compared to the GnRH group. Cleavage, euploidy rates and clinical outcomes were similar between groups. These findings suggest that the GnRH protocol may offer advantages in laboratory IVF parameters without significantly impacting early clinical pregnancy outcomes.