Comparison of euploidy rates between progestin-primed ovarian stimulation and GnRH antagonist protocols: a single-center study in a mixed-ethnicity population.

OBJECTIVE

To compare the euploidy rate between ovulation suppression protocols using PPOS and GnRH-ant, and to evaluate possible variables associated with euploidy rate such as age, BMI, infertility duration, treatment-related factors, and semen parameters, in a genetically admixed Brazilian population underrepresented in reproductive medicine research.

DESIGN

This was a retrospective non-inferiority case-control study including 268 IVF cycles, conducted between 2021 and 2022. Subjects: A total of 268 in vitro fertilization (IVF) cycles were included, all with indication for preimplantation genetic testing for aneuploidy (PGT-A), of which 64.5% (n = 173) were included in the PPOS group, and 35.5% (n = 95) in the GnRH-ant group. A statistical power of 85% was achieved for the primary outcome.

EXPOSURE: Patients underwent controlled ovarian stimulation using either progestin-primed ovarian stimulation (PPOS) or GnRH antagonist (GnRH-ant) protocols.

MAIN OUTCOME MEASURES: The primary outcome was the euploidy rate in PPOS and GnRH-ant groups.

RESULTS

No significant differences were observed in euploidy rate between the PPOS and GnRH-ant groups (25.9% vs. 27.5%; p = 0.865; r = 0.01). In the adjusted analysis, stimulation protocol was not significantly associated with euploidy rate (coefficient = 3.38; 95% CI: -14.26 to 16.03), whereas maternal age remained significantly and negatively associated with the outcome (coefficient = -7.83; 95% CI: -11.85 to -3.81). Fertilization rate was higher in the GnRH-ant group (p = 0.004), but this did not affect embryo formation or euploidy outcomes. Paternal age and semen parameters were not significantly associated with euploidy.

CONCLUSION

According to the prespecified criterion, PPOS met the formal criterion for non-inferiority in relation to GnRH-ant regarding euploidy rate, although with limited margin. These findings support PPOS as a viable option in freeze-all/PGT-A cycles, but they should be interpreted with caution given the retrospective design and baseline differences between groups.