Impact of controlled ovarian hyperstimulation protocols on aneuploidy of preimplantation blastocysts in women aged 21-37 years old.

Purpose: This study aimed to explore whether different controlled ovarian hyperstimulation (COH) protocols were associated with the incidence of aneuploid blastocysts in cycles undergoing preimplantation genetic testing for aneuploidy (PGT-A).

Methods: A retrospective analysis was conducted on 5525 blastocysts from 1722 women (21-37 years old) who underwent PGT-A cycles utilizing next-generation sequencing (NGS). The cohorts included 240 cycles employing the gonadotropin-releasing hormone agonist (GnRH-a) short protocol, 698 cycles using the GnRH-a long protocol, and 784 cycles utilizing the GnRH antagonist (GnRH-ant) protocol.

Results: A significantly elevated rate of blastocyst aneuploidy was observed in the GnRH-a short protocol group relative to both the long protocol and antagonist protocol groups (44.05% vs. 36.00% vs. 37.90%). Multivariable regression analyses, with the GnRH-a long protocol serving as the reference category, indicated that the short protocol was independently correlated with higher aneuploidy rates (OR = 1.30, 95% CI 1.06-1.60, P = 0.012). This association was particularly evident among younger patients (< 35 years) possessing preserved ovarian reserve (AMH ≥ 1.2 ng/mL) (OR = 1.38, 95% CI 1.02-1.87, P = 0.036). Although non-significant, the short protocol also trended towards a higher aneuploidy rate compared to the antagonist protocol (OR = 1.12, 95% CI 0.89-1.41, P = 0.32).

Conclusions: The findings suggest that, in the population studied (21-37 years), the GnRH-a short protocol is associated with a higher incidence of blastocyst aneuploidy compared to the long protocol, particularly in younger individuals (< 35 years) with normal ovarian reserve (AMH ≥ 1.2 ng/mL). These results highlight the need for tailored COH protocol selection based on patient characteristics in PGT-A cycles.