The effect of progesterone level on day of trigger on embryo ploidy in egg donor's cycles.

Purpose: Elevated progesterone (P4) has emerged as a cofounder for embryo quality and recently been investigated in blastocyst aneuploidy rates. In this context, we explored the prevalence of aneuploidy in blastocysts generated from donated eggs according to P4 levels on trigger's day.

Methods: This retrospective cohort study analyzed data from intracytoplasmic sperm injection (ICSI) cycles using frozen donated oocytes that underwent embryo biopsy (PGT-A) at blastocyst stage. Patients were divided into two groups according to serum P4 on trigger day: < 1.5 ng/mL (group A) and ≥ 1.5 ng/mL (group B). Only euploid embryos were transferred to recipients. Primary outcome was embryo euploidy and aneuploidy rate. Secondary outcomes were number of blastocysts, number of top-quality embryos, number of euploid/aneuploid embryos and clinical pregnancy rate.

Results: 259 ICSI PGT-A cycles with frozen donated oocytes were analyzed. Group A included 75 cycles (57 donors; 69 recipients) and group B 184 cycles (115 donors; 163 recipients). The number of blastocysts (3.60 ± 1.52 vs 3.68 ± 1.52, P = 0.667), top-quality embryos (2.27 ± 1.59 vs 2.28 ± 1.43, P = 0.802), euploid embryos (1.92 ± 1.25 vs 1.92 ± 1.13, P = 0.954) and aneuploid embryos (1.23 ± 1.01 vs 1.14 ± 0.94, P = 0.593) were not significantly different between groups A and B, respectively. Euploid embryo rate (A: 0.31 ± 0.20 vs B: 0.30 ± 0.18, P = 0.626), aneuploidy embryo rate (A: 0.21 ± 0.19 vs B: 0.18 ± 0.15, P = 0.436) and clinical pregnancy rate (A: 73% vs B: 82%, P = 0.476) were comparable between the two groups.

Conclusions: Elevated P4 values on trigger day did not affect embryo ploidy or embryo quality parameters in donated eggs cycles.