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.