Racca A, et al. - Researchers investigated if elevated late-follicular phase progesterone (EP) is associated with a deleterious impact on embryo quality (EQ) and cumulative live birth rates (LBRs). Female age and the number of oocytes retrieved increased significantly with increasing serum progesterone (P) values. A linear reduction in utilization rates was noted as P increased for Day 3 embryos, while for Day 5 embryos only the EP group was associated with a significant decrease. Findings thus suggested an association of EP with a decrease in embryo utilization and cumulative LBRs.