The effect of late-follicular phase progesterone rise on embryo ploidy, blastocyst formation rate and cumulative live birth rates following a freeze-only strategy

Abstract Research question Is late-follicular phase progesterone elevation (PE) associated with a deleterious effect on embryo euploidy, blastocyst formation rate and cumulative live birth rates (CLBRs)? Design We performed a multicenter retrospective cross-sectional study including infertile patients aged 18-40 years who underwent ovarian stimulation in a GnRH antagonist protocol and preimplantation genetic testing for aneuploidies (PGT-A) followed by a freeze-all strategy and euploid embryo transfer between August 2017-December 2019. The sample was stratified according to the progesterone levels on the day of trigger: normal (≤1.50 ng/ml) and high (>1.50 ng/ml). Moreover, sensitivity analysis were performed to determine whether different conclusions would have been drawn if different cut-offs had been adopted. The primary outcome was the embryo euploidy rate. Secondary outcomes were the blastocyst formation rate, the number of euploid blastocysts, and CLBRs. Results Overall 1495 ICSI PGT-A cycles were analyzed. Late-follicular phase PE was associated with higher late-follicular estradiol levels (2847.56±1091.10 pg/ml vs. 2240.94±996.37 pg/ml, p Conclusions Euploidy rate and CLBR do not differ among PGT-A cycles with and without late-follicular PE in a freeze-all approach.