Adverse impact of elevated progesterone levels on human chorionic gonadotropin trigger day on blastocyst transfer outcomes in gonadotropin-releasing hormone agonist cycles

Dose an elevated serum progesterone (P) level on the human chorionic gonadotropin (hCG) trigger day have a negative effect on clinical pregnancy outcomes for embryos transferred at different stages of development in long-acting gonadotropin-releasing hormone agonist (GnRHa) in vitro fertilization-embryo transfer (IVF-ET) cycles?This was a noninterventional, retrospective, observational, single-centre cohort study. A total of 1951 patients received long-acting GnRHa for pituitary downregulation in IVF-ET cycles at Nanjing Drum Tower Hospital from January 2018 to December 2020. The serum P levels on the day of hCG administration were measured, together with other cycle parameters, to explore the relationship between P levels and the clinical pregnancy rate (CPR) of different embryos transferred.When the serum P level on the hCG day was higher than 1.5 ng/mL, the CPR did not decrease significantly. There was no correlation between the CPR of cleavage-stage embryo transfer and the serum P level on the hCG day. In addition, the interaction analysis suggested that the CPR of patients undergoing blastocyst transfer decreased as serum P levels on the hCG day increased. Progesterone levels on the day of hCG administration were closely related to the CPR of blastocyst transfer rather than cleavage-stage embryo transfer.An increased serum P level on the day of hCG administration did not affect the CPR of cleavage-stage embryo transfer, but it reduced the CPR of blastocyst transfer cycles.