Progesterone rise on hCG day is negatively correlated with IVF-ET outcomes in natural cycles

Objective: To investigate the effect of progesterone rise on hCG day on the laboratory and clinical outcomes in natural cycles and to explore the possible factors related to the occurrence of progesterone elevation. Patients and study methods: Retrospective analysis was performed in 1157 infertile women with decreased ovarian reserve. Eligible infertile women undergoing IVF in natural cycles were assigned to four groups according to serum progesterone levels on the day of hCG administration: group 1, P < 2 nmol/L; group 2, 2 < P < 2.9 nmol/L; group 3, 3 < P < 3.9 nmol/L; group 4, P >= 4.0 nmol/L. Data on clinical outcomes and LH level were collected and analyzed. Results: Number of retrieved oocytes, pronucleus cells, fertilized cells, and good embryos significantly decreased (p < 0.05). A significant elevation of cancelled cycle rate, early follicle elimination rate and LH level on hCG day occurred when the serum progesterone levels were higher than 4.0 nmol/L on the day of hCG administration (p < 0.05). Conclusion: In natural cycles, progesterone rise on the day of hCG administration (in this study, P 4.0 nmol/L) may negatively correlated with the quality of oocytes and embryos.