This study is designed to investigate the effects of increased progesterone (P4) levels on the quality of retrieved oocytes and embryos during IVF. This retrospective analysis included 982 all-freezing in vitro fertilization (IVF) cycles (conducted between November 2019 and June 2020 at CHA Fertility Center Bundang, South Korea) in which serum P4 levels were measured on the day of human chorionic gonadotropin (hCG) administration. Our study revealed that the serum P4 levels on the day of hCG administration are strongly associated with the rates of oocyte maturation, displaying a positive correlation in patients with serum P4 < 2.25 ng/mL (p = 0.025). Moreover, patients with serum P4 < 1.25 ng/mL showed relatively low fertilization rates (p = 0.037), and the rates of good embryo retrieval were significantly increased with the serum P4 level < 1.5 ng/mL (p = 0.001). Interestingly, serum P4 level on the day of hCG administration affects the rate of good-quality embryo development, especially at the cleavage stage, and is associated with the status of ovarian responses. Our current study suggests that serum P4 level on the day of hCG administration negatively affects the rates of oocyte maturation, fertilization, and the development of good embryos.
Keywords: embryo development; fertilization; in vitro fertilization; oocyte maturation; progesterone levels.