Relationship between fertilization results after intracytoplasmic sperm injection, and intrafollicular steroid, pituitary hormone and cytokine concentrations

Previous studies relating hormone and cytokine concentrations in follicular fluid to oocyte fertilizability were flawed by the uncertainty about the actual oocyte maturity status at the time of recovery and by the possible contribution of the male factor to failures of conventional in-vitro fertilization. This is the first study in which oocyte maturity was assessed immediately after recovery and only mature oocytes were selected for treatment by intracytoplasmic sperm injection. Fertilization outcomes were related to follicular fluid concentrations of 17β-oestradiol, progesterone, follicle stimulating hormone, luteinizing hormone (LH), growth hormone (GH), prolactin (PRL), interleukin-1 (IL-1) and tumour necrosis factor-α (TNFα). Those oocytes that subsequently showed normal fertilization were harvested from follicles with higher concentrations of progesterone, GH, PRL, IL-1 and TNFα as compared with those of oocytes that failed to fertilize. Among the normally fertilized oocytes, low GH concentrations were associated with the failure of cleavage and with poor morphology of cleaving embryos, whereas rapidly cleaving embryos developed from oocytes recovered from follicles with high concentrations of LH and IL-1. These data suggest important roles for GH, IL- 1 and TNFα, and of residual LH after pituitary suppression, as positive regulators of the final phase of oocyte intrafollicular development.