Analysis of follicular fluid hormone concentrations and granulosa cell mRNA levels for the inhibin-activin-follistatin system: relation to oocyte and embryo characteristics

Abstract

Objective: To explore the potential roles of inhibin, activin, and follistatin in human oocyte development by quantifying their intrafollicular biosynthesis. Design: Prospective, nonrandomized study. Setting: An IVF unit and academic research laboratory. Patient(s): Thirty one patients undergoing IVF. Intervention(s): Human menopausal gonadotropins or human FSH (or both) were administered. Single-follicle aspirates (n = 110) were collected for analysis. Main Outcome Measure(s): Concentrations of dimeric, total and pro-αC inhibin forms; activin A; follistatin; estradiol; and progesterone were measured in follicular fluids. Granulosa-cell mRNA was analyzed for α, βA, and βB inhibin and activin subunits; follistatin; activin receptors; and β-actin. Hormone concentrations and mRNA levels were correlated with oocytes or embryos from the same follicles. Result(s): Levels of progesterone and follistatin were significantly greater in follicles containing MI or MII oocytes than in those containing GV oocytes. Inhibin α-subunit mRNA levels were significantly higher in follicles containing maturing oocytes, the highest-quality oocytes, and oocytes that were subsequently fertilized. In contrast, inhibin α-subunit mRNA levels were significantly lower in follicles from which higher-quality embryos were obtained. Conclusion(s): Inhibin α-subunit biosynthesis is associated with normal oocyte and follicle maturation, but excessive α-inhibin is associated with poor embryo quality. None of the hormones analyzed were associated with oocyte or embryo quality.