Relationship between the inhibin in follicular fluid and the fertilizing capacity of the oocyte

Abstract

Synopsis To evaluate the possible relationship between the follicular inhibins and fertilizing capacity of the human oocyte, this study was carried out in women undergoing assisted conception. Follicular fluids (FFs) were collected from individual follicles during oocyte retrieval for in vitro fertilization with the informed consent. The concentrations of dimeric inhibin A, inhibin B in FFs were measured using a solid phase sandwich enzyme linked immunosorbent assays and the concentrations of estradiol, testosterone, and progesterone in FFs were measured using RIA. Hormone concentrations were compared with FFs volume, oocyte quality and embryo development.
Inhibin A concentrations in FFs did not correlate with the volume, whereas inhibin B concentrations in FFs negatively correlated with the volume. The mean concentration of inhibin B was significantly higher in FFs containing immature oocyte than that of FF containing mature oocyte. FFs from small immature follicles in which we could not get oocyte showed high concentrations of inhibin B. The mean concentration of inhibin B was significantly higher in FFs containing non-fertilized oocyte than that of FF containing fertilized oocyte. FFs containing oocyte which was revealed to be high quality embryo after subsequent development showed lower concentrations of inhibin B compared with FFs containing oocyte which was revealed to be a low quality embryo. The significant correlation between the concentrations of inhibin A and progesterone in FFs was observed, while no significant correlation was found between the concentrations of inhibin B and progesterone in FFs. The concentrations of inhibin B in FFs were significantly lower in mature follicles including oocytes with fertilizing capacity than those in immature follicles. On the other hand, the concentrations of inhibin A in FFs were correlated with the concentrations of progesterone in FF, whereas they did not show any relationship with oocyte maturity and its fertilizing capacity. These results indicate that the concentrations of inhibin B in FFs might be a potential predictor in the assessment of oocyte quality and fertilizing capacity. [Adv Obstet Gynecol, 56 (2) : 62 -69 , 2004 (H16.5)]