Peri-ovarian adhesions interfere with the diffusion of gonadotrophin into the follicular fluid

In previous studies, patients with severe peri-ovarian adhesions have been found to show low pregnancy rates and a poor response to gonadotrophin stimulation during in-vitro fertilization (IVF) treatment. The purpose of this retrospective pharmacokinetic study was to assess the diffusion of exogenous human chorionic gonadotrophin (HCG) in patients with peri-ovarian adhesions by examining the concentration of exogenous HCG in the follicular fluid in patients undergoing down-regulation and IVF due to infertility. The patients underwent laparoscopic examination for the scoring of peri-ovarian adhesions (using the classification of adnexal adhesions adopted by the American Fertility Society, a score of 0 means no adhesions, and a score of 32 represents bilateral expanded dense adhesions). Oocytes were recovered after human menopausal gonadotrophin-human chorionic gonadotrophin (HMG-HCG) stimulation with gonadotrophin-releasing hormone agonist. Serum and follicular fluid were collected at the time of oocyte recovery for measuring the HCG ratio (the follicular HCG concentration to the serum HCG concentration; a reflection of the diffusion of exogenous gonadotrophin) by time-resolved fluoroimmunoassay. A negative correlation was found between the number of oocytes recovered and the peri-ovarian adhesion score (r = -0.62, P < 0.01). In a given patient, the follicular HCG concentration was always lower than the serum HCG at the time of oocyte recovery. The HCG ratio in all samples was 0.9 or less (0.51 +/- 0.20; range, 0.09-0.90). Significant negative correlations were found between the peri-ovarian adhesion score and both the follicular HCG concentration (r = -0.80, P < 0.01) and the HCG ratio (r = -0.75, P < 0.01). In conclusion, severe peri-ovarian adhesions interfered with the diffusion of exogenous gonadotrophin into the follicular fluid during IVF treatment. Thus, the diffusion of exogenous gonadotrophin into the follicular fluid may represent a new parameter in the assessment of ovarian blood flow and IVF outcome.