Follicular development and hormonal levels following highly purified or recombinant follicle-stimulating hormone administration in ovulatory women undergoing ovarian stimulation after pituitary suppression for in vitro fertilization: Implications for implantation potential

Purpose: The main goal in the present study was to compare follicular devel opment and estradiol levels after ovarian stimulation in pituitary suppress ed normally ovulating women undergoing IVF, using highly purified urinary f ollicle stimulating hormone (FSH) (u-FSH-HP) and recombinant FSH (rec-FSH). A secondary variable in our study was embryo implantation potential, which is closely related to appropriate follicular development and oocyte compet ence. Methods: For the main purpose of this study, 30 IVF patients (group 1) were treated during IVF consecutive cycles, using the same stimulation protocol , with u-FSH-HP in the first treatment study cycle and rec-FSH in the secon d one. As a control group (group 2) for implantation rates obtained in cycl es treated with rec-FSH, 30 additional IVF patients were included who under went a second IVF attempt again with u-FSH-HP. Results: The total dose of FSH used and ovarian response obtained in terms of estradiol plasma levels and the total number of growing follicles on the day of human chronic gonadotropin (HCG) injection were similar in both tre atment cycles in group 1 but better follicular dynamics and oocyte maturity were obtained with rec-FSH. The implantation rate was significantly higher in rec-FSH treated cycles in patients in group 1 than in control women (gr oup 2). Conclusions: rec-FSH is more efficacious than u-FSH-HP when used in the sam e patient in inducing multiple follicular development in down-regulated cyc les as indicated by ovarian performance and oocyte maturity In addition, re c-FSH yields significantly higher implantation rates than u-FSH-HP when use d In patients undergoing their second IVF attempt.