Recombinant and urinary FSH preparations: A comparative analysis of multifollicular development and IVF/ICSI outcome in different categories of ovarian responders

Objectives: To compare recombinant and urinary FSH preparations in their capacity to induce ovarian multifollicular development and impact of IVF/ICSI outcome in different categories of ovarian responders. Design: Retrospective, comparative analysis. Setting: Academic fertility care institution. Subjects: Seven hundred and seventy-nine patients undergoing 835 consecutive treatment cycles. Intervention: Patients were stimulated with urinary FSH (uFSH), highly purified urinary FSH (hpFSH) or recombinant FSH (rFSH) in combination with two different GnRH agonist (GnRH-a) regimens (long and stop GnRH-a protocols). Main outcome measures: Peak serum estradiol (E2) levels on day of hCG, number of gonadotropin ampoules administered, cancellation rate, number of mature oocytes recovered, fertilization and pregnancy rates. Results: In intermediate and high responder patients (long GnRH-a protocol) the FSH preparations were equally effective in inducing multifollicular development. Importantly, rFSH resulted in significantly higher implantation and ongoing pregnancy rates than the urinary preparations. In low responders (stop GnRH- a protocol) the FSH preparations demonstrated similar effects in terms of ovarian response and pregnancy outcome. Separate analysis of IVF and ICSI patients revealed a similar positive impact of rFSH on implantation and pregnancy outcome in high and intermediate responders undergoing both treatments. Conclusions: This study demonstrated that recombinant FSH appeared to be equally effective as urinary preparations in inducing multifollicular development. However, rFSH appeared to be superior in achieving an ongoing pregnancy in IVF and ICSI treatments in intermediate and high responders.