Ovarian stimulation during assisted reproduction treatment: a comparison of recombinant and highly purified urinary human FSH. On behalf of The Feronia and Apis study group.

This randomized, single-blind, multicentre, multinational study compared recombinant human FSH (rhFSH, Gonal-F) with highly purified urinary human FSH (uhFSH, Metrodin HP) in women undergoing ovarian stimulation for IVF/intracytoplasmic sperm injection (ICSI). Following desensitization in a long gonadotrophin-releasing hormone (GnRH) agonist protocol, patients received s.c. Gonal-F or Metrodin HP, at a fixed dose of 150 IU, until there was adequate follicular development. Of 496 women randomized, 232 and 231 in the Gonal-F and Metrodin HP groups respectively received human chorionic gonadotrophin (HCG). The duration of FSH treatment was significantly shorter with Gonal-F than with Metrodin HP (11.6 +/- 1.9 days versus 12. 4 +/- 2.7 days; P < 0.0001) and significantly fewer ampoules were required (mean 22.6 +/- 5.0 versus 24.3 +/- 5.1, P < 0.0002). There were, however, significantly more follicles > or =10 mm in diameter with Gonal-F (15.6 +/- 8.2 versus 13.6 +/- 7.1, P < 0.01) and oocytes retrieved (13.1 +/- 7.7 versus 11.4 +/- 7.6, P < 0.002). Although no statistical difference in pregnancy rate was recorded, patients receiving Gonal-F had a higher pregnancy rate per cycle than patients given Metrodin HP (25.1 versus 20.1%). Moderate to severe ovarian hyperstimulation syndrome occurred in 2.8 and 1.2% of Gonal-F and Metrodin HP patients respectively (not significant). In conclusion, FSH stimulation in combination with a long GnRH agonist protocol is effective in inducing multiple follicular development and embryos with a high implantation potential. However, Gonal-F is clearly more effective than Metrodin HP in inducing multifollicular development.