Pure and highly purified follicle-stimulating hormone alone or in combination with human menopausal gonadotrophin for ovarian stimulation after pituitary suppression in in-vitro fertilization

The use of pure follicle stimulating hormone (pFSH) and highly purified FSH (FSH-HP) versus the combinations pFSH/human menopausal gonadotrophin (HMG) and FSH HP/HMG, respectively, was compared for stimulating follicular development after gonadotrophin-releasing hormone agonist (GnRHa) suppression in women undergoing in vitro fertilization (IVF)-embryo transfer. Two consecutive prospective, randomized studies were carried out at the Assisted Reproduction Unit of the Hospital Clinic i Provincial in Barcelona, a tertiary care setting. Two groups of 188 (study 1) and 252 (study 2) consecutive infertile patients respectively, scheduled for IVF-embryo transfer were included. Pretreatment with leuprolide acetate (long protocol) was followed by gonadotrophin treatment in all patients. In study 1, 92 patients received i.m. pFSH alone (group pFSH) and 96 were treated with the combination of i.m. pFSH and i.m. HMG (group HMG-1). In study 2, 123 patients received s.c. FSH-HP alone (group FSH-HP) and 129 patients were given the combination of s.c. FSH-HP and i.m. HMG (group HMG-2). Main outcome measures included follicular development, oocyte retrieval, fertilized oocytes, duration and dose of gonadotrophin therapy, and clinical pregnancy. There were no significant differences between pFSH and pFSH/HMG nor between FSH-HP and FSH-HP/HMG cycles with regard to the number of ampoules of medication used, day of human chorionic gonadotrophin (HCG) administration, mean peak serum oestradiol concentrations, number of follicles punctured, and number of oocytes aspirated, embryos transferred, or pregnancies. We conclude that urinary FSH (either purified of highly purified) alone is as effective as the conventional combination of urinary FSH/HMG for ovarian stimulation under pituitary suppression in IVF cycles. Therefore, they can be used interchangeably in IVF programmes.