Ovarian stimulation with buserelin/HMG/HCG: prospective randomized study of short versus long protocol.

The combined administration of the gonadotrophin-releasing hormone (GnRH) agonist buserelin and human menopausal gonadotrophin (HMG) was evaluated in 527 cycles (428 patients) of an assisted reproduction programme. All women were randomly allocated according to the ovulation induction protocol into two groups: group I (short protocol; 318 cycles) was given buserelin (1 mg/day) intranasally from cycle day 1 and HMG (2 ampoules/day) from day 3 until human chorionic gonadotrophin (HCG) administration: group II (long protocol; 209 cycles) was given buserelin (1 mg/day) intranasally from cycle day 1 for at least 14 days and then 2 ampoules HMG/day were added, increasing progressively according to the ovarian response. The number (mean +/- SEM) of follicles developed was higher in group II than in group I (9.1 +/- 0.4 versus 7.7 +/- 0.3, respectively; P < 0.05). More oocytes were retrieved in group II (8.4 +/- 0.5) than in group I (6.5 +/- 0.3) (P < 0.001), as well as more embryos (6.3 +/- 0.5 and 4.0 +/- 0.3, respectively; P < 0.001). Moreover, in group II there was a better correlation between oestradiol and the total follicular volume (r = 0.5391) on cycle day 0 compared with group I (r = 0.458), while oestradiol values were similar between the two groups. No differences were observed in the cancellation rate, fertilization rate and maturity of the oocytes between the two groups. The pregnancy rate per transfer was slightly better in group II (25.8%) than in group I (19.4%), but this difference was not significant.(ABSTRACT TRUNCATED AT 250 WORDS)