A prospective, randomized comparison of two starting doses of recombinant FSH in combination with cetrorelix in women undergoing ovarian stimulation for IVF/ICSI

BACKGROUND: A prospective randomized study was carried out in two centres to compare the number of oocytes retrieved after two different starting doses of recombinant human FSH (rhFSH) (Gonal-F-(R)) in women undergoing ovarian stimulation for IVF/intracytoplasmic sperm injection (ICSI) cycles using the multiple dose regimen of the gonadotrophin-releasing hormone (GnRH) antagonist cetrorelix (Cetrotide((R))) to prevent induction of the premature LH surge. METHODS: Sixty women were randomized to receive rhFSH 150 IU ('low'), and 60 women to receive rhFSH 225 IU ('high') as the starting dose for the first 5 days of stimulation. From stimulation day 6 and onwards, including the day of human chorionic gonadotrophin (HCG) administration, the women received 0.25 mg of cetrorelix as a daily dose. The primary endpoint was the number of oocytes retrieved. RESULTS: The mean number (+/- SD) of oocytes was 9.1 +/- 4.4 and 11.0 +/- 4.6 in the 'low' and 'high' groups respectively (P = 0.024). The mean number of 75 IU ampoules of rhFSH was significantly lower in the 'low' group (23.0 +/- 6.3 versus 30.5 +/- 5.6, P < 0.0001). The ongoing pregnancy rate per started cycle and per embryo transfer were 25.9 and 28.8% versus 25.4 and 26.8% respectively in the 'low' and 'high' rhFSH groups (P = NS). CONCLUSIONS: When using a starting dose of 225 IU rhFSH combined with the multiple dose of 0.25 mg cetrorelix from stimulation day 6, significantly more oocytes were obtained than with a starting dose of 150 IU rhFSH.