Tailoring the GnRH antagonist cetrorelix acetate to individual patients' needs in ovarian stimulation for IVF:: results of a prospective, randomized study

INTRODUCTION: This study was performed to evaluate whether a tailored approach to the administration of the GnRH antagonist cetrorelix acetate according to follicular size leads to a reduction in the amount of Cetrotide(R) vials used and/or an increased number of monitoring visits. METHODS: Sixty patients were prospectively randomized (using sealed envelopes) to receive either the fixed multiple dose antagonist protocol starting on day 6 of stimulation (group 1), or an individualized protocol with the time of antagonist start according to follicle size (14 mm, group 2), or an individualized single dose protocol (group 3). Recombinant human (rh)FSH was used. The primary endpoints were the number of Cetrotide vials and number of monitoring visits. Statistical power for the parameter Cetrotide vials was 80%. RESULTS: Patients in group 1 needed significantly more Cetrotide vials (6.81 +/- 1.61) than patients of group 2 (4.59 +/- 1.65; P < 0.01). The number of monitoring visits was similar between the three groups. Surprisingly, the number of retrieved oocytes was significantly higher in the individualized groups as compared with group 1. Despite a significantly lower total amount of rhFSH used, estradiol levels were significantly higher in group 2 as compared with group 1. CONCLUSION: Tailoring of GnRH antagonist protocols leads to an optimization of ovarian stimulation with more oocytes retrieved despite less rhFSH used, and the same number of monitoring visits.