The effect of an individualized GnRH antagonist protocol on folliculogenesis in IVF/ICSI.

BACKGROUND The aim of this study was to assess the effect of an individualized GnRH antagonist regimen on folliculogenesis. METHODS In a multicentre, randomized, clinical trial, IVF/ICSI patients were allocated to a standard regimen, in which they received daily 0.25 mg GnRH antagonist ganirelix (Orgalutran) from the 6th day of stimulation onward (fixed regimen n = 102) or to an individualized regimen, in which IVF/ICSI patients received daily 0.25 mg GnRH antagonist starting on the day that the dominant follicle had reached a diameter of > or = 15 mm (flexible regimen n = 103). The primary endpoint was to assess the difference in the total number of oocytes. RESULTS The mean (SD) number of retrieved oocytes was not statistically significantly different: 9.4 (5.8) in the flexible group versus 9.7 (6.5) in the fixed group. The clinical and ongoing pregnancy rates were 22.7 and 21.8% respectively in the flexible group versus 33 and 31.1% in the fixed group [relative rate ratio 0.69 (95% confidence interval 0.44-1.08) and 0.7 (0.44-1.12) respectively]. CONCLUSION The individualized flexible regimen did not result in an increase in the total number of oocytes obtained.