Effect of different gonadotrophin priming on IVM of oocytes from women with normal ovaries: a prospective randomized study

This study was designed to determine if the efficiency of in-vitro maturation (IVM) in women with normal ovaries can be improved by gonadotrophin administration. 400 women were randomly allocated in four groups: group A, non-primed cycles; group B, human chorionic gonadotrophin (HCG)-primed cycles; group C, FSH-primed cycles; and group D, FSH- plus HCG-primed cycles. There were significant differences in the IVM rate among the groups. In groups where HCG was used, the overall maturation rate was higher (57.9% in group B and 77.4% in group D; 48.4% in group A and 50.8% in group C) and the percentage of total available metaphase II-stage oocytes was higher (60.4% in group B and 82.1% in group D; 48.4% in group A and 50.8% in group C). The overall clinical pregnancy rate per transfer (CPR) was 18.3% and the implantation rate (IR) was 10.6%. There was a difference in CPR among the groups: group D (29.9%) versus group A (15.3%), P = 0.023; group D versus group B (7.6%), P < 0.0001; group D versus group C (17.3%), P = 0.046. The results of this study are clearly in favour of FSH plus HCG priming. FSH priming and HCG priming alone showed no significant effects on clinical outcome.