GNRH1 and Infertility: All the other variables were found as not determinant: the number of embryos transferred, secondary vs. primary infertility, GnRH down-regulation agonist or antagonist, FSH supplementation, stimulation duration (mean value over all cycles and the separate values for each cycle), hCG supplementation, hCG dosage, mean total number of oocytes and mean total number of embryos.