GNRH1 and ovarian hyperstimulation syndrome: GnRH antagonists protocols have several advantages over the long agonist, including the rapid decrease luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels, without flare-up effect, a lower consumption of used gonadotropins, shorter overall treatment duration [2], especially for reducing the incidence of ovarian hyper-stimulation syndrome (OHSS) [3, 4].