GNRH1 and ovarian hyperstimulation syndrome: Martinaz et al. [22] replaced GnRH agonist with GnRH antagonist in the early stages of ovarian stimulation (after 6 to 8 days of gonadotropins administration) in a series of 19 patients who were at high risk for OHSS (more than 10 follicles per ovary and/or serum estradiol > 900 pg/ml and the follicles expected to need 3 or more days to reach triggering criteria).