Several risk factors for OHSS have been identified, including young age (<30 years), low body mass index (BMI), polycystic ovarian syndrome (PCOS), high basal antral follicle count, establishment of pregnancy during ART, human chorionic gonadotrophin (hCG) supplementation of the luteal phase, long menstrual cycle length, high basal serum anti-Mullerian hormone (AMH), and high or rapidly increasing serum estradiol and the use of a gonadotropin-releasing hormone (GnRH) agonist treatment cycle (3, 4). This evidence concerns the gene GNRH1 and ovarian hyperstimulation syndrome.