GNRH1 and polycystic ovary syndrome: If AC cycle with or without GnRH-agonist pre-treatment has long been the first choice for PCOS patients, current trends follow the principles of individualization, securitization and optimization in endometrial preparation, as mean endometrial thickness, implantation rates, clinical pregnancy rates, ongoing pregnancy rates and live birth rates are similar in artificial cycle and stimulated cycle for endometrial preparation prior to FET in PCOS (46, 47).