GNRH1 and polycystic ovary syndrome: Lee et al believed that the use of GnRH-ant from the early follicular phase could stabilize the endocrine level of patients with PCOS close to the conditions of normal physiological cycles.[36] Studies showed that the use of GnRH-ant throughout the whole process of COS in patients with PCOS can achieve a satisfactory pregnancy rate,[37] indicating that the use of GnRH-ant in the early follicular phase did not affect the growth of follicles.