GNRH1 and adenomyosis: Our results showed that under GnRH agonist pretreatment before FET to achieve a relatively normal CA-125 serum level, the live birth rates of patients with adenomyosis approached those of patients under the age of 38 years in groups E and C. However, in patients aged ≥ 38 years, LBRs and cLBR were still lower than those of the control group.