Efficacy and uterine bleeding patterns in initiating goserelin therapy during different menstrual phases in patients with adenomyosis: a prospective cohort study

Objective We carried out this study to explore the possibility of initiating goserelin therapy during the non-menstrual period in patients diagnosed with adenomyosis.Methods 115 premenopausal adenomyosis patients were enrolled and divided into three groups based on their menstrual cycle phase during the initial outpatient visit: menstrual, follicular, and luteal. Each received a 3.6 mg subcutaneous dose of goserelin monthly for three months. The endpoints encompassed alterations in uterine volume, dysmenorrhea Numerical Rating Scale (NRS) score, CA125 level, hemoglobin (HGB) after a 12-week treatment course, and the occurrence and duration of uterine hemorrhage during the first treatment cycle.Results Analysis revealed that the timing of goserelin therapy initiation in the menstrual cycle did not significantly impact its effectiveness in reducing uterine size, alleviating pain, lowering CA125 levels, or improving hemoglobin concentrations. However, patients starting treatment during the luteal phase experienced increased uterine bleeding (reference: menstrual period, OR = 4.33, 95% CI 1.23–15.25, p = .023).Conclusions The results suggested non-inferiority of goserelin therapy initiated during the non-menstrual period, but the uterine bleeding rate was higher in the luteal phase group. Therefore, goserelin treatment for outpatient adenomyosis patients should not be limited to starting during the menstrual period; it can also be initiated outside the menstrual period, providing more convenience for patients as most consultations occur outside the menstrual period. However, the use of goserelin during the luteal phase should be avoided to reduce the risk of exacerbated bleeding, especially in anemic patients with heavy menstrual bleeding. This study highlights the importance of individualizing treatment initiation based on the patient’s health profile to optimize therapeutic outcomes and minimize adverse effects.Trial registration ChiCTR2200059548