Guangdong Provincial Endometriosis Clinical Research Cohort

This is a prospective observational cohort study designed to characterize the clinical course and reproductive outcomes of women with endometriosis. The study will prospectively enroll women aged 18 to 45 years with a clinical, imaging, or surgical diagnosis of endometriosis. Age- and body mass index-matched healthy women with regular menstrual cycles may also be enrolled as a control cohort.

Baseline data will include demographic characteristics, reproductive history, lifestyle factors, clinical symptoms, pain scores, disease phenotype, lesion characteristics, rASRM stage, previous surgery, laboratory findings, ovarian reserve indicators, and assisted reproductive treatment information, when applicable. Treatments received as part of routine clinical care, including gonadotropin-releasing hormone agonists and progestogens, will be recorded as observational exposures. The study protocol will not assign participants to a specific medication, procedure, or assisted reproductive treatment.

Participants will be followed for 24 months. Follow-up assessments will be conducted every 3 months during the first year and every 6 months thereafter, with clinically important outcome events recorded when they occur. Outcomes of interest include cyst recurrence, pain recurrence, pregnancy outcomes, live birth, and other long-term clinical complications.

Associations between baseline clinical characteristics, disease severity, routine treatment patterns, and subsequent outcomes will be evaluated using appropriate descriptive and multivariable statistical methods. Time-to-event outcomes may be analyzed using Kaplan-Meier methods and Cox proportional hazards regression, with adjustment for potential confounding factors.