The ReSTAGE Collaboration: Defining Optimal Bleeding Criteria for Onset of Early Menopausal Transition

Objective Criteria for staging the menopausal transition are not established. This article evaluates five bleeding criteria for defining early transition and provides empirically based guidance regarding optimal criteria. Design/Setting Prospective menstrual calendar data from four population-based cohorts: TREMIN, Melbourne Women's Midlife Health Project (MWMHP), Seattle Midlife Women's Health Study (SMWHS), and Study of Women's Health Across the Nation (SWAN) with annual serum FSH from MWMHP and SWAN. Participants 735 TREMIN, 279 SMWHS, 216 MWMHP, and 2270 SWAN women aged 35–57 at baseline who maintained menstrual calendars. Main Outcome Measure(s) Age at and time to menopause for: standard deviation >6 and >8 days, persistent difference in consecutive segments >6 days, irregularity, and ≥45 day segment. Serum FSH concentration. Result(s) Most women experienced each of the bleeding criteria. Except for a persistent >6 day difference that occurs earlier, the criteria occur at a similar age and at approximately the same age as late transition in a large proportion of women. FSH was associated with all proposed markers. Conclusion(s) The early transition may be best described by ovarian activity consistent with the persistent >6 day difference, but further study is needed, as other proposed criterion are consistent with later menstrual changes.