Background: To determine the frequency of spontaneously occurring postmenopausal bleeding in the population, a prospective observational population study was undertaken.
Methods: Out of a population-based sample of 2000 Danish women aged 45-54 years, 1616 women responded to an initial questionnaire. Of these, 1059 women with natural gynecologic functions were eligible for the diary study, and of these, 951 (89.8%) women completed 1 year of daily recording of bleeding, medication relevant to bleeding, and medical consultations for gynecologic matters. Of the 951 women, 271 were postmenopausal.
Main outcome measures: Occurrence of spontaneous postmenopausal bleeding including strength and length of each bleeding.
Results: Of 271 postmenopausal women, 29 (10.7%, 95% confidence interval 7.3-15.0%) recorded spontaneous postmenopausal bleeding. The incidence of women with bleeding was strongly correlated with time since menopause (P = 0.0001), with an estimated incidence of 409/1000 (218/1000-771/1000) person-years immediately after the first 12 months of amenorrhea following the menopause falling to 42/1000 (17/1000-102/1000) more than 3 years after menopause.
Conclusions: This study indicates that recurrence of bleeding is very common in the time immediately after the 12 months of amenorrhea after what is currently defined as the final menstrual period, declining to low frequencies more than 3 years after the final menstrual period.