Menstrual and reproductive characteristics and age at natural menopause.

Data from women who enrolled between 1935 and 1939 in a long-term prospective study [in Minnesota] of menstrual and reproductive health in which menstrual cycles and other events were recorded as they occurred were analyzed to examine factors associated with age at natural menopause. Analysis was restricted to 561 women who enrolled before age 25 years and recorded data through at least age 44 years. Factors considered include menstrual cycle length pregnancy history parity and age at menarche. (EXCERPT)