Variations in the reporting of menstrual histories.

This investigation examined the accuracy of recall of females to questions concerning ages at memarche, natural and surgical menopause, first use of oral contraceptives and mean menstrual cycle length and variance. A sample of 160 women who had recorded their menstrual and reproductive events as they occurred were administered a questionnaire concerning these events, with responses compared to the original data. For the variables age at menarche, age at natural memopause, age at surgical menopause and age at first use of oral contraceptives, the percentage of women who correctly recalled within a year ranged from 75% to 90%. Recollection of menstrual cycle length and variability by interview was considered unreliable. These findings are encouraging regarding the ability to recall the age when certain menstrual and reproductive events occur, but not for menstrual cycle intervals or patterns. Because these women were well-educated and had once recorded study variables, these results might be considered optimal.