Menarcheal age in Stockholm girls, 1967

Using the status quo method on 917 girls aged 10-17 years in 1967, mean age at menarche was computed to be 13-09 +/- 0-08 years (SD 1-10). There was no difference in mean age at menarche between girls from different social groups defined by father's or mother's occupation. The menstrual periods evoked severe discomfort in 9 per cent of the individuals. These were on an average significantly younger at menarche than the other girls. The percentage of the girls feeling discomfort during the menstrual periods as well as its intensity increased with time since menarche.