The relationships of calculated percent body fat, sports participation, age, and place of residence on menstrual patterns in healthy adolescent girls at an independent New England high school.

A prospective study was undertaken to determine normal menstrual patterns in healthy girls in an independent high school and assess the effects of exercise (type and hours per day), age (chronologic and gynecologic), calculated estimate of body fat, and place of residence (boarding and day students) on menstrual function. Three hundred twenty-seven girls (means age 15.5 +/- 1.1 years) answered a questionnaire on menstrual history; 306 (93.6%) were postmenarchal and 21 (6.4%) premenarchal. Calculated estimate of percent body fat was significantly lower in premenarchal than postmenarchal girls (22.4% versus 27.3% p less than 0.0001). Ninety-three percent of adolescents reported flow lasting 4-7 days; 59.7% dysmenorrhea; and 63% premenstrual symptoms. There was no correlation between estimated body fat or hours per day of exercise and the regularity of menses, duration of flow, or dysmenorrhea. With the exception of gymnastics and dancing, sports participation had little or no impact on menstrual patterns. Follow up questionnaires and menstrual calendars were obtained from 87 girls eight to fifteen months after the initial questionnaires. All girls whose cycles had changed from regular to irregular were boarding students, confirming previous anecdotal reports that separation from home may be a significant stress for adolescents.