Menstrual irregularity and use of oral contraceptives in female adolescent athletes in Swedish National Sports High Schools.

Objective Female adolescent athletes seem to use oral contraceptives (OCs) in the same proportion as the general population. In athletes not using OCs, menstrual irregularity (MI) is reported to be common but there are few studies of MI in adolescent athletes. The aim of the study was to survey menarche, menstrual irregularity and use of OCs in adolescent athletes in the National Sports High Schools in Sweden. A further aim was to study the associations between current sport injury and menstrual irregularity as well as use of OCs. Subjects Two hundred and ninety-eight female adolescent athletes at Swedish National Sports High Schools. Methods A web-based questionnaire containing questions related to menstrual status, contraception and current injury. Results One third (32.6%) of the athletes used OCs and of the remaining athletes 31.8% had MI. The group of athletes with MI had a significantly (p = 0.038; Cohen's d, 0.32) lower BMI and consisted of a significantly (p = 0.043) higher proportion of endurance athletes. OC users were less likely to participate in endurance sports compared to non-OC users (p = 0.024). Current injury was equally distributed in the OC and the non-OC group but athletes with MI had fewer sports injuries compared to eumenorrheic women. Conclusion OCs are frequently used among athletes at Swedish National Sports High Schools. OC users were less likely to participate in endurance sports compared to non-OC users. MI was common and athletes with MI had lower BMI compared to eumenorrheic athletes. Sports injuries were not associated with use of OC and eumenorrheic athletes had a higher proportion of current injury.