Menstrual Irregularity in Female Military Cadets: Comparison of Data Utilizing Short-term and Long-term Recall

Study Objectives: (1) To assess menstrual function in freshman cadets at a structured, rigorous military college utilizing a weekly e-mail questionnaire, (2) to compare these results to longer-term recall results from written questionnaires completed at the start and end of the same year, and (3) to determine if a relationship exists between personality attributes and menstrual regularity in this setting.

Design, Setting, Participants: A questionnaire developed by the investigators about menstrual function was distributed weekly via e-mail and completed satisfactorily by 116 female freshman at the United States Military Academy (USMA), class of 1995. These data were compared to questionnaires completed by this same cohort at the start and end of the year, as well as to personality questionnaires distributed to some of these cadets as part of a larger study. Pearson's chi-square and analysis of variance were performed to determine statistical significance.

Results: Weekly e-mail data revealed that only 1.7% of cadets had regular menstrual periods throughout the whole year. The remaining 98.3% were irregular: 10.3% mildly, 35.3% moderately, 30.2% severely, and 22.4% extremely irregular. Only 0.8% of subjects did not menstruate at all during the year. In comparison, on long-term recall data, 90% reported some change in menstrual function, with 48% specifically reporting menstrual irregularity. Those with the greatest irregularity prior to USMA and those who expected greater irregularity at USMA reported the greatest irregularity during the year. Irregularity was associated with coping and with commitment to health on personality questionnaires.

Conclusions: On data collected via weekly e-mail, almost all freshman females at USMA experienced menstrual irregularity. This data, utilizing short-term recall, yielded different, more dramatic results than the data utilizing long-term recall. A link between menstrual irregularity and both coping and commitment suggests that menstrual irregularity may be adaptive in this environment.