Comparison of relevant studies assessing menstrual disturbance in military trainees
| Study | Design | Setting, participants | Qualitative outcomes | Hormonal contraceptive usage | Prevalence reported |
|---|---|---|---|---|---|
| Anderson (1979)22* | USMA, long-term recall | Freshmen commencing 1977, n=88, age NR | ‘Secondary amenorrhoea’ (duration not defined) | NR | Amenorrhoea 75% at 1 month 45% at 4 months 8% at 12 months |
| Anderson (1979)22* | USMA, long-term recall | Freshmen commencing 1976, n=70, age NR | ‘Secondary amenorrhoea’ (duration not defined) | NR | Amenorrhoea 73% at 1 month, 41% at 6 months, 29% at 9 months, 20% at 12 months |
| Welch (1989)21* | USMA freshmen and sophomore, long-term recall | n=65 (class of 1990), n=45 (class of 1991), age NR; excluded those with prior menstrual irregularity | ‘Menstrual irregularity, secondary amenorrhoea’(duration not defined) | NR (these women were excluded) | Menstrual irregularity: 68% (1990), 72% (1991) Resumption of normal menses: 78% after first year (1990) 26% during first year (1991) |
| Friedl et al (1992)10 | Mail shot survey to all 2462 focused on self-reported stress fracture | US Army soldiers in Fort Lewis, Washington, n=1630, median age 24 (IQR 18–52) years | Amenorrhoea—no menses 6 months in the absence of pregnancy | 34.9% | Amenorrhoea 14.9% |
| Lauder (1997)23 | USMA, questionnaire | USMA reserve officer training camp cadets, June 1996—n=310 mean age 21.5 (SD 1.9) years | ‘Occasionally skipped periods’, ‘only a few times per year’ | NR | ‘Occasionally skipping periods’ 12%, ‘only a few times per year’ 5% |
| Schneider et al (1999)4 | USMA, long-term recall questionnaire | USMA, n=158, mean 18.4 (SD 0.81) years | Regularity ‘increased or decreased’ | NR (these women were excluded) | 48.2% decreased frequency, 10.1% increased |
| Lauder et al (1999)12 | USMA, interview | USMA, active duty cadets, n=423, mean age 27.5 (SD 7.7) years | Oligomenorrhoea—<9 menses in 12 months; amenorrhoea—≥3 previous cycle equivalents | 24.6% of the 33.6% who met eating disorder screening criteria | 2.1% amenorrhoea, 3.3% oligomenorrhoea |
| Schneider et al (2003)11 | USMA, short-term recall by email | USMA, n=116 freshmen, mean age 18.4 (SD 0.81) years | Menstrual irregularity—percentage of cycles outside 21–45 days (moderate ≤25%, severe 26–50%, extremely severe >50%; mild: >7 day variation in cycle) | NR (these women were excluded) | Regular: 1.7%; irregular—mildly 10.3%, moderately 35.3%, severely 30.2%, extremely 22.4% |
*Anderson and Welch hypothesise that the pattern of initially high prevalence of amenorrhoea, consistently falling in both studies, was due to psychological and physiological stress, which subsided as training progressed.
NR, not reported; USMA, United States Military Academy, West Point, New York.