TABLE 2.
Menstrual cycle characteristics for all participants and by late reproductive stage and menopausal transition+ (N = 1,298)
| Menstrual cycle characteristics | All N (%) (n = 1,298) | Late reproductive stage (n = 946) | Menopausal transition+ (n = 352) | Test statistics |
| Cycle length | n = 1,254 | n = 933 | n = 321 | |
| <20 days | 39 (3%) | 31 (3%) | 8 (2%) | |
| 21-24 days | 160 (13%) | 141 (15%) | 19 (6%) | |
| 25-28 days | 491 (39%) | 442 (47%) | 49 (15%) | |
| 29-31 days | 219 (17%) | 182 (20%) | 37 (12%) | |
| 32-35 days | 63 (5%) | 36 (4%) | 27 (8%) | |
| 36+ days | 94 (7%) | 8 (<1%) | 86 (27%) | |
| Varies by >4 days | 153 (12%) | 76 (8%) | 77 (24%) | |
| Do not know | 33 (3%) | 16 (2%) | 17 (5%) | |
| Changes in cycle length | n = 1,298 | n = 946 | n = 352 | Chi Sq = 208, 4 df, P < 0.001 |
| No changes | 247 (19%) | 221 (23%) | 26 (7%) | |
| Yes, getting shorter | 435 (34%) | 381 (40%) | 54 (15%) | |
| Yes, getting longer | 176 (14%) | 69 (7%) | 107 (30%) | |
| Yes, inconsistent | 374 (29%) | 237 (25%) | 137 (39%) | |
| Other | 66 (5%) | 38 (4%) | 28 (8%) | |
| Changes in menstrual flow | n = 1,298 | n = 946 | n = 352 | Chi Sq = 23.0, 7 df, P < 0.002 |
| No changes | 55 (4%) | 42 (4%) | 13 (4%) | |
| Much heavier | 365 (28%) | 264 (28%) | 101 (29%) | |
| Slightly heavier | 119 (9%) | 98 (10%) | 21 (6%) | |
| Slightly lighter | 150 (12%) | 118 (13%) | 32 (9%) | |
| Much lighter | 162 (13%) | 102 (11%) | 60 (17%) | |
| Some heavier and some lighter | 381 (29%) | 278 (29%) | 103 (29%) | |
| Unsure | 24 (2%) | 20 (2%) | 4 (1%) | |
| Changes in menstrual flow days | n = 1,298 | n = 946 | n = 352 | Chi Sq = 15.8, 4 df, P < 0.003 |
| Fewer days of bleeding | 530 (41%) | 395 (42%) | 135 (38%) | |
| More days of bleeding | 352 (27%) | 251 (27%) | 101 (29%) | |
| No change | 259 (20%) | 191 (20%) | 68 (19%) | |
| Unsure | 92 (7%) | 74 (8%) | 18 (5%) | |
| Days of menstrual flow | n = 1,298 | n = 944 | n = 352 | Chi Sq = 37.6, 7 df, P = 0.000 |
| 1 | 6 (3%) | 1 (<1%) | 5 (1%) | |
| 2 | 28 (2%) | 16 (2%) | 12 (3%) | |
| 3 | 132 (10%) | 98 (10%) | 34 (10%) | |
| 4 | 263 (20%) | 207 (22%) | 56 (16%) | |
| 5 | 349 (27%) | 269 (29%) | 80 (23%) | |
| 6 | 224 (17%) | 166 (18%) | 58 (17%) | |
| 7 or more | 241 (19%) | 159 (17%) | 82 (23%) | |
| Menstrual cramps | ||||
| Menstrual cramps worse | 33823% | 26028% | 7616% | Chi sq = 26, 1 df, P < 0.001 |
| Menstrual cramps returned | 21915% | 17218% | 449% | Chi sq = 22, 1 df, P < 0.001 |
| Abdominal cramps like menstrual, not premenstrual | 35124% | 22123% | 12526% | NS |
| Periods less predictable | 611 (47%) | 360 (38%) | 251 (71%) | |