Table 1.
Reproductive characteristics of women aged 30–60 years in the population-based Canadian Multicentre Osteoporosis Study.
| Characteristic | Mean (SD/%) | n |
|---|---|---|
| Age, years | 51.48 (7.43) | 1653 |
| Age at menarche, years | 12.75 (1.54) | 1646 |
| ≤10 years at menarche, n (%) | 97 (5.9) | |
| ≥16 years at menarche, n (%) | 84 (5.1) | |
| Regular menses after menarche, n (%) | ||
| Immediately | 1318 (79.8) | 1651 |
| Became regular spontaneously | 64 (19.5) | 329 |
| Became regular with medication | 151 (56) | 268 |
| Parity, n (%) | 1403 | |
| Nulliparous (0 births) | 62 (4.4) | |
| 1–2 births | 874 (62.3) | |
| 3 or more births | 467 (31.1) | |
| 1 Breast feeding, n (%) months | 1328 | |
| Never | 496 (37.3) | |
| ≤6 months | 367 (27.6) | |
| >6 months | 465 (35) | |
| 1 CHC use, n (%) duration | 1390 | |
| ≤3 months = “never” | 66 (4.7) | |
| 4–12 months | 215 (15.5) | |
| >12 months | 1109 (79.8) | |
| 2 Oligomenorrhea, yes, n (%) | 164 (10.1) | 1505 |
| 3 Amenorrhea, yes, n (%) | 137 (8.3) | 1516 |
| Infertility, n (%) | 145 (8.8) | 1653 |
| Hormonal | 45 (2.7) | |
| Anatomical, obstructive | 37 (2.2) | |
| Male factor | 15 (0.9) | |
| 4 Other | 48 (2.9) | |
| Androgen Excess, yes, n (%) | 199 (13.0) | 1653 |
| Hysterectomy, yes, n (%) | 393 (23.8) | 1653 |
| Ovariectomy, n (%) | 230 (13.9) | 1653 |
| Unilateral | 95 (5.7) | |
| Bilateral | 130 (7.9) | |
| Unsure | 5 (0.3) | |
| Natural menopause, yes, n (%) | 532 (43.7) | 1217 |
| Age at natural menopause, years | 50.6 (4.1) | |
| Reproductive lifespan, years | 38.7 (7.6) |
1 CHC = combined hormonal contraception (could be as a pill, patch or vaginal ring) used for ≥3 months; 2 If a women recorded her periods as >35 to 89 days apart at any time; 3 If a women reported her periods as ≥90 days apart at any time; 4 Including undetermined, uterine structural disorders, multiple factors.