Characteristics related to menstrual and reproductive function in the study population
| Lifetime cumulative number of menstrual cycles | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| ≤415 (n = 1,313) | 416-453 (n = 1,203) | 454-490 (n = 1,329) | ≥491 (n = 1,388) | Always irregular (n = 798) | ||||||
| Age at menarche* | 14.1 (1.8) | 13.69 (1.5) | 13.3 (1.5) | 12.8 (2.0) | 13.8 (1.8) | |||||
| Establishment of regular periods (%)† | ||||||||||
| Immediately after menarche | 994 (12.4) | 918 (76.3) | 989 (74.4) | 1,088 (78.4) | ||||||
| 1-2 y after menarche | 243 (18.5) | 241 (20.0) | 283 (21.3) | 247 (19.8) | ||||||
| 3-4 y after menarche | 31 (2.3) | 9 (0.8) | 26 (1.9) | 21 (1.5) | ||||||
| First 10 y not regular | 18 (1.4) | 11 (0.9) | 13 (1.0) | 20 (1.4) | ||||||
| Regular after FFTP | 27 (2.1) | 24 (2.0) | 18 (1.4) | 12 (0.9) | ||||||
| Periodicity pattern (%)† | ||||||||||
| Every 26, 25, 24 d or less | 163 (12.4) | 184 (15.3) | 289 (21.8) | 738 (53.2) | ||||||
| Every 27, 28 or 29 d | 906 (69) | 862 (71.7) | 928 (69.8) | 610 (43.9) | ||||||
| Every 30, 31, 32 d or more | 244 (18.6) | 157 (13.0) | 112 (8.4) | 40 (2.9) | ||||||
| Nulliparous (%) | 114 (8.6) | 126 (10.5) | 188 (14.1) | 333 (24.0) | 140 (17.5) | |||||
| Age at FFTP*,‡ | 25.2 (3.8) | 25.4 (3.6) | 25.7 (3.9) | 26.4 (4.3) | 25.4 (4.0) | |||||
| Number live born children*,‡ | 3.43 (1.8) | 2.91 (1.2) | 2.7 (1.1) | 2.5 (1.13) | 2.85 (1.4) | |||||
| Miscarriage and abortions (%) | ||||||||||
| Never pregnant | 99 (7.5) | 114 (9.5) | 168 (12.6) | 314 (22.6) | 125 (15.7) | |||||
| None | 804 (61.2) | 747 (62.1) | 849 (63.9) | 820 (59.1) | 476 (59.6) | |||||
| 1 | 274 (20.9) | 247 (20.5) | 222 (16.7) | 185 (13.3) | 141 (17.7) | |||||
| ≥2 | 136 (10.4) | 95 (7.9) | 90 (6.8) | 69 (5.0) | 56 (7.0) | |||||
| Stillbirth (%) | ||||||||||
| Never pregnant | 99 (7.5) | 114 (9.5) | 168 (12.6) | 314 (22.6) | 125 (15.7) | |||||
| None | 1,155 (88) | 1,044 (86.8) | 1,118 (84.1) | 1,041 (75.0) | 649 (81.3) | |||||
| ≥1 | 59 (4.5) | 45 (3.7) | 43 (3.3) | 33 (2.4) | 24 (3.0) | |||||
| Fertility consult ever (%) | 128 (9.7) | 100 (8.3) | 153 (11.5) | 171 (12.3) | 118 (14.8) | |||||
| Age at menopause* | 45.3 (4.4) | 49.2 (2.5) | 50.9 (2.3) | 52.7 (2.7) | 48.7 (5.5) | |||||
| Oral contraceptive use (%) | 619 (47.1) | 624 (51.9) | 683 (51.4) | 591 (42.6) | 410 (51.4) | |||||
| OC use (y)§ | 6.1 (4.6) | 6.5 (4.8) | 7.0 (5.21) | 6.7 (5.5) | 5.9 (5.1) | |||||
| HRT use (%) | 144 (11.0) | 112 (9.3) | 100 (7.1) | 98 (7.1) | 91 (11.4) | |||||
| HRT use (y)∥ | 3 (3.7) | 2.2 (2.1) | 2.5 (2.2) | 2.6 (2.5) | 2.7 (2.6) | |||||