Table 2.

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 menarche994 (12.4)918 (76.3)989 (74.4)1,088 (78.4)
    1-2 y after menarche243 (18.5)241 (20.0)283 (21.3)247 (19.8)
    3-4 y after menarche31 (2.3)9 (0.8)26 (1.9)21 (1.5)
    First 10 y not regular18 (1.4)11 (0.9)13 (1.0)20 (1.4)
    Regular after FFTP27 (2.1)24 (2.0)18 (1.4)12 (0.9)
Periodicity pattern (%)
    Every 26, 25, 24 d or less163 (12.4)184 (15.3)289 (21.8)738 (53.2)
    Every 27, 28 or 29 d906 (69)862 (71.7)928 (69.8)610 (43.9)
    Every 30, 31, 32 d or more244 (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 pregnant99 (7.5)114 (9.5)168 (12.6)314 (22.6)125 (15.7)
    None804 (61.2)747 (62.1)849 (63.9)820 (59.1)476 (59.6)
    1274 (20.9)247 (20.5)222 (16.7)185 (13.3)141 (17.7)
    ≥2136 (10.4)95 (7.9)90 (6.8)69 (5.0)56 (7.0)
Stillbirth (%)
    Never pregnant99 (7.5)114 (9.5)168 (12.6)314 (22.6)125 (15.7)
    None1,155 (88)1,044 (86.8)1,118 (84.1)1,041 (75.0)649 (81.3)
    ≥159 (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)
  • NOTE: Abbreviation: HRT, hormone replacement therapy.

  • * Mean ± SD.

  • Participants in the irregular category reported to be never regular.

  • Among parous women.

  • § Mean ± SD among OC users.

  • Mean ± SD among HRT users.