Table 1.
Never Smoker | Current smoker: number of cigarettes/day | Former smoker: time since cessation, years | ||||||
---|---|---|---|---|---|---|---|---|
<1 | 1–4 | 5–9 | 10–19 | ≥20 | 1–1.9 | ≥2 | ||
Number of women | 2,346 | 212 | 70 | 146 | 223 | 35 | 135 | 606 |
Participant’s age, years (mean) | 28.3 | 28.0 | 28.1 | 26.9 | 27.3 | 27.5 | 28.4 | 29.9 |
Male Partner’s age, years (mean) | 30.8 | 30.5 | 29.6 | 30.9 | 31.5 | 32.3 | 30.9 | 31.2 |
Smoking duration, years (mean) | 0 | 10.1 | 11.8 | 12.0 | 12.5 | 13.7 | 10.5 | 7.1 |
Partner is a regular smoker (%) | 11 | 23 | 58 | 60 | 71 | 76 | 16 | 12 |
Passive smoking exposure in adulthood (%) | 23 | 49 | 56 | 72 | 83 | 80 | 52 | 36 |
Participant’s mother smoked while pregnant (%) | 34 | 29 | 30 | 43 | 55 | 66 | 35 | 35 |
Intercourse frequency ≥4/week (%) | 18 | 16 | 24 | 26 | 29 | 21 | 20 | 17 |
Doing something to time intercourse (%) | 46 | 46 | 45 | 43 | 46 | 45 | 49 | 49 |
Body mass index of participant, kg/m2 (mean) | 24.0 | 23.7 | 24.4 | 24.4 | 25.2 | 25.2 | 24.4 | 24.4 |
Body mass index of partner, kg/m2 (mean) | 25.3 | 25.0 | 25.8 | 26.3 | 26.0 | 26.0 | 25.3 | 25.6 |
Last contraceptive method: hormonalb (%) | 63 | 64 | 65 | 60 | 64 | 81 | 68 | 57 |
Parous (%) | 31 | 27 | 41 | 43 | 40 | 32 | 21 | 44 |
Ever pregnant (%) | 41 | 44 | 56 | 66 | 57 | 67 | 39 | 54 |
History of infertility (%) | 8 | 7 | 15 | 14 | 13 | 13 | 11 | 9 |
History of pelvic inflammatory disease (%) | 14 | 15 | 21 | 20 | 25 | 40 | 15 | 17 |
Regular cycles (%) | 76 | 74 | 80 | 76 | 84 | 78 | 74 | 74 |
No vocational training or higher education (%) | 10 | 10 | 11 | 18 | 27 | 25 | 13 | 11 |
Household income <25,000 Danish Kroner/year (%) | 13 | 18 | 14 | 17 | 16 | 33 | 14 | 11 |
Participant exposure to environmental hazards (%) | 17 | 19 | 19 | 22 | 29 | 25 | 26 | 18 |
Partner exposure to environmental hazards (%) | 22 | 24 | 31 | 34 | 39 | 45 | 30 | 28 |
Caffeine intake, mg/day (mean) | 108 | 170 | 141 | 184 | 239 | 322 | 160 | 160 |
Consumes ≥7 alcoholic beverages/week (%) | 8 | 26 | 26 | 10 | 18 | 23 | 16 | 12 |
All characteristics except age are age-standardized to the distribution of the cohort at baseline.
Includes oral contraceptive pills and other hormonal contraceptives such as patch and injection.