Table 5.
Age at First Birth, years | Cases (n = 683) |
Controls (n = 776) |
Adjusted Odds Ratiob | 95% Confidence Interval | ||
No. | % | No. | % | |||
Nulliparous | 149 | 22 | 117 | 15 | 1 | Referent |
<20 | 90 | 13 | 95 | 12 | 0.55 | 0.35, 0.85 |
20–24 | 268 | 39 | 303 | 39 | 0.48 | 0.34, 0.68 |
25–29 | 115 | 17 | 184 | 24 | 0.43 | 0.29, 0.64 |
≥30 | 61 | 9 | 77 | 10 | 0.60 | 0.36, 0.99 |
Participants enrolled in the study between 1992 and 2002 had data collected on age at first birth.
Adjusted for age, smoking status, pack-years of smoking, years since quitting smoking, and number of children.