Characteristics | Cohort | Cases | Controls | p-value |
Subjects | 3689 | 932 | 2757 | |
Demographics | ||||
Age years | 31.0±4.8 | 31.4±4.7 | 30.8±4.8 | <0.001 |
BMI# kg·m−2 | 23.6±4.3 | 24.1±4.6 | 23.4±4.1 | <0.001 |
Current smokers | 238 (6.5) | 39 (4.2) | 199 (7.2) | 0.001 |
Primiparity | 2125 (57.6) | 626 (67.2) | 1499 (54.4) | <0.001 |
Single parent | 127 (3.4) | 40 (4.3) | 87 (3.2) | 0.100 |
Same sex partner | 18 (0.5) | 7 (0.8) | 11 (0.4) | 0.182¶ |
Data are presented as n, n (%), or mean±sd. Values in bold type are significant (p<0.05). BMI: body mass index. #: information was missing for 26 control subjects; ¶: p-value determined from analysis with Fisher's exact test.