Table 3 Adjusted odds ratios (95% credible intervals) for predictors of preterm birth, physical exercise per day in minutes included as spline
Characteristics | Odds ratio (95% credible interval) |
|---|---|
Physical exercise per day in minutes: included as spline | |
Maternal age (Reference: 25 to < 30 years) | |
  < 20 | 1.70 (1.45, 1.99) |
 20–24.9 | 1.17 (1.03, 1.32) |
  > =30 | 1.27 (0.98, 1.63) |
Education (Reference: less than high school) | |
 High school or occupational school | 0.97 (0.83, 1.15) |
 College | 1.16 (0.99, 1.37) |
 Graduate school | 0.98 (0.73, 1.29) |
Income (Reference: middle income 3000–6999 RMB) | |
 Low income (< 3000 RMB) | 1.22 (1.02, 1.46) |
 High income (> = 7000 RMB) | 1.06 (0.93, 1.20) |
Family history | 2.30 (1.81, 2.94) |
Neonatal gender: male | 1.28 (1.15, 1.42) |
Parity: more than one | 0.97 (0.82, 1.13) |
BMI prior to pregnancy (Reference: normal weight) | |
 Underweight | 1.02 (0.90, 1.17) |
 Overweight/Obesity | 1.01 (0.81, 1.26) |
Weight gain (per one kilogram increase) | 0.96 (0.94, 0.97) |
Maternal comorbidity | 1.71 (1.41, 2.08) |
Anemia | 0.98 (0.82, 1.18) |
Colporrhagia | 1.91 (1.70, 2.15) |
Indoor air pollution | 0.97 (0.85, 1.12) |