Table 2. Odd Ratios and 95% confidence intervals for GDM according to number of pregnancies.
| Number of pregnancy | Number of subjects | Model 1: unadjusted | Model 2: model 1+BMI | Model 3: fully-adjusted model* |
| Total population | ||||
| 1 | 4,060 | 1 | 1 | 1 |
| 2 | 1,698 | 1.29 (1.10, 1.51) | 1.27 (1.08, 1.49) | 1.16 (0.98, 1.37) |
| ≥3 | 1,250 | 1.89 (1.60, 2.23) | 1.79 (1.51, 2.11) | 1.27 (1.05, 1.54) |
| Age <30 years | ||||
| 1 | 3,091 | 1 | 1 | 1 |
| 2 | 1,093 | 1.12 (0.90, 1.38) | 1.11 (0.90, 1.38) | 1.08 (0.87, 1.35) |
| ≥3 | 517 | 1.22 (0.93, 1.61) | 1.19 (0.90, 1.57) | 1.04 (0.77, 1.39) |
| Age ≥30 years | ||||
| 1 | 969 | 1 | 1 | 1 |
| 2 | 605 | 1.40 (1.08, 1.82) | 1.38 (1.06, 1.80) | 1.32 (1.01, 1.73) |
| ≥3 | 733 | 1.94 (1.52, 2.46) | 1.89 (1.49, 2.40) | 1.54 (1.17, 2.01) |
| BMI <24 kg/m2 | ||||
| 1 | 3631 | 1 | 1 | 1 |
| 2 | 1487 | 1.27 (1.06, 1.53) | 1.27 (1.06, 1.52) | 1.15 (0.95, 1.38) |
| ≥3 | 1058 | 2.00 (1.66, 2.40) | 1.94 (1.62, 2.33) | 1.35 (1.09, 1.67) |
| BMI ≥24 kg/m2 | ||||
| 1 | 426 | 1 | 1 | 1 |
| 2 | 209 | 1.24 (0.85, 1.82) | 1.25 (0.85, 1.83) | 1.20 (0.81, 1.78) |
| ≥3 | 192 | 1.23 (0.83, 1.82) | 1.23 (0.83, 1.82) | 0.95 (0.60, 1.50) |
BMI, body mass index.
*fully-adjusted model: adjusted for age, pre-pregnancy BMI, education background, annual household income, smoking status, drinking status and passive smoking exposure.