Table 3.
Interactive associations of passive smoker and prepregnancy overweight/obesity for macrosomia and LGA
| Model 1 | Model 2 | Model 3 | Model 4 | |
|---|---|---|---|---|
| Macrosomia as the outcome | ||||
| Independent models | ||||
| Among prepregnancy BMI ≥24 kg/m2 | ||||
| Passive smoking versus nonpassive smoking | 1.27 (1.06–1.52) | 1.25 (1.04–1.51) | 1.22 (1.01–1.48) | 1.23 (1.01–1.49) |
| Among prepregnancy BMI <24 kg/m2 | ||||
| Passive smoking versus nonpassive smoking | 1.01 (0.87–1.18) | 1.08 (0.92–1.26) | 1.07 (0.91–1.26) | 1.08 (0.92–1.26) |
| Additive interaction models | ||||
| BMI <24 kg/m2 and nonpassive smoking | 1.00 | 1.00 | 1.00 | 1.00 |
| BMI <24 kg/m2 and passive smoking | 1.01 (0.87–1.18) | 1.05 (0.90–1.24) | 1.04 (0.89–1.23) | 1.06 (0.90–1.24) |
| BMI ≥24 kg/m2 and nonpassive smoking | 2.06 (1.71–2.48) | 2.13 (1.75–2.59) | 2.04 (1.67–2.48) | 2.01 (1.65–2.45) |
| BMI ≥24 kg/m2 and passive smoking | 2.61 (2.23–3.O6) | 2.70 (2.28–3.20) | 2.52 (2.13–3.00) | 2.51 (2.11–2.98) |
| LGA as the outcome | ||||
| Independent models | ||||
| Among prepregnancy BMI ≥24 kg/m2 | ||||
| Passive smoking versus nonpassive smoking | 1.21 (1.02–1.43) | 1.22 (1.01–1.47) | 1.19 (0.98–1.44) | 1.19 (0.98–1.44) |
| Among prepregnancy BMI <24 kg/m2 | ||||
| Passive smoking versus nonpassive smoking | 0.99 (0.85–1.16) | 1.03 (0.88–1.21) | 1.02 (0.87–1.19) | 1.03 (0.88–1.21) |
| Additive interaction models | ||||
| BMI <24 kg/m2 and nonpassive smoking | 1.00 | 1.00 | 1.00 | 1.00 |
| BMI <24 kg/m2 and passive smoking | 0.99 (0.85–1.16) | 1.02 (0.87–1.20) | 1.01 (0.86–1.18) | 1.02 (0.87–1.19) |
| BMI ≥24 kg/m2 and nonpassive smoking | 2.11 (1.75–2.54) | 2.05 (1.69–2.49) | 1.94 (1.60–2.36) | 1.93 (1.59–2.34) |
| BMI ≥24 kg/m2 and passive smoking | 2.59 (2.21–3.04) | 2.49 (2.11–2.95) | 2.30 (1.94–2.73) | 2.30 (1.94–2.72) |
Model 1: univariable analysis. Model 2: multivariable analysis, adjusted for age, height, parity, education >12 years, gestational age at delivery (only for macrosomia), gender (only for macrosomia), weight gain from prepregnancy to GCT, insulin treatment, alcohol drinker during pregnancy, multiple pregnancies, and systolic blood pressure at first antenatal care visit. Model 3: further adjusted for GDM, in addition to the variables listed in model 2. Model 4: further adjusted for GCT value, in addition to the variables listed in model 2. BMI, body mass index; LGA, large for gestational age; GDM, gestational diabetes mellitus; GCT, glucose challenge test.