Table 4.
Adjusted incidence rate ratio (IRR) and 95% confidence intervals (CI) for the association of ambient air pollution (PM2.5 and PSI in quartiles *) during pregnancy by trimester and episodes of wheezing by 2 years old.
| Stratified by Pre-Pregnancy BMI ≥23 | ||||||||
|---|---|---|---|---|---|---|---|---|
| Trimester | Trimester | |||||||
| Episodes of Wheezing | Entire Pregnancy | First | Second | Third | Entire Pregnancy | First | Second | Third |
| Model 1 | ||||||||
| PM2.5 Q2 | 1.07 (0.85–1.34) | 1.53 (1.22–1.93) * | 0.73 (0.59–0.91) * | 1.41 (1.12–1.77) * | 0.89 (0.64–1.25) | 1.75 (1.24–2.48) * | 0.90 (0.65–1.25) | 1.43 (1.02–1.99) * |
| Q3 | 1.36 (1.10–1.69) * | 1.50 (1.20–1.87) * | 0.85 (0.70–1.04) | 1.32 (1.04–1.67) * | 1.08 (0.78–1.48) | 1.54 (1.10–2.17) * | 1.29 (0.94–1.76) | 1.42 (1.00–2.02) * |
| Q4 | 1.32 (1.06–1.65) * | 1.57 (1.26–1.97) * | 0.70 (0.56–0.87) * | 1.62 (1.29–2.02) * | 1.33 (0.96–1.85) | 1.81 (1.27–2.56) * | 0.72 (0.52–1.01) | 1.39 (1.00–1.94) * |
| PSI Q2 | 1.21 (0.96–1.51) | 1.25 (1.00–1.56) * | 0.97 (0.79–1.19) | 1.27 (1.01–1.60) * | 0.96 (0.68–1.34) | 1.21 (0.88–1.66) | 1.26 (0.93–1.71) | 1.46 (1.03–2.05) * |
| Q3 | 1.26 (1.00–1.58) * | 1.13 (0.91–1.41) | 0.80 (0.64–1.00) | 1.22 (0.97–1.54) | 1.13 (0.81–1.59) | 0.81 (0.57–1.15) | 0.87 (0.61–1.24) | 1.44 (1.02–2.04) * |
| Q4 | 1.67 (1.34–2.07) * | 1.30 (1.04–1.62) * | 0.80 (0.65–1.00) | 1.54 (1.25–1.91) * | 1.39 (1.02–1.89) * | 1.25 (0.90–1.74) | 0.94 (0.68–1.31) | 1.40 (1.02–1.92) * |
| Model 2 (multi-trimester) | ||||||||
| PM2.5 Q2 | (-) | 1.55 (1.19–2.01) * | 0.82 (0.61–1.10) | 1.22 (0.95–1.56) | (-) | 1.82 (1.24–2.67) * | 1.04 (0.67–1.61) | 1.24 (0.87–1.78) |
| Q3 | (-) | 1.33 (0.98–1.82) | 1.29 (0.92–1.80) | 1.28 (0.92–1.77) | (-) | 1.70 (1.06–2.72) * | 2.42 (1.43–4.09) * | 1.50 (0.92–2.44) |
| Q4 | (-) | 1.56 (1.18–2.06) * | 1.05 (0.77–1.43) | 1.56 (1.07–2.28) * | (-) | 2.07 (1.37–3.12) * | 1.33 (0.81–2.19) | 1.76 (0.98–3.18) |
| PSI Q2 | (-) | 1.31 (1.05–1.65) * | 1.14 (0.88–1.47) | 1.33 (1.03–1.71) * | (-) | 1.29 (0.93–1.80) | 1.70 (1.12–2.57) * | 1.51 (1.03–2.22) * |
| Q3 | (-) | 0.92 (0.71–1.18) | 1.07 (0.72–1.57) | 1.31 (0.96–1.80) | (-) | 0.65 (0.44–0.96) | 1.18 (0.64–2.19) | 1.62 (0.98–2.67) |
| Q4 | (-) | 1.23 (0.92–1.63) | 1.14 (0.78–1.66) | 1.84 (1.31–2.59) * | (-) | 1.32 (0.84–2.05) | 1.47 (0.81–2.67) | 1.97 (1.17–3.32) * |
| Model 3 (+postnatal) | ||||||||
| PM2.5 Q2 | 1.50 (1.11–2.03) * | 1.49 (1.13–1.96) * | 0.76 (0.56–1.03) | 1.29 (1.00–1.67) | 1.13 (0.73–1.75) | 1.85 (1.23–2.78) * | 1.02 (0.65–1.59) | 1.27 (0.86–1.89) |
| Q3 | 1.56 (1.17–2.08) * | 1.29 (0.94–1.77) | 1.22 (0.86–1.74) | 1.40 (0.96–2.05) | 1.15 (0.76–1.75) | 1.76 (1.08–2.85) * | 2.38 (1.34–4.20) * | 1.52 (0.86–2.69) |
| Q4 | 1.38 (0.96–1.99) | 1.27 (0.88–1.83) | 1.14 (0.80–1.62) | 1.60 (1.08–2.38) * | 1.69 (0.99–2.91) | 1.90 (1.10–3.27) * | 1.45 (0.80–2.61) | 1.84 (0.99–3.41) |
| PSI Q2 | 1.14 (0.87–1.49) | 1.47 (1.14–1.90) * | 1.08 (0.82–1.43) | 1.05 (0.78–1.39) | 0.70 (0.46–1.08) | 1.30 (0.90–1.87) | 1.48 (0.94–2.33) | 1.20 (0.77–1.85) |
| Q3 | 1.37 (1.07–1.76) * | 1.03 (0.78–1.37) | 0.97 (0.64–1.47) | 1.08 (0.75–1.54) | 1.13 (0.78–1.64) | 0.56 (0.37–0.86) * | 0.98 (0.51–1.88) | 1.45 (0.83–2.54) |
| Q4 | 1.87 (1.49–2.34) * | 1.68 (1.20–2.34) * | 1.31 (0.84–2.06) | 1.42 (0.96–2.09) | 1.45 (1.04–2.02) * | 1.83 (1.12–2.98) * | 1.48 (0.94–2.33) | 1.82 (1.02–3.25) * |
* Reference to first quartile (Q). Adjusted with maternal age at delivery, ethnicity, education level, parity, maternal atopy, maternal smoking during pregnancy and ETS, child’s gender, gestation age, and birthweight.