Associations between PM2.5 and NO2 exposure in different pregnancy periods and mental and psychomotor developmental delay
| Crude models | Adjusted models* | Co-exposure models† | |||||
| Per IQR increase in | MDD (95% CI) | PDD (95% CI) | MDD (95% CI) | PDD (95% CI) | MDD (95% CI) | PDD (95% CI) | |
| (N=946) | (N=946) | (N=945) | (N=945) | (N=945) | (N=945) | ||
| Estimated exposure to PM2.5 | 90 days prior to conception | 1.45 (1.16 to 1.83) | 1.49 (1.20 to 1.83) | 0.95 (0.64 to 1.42) | 2.12 (1.45 to 3.11) | 0.97 (0.63 to 1.51) | 1.78 (1.17 to 2.71) |
| First trimester | 1.05 (0.83 to 1.33) | 1.04 (0.84 to 1.28) | 1.14 (0.73 to 1.79) | 1.42 (0.96 to 2.11) | 1.35 (0.80 to 2.25) | 1.16 (0.74 to 1.82) | |
| Second trimester | 0.63 (0.49 to 0.80) | 0.77 (0.63 to 0.95) | 0.81 (0.54 to 1.22) | 0.72 (0.51 to 1.02) | 0.83 (0.52 to 1.31) | 0.57 (0.38 to 0.85) | |
| Third trimester | 1.23 (0.96 to 1.58) | 1.19 (0.95 to 1.49) | 1.25 (0.82 to 1.90) | 1.17 (0.80 to 1.70) | 1.39 (0.87 to 2.23) | 0.98 (0.64 to 1.49) | |
| Total pregnancy | 0.84 (0.69 to 1.03) | 0.98 (0.82 to 1.18) | 1.07 (0.82 to 1.39) | 1.07 (0.84 to 1.35) | 1.17 (0.86 to 1.59) | 0.90 (0.68 to 1.20) | |
| Estimated exposure to NO2 | 90 days prior to conception | 1.20 (0.99 to 1.45) | 1.41 (1.19 to 1.67) | 0.97 (0.77 to 1.21) | 1.42 (1.16 to 1.75) | 0.97 (0.76 to 1.25) | 1.24 (0.99 to 1.56) |
| First trimester | 0.97 (0.80 to 1.17) | 1.18 (0.99 to 1.40) | 0.91 (0.72 to 1.13) | 1.29 (1.05 to 1.58) | 0.84 (0.65 to 1.09) | 1.24 (0.99 to 1.57) | |
| Second trimester | 0.79 (0.66 to 0.95) | 1.04 (0.88 to 1.22) | 0.94 (0.76 to 1.15) | 1.14 (0.95 to 1.38) | 0.98 (0.77 to 1.24) | 1.31 (1.06 to 1.63) | |
| Third trimester | 1.04 (0.85 to 1.28) | 1.25 (1.04 to 1.50) | 0.94 (0.73 to 1.21) | 1.27 (1.01 to 1.60) | 0.86 (0.65 to 1.14) | 1.28 (0.99 to 1.65) | |
| Total pregnancy | 0.92 (0.79 to 1.07) | 1.16 (1.01 to 1.33) | 0.94 (0.80 to 1.11) | 1.17 (1.02 to 1.36) | 0.9 (0.75 to 1.08) | 1.21 (1.02 to 1.43) | |
All significant findings in the table are bold.
*Models adjusted for maternal age at enrolment, infant’s sex, maternal BMI at 11–14 weeks’ gestation, primiparity, monthly household income level and season of births.
†Models adjusted for maternal age at enrolment, infant’s sex, maternal BMI at 11–14 weeks’ gestation, primiparity, monthly household income level and season of births, and adjusted for the other air pollutant.
BMI, body mass index; MDD, mental developmental delay; NO2, nitrogen dioxide ; PDD, psychomotor developmental delay; PM2.5, particulate matter with diameter ≤2.5.