Table 3.
Associations between Trimester-Specific Pollutant Exposures and Hypertensive Disorder of Pregnancy
| Pollutant | Trimester | Case/Control | Adjusted OR (95% CI)** |
|---|---|---|---|
| CO (ppm) | 1st | 136/162 | 2.83 (1.29, 6.20) |
| 2nd | 136/162 | 0.90 (0.45, 1.79) | |
| 3rd | 135/162 | 1.16 (0.61, 2.20) | |
| NO2 (ppb) | 1st | 136/162 | 1.42 (0.75, 2.67) |
| 2nd | 136/162 | 0.60 (0.33, 1.11) | |
| 3rd | 135/162 | 1.00 (0.56, 1.79) | |
| O3 (ppb) | 1st | 136/162 | 0.91 (0.54, 1.52) |
| 2nd | 136/162 | 2.05 (1.22, 3.46) | |
| 3rd | 135/162 | 1.19 (0.71, 1.98) | |
| PM2.5 (µg/m3) | 1st | 136/162 | 3.94 (1.82, 8.55) |
| 2nd | 136/162 | 1.86 (0.95, 3.63) | |
| 3rd | 135/162 | 1.44 (0.76, 2.70) | |
| PM10 (µg/m3) | 1st | 136/162 | 0.76 (0.43, 1.36) |
| 2nd | 136/162 | 0.76 (0.44, 1.32) | |
| 3rd | 135/162 | 1.41 (0.77, 2.57) | |
*
The odds ratios (ORs) and 95% confidence intervals (CIs) are reported per 2 standard deviations (2SD) increase in the pollutant concentration. The 2SDs for CO, NO2, O3, PM2.5, and PM10 were 1ppm, 14 ppb, 15 ppb, 7µg/m3 and 13µg/m3, respectively.
**
ORs adjusted for maternal age (continuous), parity, maternal smoking history, exposure to secondhand smoke during pregnancy, and year of conception (before or after 2002).
One case was excluded from the 3rd trimester analyses due to missing exposure.