Table 3.
Minimally adjusted and fully adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for the association of each pollutant birth address exposure with risk of ASD
| Pollutant exposure window | Minimally adjusted HRa,b,d (95% CI) | Fully adjusted HRa,c,d (95% CI) |
|---|---|---|
| O3 | ||
| Preconception | 0.99 (0.93–1.04) | 0.98 (0.93–1.04) |
| Entire pregnancy | 1.13 (0.99–1.28) | 1.10 (0.95–1.26) |
| First trimester | 0.97 (0.92–1.03) | 0.97 (0.91–1.02) |
| Second trimester | 1.04 (0.98–1.10) | 1.03 (0.97–1.10) |
| Third trimester | 1.05 (1.00–1.11) | 1.05 (0.99–1.11) |
| First year of life | 1.00 (0.87–1.16) | 0.94 (0.80–1.11) |
| PM2.5 | ||
| Preconception | 1.13 (1.06–1.22) | 1.11 (1.03–1.20) |
| Entire pregnancy | 1.18 (1.06–1.32) | 1.17 (1.04–1.33) |
| First trimester | 1.11 (1.03–1.20) | 1.10 (1.02–1.19) |
| Second trimester | 1.07 (0.99–1.15) | 1.06 (0.97–1.14) |
| Third trimester | 1.09 (1.01–1.18) | 1.08 (1.00–1.18) |
| First year of life | 1.22 (1.07–1.39) | 1.21 (1.05–1.40) |
| PM10 | ||
| Preconception | 1.06 (0.97–1.15) | 1.05 (0.96–1.14) |
| Entire pregnancy | 1.03 (0.91–1.16) | 1.01 (0.89–1.15) |
| First trimester | 1.02 (0.93–1.11) | 1.00 (0.92–1.10) |
| Second trimester | 1.03 (0.94–1.12) | 1.02 (0.93–1.12) |
| Third trimester | 1.01 (0.93–1.11) | 1.00 (0.91–1.10) |
| First year of life | 1.06 (0.94–1.21) | 1.06 (0.92–1.22) |
| NO2 | ||
| Preconception | 1.09 (1.01–1.18) | 1.07 (0.99–1.17) |
| Entire pregnancy | 1.08 (0.96–1.22) | 1.05 (0.91–1.20) |
| First trimester | 1.04 (0.97–1.13) | 1.03 (0.95–1.11) |
| Second trimester | 1.02 (0.95–1.10) | 1.01 (0.93–1.09) |
| Third trimester | 1.04 (0.96–1.12) | 1.02 (0.94–1.11) |
| First year of life | 1.15 (1.00–1.31) | 1.12 (0.97–1.30) |
Separate models were estimated for each time window.
Models for minimally adjusted hazard ratios specified family as a random effect, and birth year and KPSC medical center service areas were adjusted for as covariates.
Models for fully adjusted hazard ratios were adjusted for adjusted for birth year, KPSC medical center service areas, maternal age, parity, maternal race/ethnicity, maternal education, census tract median household income, maternal history of comorbidities before pregnancy (≥1 diagnosis of heart, lung, kidney, liver disease or cancer), child sex, and family specified as a random effect.
Hazard ratios were scaled per 6.5 μg/m3 PM2.5; per 16.1 μg/m3 PM10; per 10.4 ppb NO2; and per 15.7 ppb O3.