Table 2.

Crude and adjusted ORs (95% CIs) for SGA associated with every 1 μg/m³ increase in air pollutants

Exposure	Crude			Adjusted
	ORa	95% CI	P	aORb	95% CI	P
PM10
Entire pregnancy	1.692	1.384–2.042	< 0.001	1.055	1.035–1.076	< 0.001
Trimester 1	0.817	0.753–0.886	< 0.001	0.979	0.971–0.987	< 0.001
Trimester 2	1.138	1.062–1.219	< 0.001	1.013	1.006–1.020	< 0.001
Trimester 3	1.184	1.116–1.255	< 0.001	1.018	1.012–1.024	< 0.001
PM2.5
Entire pregnancy	2.179	1.644–2.917	< 0.001	1.084	1.053–1.116	< 0.001
Trimester 1	0.792	0.722–0.877	< 0.001	0.976	0.966–0.986	< 0.001
Trimester 2	1.207	1.094–1.318	< 0.001	1.019	1.009–1.028	< 0.001
Trimester 3	1.219	1.127–1.331	< 0.001	1.022	1.013–1.030	< 0.001
NO2
Entire pregnancy	1.020	0.638–1.629	0.947	1.000	0.953–1.049	0.913
Trimester 1	0.665	0.580–0.776	< 0.001	0.959	0.945–0.973	< 0.001
Trimester 2	1.184	0.990–1.411	0.065	1.016	0.998–1.035	0.079
Trimester 3	1.424	1.195–1.692	< 0.001	1.037	1.019–1.056	< 0.001
SO2
Entire pregnancy	1.629	0.722–3.707	0.238	1.051	0.968–1.141	0.253
Trimester 1	0.319	0.224–0.449	< 0.001	0.887	0.857–0.919	< 0.001
Trimester 2	1.357	0.951–1.913	0.091	1.029	0.993–1.066	0.120
Trimester 3	2.814	2.061–3.873	< 0.001	1.117	1.082–1.153	< 0.001

^aCrude ORs of air pollutants

^bAdjusted ORs for covariates, including maternal age, parity, gestational hypertension, gestational diabetes mellitus, delivery mode, and infant sex