Table 5.

Percent Change in Risk (And 95% Confidence Intervals) of SGA and VSGA Associated with Each Incremental (Interquartile Range) Increase in Mean Trimester Specific PM_2.5 and NO₂ Concentrations (Single pollutant and Two pollutant models). New Jersey Air Pollution and Adverse Birth Outcomes Study 1999-2003 (n=59,955).

Trimester of mean concentration	Model Type (Single or Two pollutant)	Pollutant	Interquartile range	Small for gestational age	Very small for gestational age
1st Trimester	Single*	PM2.5	4 μg/m3	4.6 (−0.3, 9.8)	4.5 (−4.0, 13.7)
	Single*	Nitrogen Dioxide	10 ppb	1.0 (−2.9, 5.0)	9.2 (2.0, 17.0)
	Two	PM2.5	4 μg/m3	4.5 (−0.4, 9.7)	3.2 (−5.2, 12.4)
		Nitrogen Dioxide	10 ppb	0.6 (−3.3, 4.6)	8.9 (1.6, 16.7)
2nd Trimester	Single*	PM2.5	4 μg/m3	−3.2 (−7.8, 1.6)	−0.6 (−8.7, 8.3)
	Single*	Nitrogen Dioxide	10 ppb	0.3 (−3.2, 4.0)	9.5 (2.8, 16.8)
	Two	PM2.5	4 μg/m3	−3.3 (−8.0, 1.5)	−2.0 (−10.1, 6.9)
		Nitrogen Dioxide	10 ppb	0.6 (−3.0, 4.4)	9.7 (2.9, 17.0)
3rd Trimester	Single*	PM2.5	4 μg/m3	8.2 (3.4, 13.2)	6.4 (−1.7, 15.2)
	Single*	Nitrogen Dioxide	10 ppb	0.3 (−3.2, 3.8)	9.1 (2.5, 16.0)
	Two	PM2.5	4 μg/m3	8.2 (3.5, 13.2)	5.3 (−2.8, 14.1)
		Nitrogen Dioxide	10 ppb	−0.4 (−3.8, 3.2)	8.6 (2.1, 15.5)

NOTE: All risk estimates adjusted for maternal race/ethnicity, maternal education, maternal age, marital status, trimester prenatal care began; maternal alcohol use, maternal smoking, maternal drug use, percentage of population (≥ 25 years) in maternal residence census tract with < 12 years of education, percentage of population (≥ 25 years) in maternal residence census tract with at least 4 years of college, and percentage of population in maternal residence census tract below federally defined poverty line.

^*Note, these single pollutant models differ from those in Table 4 only by the number of births used in the analysis.