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. Author manuscript; available in PMC: 2015 Oct 1.
Published in final edited form as: Environ Res. 2014 Aug 28;134:198–204. doi: 10.1016/j.envres.2014.08.002

Table 5.

Adjusted odds ratio for the association between air pollutants and adverse birth outcomes for every interquartile (IQR)a increase in exposure using closest monitor values among births within 5 miles from a monitor station.

Pollutants Term LBWb PTDc VPTDc
n(LBW/total) Adjusted OR n(PTD/total) Adjusted OR n(VPTD/total) Adjusted OR
O3 (ppb)
Trimester 1 2,569/112,500 0.966 (0.911, 1.025) 10,193/112,500 1.047 (1.015, 1.079)* 1,499/112,500 1.123 (1.041, 1.212)*
Trimester 2 2,569/112,500 1.017 (0.961, 1.075) 10,193/112,500 1.056 (1.023, 1.089)* 1,499/112,500 1.121 (1.037, 1.212)*
Trimester 3 2,569/112,500 0.960 (0.907, 1.016) 10,193/112,500 0.985 (0.956, 1.015) 1,499/112,500 0.972 (0.888, 1.063)
Pregnancy 2,569/112,500 0.974 (0.920, 1.031) 10,193/112,500 1.057 (1.023, 1.091)* 1,499/112,500 1.171 (1.079, 1.271)*
PM2.5 (μg/m3)
Trimester 1 2,887/123,207 1.027 (0.977, 1.080) 11,656/123,207 1.060 (1.037, 1.084)* 1,867/123,207 1.101 (1.047, 1.159)*
Trimester 2 2,887/123,207 1.054 (1.005, 1.106)* 11,656/123,207 1.149 (1.125, 1.173)* 1,867/123,207 1.226 (1.169, 1.285)*
Trimester 3 2,887/123,207 1.031 (0.988, 1.075) 11,656/123,207 1.052 (1.031, 1.073)* 1,867/123,207 1.031 (0.975, 1.090)
Pregnancy 2,887/123,207 1.048 (0.989, 1.110) 11,656/123,207 1.110 (1.081, 1.141)* 1,867/123,207 1.146 (1.077, 1.220)*
a

Interquartile range for O3 in ppb: 8.9 for trimester 1, 9.1 for trimester 2, 8.5 for trimester 3, 5.9 for the entire pregnancy; for PM2.5 in μg/m3: 2.4 for trimester 1, 2.5 for trimester 2, 2.5 for trimester 3, and 2.5 for the entire pregnancy.

b

Adjusted for maternal education, ethnicity, marital status, age, infant gender, prenatal care status, season of conception, alcohol, smoking, census tract income, urbanicity, presence or absence of maternal risk factor, infection, PTD status, or co morbidity.

c

Adjusted for maternal education, ethnicity, marital status, age, infant gender, prenatal care status, alcohol, smoking, census group income, urbanicity, presence or absence of maternal risk factor, LBW status, or comorbidity.

*

Indicates statistical significance at p<0.05