Table 2 Associations between birth weight, SGA z score, and tobacco smoke exposure

Birth weight (in Kg)

N = 8091

N = 2256

N = 6395

Mean Birthweight (SE)†

3.448 (0.007)

3.389 (0.014)

3.279 (0.009)

Crude mean difference compared to Non-Smoker, Non ETS exposed (95% CI)

-

-0.059 (-0.090 to -0.027)

p < 0.001

-0.168 (-0.191 to -0.146)

p < 0.001

Adjusted Mean difference* (95% CI)

-

-0.036 (-0.067 to -0.005)

p = 0.025

-0.146 (-0.171 to -0.122)

p < 0.001

SGA z score

N = 8024

N = 2228

N = 6338

Mean Z score (SD)†

0.077 (0.014)

0.006 (0.026)

-0.237 (0.016)

Crude mean difference compared to Non-Smoker, Non ETS exposed (95% CI)

-

-0.070 (-0.128 to -0.013)

p = 0.016

-0.314 (-0.354 to -0.273)

p < 0.001

Adjusted Mean difference* (95% CI)

-0.038 (-0.093 to 0.018)

p = 0.18

-0.275 (-0.319 to -0.231)

p < 0.001