Skip to main content

Table 2 Associations of maternal smoking during pregnancy with term birth weight and the risk of being SGA: overall and in strata of maternal pre-pregnancy overweight

From: The joint effect of maternal smoking during pregnancy and maternal pre-pregnancy overweight on infants’ term birth weight

 

Birth weight (g)

SGA

Crude Diff (g)

(95% CI)

Adjusted Diff a (g)

(95% CI)

SGA/Total

(%)

Crude OR

(95% CI)

Adjusted OR b

(95% CI)

Main effect

 Non-smoking

0 (Ref)

0 (Ref)

179/2681 (6.7%)

1.0 (Ref)

1.0 (Ref)

 Smoking

− 167.6 (− 211.5, − 123.7)

−158.4 (−203.4, −113.4)

69/545 (12.7%)

2.02 (1.51, 2.72)

1.92 (1.42, 2.60)

Strata of maternal pre-pregnancy overweight:

 Non-overweight

  Non-smoking

0 (Ref)

0 (Ref)

157/2168 (7.2%)

1.0 (Ref)

1.0 (Ref)

  Smoking

−177.1 (− 226.6, − 127.6)

−164.5 (−215.2, −113.8)

58/418 (13.9%)

2.06 (1.49, 2.85)

1.96 (1.41, 2.72)

 Overweight

  Non-smoking

0 (Ref)

0 (Ref)

22/513 (4.3%)

1.0 (Ref)

1.0 (Ref)

  Smoking

− 156.9 (− 250.4, −63.5)

−145.2 (−241.1, −49.3)

11/127 (8.6%)

2.12 (0.99, 4.48)

1.89 (0.87, 4.09)

  1. Abbreviations: Diff mean difference, SGA Small for gestational age, OR Odds ratio, CI Confidence interval
  2. aMultivariable linear regression adjusted for maternal age and education
  3. bMultivariable logistic regression adjusted for maternal age and education