Table 2 Binominal logistic regression analysis of maternal smoking and maternal exposure to ETS for predicting offspring’s smaller circumference.

Total offsprings (n = 84,856)

Maternal smoking^a

Crude model

Adjusted model^c

1

1.000 (reference)

1

1.000 (reference)

2

0.894 (0.812–0.985)

2

0.988 (0.892–1.094)

3

1.032 (0.922–1.156)

3

0.982 (0.868–1.110)

4

1.513 (1.296–1.766)

4

1.653 (1.387–1.969)

Maternal exposure to ETS^b

Crude model

Adjusted model^c

1

1.000 (reference)

1

1.000 (reference)

2

1.107 (1.004–1.22)

2

1.066 (0.963–1.181)

3

1.197 (1.083–1.322)

3

1.091 (0.973–1.222)

The offsprings of mothers with “never smoked” (n = 48,381)

Maternal exposure to ETS^c

Crude model

Adjusted model^d

1

1.000 (reference)

1

1.000 (reference)

2

1.048 (0.918–1.195)

2

1.017 (0.887–1.166)

3

1.069 (0.908–1.258)

3

1.039 (0.876–1.232)

The offsprings of mothers with “smoking during pregnancy” (n = 3,953)

Number of daily cigarettes

Crude model

Adjusted model^c

 < 5

1.000 (reference)

 < 5

1.000 (reference)

5–9

0.781 (0.503–1.212)

5–9

0.780 (0.496–1.227)

10–14

0.838 (0.549–1.279)

10–14

0.933 (0.602–1.445)

15–19

0.939 (0.535–1.646)

15–19

1.114 (0.627–1.982)

 >  = 20

0.816 (0.466–1.430)

 >  = 20

0.927 (0.517–1.661)