Comparison of birth weight of infants and proportion of low birth weight (LBW)* by smoking status of pregnant women (n = 9499)
| Smoking status | Number (%) | Mean (SD) birth weight (g) | LBW infants | OR‡ | (95% CI) | OR§ | 95% CI | |
|---|---|---|---|---|---|---|---|---|
| Number | Rate (%) | |||||||
| *LBW defined as birth weight less than 2500 g. | ||||||||
| †Mean birth weight is statistically smaller than that of never smoking mothers and that of quitting mothers, p<0.05. | ||||||||
| ‡Odds ratios (OR) of quitting mothers or non-quitting mothers in having LBW infants, when compared with proportion of LBW infants by non-smokers. | ||||||||
| §Adjusted for mothers’ age, educational level of mothers, sex of infants, parity, and alcohol drinking habit. | ||||||||
| Never smoking mothers | 8892 (93.6%) | 3184 (430) | 430 | 4.8 | 1.0 | 1.0 | ||
| Quitting mothers | 400 (4.2%) | 3195 (447) | 23 | 5.8 | 1.1 | (0.9 to 1.4) | 1.1 | (0.9 to 1.4) |
| Non-quitting mothers | 207 (2.2%) | 3027 (450)† | 17 | 8.2 | 1.8 | (1.1 to 2.9) | 1.7 | (1.0 to 2.8) |