Table 1.
Characteristics of mothers and infants by maternal smoking status during pregnancy
| Never smoked (n = 11 747) 64.3% | Quit smoking (n = 2320) 12.7% | Light smoker (n = 2378) 13.0% | Heavy smoker (n = 1818) 9.95% | |
|---|---|---|---|---|
| Mean (SE) | Mean (SE) | Mean (SE) | Mean (SE) | |
| Infant birth weight (kg)** | 3.37 (0.05) | 3.41 (0.02) | 3.20 (0.02) | 3.17 (0.02) |
| Infant length of gestation (days)* | 277 (0.18) | 278 (0.33) | 276 (0.31) | 276 (0.30) |
| Mother’s age (years)*** | 30.2 (0.62) | 27.2 (0.53) | 26.8 (0.40) | 27.4 (0.32) |
| Mother consumed alcohol during pregnancy | 26.3% | 34.9% | 31.2% | 33.8% |
| History of maternal depression*** | 18.9% | 29.3% | 35.4% | 41.4% |
| Partner-perpetrated domestic violence*** | ||||
| Yes | 2.6% | 4.3% | 4.6% | 6.7% |
| Prefer not to answer | 2.3% | 2.6% | 3.8% | 4.8% |
| Marital status*** | ||||
| Married | 70.7% | 39.3% | 31.3% | 27.9% |
| Cohabiting | 17.4% | 35.0% | 35.5% | 34.7% |
| Single | 11.9% | 25.7% | 33.1 % | 37.4% |
| Household income-related poverty*** | 27.3% | 34.9% | 51.6% | 62.9% |
| Mother’s educational qualifications** | ||||
| None | 13.7% | 12.0% | 21.9% | 36.3% |
| NVQ1 | 6.4% | 10.2% | 14.1 % | 14.6% |
| NVQ2 | 26.8% | 37.0% | 37.2% | 31.0% |
| NVQ3 | 14.9% | 16.7% | 14.1 % | 10.4% |
| NVQ4 | 33.4% | 21.8% | 11.9% | 7.2% |
| NVQ5 | 4.7% | 2.3% | 0.9% | 0.4% |
| Mother’s social class*** | ||||
| Routine and semi-routine occupation | 28.6% | 42.5% | 53.2% | 58.5% |
| Mother’s ethnic group*** | ||||
| White | 59.6% | 14.2% | 14.6% | 11.6% |
| Mixed | 52.7% | 19.1% | 19.7% | 8.5% |
| Indian | 93.9% | 3.8% | 1.7% | 0.8% |
| Pakistani/Bangladeshi | 96.0% | 1.0% | 2.2% | 0.7% |
| Black/black British | 81.8% | 8.9% | 7.5% | 1.8% |
| Other | 87.0% | 7.5% | 4.3% | 1.2% |
NVQ, national vocational qualification.
Differences were statistically significant at *p<0.01, **p<0.001, ***p<0.0001.