Table 1.
Summary of potential confounders for 5 689 white singleton children enrolled in ALSPAC with information on maternal smoking in pregnancy and DXA data at mean age 9.9 years
| N | Mean | SD | ||
|---|---|---|---|---|
| Child age (years) | 5689 | 9.9 | 0.3 | |
| Child height (cm) | 5689 | 139.7 | 6.3 | |
| Maternal age (years) | 5689 | 29.2 | 4.5 | |
| Maternal height (cm) | 5509 | 164.2 | 6.6 | |
| Maternal BMI (kg/m2) | 5262 | 22.9 | 3.7 | |
| Partner height (cm) | 4258 | 176.4 | 6.8 | |
| Partner BMI (kg/m2) | 4220 | 25.2 | 3.3 | |
| Birthweight (kg) | 5624 | 3.4 | 0.5 | |
| Gestation (weeks) | 5689 | 39.6 | 1.7 |
| N | % | ||
|---|---|---|---|
| Sex | Male | 2800 | 49.2 |
| Female | 2889 | 50.8 | |
| Parity | Primap | 2546 | 45.5 |
| Multip | 3051 | 54.5 | |
| Social class | V | 185 | 3.3 |
| IV | 737 | 13.2 | |
| III Manual | 1502 | 27.0 | |
| III Non manual | 1467 | 26.3 | |
| II | 1478 | 26.5 | |
| I | 201 | 3.6 | |
| Maternal education | None/CSE | 700 | 12.3 |
| Vocational | 475 | 8.4 | |
| O levels | 2028 | 35.7 | |
| A levels | 1539 | 27.1 | |
| Degree | 937 | 16.5 | |
| Breastfed | Exclusive | 1832 | 34.4 |
| Partial | 2630 | 49.4 | |
| Never | 864 | 16.2 | |
| Age at introduction to solids | ≤2 months | 750 | 13.8 |
| 3-4 months | 4456 | 82.2 | |
| ≥5 months | 213 | 3.9 |