Description of participating infants and families
| Count (%) | 95% CI* | |
|---|---|---|
| Gender | ||
| Male | 15 (43%) | (26 to 60) |
| Female | 20 (57%) | |
| Birth weight, g, mean (SD) | 3515 (644) | |
| Gestation weeks, mean (SD) | 39.6 (1.35) | |
| Feeding | ||
| Breast fed or partial breast fed | 29 (73%) | (66 to 93) |
| Bottle fed only | 6 (17%) | |
| Social class† | ||
| Managerial/professional | 16 (46%) | (29 to 63) |
| Administration/sales/service | 5 (14%) | (5 to 30) |
| Technical/skilled | 13 (37%) | (21 to 55) |
| Unskilled | 1 (3%) | (0.07 to 14) |
| Smoking status | ||
| Non-smoking | 19 (54%) | |
| Smoking | 16 (46%) | (29 to 63) |
| Birth order, mean (SD) | 1.7 (0.94) | |
| Weight at 10 weeks, g, mean (SD)‡ | 5577 (973) | |
| Maternal age, years, mean (SD) | 31.2 (6.59) | (range 18–43) |
| Paternal age, years, mean (SD) | 34.0 (8.34) | (range 21–53) |
*95% CI for the proportion (for continuous variables) % (categorical variables).
†Social class was based on the reported occupation of the highest earner in the household (National Statistics Socio-economic Classification: managerial/professional class I/II; administration/sales/service class II/IV; technical/skilled class V/VI and unskilled class VII/VIII).
‡Measurement taken at time of monitoring visit.