Factors affecting a mother's recall of her baby's birth weight.
ABSTRACT The Millennium Cohort Study of UK babies born this century obtained maternal report of birth weight and data on the family's characteristics, including parental ethnicity, education, and social circumstances. Parental permission to link babies to their birth registration data provided the opportunity to investigate factors affecting accuracy of maternal recall of birth weight and to determine possible causes of error.
Logistic regression was used to investigate the relationship between maternal factors and recall of birth weight. Numerical and graphical methods were used to identify potential causes for birth weight discrepancies.
Data were obtained from the birth registry and Millennium Cohort Study for 11 890 of the 14 294 cohort children born in England and Wales. Weight was reported in imperial units by 84% of mothers and this was more common in younger mothers. Accuracy within 100 g was 92% overall, varying from 94% among British/Irish white mothers to 69-89% for other ethnic groups and was lower among the long-term unemployed and those living in disadvantaged or ethnic wards. Explanations (mostly rounding and transcription errors) were identified for 27% of the discrepancies of 100 g or more. Conclusion Mothers' reports of their infants' birth weight showed high level of agreement with registration data, the mean discrepancy being consistently close to zero. However, the variance of the discrepancy differed according to ethnic group, ward type, and socioeconomic status. These sources of differential variability should be taken into account in analyses using birth weight, and possibly other reported data, from socially mixed populations.
[show abstract] [hide abstract]
ABSTRACT: The influence of infant feeding practices on weight gain during childhood remains unresolved, with few studies adjusting appropriately for confounding factors. This study examined the effect of breastfeeding initiation, breastfeeding duration and age at introduction of solid foods on weight gain from birth to 3 years. Nationally representative prospective study. England, Wales, Scotland and Northern Ireland. 10,533 3-year-old children from the UK Millennium Cohort Study. Conditional weight gain z-scores from birth to 3 years (adjusted for birthweight); multiple linear regression analyses were conducted to examine the impact of infant feeding practices on this measure after adjustment for confounding factors. Breastfeeding initiation and breastfeeding duration were significantly associated with weight gain from birth to 3 years. Infants receiving no breast milk grew faster than those whose mothers initiated breastfeeding (adjusted regression coefficient (difference in z-scores) 0.06, 95% CI 0.02 to 0.09), as did those breastfed for less than 4 months (0.05, 95% CI 0.01 to 0.09) versus those breastfed 4 months or longer. Early introduction of solids was not associated with faster weight gain after adjustment for height z-score at 3 years (-0.01, 95% CI -0.04 to 0.03). Initiating and prolonging breastfeeding may reduce excess weight gain by preschool age. Association of the early introduction of solids with rapid weight gain during early childhood is mediated through childhood stature. Although effects sizes are small, at a population level they are of public health importance as these risk factors are potentially modifiable. Strategies to support mothers to follow internationally recommended infant feeding practices are required.Archives of Disease in Childhood 12/2008; 94(8):577-82. · 2.88 Impact Factor