Determinants of infant growth in the slums of Dhaka city: size and maturity at birth and breast-feeding

Abstract

Objective: Investigate the effect of low birth weight (LBW), intrauterine growth retardation (IUGR), prematurity, and breast-feeding on infant growth. Methodology: The sample consisted of 1,654 infants born in selected slum areas of Dhaka city. They were enrolled at birth and followed up prospectively till their first birthday. Apart from repeated anthropometric measurements, the mothers were also interviewed for information on infant feeding and morbidity at each follow-up visit. Analytical techniques included correlation analysis and random effects regression for modelling infant growth. Results: Correlation was high and stationary between repeated body weight measurements from 3 months onward. Correlation between weights before 3 months and later weights was lower and declined rapidly with increasing age gap, suggesting greater plasticity of growth in the first 3 months of life. After adjusting for other variables, the mean differences in body weight by birth weight, IUGR, and prematurity categories remained constant throughout infancy. For example, low- and normal-birth-weight infants differed by 556-603 g, while the differences between symmetric and asymmetric IUGR babies were 172-184 g. A positive impact of exclusive breast-feeding in the first 3-5 months on infant growth was detectable at 12 months of age (+95g). The overall growth in this sample was of the pattern that heavier babies grew even heavier. However, exclusive breast-feeding appeared to counteract this pattern by equally benefitting the lighter and heavier infants. Conclusion: The study has demonstrated the important role of weight at birth and appropriate breast-feeding practices in determining nutritional status in infancy. Effective strategies for improving birth weight, till now a poorly-addressed issue in Bangladesh, are urgently needed. The sustained effect on growth and the beneficial effect on LBW infants are compelling reasons for increased and effective promotion of exclusive breast-feeding in early infancy.