Determinants of infant growth in the slums of Dhaka: size and maturity at birth, breastfeeding and morbidity

Objective: To investigate the influences of size at birth, breastfeeding and morbidity on growth during infancy in poor areas of urban Bangladesh. Design: This was a prospective observational study of a cohort of newborn infants followed until 12 months of age. Setting: Slum areas of Dhaka City in Bangladesh. Subjects: A total of 1654 newborn infants were enrolled at birth, and follow-up was completed for 1207 infants. Repeated anthropometric measurements and interviews of caretakers on infant feeding and morbidity were conducted. A mixed effects regression method was used for modeling infant growth. Results: After adjusting for other variables, mean differences in body weight by birth weight and length, small-for-gestational age and prematurity categories remained relatively constant throughout infancy. A positive impact of exclusive breastfeeding in the first 3 - 5 months on infant growth was detectable at 12 months of age. Although the bigger babies in the sample tended to grow relatively even bigger; exclusive breastfeeding appeared to counteract this pattern. Reported diarrhoea was associated with lower body weights and lengths even after adjusting for feeding patterns. Conclusions: Size at birth has an important role in determining growth during infancy. Effective strategies for improving birth weight, poorly addressed till now in Bangladesh, are needed. The sustained effect on growth and the even more beneficial effect in lighter infants are compelling reasons for promotion of exclusive breastfeeding in early infancy.