DETERMINANTS OF GROWTH FROM BIRTH TO 12 MONTHS AMONG BREAST-FED HONDURAN INFANTS IN RELATION TO AGE OF INTRODUCTION OF COMPLEMENTARY FOODS

Objectives. To evaluate the impact of introducing complementary foods to exclusively breast-fed infants at 4 vs 6 months on growth from 6 to 12 months, and to compare growth patterns of Honduran infants with th ose of breast-fed infants in the United States. Design. Randomized int ervention trial from 4 to 6 months and longitudinal study of infants f rom birth to 12 months. Setting. Low-income communities in San Pedro S ula, Honduras. Subjects. Primiparous, breast-feeding mothers and their infants (n = 141) recruited from public maternity hospitals. Interven tion. Infants were randomly assigned to exclusive breast-feeding to 6 months, or exclusive breastfeeding with addition of hygienically prepa red, nutritionally adequate complementary foods at 4 months, with or w ithout maintenance of baseline breast-feeding frequency. After 6 month s, mothers continued to breastfeed and also fed their infants home-pre pared foods after receiving instruction in appropriate feeding practic es. Outcome Measures. Infant weight was measured monthly during the fi rst year of life and infant length monthly from 4 to 12 months. Statis tical Analysis. Growth parameters were compared between the Honduran a nd US cohorts using multiple-regression and repeated-measures analysis of variance. Stepwise multiple regression was used to identify determ inants of infant growth. Results. There were no differences in growth patterns by intervention group. Mean birth weight of the Honduran infa nts was significantly less than that of a cohort of breast-fed infants in an affluent US population (n = 46) (2889 +/- 482 vs 3611 +/- 509 g ), but the Honduran infants exhibited rapid catch up in weight in the first few months of life, and the cohorts were similar in weight by 3 months. Mean weight and length gain were similar to those of the US co hort from 4 to g months but were lower from 9 to 12 months. Mean lengt h for age was significantly less than that of the US cohort from 4 to 12 months; this was attributable to the difference in maternal height (12 cm shorter in Honduras on average). Within the Honduran cohort, gr owth velocity of low birth weight infants (<2500 g; n = 28) was simila r to that of their normal birth weight peers; thus, the former subgrou p remained smaller than the latter throughout the first year of life. Conclusions. In poor populations, when breast-feeding is exclusive for the first 4 to 6 months, continues from 6 to 12 months, and is accomp anied by generally adequate complementary foods, faltering in weight d oes not occur before 9 months among infants born with birth weights of more than 2500 g.