An assessment of the impact of supplementary feeding to pregnant women on low birth weight rates in S. Paulo city (Brazil)

Abstract

The impact of supplementary feeding to pregnant women on the incidence of low birth weight (< 2500 g) was investigated in 8 maternity hospitals which attend low socioeconomic population in the city of S. Paulo, Brazil. Only mothers who had received prenatal care were studied: 1060 supplemented during pregnancy and 664 unsupplemented during pregnancy. The incidence of low birth weight was similarly high in both groups: around 11%. A multivariate analysis done for controlling possible confounding variables failed to demonstrate any association between supplementation and birth weight. On the other hand, the same multivariate analysis demonstrated that smoking and disease during pregnancy and certain maternal anthropometric and reprodutive characteristics previous to pregnancy are important high risk factors for low birth weight. The most likely explanation for the absence of impact of maternal supplementation on birth weight does not appear to lie in the quantity of food offered to mothers (370 Kcal/day), but on the relative predominance of non dietary factors in the etiology of low birth weight in the population studied. Recommendations for the control of low birth weight are made with this in mind.