The incidence of low birth weight ( ≤ 2.5 kg [5.5 lb]) is excessive in rural and urban low socioeconomic groups in preindustrialized countries (Fig 1). Since the large part of the population in these countries is in this socioeconomic stratum, low-birth-weight infants constitute a large proportion of the total newborn population. About 3 million infants born in Latin America alone during 1973 were of low birth weight. Since most of them presumably were full-term newborns, their low weights reflected fetal growth retardation.
Low-birth-weight infants have a higher mortality during the first year of life than do infants of normal birth weight.1,2 In addition, they show impaired mental development.3,4 It is possible that this impairment influences their ability to develop into functioning adults.
Influence of Maternal Nutrition on the Proportion of Low-Birth-Weight Babies
Experiments in animals have shown that severe caloric or protein malnutrition in the mother delays fe