The Bacon Chow study: maternal nutritional supplementation and birth weight of offspring

Abstract

This study is a randomized controlled double-blind trial on the effects of nutrition supplementation of pregnant and lactating women on their offspring. The study was conducted by the late Dr. Bacon Chow in 14 villages in Sui-Lin township, a farming area about 180 miles from Taipei, Taiwan. Two hundred ninety-four women were randomly assigned to one of two treatment groups. The daily supplement for one group provided 800 kcal and 40 g of protein/day; for the other group it only provided 80 kcal/day. Supplementation began after 3 wk of the delivery of a first study infant, continued throughout lactation, and through the pregnancy and lactation of a second study infant. Between group comparisons on the birth weight, number of low birth weight infants, or incidence of fetal deaths showed no statistically significant findings. However, the birth weight of the second study infant was statistically different and higher than that of the first study infant in the high supplement group. Moreover, in the low supplement group there was a correlation of 0.22 (p = 0.06) between the change scores for birth weight from the first to the second study infant and the quantity of supplements consumed during the last trimester of pregnancy. There was also in this same group a significant slope in a linear regression of birth weight on total daily caloric intake during the 3rd trimester of pregnancy for the male second study infants. These findings are partly in agreement with findings from three other large supplementation studies in Colombia, Guatemala, and New York. In this study the findings indicate that caloric supplementation does result in a small yet statistically meaningful increment in birth weight within a population which is not nutritionally at risk.