Abstract
Low birthweight (less than 2500 g) is the major factor associated with the death of infants within the first 4 weeks of life. The mean birthweight of newborn babies of a certain geographic area reflects the quality of maternal and child health care service as well as the degree of socioeconomic development of that particular region. Hence, birthweight is being used increasingly as an indicator for health and socioeconomic planning. However, in a developing country such as Thailand, two-fifths of the babies are delivered at home and are not weighed because scales are not available. To solve this problem in rural areas, a circular nomographic chart was developed with which the birthweight can be computed from a newborn baby's chest and mid-arm circumferences. Preliminary trials comparing these charts with standard baby scales showed a high degree of accuracy with sufficient sensitivity and specificity.