USE OF MIDARM AND CHEST CIRCUMFERENCES TO PREDICT BIRTH-WEIGHT IN RURAL NORTH-INDIA

Study objective - To determine the most appropriate surrogate indicato r and its cut off point for identifying low birthweight babies in nort hern India. Study setting - A secondary level hospital at Ballabgarh. The patients were from nearby rural and urban areas and mostly belonge d to lower and middle socio-economic strata. Participants - These comp rised 733 singleton newborns delivered in the hospital between April a nd December 1991. Design - Birth weight, arm circumference, and chest circumference were measured in all the newborns. Different cut off poi nts for each index were identified and their validity was tested. Base d on the regression equations, a simple chart was drawn up and was use d to predict weights for different arm and chest circumferences in the hospital and community settings. Main results - Cut off points for ar m and chest circumferences of 8.5 cm and 29.5 cm respectively gave a s ensitivity and specificity of around 80%. When the chart based on the regression equations was tested in both the hospital and the community , chest circumference was found to be the better of the two indicators . Conclusion - Chest circumference seems to be the most appropriate su rrogate measure for birth weight. Cut off points of 29.5 cm and 27.5 c m seem to be satisfactory for predicting birth weight below 2500 g and 1800 g respectively. The birthweight prediction card using chest circ umference was effective in predicting birth weight.