Anthropometric measurements– a study on options for identification of small babies in need of extra care

Abstract

Introduction:A large number of babies born in India and many developing countries are born at home and majority of them have no access to scales or other means by which they can be identified as LBW. The aim of our study was to determine the correlation of chest circumference and foot length with birth weight and gestational age and to determine the most sensitive and specific cut-off values for detection of Low birth weight and preterm babies using foot length and chest circumference. Methods: This was a prospective observational study done at a tertiary care centre in south India. We analyzed 1000 newborn babies within 24 hours of birth. For each baby we measured 1. chest circumference (CHC), 2. Foot length (FL), 3. Weight (BW) and 4. Gestational age (GA). Babies were classified according to GA (preterm/term) and BW (kg) as Very Low Birth Weight (VLBW) (<1.5kg), Low Birth Weight (LBW) (1.5-2.5kg) and Normal Birth Weight (NBW) (>2.5kg). Results: Significant positive correlation of 0.921 was found between FL and BW (p<0.001). The two ROC curves for FL and CHC were close to each with AUC 0.982 and 0.969 respectively and difference in the areas was statistically significant (Z = 4.303, p < 0.0001) which suggested that FL was better indicator of BW. FL <= 6.4cm predicts VLBW; between 6.4cm and 7.3cm predicts LBW and > 7.3cm predicts NBW. For estimating preterm birth FL cut off was <=7.1cm. Conclusion: FL and CHC both can be used as predictor for BW and GA estimation and FL was more appropriate than CHC considering its ease of measurement also. Screening of babies who are in need of extra care can be done using our cut off values and this can help in reducing neonatal mortality by early referrals.