Mid Upper Arm Circumference as the Best Surrogate Marker for Identification of Low Birth Weight in Newborns within the First 24 Hours of Life- A Cross-sectional Study

Introduction: Birth weight is a very important determinant factor regarding perinatal morbidity and mortality. However, in developing countries like India weighing facility may not be available in rural areas where an alternative anthropometric parameter like Mid Upper Arm Circumference (MUAC) may be considered alternative to birth weight. Aim: To determine the accuracy of MUAC by comparing it with different anthropometric parameters for identification of LBW in neonates within the first 24 hours of life. Materials and Methods: The present study was a hospital based cross-sectional study conducted in labour ward, Postnatal Care (PNC) wards and Neonatal Intensive Care Unit (NICU) of Indira Gandhi Medical College, Nagpur. Total 640 babies were enrolled over a period of 2 years from September 2018 to September 2020. Anthropometric parameters like weight, length, head circumference, Chest Circumference (CC), MUAC, ponderal index were taken by a researcher using standard techniques within first 24 hours of life and correlated with birth weight by using Pearson’s correlation coefficient. The comparison of the quantitative and qualitative variables was analysed using independent t-test and chi-square test, respectively. Receiver Operating Characteristic (ROC) curve was used to find out cut- off point of anthropometric parameters for predicting birth weight (<2000 gm, <1500 gm, <1000 gm). DeLong test was used for comparison of area under curve between different anthropometric parameters for predicting birth weight (<2000 gm, <1500 gm, <1000 gm). Univariate linear regression was used to assess the effect of anthropometric parameters on birth weight. The data entry was done in the Microsoft EXCEL spreadsheet and final analysis was done with the use of Statistical Package for Social Sciences (SPSS) software version 21.0. Results: Among 640 newborns, 334 (59.19%) were females and 306 (47.81%) were males. The mean birth weight was 1903.93 grams and MUAC of 8.3cm. All the chosen parameters showed significant correlation with birth weight (p<0.001). However, MUAC showed strongest correlation (r=0.890) with birth weight and easy to measure. Cut-offs of MUAC ≤8.45 cm, ≤7.5 cm, ≤6.8 cm predict birth weight of <2000gm, <1500gm, <1000gm with sensitivity of 91.22%, 92.81%, 100% and specificity of 88.95%, 89.12%, 89.35%, respectively. Conclusion: MUAC is the most simple and best surrogate measure that can be used in domiciliary outreach when it is impossible to record weight of baby at birth.