Assessing the role of mid upper arm circumference in identification of low birthweight and wasting in early infancy in India

Aim: We conducted this study to examine the mid upper-arm circumference (MUAC) of full-term infants from birth to 6 months; construct gender-specific MUAC graphs; and assess the role of MUAC as a surrogate marker for low birthweight and wasting in infants younger than 6 months.

Methods: This is a prospective longitudinal study of 268 (133 female and 135 male) new-borns in a tertiary care centre in Navi Mumbai, India. We measured weight, length, head circumference and MUAC. We drew the MUAC curves for the first 6 months using the mean MUAC and standard deviation (SD) values and assessed the diagnostic test properties of MUAC at birth as a marker of low birthweight.

Results: The mean (SD) birthweight of the male and female new-borns was 2756.2 g (368.1) and 2803.8 g (326.2), respectively (P = 0.25). The mean (SD) MUAC at birth was 8.7 (0.3) cm in males and 8.8 (0.2) cm in females, respectively (P = 0.14). The plotted mean MUAC curve in infants who were classified with wasting was between the -1SD and -2SD in both genders. The sensitivity and NPV for detecting low birthweight were 100% at cut-off of 8.6 cm in females and 8.7 cm in males, respectively (area under the curve: 0.92 (females) and 0.96 (males)).

Conclusion: MUAC may be a good proxy for low birthweight at birth and the curves from our study show that it may also help in the diagnosis of wasting in infants below 6 months of age in the community, particularly in resource-constrained settings.