The Effect of Child's Body Size at Birth on Infant and Child Mortality in India

Low birth weight is one of the strongest predictors of infant mortality, especially in the neonatal period. In this paper, we use data from the 2015-2016 India's National Family Health Survey to examine the effect of mother's assessment of child's body size at birth on four measures of mortality: infant mortality, neonatal mortality, post-neonatal mortality, and child mortality. Using the Cox proportional hazards model, we found that small babies were slightly more than one and a half times and very small babies nearly four times more likely than average or larger size babies to die in the neonatal period. This was true even when potential confounders were held constant. However, the effect of child size on mortality risk became progressively weaker, though highly significant, in the post-neonatal and early childhood periods. We also found that, in spite of significant sex differences in mortality during infancy and early childhood, boys and girls were equally sensitive to the harmful effects of smaller body size at birth on mortality risks.