 This is an observational study to characterize human milk of mothers delivering term SGA and term AGA infants. This is an observational, exploratory, longitudinal from birth to 6 months postpartum, 4 parallel groups, and multi-centric study. Total 300 subjects will be randomised in the study assuming 20 dropout, 240 subjects will be enrolled. The recruitment period for the study in India is for 6 months. 