[Nutritional composition of donor human milk according to lactation period]

Introduction: when own mother´s breast milk is unavailable, donor human milk is the best option to guarantee the nutritional requirements of preterm or ill newborns. Objectives: to analyze the macronutrient composition of donor breast milk and its evolution over lactation periods. Material and methods: we retrospectively analyzed the nutritional composition of 822.423 L of donor breast milk from 160 donors at the human milk bank of a third-level hospital between February 1, 2017 and December 31, 2019. Results: lipid and carbohydrate composition remains constant throughout lactation. However, protein content decreases initially to increase again starting in the second year of lactation. Conclusions: donor human milk banks should be aware of the variations in macronutrient composition donor human milk shows in order to optimize nutrition for preterm newborns.