Prolonged refrigeration of fresh HM for 96 hours maintained its overall lipid composition. The limited lipolysis during storage should be ascribed to the activity of lipoprotein lipase, responsible for the decrease in pH. Our study demonstrates that infants who receive expressed milk stored for up to 96 hours receive essentially the same supply of fatty acids and active lipases as do infants fed directly at the breast.

Breastfeeding and human milk are the normative standards for feeding and nutrition of both term and pre-term infants. Fresh mother's own milk is recognized as the optimal choice for feeding all newborns, including preterm and very low birth weight infants. Evidence documents short and long-term metabolic, immunologic and neurodevelopmental advantages of breastfeeding when compared to formula. Moreover, benefits of breastfeeding on psychological and relational aspects have to be considered. Currently, human milk supplementation is usually performed to meet the specific nutritional requirements of preterm infants. When mother's milk is unavailable or in short supply, donor milk represents the best alternative, although some nutritional elements are inactivated by the necessary pasteurization process. Aim of this review is to briefly summarize the main biological and nutritional factors that contribute to the beneficial effects of human milk feeding for preterm infants.