MicroRNA: problems of conservation in expressed breast milk

This review focuses on the issues of preservation of the qualitative characteristics of expressed breast milk with different methods of its conservation. The separation of a mother from her child hospitalized in the intensive care unit due to severe neonatal pathology fundamentally changes the pattern of interaction in the mother-child dyad. The realization of breastfeeding, which is optimal for a newborn, is often complicated by a complex set of medical and social problems. At the same time, providing a child with expressed breast milk while maintaining lactation is a technical burden that is imposed on the staff of medical institutions, particularly the neonatal intensive care and nursing units. Today, many neonatal institutions have organized breastfeeding units with breast milk jars, which solves this problem, but current research on the composition of breast milk poses new challenges to practitioners in preserving the quality of breast milk. Discoveries made in the last decade point to a more expanded structure and profound impact of breast milk on the growth, maturation, and formation of organs and structures of the newborn. MicroRNA is one of the important biologically active molecules. These molecules mediate the expression of about 60% of human genes. The results obtained in recent decades suggest a direct and indirect effect of microRNAs on the formation and maturation of fetus in intrauterine and extrauterine conditions through the mother-to-child information transmission by breast milk. The preservation of these molecules during the conservation of breast milk represents a significant task that implies a deeper understanding of the interaction in the mother-infant system. Key words: newborns, microRNA, microbiota, exovesicles, breast milk storage, breastfeeding, expressing milk, storage technologies