Abstract
Neutrophils are crucial components of the innate immunity. Differences exist in the physiological, phenotypic, and functional characteristics between neonatal and adult neutrophils. The severity of these changes is inversely proportional to gestational age, which indicates the dynamic development of these cells throughout pregnancy. Therefore, functional insufficiency of neonatal neutrophils is associated with an extremely high risk of developing neonatal infections and sepsis in infants born premature. Neonatal neutrophils are adapted to conditions that prevent unwanted triggering of proinflammatory factors. In addition, suppression of neutrophil functions is necessary to create a healthy microbiome in the postpartum period; however, it can be inhibit the development of a response to pathogenic organisms. Mechanisms underlying the normal transition of functionally limited neutrophils, capable of fully resisting pathogenic microorganisms, have not been established. This review presents features of neutrophil ontogenetic adaptation to intrauterine conditions and early neonatal period and their potential role in neonatal pathology.