Numerous physical features and functions of blood platelets were compared. A number of differences were found in relation to megakaryocytes – smaller in newborns, with a greater number of reticulated platelets (according to some investigators), more alpha granules in newborns, impaired aggregation of newborn platelets by ADP, thrombin, collagen and adrenaline,
attenuated release reaction and diminished bactericidal activity of platelets in male newborns. The knowledge of blood platelets in newborns in comparison to adults may be of some significance in clinical practice.

Keywords: Blood Platelets, newborns, adults