Red blood cell synthesised by the kidney. Just before and after leaving the bone marrow, the developing cells are known as reticulocytes; these constitute about 1% of circulating red blood cells. The functional lifetime of a red blood cell is about 100–120 days, during which time the red blood cells are continually moved by the blood flow push (in arteries), pull (in veins) and a combination of the two as they squeeze through microvessels such as capillaries. They are also recycled in the bone marrow. The aging red blood cell undergoes changes in its plasma membrane, making it susceptible to selective recognition by
Neonatal red cell transfusion baby (e.g. wristband). Paedipacks are multiple aliquots made from one adult blood donation. By using paedipacks, the baby is exposed to blood from fewer blood donors. ABO blood grouping and screening for antibodies in neonates differs from blood grouping in adults and older children. Any antibodies detected are the mother's antibodies rather than the baby's. Therefore, any donor blood given to the baby must be ABO and D compatible with both mother and baby; and antigen-negative for any clinically significant maternal antibodies. Necrotising enterocolitis may occur after a red cell transfusion in neonates, although there is an association between the