What is a significant predisposing factor for anemia of prematurity?

Anemia of prematurity is primarily associated with decreased red blood cell (RBC) lifespan in premature infants. In these infants, RBCs have a shorter life span compared to those in full-term infants. This shortened lifespan is due to various factors, including the immaturity of the infant's hematopoietic system, which is responsible for producing blood cells. The premature infant's body is less capable of compensating for the loss of red blood cells, leading to a higher incidence of anemia.

Increased birth weight does not contribute to anemia of prematurity; in fact, higher birth weight is usually associated with better outcomes regarding hematologic health. The use of vitamin supplements does not typically predispose infants to anemia; rather, certain vitamins like iron are critical for preventing anemia. Early administration of solid foods is not a factor linked to anemia of prematurity as infants are generally fed appropriately according to their development stage to ensure they receive necessary nutrients for growth and blood cell production.