Which is the most common cause of anemia in preterm newborns?

A) Frequent blood sampling
B) Respiratory distress syndrome
C) Meconium aspiration syndrome
D) Persistent pulmonary hypertension

The most common cause of anemia in preterm newborns is frequent blood-sample withdrawal and inadequate erythropoiesis in acutely ill newborns. Microsamples should be used for blood tests, and the amount of blood drawn should be monitored. Respiratory distress syndrome, meconium aspiration syndrome, and persistent pulmonary hypertension are not causes of anemia. They may require frequent blood sampling, which will contribute to the problem of decreased erythropoiesis and anemia.