What causes anemia in premature infants?

Anemia is a relatively common disease in premature babies. Children are often prone to anemia one year after birth. This is mainly because the children are born too prematurely and their physical indicators are not yet perfect. The most important factor for anemia is physiological factors, and there are also pathological factors. When premature babies suffer from anemia, they should receive regular treatment, such as blood transfusion therapy for more serious cases.

What causes anemia in premature infants?

1. Physiological factors

This may be related to the fact that the life span of premature infants' red blood cells is shorter than that of full-term infants; their rapid growth leads to expansion of plasma volume, which leads to hemodilution; and low levels of erythropoietin, which may be caused by disorders in the regulation of its gene expression or by low sensitivity of target cells to it.

2. Pathological factors

In addition to the above physiological reasons, it may be related to the following factors: ① Nutritional factors; ② Disease factors; ③ Iatrogenic blood loss. For example, a premature baby weighing 1.5 kg has a total blood volume of about 150 ml. If the cumulative blood volume reaches 7.5 to 15 ml, the blood loss will reach 5% to 10% of the total blood volume.

Treatment of anemia in premature infants

1. Blood transfusion therapy

(1) Indications for blood transfusion in premature infants Blood transfusion should not only be based on the hemoglobin value, but also on the gestational age, age at birth, clinical manifestations, hemoglobin value at birth, and blood sample volume. Blood transfusion is effective in the following situations:

2. Iron therapy

Iron deficiency is not proportional to anemia in early infancy. Early iron supplementation cannot prevent the decrease in hemoglobin except for those with a history of perinatal blood loss or repeated blood sampling. When a premature baby's weight doubles, his or her body iron stores are depleted, so iron supplements should be given. The dosage of elemental iron is ≤2 mg/(kg·d), which is equivalent to 0.4 ml/(kg·d) of 2.5% ferrous sulfate. The course of treatment is 6 to 8 weeks, and vitamin C can be added at the same time.

3. Causes of hemolysis caused by vitamin E deficiency

Some people have suggested that it is the result of peroxidation of lipid components of red blood cell membranes. Premature infants should be given vitamin E 10-15 mg/(kg·d) within 3 months to prevent anemia of premature infants caused by vitamin E deficiency.

4. Other nutrients

(1) The preventive dose of folic acid is 25-50 mg/d for 3-4 weeks.

(2) The required amount of vitamin B6 is 0.3-0.5 mg/d, and the therapeutic dose is 2 mg/d.

(3) Vitamin C 100 mg/d is used starting from the second week after birth.