Causes of Anemia in Infants (List Only):
1. Nutritional causes
- Iron deficiency
- Vitamin B12 deficiency
- Folate deficiency
- Protein-energy malnutrition
2. Blood loss
- Gastrointestinal bleeding (e.g., anal fissure, Meckel’s diverticulum
- Birth trauma or internal hemorrhage
- Iatrogenic blood loss (frequent phlebotomy in NICU)
- Occult bleeding (cow’s milk protein-induced colitis)
3. Hemolytic causes
- Hemolytic disease of the newborn (Rh or ABO incompatibility)
- G6PD deficiency
- Hereditary spherocytosis
- Thalassemia
- Sickle cell disease
- Infections causing hemolysis (e.g., malaria, sepsis)
4. Bone marrow failure / decreased production
- Aplastic anemia
- Congenital pure red cell aplasia (Diamond–Blackfan anemia)
- Transient erythroblastopenia of childhood
- Bone marrow infiltration (leukemia, storage diseases)
5. Chronic disease / inflammation
- Anemia of chronic infection or inflammation
- Renal failure (↓ erythropoietin)
6. Physiologic / other causes
- Physiologic anemia of infancy
- Prematurity (low iron stores, immature erythropoiesis)
- Hypothyroidism
- Chronic blood loss from parasites (hookworm in older infants)
