Publisher Summary During neonatal period anemia is caused by hemorrhage, hemolysis, or failure of red blood cell production. The condition of hemorrhage arises when blood loss occurs during the prenatal, intranatal, or postnatal period. Prenatal blood loss may be transplacental, intraplacental, or retroplacental or may be due to a twin-to-twin transfusion. Hemolytic anemia in the newborn is usually associated with an abnormally low haemoglobin level, an increase in the reticulocyte count and with unconjugated hyperbilirubinemia. The hemolytic process is often first detected as a result of investigation for jaundice during the first week of life. The causes of hemolytic anemia in the newborn are listed in this chapter. The failure of red blood cell production can be congenital or acquired. Viral interference (e.g., CMV, HIV) with fetal hematopoiesis may cause anemia, leukopenia and thrombocytopenia in the newborn. HIV disease may be associated with a number of hematologic abnormalities. Other kinds of anemia such as anemia of prematurity and physiologic anemia are also described in this chapter. Lastly, the chapter outlines the diagnostic approach to anemia in new born and also highlights the treatment procedure in respective cases.