Symptomatic anemia in the newborn period (Fig. 62-1) may be caused by decreased RBC production, increased RBC destruction, or blood loss.
Anemia caused by decreased production of RBCs appears at birth with pallor, a low reticulocyte count, and absence of erythroid precursors in the bone marrow. Potential causes of neonatal decreased RBC production include bone marrow failure syndromes (congenital RBC aplasia [Diamond-Blackfan anemia]), infection (congenital viral infections [parvovirus, rubella], acquired bacterial or viral sepsis), nutritional deficiencies (protein, iron, folate, vitamin B12), and congenital leukemia.
Immunologically mediated hemolysis in utero may lead to erythroblastosis fetalis, or the fetus may be spared and hemolytic disease may appear in the newborn. Hemolysis of fetal erythrocytes is a result of blood group differences between the sensitized mother and fetus, which causes production of maternal IgG antibodies directed against an antigen on fetal cells.
ABO blood group incompatibility with neonatal hemolysis develops only if the mother has IgG antibodies from a previous exposure to A or B antigens. These IgG antibodies cross the placenta by active transport and affect the fetus or newborn. Sensitization of the mother to fetal antigens may have occurred by previous transfusions or by conditions of pregnancy that result in transfer of fetal erythrocytes into the
Normal or elevated reticulocyte count (> 5−10%) Coombs positive Isoimmunization: Rh (D antigen) ABO, C, c, E, G Duffy, Kell Other minor group Drug-induced (PCN) Coombs negative Blood smear Specific RBC dysmorphology Obtain incubated osmotic fragility test Elliptocytes Poikilocytes Stomatocytes Fragmentation Basophilic stippling Spherocytes Blood cultures, obtain maternal serum for IgG, IgM, HIV, RPR/FTA RBC morphology Hypochromic microcytic RBCs Normal RBC morphology Chronic fetomaternal bleed Chronic twin-to-twin transfusion Alpha-thalassemia trait Gamma-thalassemia Consider acute blood loss due to obstetric complications, external or internal hemorrhage, DIC/sepsis, bleeding dyscrasias Low reticulocyte count (0−2%) Obtain bone marrow Obtain hemoglobin electrophoresis, KB stain Obtain specific enzyme assay Diamond-Blackfan Aase syndrome Congenital dyserythropoietic anemias Refractory sideroblastic anemia Transcobalamin II deficiency Orotic aciduria No jaundiceJaundice Other Galactosemia Alpha or gamma chain hemoglobinopathies Osteopetrosis Congenital leukemia Hemophagocytic histiocytosis syndromes Drugs (valproic acid, oxidizing agents) Congenital Enzymatic Defects G6PD Pyruvate kinase Hexokinase Glucose phosphate isomerase Others Infections Bacterial infections Parvovirus B19 TORCH infections Syphilis Malaria HIV