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    Iron deficiency
    Patient Blood Management and surgery  
    Blood product prescription 
    The Australian Red Cross Blood Service anaemia and haemostasis overview

    Key Points                                                       

    1. Iron deficiency is the most common cause of anaemia in children 
    2. Consider admission and discussion with local paediatrician or haematologist for children with red flag features


    Anaemia is defined as haemoglobin (Hb) less than the lower limit of the reference range for age


    Lower limit of normal range Hb (g/L)

    2 months


    2-6 months


    6-24 months


    2-11 years


    >12 years

    Female: 120, male: 130



    • Lethargy
    • Poor concentration
    • Weakness
    • Shortness of breath
    • Ethnic background (can be helpful in guiding investigation for haemoglobinopathies and G6PD deficiency)
    • Medication history: past and current, particularly those that may cause haemolysis in children with G6PD deficiency
    • Dietary history: iron intake (with particular attention to iron-rich foods, breast feeding and cow milk intake), vitamin B12 intake, recent fava/broad bean ingestion (may precipitate haemolysis in children with G6PD deficiency)
    • Family history: anaemia, jaundice, gallstones or splenomegaly


    • Poor growth
    • Listlessness or fatigue
    • Pallor
    • Pale conjunctivae
    • Tachycardia
    • Cardiac murmur
    • Signs of cardiac failure
    • Shortness of breath
    • Weakness
    • Signs of haemolysis (jaundice, scleral icterus, splenomegaly and dark urine)



    • FBC and film
    • Reticulocyte count
    • Ferritin
      • Iron studies or serum iron should not be requested to diagnose iron deficiency. Serum iron reflects recent iron intake and does not provide a measure of the iron stores   
    • For “Other features on the blood film appearance that prompt further investigation”, see Additional Notes below 

     MCV classification of anaemia

    The initial classification is based on the mean corpuscular volume (MCV)

     Anaemia Guideline 
    Red flags (consider admission)

    • Hb <60g/L (including iron deficiency)
    • Tachycardia, cardiac murmur or signs of cardiac failure
    • Features of haemolysis eg dark urine, jaundice, scleral icterus
    • Associated reticulocytopenia
    • Presence of nucleated red blood cells on blood film
    • Associated thrombocytopenia or neutropenia, may indicate malignancy or an infiltrative disorder
    • Severe vitamin B12 or folate deficiency
    • Need for red cell transfusion (where possible defer transfusion until a definitive diagnosis is made)

    Microcytic Hypochromic Anaemia

    Iron deficiency 

    Beta Thalassaemia minor/trait

    • Carrier of beta thalassaemia
    • Frequently seen in South East Asian, Mediterranean, Arabic families
    • There may be a positive family history
    • Usually asymptomatic
    • Microcytic hypochromic red cells with normal or borderline low Hb
    • Diagnosed on high-performance liquid chromatography (HPLC) or Hb electrophoresis (HbA2 >3.5%, often elevated Hb F)
      • HbA2 may not be elevated in the presence of concomitant iron deficiency, therefore give iron treatment (if ferritin low) before ordering test
    • Red cell distribution width (RDW) is often normal
    • Pre-pregnancy carrier testing of partner is important, ensure parents have been tested if likely to have more children

    Alpha Thalassaemia minor/trait

    • Carrier of alpha thalassaemia
    • Commonly seen in South East Asian, African, Mediterranean, Arabic families
    • Microcytic hypochromic red cells with normal or borderline low Hb
    • Cannot be diagnosed on HPLC or Hb electrophoresis. DNA testing required for formal diagnosis (not a first-line investigation, exclude other causes first)
    • Pre-pregnancy carrier testing of partner is important

    Rare causes of microcytic anaemia

    • Chronic inflammation
    • Lead poisoning (high blood lead level)
    • Sideroblastic anaemia

    Normocytic normochromic anaemia

    Haemolytic anaemia

    • Acute haemolysis in childhood can be a life-threatening illness and all cases should be discussed with a haematologist
    • Admit children with haemolytic anaemia for observation. Frequent heart rate monitoring is required to identify tachycardia which may indicate a further drop in Hb
    • Repeat FBC within 6-12 hours to detect ongoing haemolysis
    • Monitor reticulocyte count and bilirubin
    • Additional investigations will be guided by blood film findings eg Coombs test (direct antiglobulin test), blood group and antibody screening (BGAB), G6PD assay and Eosin-5 maleimide red cell staining (diagnosis of hereditary spherocytosis) 

    Sickle cell anaemia
    See Sickle cell disease

    Hypoplastic/aplastic anaemia

    • Causes
      • Acute leukaemia, aplastic anaemia, infiltrative disorders
      • Drugs (eg cytotoxics, chloramphenicol, sulfonamides)
      • Viral infection
      • Severe nutritional deficiencies (vitamin B12 or folate deficiency), however usually children present with macrocytic red cells
    • Reticulocyte count is usually low
    • Differential diagnosis based on FBC results
      • Consider bone marrow infiltration if neutrophils and/or platelets also decreased
      • If isolated anaemia with low reticulocyte count with normal platelet and neutrophil counts, consider transient erythroblastopenia of childhood (TEC) or congenital forms (eg Diamond-Blackfan anaemia)
    • Bone marrow aspirate is usually required for diagnosis

    Chronic disease

    • Normochromic normocytic anaemia can be seen with chronic inflammation and chronic disease such as renal disease
    • Reticulocyte count may be low
    • Platelet count may be elevated
    • Further investigation (eg UEC, LFT and ESR) may be indicated depending on clinical features

    Blood loss

    • Normochromic normocytic anaemia can be seen with acute blood loss
    • Reticulocyte count may be normal or elevated
    • Correlate with any bleeding symptoms

    Macrocytic anaemia

    Vitamin B12 and folate deficiency

    • Can be associated with failure to thrive or neurodevelopmental problems (regression, seizures, irritability, poor feeding)
    • Vitamin B12 deficiency may be seen in exclusively breast-fed infants of mothers with vitamin B12 deficiency, children with a vegan or vegetarian diet, pernicious anaemia and metabolic disorders
    • Characteristic blood film findings include teardrop red cells and hypersegmented neutrophils and often neutropenia or thrombocytopenia
    • Requires urgent investigation with red cell folate and active vitamin B12
    • If low active vitamin B12 suggest serum homocysteine and urine methylmalonic acid
    • Treatment must be commenced urgently, particularly if neurological symptoms or regression 

    Other causes of red cell macrocytosis with or without anaemia

    • Myelodysplasia
    • Medications eg anticonvulsants, immunosuppressants and zidovudine
    • Liver disease
    • Hypothyroidism

    Consider consultation with local paediatric team when

    Children have red flag features

    Consider transfer when

    Children require care beyond the level of comfort of the local hospital

    For emergency advice and paediatric or neonatal ICU transfers, see Retrieval Services

    Consider discharge when

    Cause for anaemia is identified and follow up is arranged

    Parent information

    Iron intake (Royal Children’s Hospital Melbourne)
    Iron for children (Queensland Health)

    Additional notes

    Other features on the blood film appearance that prompt further investigation.

    Film features



    Target cells

    Iron deficiency anaemia


    Haemoglobinopathy testing (HPLC/Hb Electrophoresis)

    Elliptocytes or pencil cells

    Iron deficiency anaemia


    Haemoglobinopathy testing (HPLC/Hb Electrophoresis)


    Hereditary spherocytosis Autoimmune haemolysis

    Direct antiglobulin test (DAT)(Coombs test)

    Blood group and antibody screening (BGAB)

    Eosin 5 maleimide (E5M)

    Fragmented red cells


    Platelet count

    Bilirubin, Reticulocyte count

    Urea + Creatinine

    Coagulation profile

    Bite and blister cells

    G6PD deficiency

    G6PD assay

    Nucleated red blood cells

    Bone marrow infiltration

    Consider bone marrow examination

    Thalassaemia testing (HPLC/Hb Electrophoresis)

    Sickle cells

    Sickle cell anaemia

    Haemoglobinopathy testing (HPLC/Hb Electrophoresis)

    Tear drop cells

    Bone marrow infiltration

    Vitamin B12 deficiency

    May need bone marrow examination

    Active vitamin B12


    Last updated November 2023

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