Anaemia in the newborn

reduced RBC prodn
1. 2 main but rare causes
  1. both cause red cell aplasia
    1. low Hb
    2. RBCs look normal
    3. diagnostic clues
      1. low reticulocyte count
      2. normal bilirubin
  2. congenital infection w/ parvovirus B19
  3. congenital red cell aplasia (Diamond-Blackfan anaemia)
increased RBC destruction (haemolytic anaemia)
1. due to
  1. antibody destroying RBCs (i.e. extrinsic cause)
    1. immune causes
      1. haemolytic disease of the newborn
        aka immune haemolytic anaemia of newborn
        caused by antibodies vs blood group antigens
        most important antibodies
        anti-D
        anti-A
        anti-B
        anti-Kell
        mum is always -ve to the relevant antigen & baby always +ve
        mum makes antibodies vs baby's blood group
        mum's antibodies cross placenta into baby's circulation
        -> fetal or neonatal haemolytic anaemia
        diag using Coombs test (direct anti-globulin test)
        only +ve in antibody-mediated anaemias
  2. intrinsic abnormality of surface or intracellular contents of RBCs
    1. red cell mb disorders
      1. hereditary spherocytosis
    2. red cell enzyme disorders
      1. glucose-6-phosphate dehydrogenase deficiency
    3. abnormal haemoglobins
      1. alpha-thal major
      2. other haemoglobinopathies rarely present w/ sx in neontal period
        but detected on Guthrie test
2. diagnostic clues
  1. raised reticulocyte count
    1. due to increased RBC prodn to compensate for anaemia
  2. raised unconjugated bilirubin
    1. due to increased RBC destruction w/ the bile pigment released into plasma
blood loss
1. feto-maternal haemorrhage
  1. occult bleeding into mum
2. twin-to-twin transfusion
  1. bleeding from one twin into the other one
3. blood loss around the time of delivery
  1. e.g. placental abruption
4. diagnostic clues
  1. severe anaemia
  2. raised reticulocyte count
  3. normal bilirubin
anaemia of prematurity
1. inadequate erythropoietin productn
2. reduced RBC lifespan
3. frequent blood sampling whilst in hospital
4. Fe & folic acid deficiency (after 2-3 months)

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	Criado por v.djabatey mais de 10 anos atrás