ABO/ Rhesus Incompatibility

Question 1

What is Rhesus and ABO incompatibility?

Answer 1

• Rhesus: https://www.youtube.com/watch?v=cMe5FbLF-wM
• ABO:
  
  • ABO antibodies =IgM and do not cross placenta.
    
    • Some blood group O have IgG anti A-haemolysin in the blood which can cross the placenta and haemolyse the red cells of group A infant
    • occassionally group B infants are affected by anti-B haemolysins

Question 2

What are the risks to the newborn of Rhesus/ ABO incompatability?

Answer 2

Rhesus

• Fetus
  
  • ​anaemic
  • hydrops fetalis, w/ oedema and ascites
  • hepatosplenomegaly
  • reduced liver function
    
    • hypoalbuminaeic –> oedematous
• At birth
  
  • ​severe jaundice development
  • bilirubin encephalopathy
• In more severe cases, there may be intrauterine death

ABO incompatibility

• Hb level only slightly reduced or normal
• Hepatosplenomegaly absent
• jaundice usually peaks at 12-72 h

Question 3

Management of Rhesus/ ABO incompatibility

Answer 3

• anti-D immunisation of mothers
• fetal blood transfusion via umbilical vein (20 weeks +)

Question 4

Understand importance of severe jaundice in the immediate neonatal period: kenicterus and later neurodevelopmental problems