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Rh incompatibility

It is a haemolytic disease of the fetus and newborn infant due to Rh incompatibility characterized by progressive agglutination end subsequent phagocytosis of the red blood cell. Rh incompatibility is a condition that occurs during pregnancy if a woman has Rh-negative blood and her baby has Rh-positive blood.

The Rh factor is a protein that can be found on the surface of red blood cells. If your blood cells have this protein, you are Rh positive. If your blood cells do not have this protein, you are Rh negative. It occurs when a mother is Rh-negative and her baby is Rh- positive. The Rh factor is a specific protein found on the surface of your red blood cells.


Presence of Rh-positive foetus in Rh-negative mother. A difference in blood type between a pregnant woman and her baby causes Rh incompatibility. The condition occurs if a woman is Rh-negative and her baby is Rh-positive. It depends on –

(a) Previous transfusion of Rh-positive blood to the Rh negative mother.

(b) Number of pregnancy.

Fig: Rh incompatibility


(A) Development of jaundice at birth.

(B) Severe damage to the liver

(C) Severe haemolytic Anaemia after birth.

(D) Kernicterus

(E) Heart failure.


  1. A mother with Rh (-ve) blood group containing Rh (+ve) fetus.
  2. During delivery, Fetal blood enters into the maternal circulation.
  3. Rh antibody develop in the maternal circulation
  4. In 2nd pregnancy, if the 2nd fetus is also Rh (+ve)
  5. Rh antibody enter into fetal circulation
  6. Agglutination and haemolysis occur.
  7. Erythroblast in blood

This is called erythroblastosis fetalis.

Prevention in mother

Injection of Anti. D antibody to mother with 72 hrs of delivery.

Treatment in newborn

Replacement of Rh (+ve) with Rh (-ve) blood after a regular interval during first few wks of life.

(a) Kernicterus: It is a neurological syndrome in which the bilirubin enters into the basal ganglia and damages it when a severe hemolytic condition occurs in fetus.

(b) Hydrops fetalis: The pt. is grossly oedematious; Foetus either dies in uterus or if born prematurely or at term, it dies within a few hours.

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