Erythroblastosis Foetalis

Erythroblastosis Foetalis also called as hemolytic disease of the new born is a condition that develops in a fetus, when the IgG molecules (one of the five main types of the antibodies) that have been produced by the mother and have passed through the placenta include ones which attack the red blood cells (RBC) in the fetal circulation.

Clinical features:

The red cells are broken down and the fetus can develop reticulocytosis and anemia. This fetal disease ranges from mild to very severe, and fetal death from heart failure (hydrops fetalis) can occur. When the disease is moderate or severe, many erythroblasts are present in the fetal blood i.e. RBCs are damaged at a very early stage and so these forms of the disease can be called erythroblastosis fetalis (or erythroblastosis foetalis).

This condition occurs when an Rh positive man marries an Rh negative women. When an Rh negative woman bears an Rh positive child the first child is safe but the second child develops the above condition.

Fetal RBCs are separated from mother’s circulation by a layer of cells in placenta called trophoblasts. At the time of delivery large amounts of fetal blood enter circulation and anti Rh antibodies are formed. During second pregnancy these Abs damage fetal RBC and causes hemolysis, breakdown of heme so bilirubin is formed in large amounts. Bilirubin is lipid soluble and accumulates in brain leads to kernicterus or brain damage to the fetus.

Diagnosis:

Blood tests on the newborn baby

1. Biochemistry tests for jaundice

2. Peripheral blood morphology shows increased reticulocytes

3. Positive Direct Coombs test

Blood tests done on the mother

Positive indirect Coombs test