the disease erythroblastosis fetalis (also called hemolytic disease of the newborn) develops in a fetus or a newborn infant with Rh-positive blood and an Rh-negative mother. Symptoms results when maternal anti-Rh antibodies cross the placenta and interact with the fetus' erythrocytes. Why are the children of Rh-positive mothers not ay risk for this disease

Explanation:

Hemolytic Disease of the newborn (HDN, Erythroblastosis Fetalis) is a blood disorder occurring at or around birth, where the blood groups of the mother and baby are not compatible. It occurs when the antibodies from a Rhesus negative (Rh-negative) mother, who has been sensitized from previous pregnancies or other means (transfusion etc), gives birth to an Rh-positive baby, and the blood of the mother and the baby eventually mixes. This causes the anti-Rhesus antibodies in the mother's blood to attack the Rhesus antigen (Also Called Anti-D antigen) on the baby's red blood cells, causing hemolysis that leads to several unpleasant symptoms.

Children of Rh-positive mothers are not at risk of developing HDN, because the mother does not produce anti-Rh antibodies since she is positive, hence there will be no antibodies to cross the placenta and react with the baby's rhesus antigens for Rh-positive babies.

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