Final answer:
The Rh+ baby (Option 4) is at risk of a hemolytic reaction in an Rh- mother with anti-Rh antibodies. Hemolytic disease of the newborn can occur if the mother's anti-Rh antibodies cross the placenta and attack the Rh+ fetal red blood cells. Preventive treatment with Rho(D) immune globulin is used to mitigate this risk.
Step-by-step explanation:
Who is at risk of a hemolytic reaction in Rh- mother with anti Rh antibodies?
The individual at risk of a hemolytic reaction in an Rh- mother who has developed anti-Rh antibodies is the Rh+ baby (Option 4). If an Rh- mother has been sensitized in a previous pregnancy or through a blood transfusion, she may have developed IgG anti-Rh antibodies. During a subsequent pregnancy, if she is carrying an Rh+ fetus, these antibodies can cross the placenta and may lead to hemolytic disease of the newborn (HDN), also known as erythroblastosis fetalis. This can result in the destruction of the fetal red blood cells, causing severe anemia and potentially fatal complications for the fetus or newborn.
To prevent this condition, Rho(D) immune globulin is administered to Rh- mothers during pregnancy and after delivery if the child is Rh+, effectively preventing the mother's immune system from being sensitized to the Rh factor. This prophylactic treatment is crucial in preventing HDN in subsequent pregnancies.