If a woman who has developed anti-Rh antibodies becomes pregnant with a second Rh+ fetus, the antibodies in her blood may pass through the placenta and react with the red blood cells of the fetus. The fetus then develops a condition called
A hereditary hemochromatosis
B hemophilia
C erythrocytosis
D erythroblastosis fetalis
The correct answer and explanation is:
The correct answer is D) erythroblastosis fetalis.
Erythroblastosis fetalis, also known as hemolytic disease of the newborn (HDN), occurs when an Rh-negative mother develops antibodies against Rh-positive fetal red blood cells. This condition typically happens when a Rh-negative woman gives birth to an Rh-positive baby, and during childbirth, small amounts of fetal blood enter the mother’s bloodstream. In response, her immune system may recognize the Rh antigen on the fetal red blood cells as foreign and start producing antibodies against it. This process is called sensitization.
If the mother becomes pregnant again with another Rh-positive fetus, her anti-Rh antibodies can cross the placenta and target the fetus’s red blood cells, causing them to break down. The fetal bone marrow, in response to the loss of red blood cells, produces immature red blood cells called erythroblasts. This leads to the term “erythroblastosis” as it signifies the presence of these immature cells in the fetal circulation.
This destruction of red blood cells results in anemia for the fetus, which can lead to severe complications such as jaundice, heart failure, and even fetal death in extreme cases. To prevent erythroblastosis fetalis, Rh-negative pregnant women are typically given an injection of Rh immunoglobulin (RhoGAM) during and after their first pregnancy and any subsequent pregnancies. This injection helps prevent the development of antibodies against Rh-positive red blood cells, thereby protecting future pregnancies from this condition.
The other options listed—hereditary hemochromatosis, hemophilia, and erythrocytosis—are unrelated to the immune response against Rh-positive blood cells and do not cause the same effects in pregnancy.