What is erythroblastosis fetalis?

• A. A disease caused by bacteria in the bloodstream
• B. A condition where antibodies from an Rh- mother attack an Rh+ fetus
• C. A genetic disorder affecting red blood cell production
• D. A type of allergic reaction to blood transfusions

Answer: (B)

Erythroblastosis fetalis is specifically characterized as a condition in which antibodies produced by an Rh-negative mother cross the placenta and attack the red blood cells of an Rh-positive fetus. This immune response can result in severe anemia and other complications for the fetus due to the mother’s immune system recognizing the fetal red blood cells as foreign. The primary underlying issue here involves the Rh factor—a specific antigen that can trigger an immune response if the mother does not have it and the fetus does.

This condition usually arises during a subsequent pregnancy after the mother has been sensitized to the Rh factor, often due to a previous pregnancy with an Rh-positive child. The maternal antibodies work to destroy the fetal red blood cells, leading to a range of potential health complications for the fetus, including jaundice and heart failure.

The other options do not accurately represent erythroblastosis fetalis. For example, the first option pertains to bacterial infections rather than antibody-mediated responses, the third option focuses on genetic issues rather than immune responses, and the fourth option relates to transfusion reactions and not the implications of Rh factor incompatibility during pregnancy.