What role do Rh factors play in pregnancy complications?

• A. They determine the blood type of the unborn child
• B. They can lead to hemolytic disease if the mother is Rh- and the fetus is Rh+
• C. They have no significant role
• D. They protect the fetus from infections

Answer: (B)

Rh factors are critical in understanding certain pregnancy complications, particularly related to the Rh(D) antigen present on red blood cells. If a mother is Rh-negative and the fetus is Rh-positive, which is possible if the father is Rh-positive, there is a risk that the mother's immune system may recognize the Rh-positive cells as foreign. In response, the mother may produce antibodies against the Rh factor.

If these antibodies cross the placenta, they can attack the red blood cells of the Rh-positive fetus, leading to a condition known as hemolytic disease of the newborn (HDN). This condition can cause serious complications such as anemia, jaundice, and if severe, can lead to hydrops fetalis or even stillbirth. Therefore, the role of Rh factors is pivotal in understanding and managing these potential complications during pregnancy.

In contrast, the other options do not accurately reflect the role of Rh factors. They are not responsible for determining the blood type of the unborn child, do have significant implications during pregnancy, and do not serve as a protective mechanism against infections.