Question

Explain Rh-incompatibility in humans

Answer 1

Rh incompatibility is a condition that occurs during pregnancy if a woman has Rh-negative blood and her baby has Rh-positive blood.

"Rh-negative" and "Rh-positive" refer to whether your blood has Rh factor. Rh factor is a protein on red blood cells. If you have Rh factor, you're Rh-positive. If you don't have it, you're Rh-negative. Rh factor is inherited (passed from parents to children through the genes). Most people are Rh-positive.

Whether you have Rh factor doesn't affect your general health. However, it can cause problems during pregnancy.

When a woman is pregnant, blood from her baby can cross into her bloodstream, especially during delivery.

If she is Rh-negative and her baby is Rh-positive, her body will react to the baby's blood as a foreign substance.

Her body will create antibodies (proteins) against the baby's Rh-positive blood. These antibodies usually don't cause problems during a first pregnancy. This is because the baby often is born before many of the antibodies develop.

However, the antibodies stay in woman's body once they have formed. Thus, Rh incompatibility is more likely to cause problems in second or later pregnancies (if the baby is Rh-positive).

The Rh antibodies can cross the placenta and attack the baby's red blood cells. This can lead to hemolytic anemia in the baby.

Hemolytic anemia is a condition in which red blood cells are destroyed faster than the body can replace them. Red blood cells carry oxygen to all parts of the body.

Without enough red blood cells, baby won't get enough oxygen. This can lead to serious problems. Severe hemolytic anemia may even be fatal to the child.