When is blood Rh a problem in pregnancy?

Blood Rh becomes a problem in pregnancy when an Rh-negative mother is carrying an Rh-positive baby, inherited from the father. If fetal blood cells enter the mother's bloodstream, her immune system may produce antibodies against the Rh-positive blood, leading to hemolytic disease of the newborn (HDN) in subsequent pregnancies. This condition can cause serious complications for the baby, including anemia and jaundice. To prevent this, Rh-negative mothers typically receive an injection of Rh immunoglobulin (RhoGAM) during and after pregnancy.