Final answer:
The prenatal cause of hearing loss due to Rh incompatibility is a maternal Rh- blood type with an Rh+ fetus. The mother's immune response to the Rh factor can result in the production of antibodies that damage the fetal red blood cells and may lead to hemolytic disease of the newborn, potentially causing hearing loss.
Step-by-step explanation:
The prenatal cause of hearing loss in Rh incompatibility is maternal Rh- blood type, when combined with a fetus that has Rh+ blood type. During pregnancy, if an Rh- mother is carrying an Rh+ baby, her immune system may become sensitized to the Rh+ red blood cells of the fetus. This can happen during delivery or any event that allows fetal blood cells to enter the maternal circulation. As a response, the mother's body produces anti-Rh antibodies which can cross the placenta and harm the fetal red blood cells in subsequent pregnancies, leading to hemolytic disease of the newborn (HDN). One of the potential outcomes of HDN is hearing loss in the newborn due to the destructive process affecting the fetal circulation and possibly impacting the development of the auditory system.