Rh incompatibility occurs in pregnancies in which mothers are Rh-negative (Rh -) and fathers are Rh-positive (Rh+). Rh antigen can commonly be found in erythrocytes (red blood cells) of monkeys and much rarely in the ones of humans. The presence or absence of Rh antigens in humans should not be considered a disease. The problem occurs when an Rh-negative mother (Rh-) has a child with an Rh-positive partner (Rh+), and the baby’s blood type is Rh-positive (Rh+).
In couples with an Rh mismatch, the mother usually does not have any specific symptoms. However, in a situation where the fetus develops anemia and edema (dropsy) due to blood incompatibility, the mother may sometimes have a condition called mirror syndrome, when the mother may also have the same symptoms. Since in the case of Rh incompatibility, the fetus (the baby in the womb) suffers first, and mirror syndrome is pretty rare, waiting for the manifestation of this problem in the mother should not be a diagnostic method. The main symptoms of Rh incompatibility occur in the fetus and can only be diagnosed by ultrasound.