Patient's question:
What is the difference between Rh-negative O-type blood and Rh-positive O-type blood?Doctor's answer:
RH negative blood is very rare! Human red blood cell blood types are composed of as many as twenty or more blood group systems. ABO and Rh blood group systems are the two most closely related to human blood transfusion. When a person's red blood cells have a D blood group substance (antigen), it is called Rh positive, denoted as Rh (+). When the D antigen is absent, it is called Rh negative, denoted as Rh (-). The distribution of Rh (-) varies greatly among different ethnic groups, with a higher proportion in Caucasians, accounting for about 15%. In the Chinese population, ethnic minorities such as the Uyghurs in Xinjiang have a distribution of about 5% for Rh (-), Mongolians have a rate close to 1%, and the Han Chinese have an extremely low proportion, accounting for only 0.3%, making it a rare blood type. If both ABO and Rh blood group systems are considered, the chance of finding an A-type Rh (-) identical donor in the Han Chinese population is less than 0.03%, making it extremely rare. The Rh (-) gene is a recessive gene. If a Rh (+) mother carries the Rh (-) gene and passes it on to the offspring, the child will be Rh (-). If one parent is Rh (-), the chance of the child being Rh (-) increases; otherwise, the chance decreases. Whether a person is Rh (-) or Rh (+), the difference is merely in blood type, and both belong to the healthy population. However, when Rh (-) individuals encounter special situations, their clinical significance should not be ignored. For example, if a pregnant woman has Rh blood type incompatibility with her fetus in two consecutive pregnancies, it is likely to cause severe harm to the fetus. Additionally, if a patient with a history of blood transfusion or induced abortion is given Rh (+) blood again, it may cause a strong hemolytic transfusion reaction. Neonatal hemolytic disease refers to a hemolytic disease caused by blood type incompatibility between the mother and child. The most common types are ABO incompatibility, while Rh incompatibility is less common and occasionally other blood group incompatibilities may also occur. The blood types causing hemolysis include A, B, AB, and O types. Type A has A antigens on red blood cells, Type B has B antigens, Type AB has both A and B antigens, and Type O has no antigens. Blood type is inherited and determined by the genetic genes of both the mother and the father. When the mother is Type O and the child is Type A or B, resulting in hemolysis, it is called ABO hemolysis. When the mother is Rh negative and the child is Rh positive, leading to hemolysis, it is called Rh hemolytic disease. Rh incompatibility is rare in China because the frequency of Rh negativity varies among ethnic groups: it accounts for about 15% in Caucasians, 5% in African Americans in the United States, and is less than 0.5% in the Han Chinese population of China.