Patient's question:
Problem Description: Seeing this message, as a medical laboratory technician, I couldn't believe it! But this actually happened in my recent work. Here's what happened: Yesterday (June 16, 2009), I drew blood for a pregnant woman to test and determine her blood type. The result was RH negative "A" type. Seeing this, I immediately repeated the test and carefully observed under a microscope, but the result was still the same. At that time, I considered that the child the pregnant woman was carrying was very likely to develop "Hemolytic Disease of the Newborn" (HDN), and since this was already the second child, the probability of HDN was relatively high. I informed the family, and then the pregnant woman gave birth to the first...Doctor's answer:
Found online, hope it helps you!Mysteries of the Rh Blood Type
In 1940, Landsteiner and Wiener injected the blood of the rhesus monkey into rabbits and obtained an immune antibody. This serum contained an immune antibody that could not only agglutinate the red blood cells of the rhesus monkey but also agglutinate 85% of the red blood cells of white people. This proved that these white people's red blood cells shared antigens with those of the monkey, and thus, the English abbreviation "Rh" of the rhesus monkey was adopted as the name of this antigen. Those with the Rh antigen are called Rh-positive, while those without are Rh-negative. Rh is a blood group system, and over 99% of people in China are Rh-positive. Since the discovery of the Rh blood type after ABO blood type, it has the greatest clinical significance and is one of the most complex blood group systems. Mismatched Rh blood transfusions can endanger the patient's life; pregnancy with Rh incompatibility between mother and child may lead to stillbirth, premature birth, and neonatal hemolytic disease. Among Han Chinese in China, the proportion of Rh-negative individuals is 0.2% to 0.5%. Rh-negative recipients and pregnant women have a 99.6% to 99.8% chance of being stimulated by Rh-positive antigens. After receiving Rh-positive blood once, more than 50% of Rh-negative individuals will produce anti-Rh antibodies. Since Rh blood antibodies are immune antibodies, if Rh-positive blood is transfused again, it is easy to cause a transfusion reaction. Therefore, Rh blood type testing is as important as ABO blood type testing.
It is important to note that Rh-negative pregnant women must undergo Rh blood type identification and testing for immune anti-Rh antibodies at the central blood station after pregnancy to prevent neonatal hemolytic disease due to blood type incompatibility between mother and child.
The discovery of the Rh blood type occurred in 1937. It is the most clinically significant red blood cell blood group system after the discovery of ABO blood type. Mismatched Rh blood transfusions may lead to life-threatening hemolytic transfusion reactions. During pregnancy, if the mother and child have Rh incompatibility, it may lead to neonatal hemolytic disease or early abortion and intrauterine stillbirth. In the Han Chinese population, more than 99% are Rh-positive, while the proportion of Rh-negative individuals is only 0.2% to 0.5%. Rh-negative individuals can produce anti-Rh (D) antibodies after receiving Rh-positive blood or having an Rh-positive fetus. Approximately 80% of Rh-negative individuals will develop anti-D antibodies after a single blood transfusion, affecting future transfusion treatments. Therefore, to ensure the safety and effectiveness of blood transfusions, Rh-negative patients must not only have the same ABO blood type as clinically required but also receive Rh-negative blood.
What is the Rh Blood Type?
1. What is the Rh Blood Type?
Human red blood cell blood types consist of more than 20 blood group systems. ABO and Rh blood types are the two most closely related to human blood transfusions. When a person's red blood cells have a D blood type substance (antigen), they are called Rh-positive and are represented as Rh(+). When the D antigen is absent, it is Rh-negative and is represented as Rh(-).
2. Is Rh(-) a Rare Blood Type?
The distribution of Rh(-) varies greatly depending on ethnicity. It is relatively high in white people, accounting for about 15%. In the Chinese population, the distribution of Rh(-) among ethnic minorities such as the Uyghurs in Xinjiang is about 5%; among Mongolians, it is close to 1%; and among Han Chinese, it is extremely rare, accounting for only 0.3%. If ABO and Rh blood group systems are considered together, the chance of finding an AB-type Rh(-) identical match in the Han Chinese population is less than 0.03%, making it very rare.
3. How Is the Rh Blood Type Inherited?
The Rh(-) gene is recessive. If Rh-positive parents carry the Rh(-) gene and pass it to their offspring, the child will be Rh-negative. If one parent is Rh-negative, the chance of their child being Rh-negative increases; otherwise, the chance decreases.
4. What Is the Significance of Rh(-)?
Whether an individual is Rh-negative or Rh-positive, the only difference is their blood type, and both belong to the healthy population. However, in special cases, the clinical significance of Rh(-) cannot be ignored. For example, if a pregnant woman with Rh incompatibility carries two consecutive pregnancies, it may cause severe harm to the fetus. Additionally, if a patient with a history of blood transfusion or induced abortion receives Rh-positive blood again, they may experience a severe hemolytic transfusion reaction.
How Can Rh(-) Individuals Protect Themselves?
--------------------------------------------------------------------------------
Remember this principle: Blood can only be transfused between identical blood types. That is, an A-type Rh(-) patient can only receive A-type Rh(-) blood, and a B-type patient can only receive B-type Rh(-) blood. If you need a blood transfusion due to illness or surgery, you must inform your doctor that you are Rh-negative so they can contact the blood center early to arrange the necessary Rh-negative blood supply.
If you are an unmarried woman, please take family planning measures to avoid induced abortion. If you have a history of induced abortion or blood transfusion, you must undergo a neonatal hemolytic disease prediction test at the blood station's blood type department during pregnancy to prevent the occurrence of neonatal hemolytic disease in the future.
In emergencies, it is a matter of life and death whether Rh-negative patients can be supplied with identical blood in time. Blood type workers at blood centers are committed to ensuring the safe transfusion of every Rh-negative patient. They tirelessly screen tens of thousands of blood donors for Rh-negative blood types. Once Rh-negative blood is found, it is immediately marked with a special label and stored in a 4°C refrigerator for emergency use.
Although blood transfusion workers have taken all precautions, the potential risk of Rh-negative patients lacking identical blood in emergencies and facing life-threatening danger still exists. In fact, the solution to this problem is simple: all Rh-negative individuals should work together. At the same time that they may be potential recipients, they can also be noble donors. In this way, the lives of all Rh-negative individuals will be guaranteed.