Blood Types

Knowing your blood group might one day save your life or the lives of others, including those of your future children. In this video I’ll explain blood groups and the important points we all need to know about them.

Scientists have classified our blood into groups, according to the presence of certain proteins on the surface of the blood cells, the red blood cells to be exact. One group of people who have the same certain protein, say, protein A, scientists have named them group A. Another group of people who have another certain protein, say, protein B, they named them group B. Another group of people, who have both of the two previous proteins – A and B – they named them group AB. Another group of people, who have neither of the two previous proteins, they named them group 0.

The importance of blood groups is vital during operations and blood transfusions. We must know your group to know from whom you can receive blood or to whom you can donate blood. Our body reacts against foreign proteins, so if you’re group A, group B will be foreign for you. And the same you’re group B, group A will be foreign to you. If you are from group A and received blood from group B, your body will recognize it as foreign bodies and will react against the protein B. So, A cannot receive from B, but if A donates blood to AB, the body of AB will recognize A as a friend, not a foreign body, and will not react against it. So, know we have understood that A can donate blood to AB without considerable problems, and the same if B donates blood to AB, the body of AB will recognize both A and B as familiar proteins. So, blood group A can donate blood to AB and to itself of course, group B can donate blood to AB and to itself of course, group AB can donate blood to itself only. Group 0 means that there are no proteins on the surface that belong to that classification. So, 0 will not be recognized as a foreign body by any other type. That’s why group 0 can donate blood to group 0, group A can receive blood from group 0 as well, the body will not recognize anything wrong. 0 can donate blood to B and also to AB. Group AB can receive blood from all blood types and 0 can donate blood to all blood types. So, 0 is called a universal donor and AB is called a universal recipient.

But hold it right there. Another scientist came along and said “hey, I found out from my researches on Rhesus monkeys, that there’s a certain protein, and I call it the RH factor, that may be present in all blood groups, or may be absent”. Now we know that group A individuals who have Rhesus factor are called A+ (A positive), so the group A individuals who have not got the Rh factor are called A- (A negative). The same for blood group B, AB and 0. They might be Rhesus positive (Rh+) or negative (Rh-). During blood transfusion Rh+ can receive from Rh-, which has no protein on the surface, and from Rh+ as well of course, because the body will recognize it as a friend and won’t do anything against it. So in fact AB+ is the general or universal recipient, which can receive blood from all blood groups, and 0- is the general donor, that can donate blood to all the other groups.

In addition to the importance of blood groups during operations and blood transfusion, they’re also important to know around the time of pregnancy and childbirth. One common example is when the parents are different in the Rhesus factor. Especially when the mother is negative and the father is positive. Rhesus factor may be inherited by the baby from his father’s side, so the mother would recognize the blood of her baby as foreign body and would react against it. The first pregnancy may pass safely, but during delivery some of the fetal blood may enter the maternal circulation and the body of the mother will recognize the Rhesus factor (the positive Rhesus factor) as foreign body, and will form antibodies against it. If the second baby is Rhesus positive like the first baby, the previously formed antibodies will react against the foreign protein, killing the fetus and causing abortion. To save the baby the mother is given a drug that can prevent Rhesus negative mothers’ antibodies from being able to react against Rhesus positive fetal blood. Rhesus negative women are given the drug around the 28th week of pregnancy. So it’s very important before marriage to do blood group testing and if the mother is Rhesus negative and the father is Rhesus positive the mother must be given a drug by the end of the first pregnancy or during the second pregnancy.

That was a summary of blood groups including the most important points we should know about this topic.

I wish you the best of health!

Alyaa Gad