There are many things to keep in mind when we choose someone to be our life partner. One such thing that needs to be checked is the blood type. It’s not something that comes to our mind at first, but differences in blood group can lead to complications. More specifically, these problems could happen during pregnancy and put the unborn child at risk.
Blood group systems
When we are getting to know other people, blood type is one of the things that is shared. You might say ‘I’m A+’ or ‘I’m B-‘. However, do we understand what those letters or signs indicate? Those two things are simply indicators of your blood groups. The blood group systems that we refer to while saying ‘A+’ or ‘B-‘ are the ABO system and the Rh system. Other than these, we have around 30 other blood group systems that are based on around 300 antigens. An antigen is a molecule that, once recognized by antibodies, will start an immune response.
ABO Blood group system
The ABO system is based upon the presence or absence of antigen A or B on the surface of your red blood cells. If you have the A blood group, it means that you have antigen A and vice versa for the B blood group. However, what if your blood group is AB or O? The AB blood group indicates that you have both antigen A and B, whereas the O blood group indicates that you have none of them. The next thing to look at is why we never transfuse blood from one type into another.
Basically, if your blood group is A, then your body will identify cells of the B blood group as foreign particles and create antibodies (anti-B) for it. In the same manner, B blood group people will produce antibodies (anti-A) for A blood group cells. These antibodies anti-A and anti-B will identify their respective antigens A and B and cause a reaction, leading to cell death. In the case of the AB blood group, there are no antibodies, which means that any other blood group can transfuse into an AB blood group individual. On the other hand, O blood group individuals can produce both the antibodies if exposed to any blood group, but the lack of any antigen makes it easier to donate.
Rh Blood group system
The Rh system has over 50 antigens. There are 5 that are commonly found in humans: D, C, c, E, and e. Out of these, D is the most important antigen in the Rh system. The presence or absence of the D antigen is indicated by a plus or minus sign. If a person with Rh-negative blood is exposed to Rh-positive blood, the body will produce antibodies that will destroy the cells. However, if Rh-negative blood is transfused into a Rh-positive person, no reaction will take place, as there are neither antigens nor antibodies.
Thus, if you say that you are ‘AB+’, then you have the antigens of A, B, and D, but if you say you are ‘O-‘, it indicates that you have none of the antigens and all of the antibodies.
Why is it important to compare blood group with your spouse?
Even though a difference in blood groups does not affect the couple, it could become a problem while trying to conceive a child. The differences in the ABO system are not a major concern, but the same cannot be said for the Rh system. Rh incompatibility is a real problem, one that can affect both mother and child.
Rh incompatibility can occur when the mother is Rh-negative and the fetus is Rh-positive. If the fetal blood (which is Rh-positive) leaks into the maternal circulation (which has Rh-negative blood), fetal cells will be recognized as foreign. This results in the mother producing antibodies, which are called Rh immunoglobulin G. These antibodies could pass through the mother’s placenta and attack the red blood cells of the fetus. Once the red blood cells break down, they produce bilirubin, which causes the child to be jaundiced.
In most of these cases, the leakage of fetal blood into maternal circulation takes place during delivery. Because of this, the mother does not produce enough antibodies, leaving the first-born baby unharmed. The severity of such a situation will continue to increase with every consecutive pregnancy involving a Rh-positive fetus. The worst-case scenario would lead to marked anemia or stillbirth.
How to treat it?
If the affected baby is born, then hydration and phototherapy using bilirubin lights can be used to treat jaundice. Bilirubin lights (emitting rays of 420-470 nm) help to convert bilirubin into a form that can be easily excreted from the body. Coupled with hydration, this makes the process quicker.
In the worst cases, the baby might have to undergo a blood transfusion while still in the uterus. A needle is inserted into the umbilical cord, directed by using an ultrasound machine. The transfusion procedure takes place once in the two or three weeks before the child is born.
Even if the treatment options are good and give positive results, prevention is still a better option. Rho(D) immune globulin is a medication used to prevent isoimmunization in mothers. If an indication is seen that there is a chance of Rh-positive cells entering maternal circulation, then it is administered at 28 to 32 weeks into the pregnancy, and again within 72 hours of delivery.
Prevention of Rh incompatibility is much easier than the difficulties faced during the treatment. Couples need to check themselves for any chance of incompatibility so that they know what steps to take in advance. Moreover, advancements in the commercial production of antibodies have helped reduce the cost of medication. It has also increased its availability. Such steps have also reduced the chances of Rh incompatibility from 10-20% down to 1%! This has given plenty of options to couples who want to avoid such complications.
- University of Wisconsin (Link 1)
- University of Wisconsin (Link 2)
- Arizona State University
- National Institutes of Health (NIH)
- University of Maryland Medical Center