Rhesus (Rh) factor is an inherited protein (known as antigens) found on the surface of red blood cells. If your blood cells have this protein, you are Rh positive (Rh+), but if your blood cells lack this protein, you are Rh negative (Rh-). An antigen is any substance that the body considers foreign and thus stimulates the body to produce antibodies against it.
Rh factor also referred to as Rhesus status is inherited, meaning it is passed from parent to child through genes, like the blood types A, B, AB and O, is inherited from one's parents. The foetus can inherit the Rh factor from the father or the mother.
Rh positive is the most common blood type. Having Rh negative blood type is not an illness and usually does not affect one’s health. However, it can affect one’s pregnancy. Your pregnancy needs special care if you're Rh negative and your baby's father is Rh positive.
How Can Rh Factor Affect One’s Pregnancy?
During pregnancy, problems can occur if you are Rh negative and your foetus is Rh positive. When a woman is Rh negative and her foetus is Rh positive, it is called Rh incompatibility.
If a small amount of blood of an Rh-positive foetus gets into the bloodstream of an Rh-negative woman, which often happens, her body will understand it is not her blood and will fight it by making anti-Rh antibodies.
The antibodies produced aren't a problem during the first pregnancy. The concern is with your next pregnancy. If your next baby is Rh positive again, your body will produce Rh antibodies that can cross the placenta and try to destroy the foetus’s blood. The anti-Rh antibodies break down the foetus’s red blood cells. Red blood cells carry oxygen to all parts of the body. Without enough red blood cells, the foetus will not get enough oxygen leading to anaemia (a condition that happens when the blood has a low number of red blood cells as a result of the red blood cells being destroyed faster than the body can replace them). This condition is called haemolytic disease or haemolytic anaemia. It can become severe enough to cause serious illness, brain damage, or even death in the foetus or newborn.
How Do I Know If I Am Rh Negative Or Rh Positive?
As part of your prenatal care, you will be offered a number of routine blood tests. One of these tests is to find out your blood group (A, B, AB or O) and your Rh factor (positive or negative). The + and – in front of the blood group is the Rh factor. So we have A+, A-, O+, O-, B+, B-, AB+ or AB-.
Another blood test, called an antibody screen, can show if an Rh-negative woman has made antibodies to Rh-positive blood.
In some cases, the baby's father might need an Rh factor test, too.
If you are Rh positive, no action is needed.
If you are Rh negative and the baby's father is Rh positive, there's a potential for your body to produce antibodies that could harm your baby. If you have vaginal bleeding at any time during pregnancy, contact your health care provider immediately. Also, talk with your health care provider about scheduling an Rh immune globulin injection during your pregnancy and make sure you remind your health care team of your Rh status during labour.
How Can My Foetus’ Blood Get Into My Bloodstream?
During pregnancy, a woman and her foetus usually do not share blood. But sometimes a small amount of blood from the foetus can mix with the woman’s blood. This can happen during labour and birth. It also can occur with any of the following:
An induced abortion or menstrual extraction
An ectopic pregnancy
A chorionic villus sampling (CVS)
Bleeding during pregnancy
Attempts before labour to manually turn a foetus from a breech presentation
Trauma to the abdomen during pregnancy
A blood transfusion
If an Rh-negative woman gets pregnant again after one of these events and has not received treatment, a future foetus may be at risk of problems if it is Rh positive.
Can Rh Problems Be Prevented?
Yes. The goal of preventive treatment is to stop an Rh-negative woman from making Rh antibodies in the first place. This is done by finding out if you are Rh negative early in pregnancy (or before pregnancy) and, if necessary, giving you a medication to prevent antibodies from forming.
What medication prevents Rh problems?
When an Rh-negative woman has not already made antibodies, a medication called Rh immunoglobulin (RhIg) can be given. RhIg stops the body from making antibodies, which can prevent severe foetal anaemia in a future pregnancy.
When is RhIg given?
RhIg is given to Rh-negative women in the following situations:
At around week 28 of pregnancy
Within 72 hours after the birth of an Rh-positive baby
A dose of RhIg also may be needed
after an ectopic pregnancy or a first-trimester miscarriage or abortion
after invasive procedures, such as amniocentesis, CVS, foetal blood sampling, or foetal surgery
Additionally, you may be given RhIg if you have had
bleeding during pregnancy
trauma to the abdomen during pregnancy
attempts to manually turn a foetus from a breech presentation
What if I have already made antibodies and my foetus is Rh positive?
Once a woman develops antibodies, RhIg treatment does not help. In this case, the well-being of the foetus will be checked during the pregnancy. If tests show that the foetus has severe anaemia, early delivery (before 37 weeks of pregnancy) may be necessary. Another option may be to give a blood transfusion through the umbilical cord while the foetus is still in the woman’s uterus. If the anaemia is mild, the baby may be delivered at the normal time. After delivery, the baby may need a blood transfusion to replace blood cells.
We need to continue to promote the awareness about our Rhesus factors.
An Rh negative girl must be extremely careful. Because of the very small number of Rh negative people, it’s extremely rare to find an Rh negative man. The possibility to get pregnant for an Rh positive man is high. Once she gets pregnant for an Rh positive man and rushes to have a quick abortion, she might have as well jeopardized her life. A lot of females are left helpless after this mistake.
Aside this, a woman with a negative Rh factor has no problem. It can however be controlled with Rh Immunoglobulin injection.
Also, an Rh- man or woman cannot receive blood donation from a Rh+. It would lead to death as the blood would immediately clog and cake.