The human body is delicately designed to protect itself from external invasion through a protective immune system. This system helps to keep diseases and infections at bay and serves as a self-defence against external invasion. All these protective activities happen behind the scenes, and we are hardly aware of them.
Sometimes though, this immune system can go out of control and attack the normal human tissue causing damage. This can occur in cases of hyperactive immune system called autoimmune disorders. In this condition, the immune system cannot differentiate between normal cells and invaders. There are many diseases that occur due to this type of loss of control.
Relatedly, there is pregnancy and childbirth condition when the immune system can attack the fetus – it is called Rhesus Incompatibility.
The Rh factor is a protein on the surface of your red blood cells. If you have it, then you are Rh positive and if not, you are Rh negative. When you check your blood group and you are told you are O positive or A negative for example, the positive or negative part of this description of blood group is with respect to the Rh factor present on your red blood cells.
How is the Rh protein passed to the fetus?
The Rh factor is inherited through the genes. This means that it can be passed from parent to child. The protein can be inherited from either the father or the mother.
When the fetus gets the Rh factor from either parent, the fetus is Rh positive. When the fetus does not inherit the protein, then it is Rh negative.
Most people are Rh positive. But in some instances, some are Rh negative. When a pregnant woman is Rh negative and the fetus is positive, then it is called Rhesus Incompatibility. The body sees the fetus (baby in the womb) as foreign, recognizing it as an external tissue, attacks it as itvwere thus causing a loss of the pregnancy.
What happens in Rhesus Incompatibility?
Normally, the blood of the fetus and that of the mother do not mix during pregnancy. However, small amounts of blood from the fetus can mix with the mother’s blood during labour and birth. Some other situations can also make this happen:
- amniocentesis or chorionic villus sampling (CVS)
- bleeding during pregnancy
- manually turning a fetus to be head-down for birth (move the fetus out of a breech presentation).
- trauma to the abdomen during pregnancy
When any of the conditions happen, the blood cells from the fetus that mix with the mother’s blood are not recognised as part of the mother’s. So, the mother produces antibodies against the red blood cells. Remember, it is the red blood cells that carry the Rhesus factor. However, there is usually no problems during the first pregnancy because the body of the pregnant woman does not have the chance to develop sufficient antibodies to cause harm to the fetus.
But if untreated, during subsequent pregnancies if the fetus is Rh positive, the woman produces more antibodies and the anti-Rh factor antibodies can cross the placenta to the fetus and attacks the red blood cells of the fetus, destroying them more rapidly than can be replaced by the body. This can lead to low level of red blood cells called anemia. This condition can develop regardless of whether the pregnancy is carried to term or not.
Red blood cells carry oxygen and so a low level of red blood cells in the fetus will reduce the capacity to supply adequate oxygen to the fetus. This can result into the death of the fetus and eventual loss of the fetus. Rh Incompatibility can also cause jaundice at birth.
As a woman, being Rhesus negative is not a disease and does not affect your life. Having a partner that is Rhesus positive is not a reason to cancel a union engagement as there are effective precautions and management for Rhesus Incompatibility.
How is Rh Incompatibility be prevented?
If an individual has Rh negative blood type and there’s a possibility that their baby might have or already has Rh positive blood, their healthcare provider might suggest administering an Rh immune globulin injection following situations where there could be potential contact between the individual’s blood and the baby’s blood, including:
- Spontaneous miscarriage
- Ectopic pregnancy—when a fertilized egg implants outside the uterus, typically in a fallopian tube.
- Termination of pregnancy
- Removal of a molar pregnancy—a benign tumor that forms in the uterus.
- Amniocentesis—a prenatal procedure involving the extraction of amniotic fluid for testing or treatment.
- Chorionic villus sampling—a prenatal test involving the removal of tissue from the placenta for examination.
- Cordocentesis—a prenatal test involving the extraction of fetal blood from the umbilical cord for analysis.
- Bleeding episodes during pregnancy
- Abdominal trauma or injury during pregnancy
- Manual rotation of a fetus in a breech presentation—such as buttocks-first position—prior to childbirth
- Childbirth.
It is important for a would-be mother to take precautions if she is Rh negative, and the husband is Rh positive because the offspring can carry the Rh protein from either parent. In other words, the fetus could be positive or negative. If it turns out to be positive, there are inherent dangers ahead if appropriate precautions are not taken.
The goal of treatment is to ensure that the woman does not produce anti Rh antibodies in the first instance, to avert a future attack on subsequent pregnancies.
So, it is advisable that couples should know their blood groups and Rh statuses by getting tested. All health care providers also owe their clients the responsibility of ensuring they know their blood group and provide counsel appropriate to their conditions. This way, they understand their risks and plan ahead to mitigate them.
Being Rhesus negative is not a disease and does not affect your life. It is not a reason to cancel a union engagement as there are appropriate treatment for Rhesus Incompatibility.
Speak with your health care provider today!
The information in this post does not replace the expert opinion of your health care provider. We have deliberately reframed from providing treatment options. If you are concerned about your risks, see your health care provider today for more information.
