Rh incompatibility is a potential complication of pregnancy that occurs when a mother with Rh-negative blood carries a Rh-positive baby. This blood incompatibility can cause the mother’s immune system to attack the baby’s red blood cells, leading to anemia, jaundice, and even brain damage.
What is the Rh factor?
The Rh factor, also called the Rhesus factor, is a specific protein discovered at the surface of red blood cells. It’s a simple yes-or-no characteristic you inherit from your mother and father, just like eye color or hair type.
Here’s a breakdown of the Rh component:
Presence: If your red blood cells have the Rh protein, you’re Rh-positive (Rh+).
Absence: If your red blood cells lack the Rh protein, you are Rh-negative (Rh-)
For example, Person A has a blood type A positive (A+): This means that Person A has A antigens on the surface of their red blood cells and is Rh positive (has the Rh factor), or
If Person B has a blood type O negative (O-): This means that Person B has neither A nor B antigens on the surface of their red blood cells and is Rh negative (lacks the Rh factor)
How does a fetus get the Rh factor?
A fetus inherits its Rh factor, similar to another physical trait, through its genes from its mother and father.
Here’s the way it works:
Humans have 23 pairs of chromosomes, with one set inherited from each parent.
Each chromosome incorporates thousands of genes, which might be like coded commands that determine our development.
The Rh factor is controlled by a particular gene positioned on chromosome 1.
Inheritance patterns:
The Rh gene is available in two variations: R (dominant) and r (recessive).
An Rh-positive person can have either RR (inherited two R genes) or Rr (inherited one R and one r gene).
An Rh-negative person has rr (inherits two recessive r genes)
Determining the fetus’s Rh factor:
a) If both the mother and father are Rh-positive (RR or Rr), the fetus will be Rh-positive.
b) If one of them is Rh-positive (Rr) and the other is Rh-negative (rr), the fetus has a probability of having 50% Rh-positive or 50% Rh-negative.
c) If both the mother and father are Rh-negative (rr), the fetus will always be Rh-negative.
What is Rh incompatibility?
Rh incompatibility, also known as Rhesus incompatibility, is a situation during pregnancy where the mother’s Rh factor and the baby’s Rh factor are different. This can lead to the mother’s immune system mistaking the baby’s red blood cells for foreign invaders and attacking them.
Causes:
During pregnancy, red blood cells from the unborn infant can pass into the mother’s blood through the placenta.
If the mother is Rh-negative, her immune system treats Rh-positive fetal cells like a foreign substance. The mom’s body makes antibodies towards the fetal blood cells. These antibodies can also go through the placenta into the developing child and damage the baby’s circulating red blood cells.
When red blood cells are broken down, they make bilirubin. This causes the infant to become yellow (jaundice). The level of bilirubin in the infant’s blood may additionally range from mild to dangerously excessive.
Firstborn toddlers are frequently not affected, except if the mother has had past miscarriages or abortions. This might sensitize her immune system. This is because it takes time for the mother to increase antibodies. All the youngsters she has later, who are also Rh-positive, can be affected.
Rh incompatibility develops only when the mother is Rh-negative and the baby is Rh-positive.
Risks and complications:
1. Hemolytic disease of the fetus and newborn (HDFN):
This is the primary problem with Rh incompatibility. The mother’s antibodies destroy the child’s red blood cells, leading to severe anemia, jaundice, and other problems. The severity of HDFN depends on the quantity of antibodies produced and the timing of their first exposure to the Rh protein.
2. Hydrops fetalis:
In severe instances, HDFN can cause extra fluid accumulation inside the child’s body, a condition known as hydrops fetalis, which can be life-threatening.
Prevention and management:
1. Rhogam injections:
Rh-negative Women who are pregnant or at risk of becoming pregnant receive Rh immunoglobulin (Rhogam) injections. These injections suppress the mother’s immune system from forming antibodies against the Rh protein, preventing HDFN.
2. Prenatal testing and monitoring:
Blood type and Rh component testing are executed early in pregnancy, and near monitoring of antibody ranges and fetal fitness is very important for handling dangers and taking appropriate preventive measures.
3. Treatment for HDFN:
Depending on the severity, treatment for HDFN may additionally include intrauterine blood transfusions to the infant, phototherapy to break down bilirubin from red blood cell breakdown, exchange transfusions (replacing the child’s blood with donor blood), or even bone marrow transplants in very rare instances.