The Rhesus Factor

The rhesus (Rh) factor is a protein found on the surface of red blood cells. If your blood has the protein you’re Rh-positive. If your blood doesn’t have the protein you’re Rh-negative. About 85 percent of people are Rh-positive and 15 percent are Rh-negative. Rh-negative blood is given to Rh-negative patients and Rh-positive blood is given to Rh-positive patients. Rhesus disease is a condition where antibodies in a pregnant woman’s body destroy her baby’s blood cells. It is also known as hemolytic disease of the fetus and newborn (HDFN) or Erythroblastosis fetalis. The thing is, Rhesus disease doesn’t harm or affect the mother but it can harm the baby and in severe cases result in the baby’s death. Hemolytic anemia (the destruction of red blood cells) and Jaundice (the yellowing of the skin and eyes of the baby) are the two major problems of rhesus in new Borns. The baby may also have low muscle tone, lack energy, and feed poorly. Some babies may develop these symptoms 2-3months after birth. The protein is passed from parents to their children through their genes. In order for a child to be RhD positive, they must inherit the protein from one parent who is also RhD positive.

 Rhesus Factor In Hemolytic Anemia in The Fetus/ Newborn.

 When there is a mix of blood between a rhesus -Ve mother and a rhesus +Ve baby which can happen during miscarriage, abortion, or after the first child, the mother becomes sensitized & her body builds antibodies (the body’s soldiers), when she gets pregnant again with a rhesus +Ve baby this antibody that has been produced now attacks the fetus as the mother’s body sees the baby as a foreign body thereby destroying the baby’s blood cells is known as hemolytic disease of the fetus or newborn. Jaundice is caused by the accumulation of bilirubin in the body. Bilirubin is a yellow substance that results when the red blood cell is broken down, normally it is removed by the liver and passed out in the urine but in babies, with rhesus disease, the liver is overwhelmed with a high amount of bilirubin which can not process as such- this bilirubin builds up in the body resulting in yellowing of the eyes and the body of the baby. It’s important to know that a woman with RhD -Ve blood can have an RhD +Ve baby if her partner’s blood type is RhD +Ve. If it happens that the father has 2copies of the RhD antigen, every baby will have RhD +Ve blood. But if the father has just a copy then it will be a 50-50 chance occurrence. Rhesus antigen is an antigen found on the surface of the red blood cells. Someone is said to be rhesus positive or negative depending on the presence or absence of the rhesus antigen on the surface of their blood cells. If the father is rhesus -Ve then there are no worries but if he is rhesus +Ve then the pregnancy is to be monitored. The mother often receives an injection at 28wks gestation and at birth to avoid the development of antibodies towards the baby. Sometimes the blood type of the unborn baby is determined when the pregnancy is 11-12wks, but if the baby happens to be rhesus -Ve then there are no worries but if the baby happens to be rhesus +Ve then the pregnancy is closely monitored. 1. There are four main blood groups: A, B, AB, and O. 2. Each of the blood groups can be either rhesus -Ve or +Ve. This is determined by the presence or absence of the rhesus antigen on the surface of the red blood cell. 3. When a rhesus -Ve woman marries a rhesus +Ve man, that is where we have a problem. The first child is usually not attacked and the mother is just “sensitized” this sensitization can also occur after a miscarriage, abortion, or after the first baby. The problem arises after this “sensitization” has taken place as in subsequent pregnancies, the mother’s antibodies promptly attack the baby and destroy the baby’s blood cells resulting in hemolytic anemia, jaundice and may result in the death of the baby if the situation is not- handled promptly and properly. 4. Rhesus disease does not harm the mother. 5. If detected on time it is treatable and the baby can be saved.

Rhesus Factor Inheritance

The protein is passed from parents to their children through their genes. In order for a child to be RhD positive, they must inherit the protein from one parent who is also RhD positive. This can happen even if the other parent is RhD negative which means that neither parent needs to be positive in order for their child to be positive. If the father of the baby is negative for rhesus D and the mother is positive, the baby will be positive. If a mother who is negative and a father who is positive conceive a baby the baby will be positive. If both parents are negative they can conceive either positive or negative babies. AB negative is the rarest of the eight blood types. If you’re Rh-negative and your baby is Rh-positive (called Rh incompatibility) it’s not usually a problem during pregnancy. But it can be a problem for your next baby if you become pregnant again. That’s because some of your baby’s Rh-positive blood cells can cross into your bloodstream during pregnancy.

If you are planning on getting married it is important to be aware of the rhesus factor compatibility table. This table is used to determine if you and your partner are compatible with each other based on your blood type. If you are incompatible it means that there is a chance that your child could have a serious health condition called hemolytic disease. This disease can be fatal so it is important to make sure that you are compatible before getting married.