Rh Factor In Pregnancy
Human blood is categorized under four major blood types: A, B, AB, or O. The types of antigens on the blood cells determine the type. Antigens are proteins on the surface of blood cells that can cause a response from the immune system. One such protein is the Rh Factor. Rhesus (Rh) factor is a type of protein on the surface of red blood cells and most people who have the Rh factor are considered to be Rh-positive. Predictably, those without it are considered to be Rh-negative.
The Importance Of Blood Tests
When a woman becomes pregnant, one of the first tests given is a blood test to determine, among other things, the Rh factor of her blood. The Rh factor may play a very significant role in the unborn baby's health, so it is important for a woman to have this information early in the pregnancy. If the mother is Rh-negative and the father is Rh-positive, the unborn baby can inherit the Rh factor from the father, thus making the baby Rh-positive too. The problem arises when the baby's blood has the Rh factor and the mother's blood does not.
The Struggle Between Positive And Negative Rh Factor
If a woman is Rh-negative, she may develop antibodies to her Rh-positive baby and if a small amount of the baby's blood mixes with the mother's blood, it could produce an allergic reaction to the baby. The mother's body may form antibodies to the Rh antigen in the baby's blood. This means there is sensitivity to the Rh factor and antibodies can cross the placenta to attack the baby's blood, recognizing it as an intruder and a potential danger to the mother. As a result, an anemia in the baby is produced as the red blood cells in the baby's blood are broken down. This condition is known as hemolytic disease or hemolytic anemia. There is potential for this condition to become severe enough to cause serious illness, brain damage, or even death in the unborn or newborn baby.
The Good News Is...
In times past, Rh incompatibility was a very serious problem, which often ended in the death of the baby. The good news is that these conditions are preventable by utilization of a blood test to determine Rh factor in both mother and baby. Antibody screening is another type of test that can show if an Rh-negative woman has developed antibodies to Rh-positive blood. Rh immunoglobulin (Rhlg), which is a blood product that can prevent sensitization of an Rh-negative mother to her unborn baby, can be injected.
The first injection is given around the 28th week of pregnancy and the second within 72 hours after giving birth. The Rh immunoglobulin prevents the mother's body from producing any potentially dangerous Rh antibodies that can cause serious complications in the newborn or complicate any future pregnancies.
...And The Other News
Rh incompatibility does not often cause problems in a first pregnancy and does not affect the health of the mother. However, in subsequent pregnancies it can be very dangerous to both mother and child. Jaundice, anemia, brain damage, and heart failure and in extreme cases, death of the newborn are potential hazards because too many red blood cells have been depleted.
It is important for a pregnant woman to be tested and to begin health care as soon as possible after conception to ensure a safe and healthy pregnancy and delivery.