Rhesus Factor: What Is It Really All About?

The human blood is classified into different groups, the most outstanding being the ABO framework in which an individual's blood is recorded as either A, B, AB or O, based on the sort of chemicals identified in the individual's red blood cells. When a patient is in a condition in which he requires blood transfusion, it is imperative that they are transfused with blood from the same blood group as their own. This implies that if an AB blood group patient requires blood transfusion, he must receive blood from either an AB blood group donor or from an O blood group (universal donor). If this is not done, a reaction to the ‘foreign’ blood may occur.

Each of the aforementioned blood types (A, B, AB, O) is also further identified by a plus or minus sign after the letter of the alphabet. For example, someone's blood may be ‘O positive’ (written O+) and another ‘O negative’ (written O-); with the positive or negative sign referring to the presence or absence of a substance in blood the human blood known as the rhesus factor. The Rhesus factor was named on the grounds that it was first discovered in rhesus monkeys.

Research has it that in Nigeria, about 95 percent of the entire population are  rhesus positive (Rh+), while the rest are rhesus negative (Rh-). Just like the manner in which we make antibodies to different infections, if a rhesus negative (Rh-) person receives Rhesus positive (Rh+) blood, their body reacts, making chemicals (antibodies) to defend against the foreign rhesus factor. Also, during childbirth, as the placenta comes away from the wall of the uterus(womb), some blood cells from the baby’s circulation might sometimes come in contact with the mother’s bloodstream. In most women, this is not an issue. Notwithstanding, it results to some complications for ladies who have Rh negative blood. In the event that the child has Rh positive blood acquired from the father, and the mother and baby’s blood cells become mixed during gestation or delivery, the mother’s body may treat the baby’s blood cells as foreign substances and produce antibodies against them (Rh antibodies) as a defense mechanism.

This doesn't frequently cause issues during the first pregnancy, in light of the fact that there's normally no significant contact between the child's and mother's blood until the point that the infant is born. Notwithstanding, in the event that she conceives a second child who is additionally Rh positive, then it is likely that the Rh antibodies from the mother's blood will move through the placenta and enter the unborn infant's bloodstream. As a result, the antibodies of the mother will at that point tie with the child's Rh positive red blood cells, making them to be destroyed. As a result of this, the baby may be born very ill, and unless a blood transfusion is given immediately after birth, the baby could die.

In each ensuing pregnancy, the mother turns out to be increasingly sensitised to the Rh positive blood and produces antibodies earlier and earlier in each one. In severe cases, the baby may die before birth if a large amount of blood cells are destroyed.

Regardless of how scary this situation might look, there is a counteractive action as medical science has developed a method to ensure the problems resulting from the incompatibility of the child's and mother's blood are minimised. Doctors give an injection of Rh antibodies, in the form of ‘anti-D’ immunoglobulin, to a mother who has Rh negative blood within a few hours after she has given birth to a baby with Rh positive blood. Such drugs helps in getting rid of any Rh positive blood cells which have been transferred to her from the baby, preventing her from producing antibodies that might harm future babies. Sometimes a woman’s Rh antibody levels need to be measured periodically during her pregnancy to anticipate whether the baby might have problems. If her antibody levels are too high, then she might need further tests to check the health of the unborn baby. Sometimes the unborn baby needs a blood transfusion, or it might need one soon after birth.