An Rh (Rhesus) factor is a protein found on the surface of some red blood cells. Not everyone carries this protein, though most people do, medics say. This factor is an important characteristic of blood cells for it indicates whether the blood of two different people is compatible when mixed-such as the blood of a mother and her baby at birth. If a person’s blood cells have this protein, they are considered to be Rh positive. If the blood cells do not have this protein, then they are Rh negative. During pregnancy, problems can occur if the mother is Rh negative and the foetus is Rh positive. Hence when expecting, health experts urge that it’s important to know this information early on in pregnancy. Emmanuel Semwaga, an obstetrician and gynaecologist explains that there are four major blood types: A, B, O, and AB. The types are based on substances on the surface of the blood cells. According to him, Rh is another blood type which is inherited through genes. “When one gets pregnant and they aren’t sure of their Rh factor, it’s always advisable to start regular prenatal care as soon as possible including blood-type testing,” he says. This, Semwaga says is so because with early detection and treatment of Rh incompatibility, one can focus on factors that will help them give birth to a healthy baby. Iba Mayale, a gynaecologist in Kigali says Rh antibodies are harmless until the mother’s second or later pregnancies. He notes that if she is ever carrying another Rh-positive child, her Rh antibodies will recognise the Rh proteins on the surface of the baby’s blood cells as foreign. “Her antibodies will pass into the babys bloodstream and attack those cells. This can make the babys red blood cells swell and rupture,” he says. According to him, this is known as haemolytic or Rh disease of the new born. It can make a babys blood count get very low. What to consider Semwaga explains that when one is pregnant, blood from the baby can cross into the mother’s bloodstream, especially during delivery. “If you are Rh-negative and your baby is Rh-positive, your body will react to the babys blood as a foreign substance. It will create antibodies (proteins) against the babys blood. These antibodies usually dont cause problems during a first pregnancy,” he says. He goes on to point out that Rh incompatibility may cause problems in later pregnancies, if the baby is Rh-positive. This is because the antibodies stay in the body once they have formed. The antibodies can cross the placenta and attack the babys red blood cells. In this case, the baby could get Rh disease, a serious condition that can cause a serious type of anaemia. When it comes to treatment, Semwaga says injections of a type of medicine called Rh immune globulin can help keep your body from making Rh antibodies. “It helps prevent the problems of Rh incompatibility. If treatment is needed for the baby, it can include supplements to help the body to make red blood cells and blood transfusion,” he says. Medics say if a pregnant woman has the potential to develop Rh incompatibility, she is given a series of two Rh immune-globulin shots during her first pregnancy. Here, she can get the first shot around the 28th week of pregnancy and the second shot within 72 hours of giving birth. Rh immune-globulin acts like a vaccine. It prevents the mother’s body from making any Rh antibodies that could cause serious health problems in the new born or affect a future pregnancy. Besides, a woman also might get a dose of Rh immune-globulin if she has a miscarriage, an amniocentesis or any bleeding during pregnancy. If a doctor finds out that a woman has already developed Rh antibodies, her pregnancy will be closely watched to make sure that those levels are not too high. Alternatively, in rare cases, if the incompatibility is severe and a baby is in danger, the baby can get special blood transfusions called exchange transfusions either before birth (intrauterine foetal transfusions) or after delivery. Health experts say exchange transfusions replace the baby’s blood with that of Rh-negative blood cells. This stabilises the level of red blood cells and minimises damage from Rh antibodies already in the baby’s bloodstream.
