Many women may not even know what their blood group is. Whether it's O, A, B or AB, it will also be shown to either feature a certain protein or not. This protein or lack of it makes a person Rhesus negative or positive. When a mother-to-be goes for her first blood tests after the pregnancy is confirmed, the Rh Compatibility test is a vital one because it will show if the mother and the fetus's blood will be able to work together during pregnancy.
What is RH Incompatibility?
Because a fetus contains qualities passed on from her father as well as her mother, she may not always have the same blood group as her mother.
If the mother is Rhesus negative while the baby is Rhesus positive, the mother's body may regard the baby in the same way as it regards all infections, as a 'foreign body', and her immune system will start to attack the new being.
There is no immediate cause for concern when a woman is first pregnant and because the blood test - which detects the antibodies created to deal with Rh Incompatibility - is carried out quite early in a pregnancy, there is now a simple and safe way to help both mother and baby enjoy a good and successful pregnancy.
How will I know if my baby and I are Rh Incompatible?
At your first ante-natal visit, blood tests include a regular test to confirm your blood group and to detect any antibodies.
If a mother-to-be knows her blood group and it is, as the vast majority of population's is, Rhesus positive, even if the fetus is Rh negative, there is no need for treatment, as it is only when the mother is Rh negative that the immune system reacts.
Being Rhesus negative is much more rare, and if the mother and the father are Rh negative, the baby will be fine.
However, the hospital will still carry out the test for antibodies, because a previous pregnancy can produce antibodies if a previous fetus was positive. If it is your first child and both parents are negative, you may well be fine. However, an abortion or miscarriage with a previous Rh-postive fetus can set up the antibodies that will affect a later pregnancy. Some women may have suffered a very early miscarriage at some point even without knowing it, so this simple blood test is advisable.
What happens if we are Rh Incompatible?
If the incompatibility goes undetected, it can cause anything from mild to very serious anaemia in the fetus, because antibodies can cross the placenta. The damage done to the fetus's red blood cells can, in extreme cases, be fatal.
HOWEVER, the routine test is well observed. When there is incompatibilty found, a mother will be treated with injections of a Rh-immune globulin during the pregnancy and be monitored for any neccessary treatment after the birth.
In extreme and now very rare cases, a blood tranfusion may be neccessary either during pregnancy for the fetus, or after the birth for the new baby.
