The Rh or Rhesus Blood group system that identifies blood types is important for a number of reasons. Our blood is not only identified by its type or groups – A, B O or AB but also by its Rhesus factor; whether positive or negative.
During pregnancy the Rhesus factor assumes great importance. Since most people are Rh + or Rhesus positive, there is usually no problem with relation to this. However when one of the parents is Rhesus negative and the other is positive, there are certain risks and complications that could occur with the pregnancy.
The problems that Rh incompatibility could cause
If a woman is Rh positive, there is usually little cause for worry. Also in a first pregnancy, there are generally no negative repercussions.
In particular there could be a problem when the mother is Rh negative and the father is Rh positive. This could mean that the baby’s blood group is Rh positive and this could be viewed by the mother’s immune system as an intruder to be ejected.
Because of this the mother’s immune system will start to produce certain antibodies that may cause problems for the baby: anemia, hemolytic disease and other related illness, brain damage and even death could result.
Blood tests for the Rh factor and injections that will be given
One of the reasons for routine blood testing during early pregnancy is to find out what the mother’s blood type is. At times the father’s blood test may also be required.
For Rh negative women, another test will generally be required for antibody screening during the first trimester of pregnancy, as well as later at about 28 weeks. An injection to prevent the production of antibodies may then be administered to the woman. If the mother’s body has already started to produce antibodies, the injection will be of little use and the pregnancy will then be monitored very closely. One of the possibilities is that the baby could be given a blood transfusion through the umbilical cord during pregnancy or as soon as possible after the delivery.
Even after birth, caution has to be exercised by the mother. If the baby is born Rh negative, there is no problem. But if the baby is born with an Rh positive blood group, there will be a need for the mother to have an injection then as well as for future pregnancies.