RH negative pregnancy: What it means for you and your baby

RH negative during pregnancy

What do you mean by the Rh factor?

Just like there are different blood groups, such as A type and B type, there also exists an Rh factor. Rh is a protein that is present on the surface of your RBCs or red blood cells. Most people have an Rh factor or the presence of a D-antigen, which means that they are Rh positive. Others do not have the Rh factor—they are Rh negative. Most Indians are Rh+. Only 5-9% of our population is Rh-. But given the population density of our country, that is still a huge number of people.

How will I know if I am Rh negative?

One of the first tests that you will be given when your pregnancy is confirmed, is a blood test, to determine your blood type. If you do not have the Rh antigen, you will be deemed as being Rh-negative. Conversely, if you have the Rh antigen, you are Rh-positive.

How does my RH negative factor affect my baby?

Problems can arise when the fetus’s blood has the Rh factor and the mother’s blood does not. The baby inherits his Rh+ status from the dad’s genes. If your baby's blood mixes into your own bloodstream, your immune system attacks it as if it were a “foreign particle” and hence produces antigens against it. This process of making your blood used to the fact that it has foreign particles in it is called “sensitising”.

Even still, this sensitising is usually of no concern during a first pregnancy. However if you get pregnant again and your new baby is also Rh+, then there is a possibility that the antibodies that were previously formed and are now a part of your blood system, could cross over the placenta and attack your baby’s blood cells. This can cause your baby to have anaemia. This is a cause for concern, because, if the anaemia were to get severe, it can be a threat to the baby’s life causing heart failure or fluid retention. Even after he is born, your baby’s liver cannot handle the volume of his blood cells that need to be broken down, ending up in his developing jaundice.

You can have a shot of anti-D - an injection that can prevent your immune system from making antibodies. And this is important to be done during your first pregnancy itself, because once the antibodies are formed, they are present in your blood forever. Anti-D fights and destroys any baby blood cells in your blood before your immune system has a chance to make any antibodies.

What can be done to minimise problems if I have a RH negative pregnancy?

During pregnancy, the expectant mother and fetus do not share blood systems. However, sometimes small amounts of blood from the fetus can cross the placenta and into the mother’s blood system. This sometimes may happen during pregnancy, labor or during birth. These are things which will be done in case you are Ph negative.

  • A blood test will be done to provide you with your blood type and Rh factor.
  • An Antibody screening will be done through a blood test that will show if an Rh-negative expectant mother has developed antibodies to Rh-positive blood.
  • An injection of Rh immunoglobulin (RhIg), will be administered. Rhlg is a product for the blood stream that helps in the prevention of the sensitization of an Rh-negative mother.

After the baby is born in an RH negative pregnancy

Once your baby is born, his blood group and Rhesus status are found out by testing. If your baby is Rh+, you will be given another shot of anti-D. Once again, this has to be done super quickly, so that your immune response is not triggered. This is administered within 72 hours of your baby’s birth. As always, your doctor is aware of all these complications and necessities and will act appropriately. If you are aware of your Rh status, make sure to mention it to your doctor at the very beginning.