what is important of anti-D inj.?

Answer 1

In layman's terms: Most people have blood groups called Rh that ~85% of Americans have. The Rh (which is D)(there are other Rh groups called C,c,E,e but that's ignored in this case) is passed by autosomal dominance so let's say dad is Rh+ and mom is Rh- and the baby is Rh+ by getting the gene from dad. Because blood from the fetus can passively enter the blood stream of the mom who is Rh-, she gets exposed to Rh+ blood and starts producing antibodies against the Rh antigen. These antibodies (IgG) have the ability to cross the placenta and attack the baby from within the womb which causes Hemolytic Disease of the Newborn/Fetus. This is usually not a problem with the firstborn child because the mother has not yet produced enough antibody, but when subsequent pregancies arise, then it becomes problematic. So what doctors do when they discover that the mother is Rh- and there's a possibility that the baby is Rh+, they give premade Rh antibodies (the anti-D or Rhogam) to the mom. It seems to be a strange concept to give the mom something she will eventually produce anyway if there is Rh+ fetal blood in her bloodstream, but the way it works is simple. If the manufactured Rhogam can get to the Rh+ fetal blood before her immune system can get to it, the fetal blood will be neutralized and removed from the body faster, so it would be as if mom was never exposed to the fetal blood in the first place. (simply speaking). To figure out how many doses of the Rhogam a doctor has to give, they will have lab people perform a Kleihauer-Betke test that counts the percentage of fetal red blood cells to mom's cells in mom's blood. Doing this prevents a lot of heartache down the road because the consequences of Rh caused Hemolytic Disease of the Newborn is major.

Answer 2

The National Institute for Clinical Excellence (NICE) is now recommending routine anti-D at 28 and 34 weeks to all RhD-negative mothers to prevent antibodies being produced following small silent bleeds which happens in about 1 and 1.5% of all pregnancies.This prophylaxis prevents hemolysis in babies inheriting Rh positive blood from father.