Patient: I am 35 weeks pregnant and have rh negative blood while my partner is rh positive. I was tested for antibodies in the 5th month (indirect coombs) and was negative. I then got the rhogamm shot at 28 weeks. My obgyn recently recommended I get tested once again and this time it was positive. Is there an explanation for this? Will I need to deliver before? Are there any repercussions for the baby?
Doctor: Hi.Read and understood your history and concerns.Indirect Coomb’s test looks for the antibodies to the Rh + antige n in Mother, which was obviously negative at the 5 th month.You were subsequently appropriately given the Rhogam shot. After this it was tested again and found to have a positive indirect coombs test. This subsequent positive test is expected because you were given the Rh+ antibody (in the Rhogam).A woman with Rh-negative blood can get a shot of Rh immunoglobulin (such as RhoGAM) that almost always stops sensitization from occurring. Problems from Rh sensitization have become very rare since Rh immunoglobulin was developed.If your baby id Rh negative no harm will be done to him/her.If the baby is Rh positive and is the first baby still harm will not be done.This Rhogam saves the next baby if he is positive.So if this is your first pregnancy without any history of miscarriage or abortion, nothing to worry at all.Since this is all a discussion on a virtual world, you are strongly advised to discuss all the relevant points with your Obstetrician top clear all the points and doubts as the direct discussions will help you to clear any doubts if still present.The mode of delivery and the time will be decided by your treating Doctor , hence not commented upon. It is better to be decided by your Doctor.Please feel free to ask further relevant questions if you still have in mind.I shall be happy to assist you more.
Comments / Follow Ups
Doctor: Generally the second test (indirect Coombs) is not done as it will be positive due to the Rhogam is already given as will make the test positive. So do not worry. This in fact indicates that Rhogam has acted upon well.
Rho-GAM prevents an antibody response in mom and also prevents hemolytic disease of the newborn in the mom’s “future pregnancy”.