RhoGAM and Coombs - page 2

by ACNP2B 40,478 Views | 27 Comments

I'm a nursing student and we just took our OB final this morning. There was a question on the test that I'm confused by and I was hoping someone might be able to explain. Let me preface by saying that when we covered this... Read More


  1. 0
    Quote from randomramblings
    So then, they DO give it to Rh neg moms regardless of positive or negative coombs?


    To my knowledge, no. It is like closing the barn door after the horse gets out. Rhogam prevents the production of antibodies by RH- mothers who have been exposed to Rh+ fetal blood. In the case of a mother whose indirect coombs is positive, the antibodies are already circulating freely in her bloodstream, and Rhogam is ineffective. There is no benefit to exposing mother to the potential risks and side-effects of the drug.

    This is a fairly rare occurance, in my experience. Most Rh negative mothers are given Rhogam prophylactically upon miscarriage, abortion, any procedure that may potentially result in mixing of fetal and maternal blood (such as amniocentesis) or at 28 weeks gestation of pregnancy, making it unlikely that an Rh negative mom will develop sensitization. So a mother with a positive indirect coombs test is a rarity. The article I linked in my earlier post indicates what is done in that case. You can also "google" Rhogam for more information.
  2. 0
    Here is all I know about it. A pregnant woman who is Rh negative gets Rhogam during her pregnancy. After birth, if the baby is Rh neg. also, we don't give Rhogam, but if the baby is positive, we do.
  3. 0
    Quote from jhhrn68
    Here is all I know about it. A pregnant woman who is Rh negative gets Rhogam during her pregnancy. After birth, if the baby is Rh neg. also, we don't give Rhogam, but if the baby is positive, we do.
    Yes I believe this is our practice also.
  4. 2
    In refrence to your question : Rho-GAM is a blood product given to,
    • RH(-) moms delivering an RH(+) baby.
    A type and antibody test is done on all moms early in pregnancy and if indicated at 28wks she may recieve Rho-GAM. Later on at delivery a blood sample is taken from the infants umbilical cord (this is called cord blood) and the test done with this blood is called a coombs test. If this coombs test is positive and mom is RH(-), Rho-GAM will be given within 72 hours of delivery.
    • Rho-GAM prevents an antibody response in mom and also prevents hemolytic disease of the newborn in the mom's future pregnancy
    • Rho- GAM is given in the deltiod muscle to the mom.
    Hope this is helpful.
    k7redeemed and Sarah K, RN like this.
  5. 0
    Rh and Coombs are separate and different. The Coombs tests will be part of a rhogam work up for an Rh neg mom after baby's blood type comes back Rh positive.

    Also please note that coombs testing done on babies born to all type O mothers is testing for ABO incompatibility and is not related to Rh status and has no bearing on whether or not mom gets rhogam.

    Rh isoimmunization is a problem for mom, ABO incompatibility is a problem for baby.

    ITA with Jolie. Your PP notes are correct. Rhogam would only be indicated when the coombs are both neg, indicating no isoimunization.

    Many women do not receive adequate prenatal care and therefore it cannot be assumed that every Rh negative mother received a dose of Rhogam at 28 weeks.
    Last edit by RNmommy on Mar 2, '08
  6. 0
    Quote from cnovice
    Later on at delivery a blood sample is taken from the infants umbilical cord (this is called cord blood) and the test done with this blood is called a coombs test. If this coombs test is positive and mom is RH(-), Rho-GAM will be given within 72 hours of delivery.
    That is not correct. The direct coombs on the cord blood will indicate only ABO incompatibility in the baby. The blood type will indicate the need for rhogam for mom.

    The question in the OP is referring to coombs testing on the mother and it's indication for rhogam administration.
  7. 1
    I don't see where a Coombs test would have any bearing on whether or not a mother gets Rhogam or not, as it would be of no help by that point, just as Jolie pointed out.

    I've actually been learning a lot about this very thing lately because my little primary at work was born to a mother that didn't get Rhogam after her first miscarriage because she is from another country and for some reason they didn't give it over there. Therefore the mom was already sensitized ..... made for a very sick baby.
    Elvish likes this.
  8. 0
    Quote from RainDreamer
    I don't see where a Coombs test would have any bearing on whether or not a mother gets Rhogam or not, as it would be of no help by that point, just as Jolie pointed out.
    It would be pointless to give a mom with a positive direct and indirect Coombs rhogam, as isoimmunization has already occurred. However, rhogam IS indicated when an Rh neg AND coombs negative mom gives birth to an Rh pos baby to protect her FUTURE babies from hemolytic anemia.
  9. 0
    Quote from RNmommy
    It would be pointless to give a mom with a positive direct and indirect Coombs rhogam, as isoimmunization has already occurred. However, rhogam IS indicated when an Rh neg AND coombs negative mom gives birth to an Rh pos baby to protect her FUTURE babies from hemolytic anemia.
    Correct.
  10. 0
    Can someone explain what blood type has to do with Rh. I totally understand that if the mother is Rh- and baby is Rh+ then mother needs Rhogam but every once in awhile I read things about Type O blood and I have no idea what blood type has to do with it.


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