Rh Immune globulin is a medication given to a pregnant woman who has Rh negative blood. Rhogam prevents the Rh negative women from making antibodies that could destroy the RBCs of a Rh positive fetus. Rhogam is basically a protein (or antigen) that tells the immune system to not make antibodies.
The main thing to remember is that Rh- negative pregnant women will get administration of RhoGam (Rh immune globulin) if the fetus is Rh+ positive or fetus’s Rh status is unknown.
The reason a pregnant woman would get RhoGAM is because if the fetus she is carrying has Rh positive blood, but the woman has Rh negative blood. The woman could form antibodies against the fetus’s blood. This would destroy the unborn fetus’s red blood cells and cause a hemolytic disease in the fetus.
So, if the pregnant women’s Rh is negative, she will get Rh immune globulin at about 28 weeks’ pregnant and within 72 hours after delivery (if the baby is Rh positive). It’s sometimes given following a miscarriage or abortion.
Why is rhogam given at 28 weeks? This is about the time that fetus blood might intermingle with maternal blood.
Why is rhogam also given after a miscarriage? Because if the Rh negative women had an Rh positive fetus, then the women would have started making antibodies. So Rhogam prevents any more antibodies from forming.
What?! Students are frequently confused on what Rh factor, Rh antibodies, Rh antigens and Rh Immune globulin (AKA, Rhogam) all means. I’m here to help you understand and show you a few practice questions to see it in action.
Rh has to do with blood types. There’s several different types of blood: A, B, AB & O. There is also the Rh factor. You can either be Rh- negative or Rh+ positive. You might hear someone as having Type B positive blood. Positive indicates that they are positive for Rh factor. But what is Rh factor?
Rh factor
Rh factor is a protein that occurs on someone’s red blood cells. It can also be called an antigen. It’s genetically determined.
Rh positive indicates Rh factor/antigen on your blood.
Rh negative indicates no Rh on your blood.
Rh+ positive blood can get both Rh+ or Rh- blood.
Rh- negative blood can only get Rh- blood.
Rh antibodies & Rh Incompatibility – A BIG Problem
Rh antibodies are molecules that will destroy the blood. If a person gets the wrong blood, their body will form antibodies to destroy the blood. Antibodies are like little bombs. I call them antibody bombs.
If someone is Rh- and they get Rh+ blood, the Rh- person will produce antibody bombs and their own RBCs will get destroyed. It’s called hemolysis.
If a fetus is Rh+, but the mom is Rh-, then the women can form antibody bombs AND DESTROY the fetus’s RBCs.
Resources cited: Maternity and Women’s Healthcare 11th edition by Lowdermilk, Perry, Cashion & Alden, My Imagination/Brain, https://www.redcrossblood.org/local-homepage/news/article/what-is-the-rh-factor–why-is-it-important-.html,
Let’s try out this content in a few NCLEX-style questions.
NCLEX-style Practice Questions in Action
Example 1
A multigravid client at 32 weeks’ gestation has experienced hemolytic disease of a newborn in a previous pregnancy. The nurse should prepare the client for frequent antibody titer evaluations obtained from which source?
- placenta blood
- amniotic fluid
- fetal blood
- maternal blood
Explanation: For the Rh- negative client who may be pregnant with an Rh positive fetus, an indirect Coombs test measures antibodies in the maternal blood. Titers should be performed monthly during the first and second trimesters and biweekly during the third trimester and the week before the due date. Answer is # 4.
Example 2
The postpartum client’s blood type is A negative and her newborn infant’s blood type is AB negative. The client received RhoGAM in her second trimester and another dose in her third trimester, after a minor car accident. The client is preparing for discharge and asks the nurse when she will recieve her RhoGAM injection. The nurse correctly responds with which statement?
- “You already received two doses of RhoGAM and do not need an additional dose.”
- “I will give your last dose of RhoGAM today, before you are discharged home.”
- “You and your baby have negative blood types; a dose of RhoGAM is not needed.”
- “RhoGAM would have been already given while you were in the delivery room.”
Explanation: The number of RhoGAM doses given in pregnancy does not affect whether or not the client receives a dose postpartum. Rh immune globulin (RhoGAM) is administered to women with Rh negative blood types at approximately 28 weeks of gestation and again after any trauma, such as a car accident or fall. After delivery, RhoGAM is only indicated if the newborn has a positive blood type; both the client and newborn are Rh negative. For postpartum clients who require RhoGAM, the dose is given within 72 hours of delivery. However, no dose is necessary because the client and newborn are both Rh negative. Answer is #3.
Example 3
At 28 weeks’ gestation, an Rh-negative woman receives RhoGAM. Which of the following would indicate that the medication is effective?
- The baby’s Rh status changes to Rh negative.
- The mother produces no antibodies.
- The baby produces no Rh antibodies.
- The mother’s Rh status changes to Rh positive.
Explanation: The baby’s Rh status and mother’s Rh status cannot change. The baby will not produce antibodies. The goal of RhoGAM administration is that the mother produces no Rh antibodies. Answer is #2.
Example 4
A nurse is about to inject RhoGAM into an Rh negative mother. Which of the following is the preferred site for the injection?
- Deltoid
- Dorsogluteal
- Vastus lateralis
- Ventrogluteal
Explanation: In the deltoid the antibodies are absorbed optimally from that site and therefore are more ready to suppress the mother’s immune system. Answer is # 1.
