Learning About Rh Immunoglobulin Shots

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An Rh immunoglobulin shot is given to pregnant women who have Rh-negative blood.

You may have Rh-negative blood, and your baby may have Rh-positive blood. If the two types of blood mix, your body will make antibodies. This is called Rh sensitization. Most of the time, this is not a problem the first time you're pregnant. But it could cause problems in future pregnancies.

This shot keeps your body from making the antibodies. You get the shot around 28 weeks of pregnancy. After the birth, your baby's blood is tested. If the blood is Rh positive, you will get another shot. You may also get the shot if you have vaginal bleeding while you are pregnant or if you have a miscarriage. These shots protect future pregnancies.

Women with Rh negative blood will need this shot each time they get pregnant.


  • Rh immunoglobulin (HypRho-D, MICRhoGAM, and RhoGAM)

Possible side effects

Rare side effects may include:

  • Some mild pain where you got the shot.
  • A slight fever.
  • An allergic reaction.

You may have other side effects not listed here. Check the information that comes with your medicine.

What to know about taking this medicine

  • You may need more than one shot. You may need the shot again:
    • After amniocentesis, fetal blood sampling, or chorionic villus sampling tests.
    • If you have bleeding in your second or third trimester.
    • After turning of a breech baby.
    • After an injury to the belly while you are pregnant.
    • After a miscarriage or an abortion.
    • Before or right after treatment for an ectopic or a partial molar pregnancy.
  • Tell your doctor if you have any allergies or have had a bad response to medicines in the past.
  • If you get this shot within 3 months of getting a live-virus vaccine, the vaccine may not work. Your doctor will tell you if you need more vaccine.
  • Check with your doctor or pharmacist before you use any other medicines. This includes over-the-counter medicines. Make sure your doctor knows all of the medicines, vitamins, herbs, and supplements you take. Taking some medicines at the same time can cause problems.

Where can you learn more?

Go to https://www.healthwise.net/patientEd

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The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.