Did your initial round of prenatal bloodwork reveal that you’re Rh negative? That could mean that you and your baby are Rh incompatible. In that case, your doctor may suggest a shot of Rh immunoglobulin — commonly known in the U.S. by the brand name RhoGAM — during pregnancy and after delivery if you have an Rh positive baby.
While the term “Rh incompatibility” may sound serious, the treatment is simple and low-risk. Here’s what to expect if you need a RhoGAM shot.
What is the Rh factor?
Rh factor is a type of protein often found on the surface of red blood cells, which carry oxygen throughout the body. But not everyone has it. If you carry the protein, you’re Rh positive. If you don’t, you’re Rh negative.[1]
Most people are Rh positive. Negative Rh factor occurs in about 15 percent of white people, between 4 and 8 percent of Black people and 0.3 percent of Asian people.[2]
If you’ve ever gotten a blood test or given blood, you probably noticed the “+” or “–” at the end of your blood type. This symbol indicates whether or not the Rh factor is in your bloodstream. O+ blood, for instance, has the Rh factor, while O- blood does not.
Whether you’re Rh positive or negative doesn’t matter much, except when it comes to pregnancy.
What is Rh incompatibility?
Rh incompatibility happens when an expecting mom is Rh negative and her baby is Rh positive. If your baby’s blood comes into contact with yours during pregnancy or delivery, your body can build antibodies against the Rh factor.[3]
This can lead to potential complications (especially if you become pregnant with another Rh positive baby in the future) because your immune system will mount an attack against those Rh positive red blood cells. That’s why your doctor will test your Rh factor early on in pregnancy.
More About Prenatal Testing
The good news is that Rh incompatibility is easy to treat with a RhoGAM shot.
What is RhoGAM?
RhoGAM is the injection used to prevent Rh incompatibility from developing during pregnancy. The shot contains antibodies (collected from plasma donors) that stop your immune system from reacting to your baby’s Rh positive blood cells.
In other words, it keeps you and your baby’s Rh incompatibility from causing any possible problems should your blood types mix at any point during your pregnancy or delivery.
Like other shots, RhoGAM is injected into your arm or backside.
Do I need the RhoGAM shot during pregnancy?
If you test Rh positive, the shot isn't necessary. If you test Rh negative and the baby’s father subsequently tests Rh positive, your doctor will recommend that you get the RhoGAM shot.
Getting a RhoGAM shot is the best way to prevent any possible complications from Rh incompatibility. It protects your baby’s red blood cells from attack if her blood comes into contact with yours during labor and delivery and helps prevent Rh-related complications from happening in later pregnancies.
Speaking of later pregnancies, if you’re Rh negative, it’s important to get the RhoGAM shot with each baby unless your provider says otherwise. (If it’s determined that your baby is Rh negative too, you won’t need the shot.)
When should I get the RhoGAM shot?
If your doctor determines that you may have Rh incompatibility, you’ll get a shot of RhoGAM when you’re between 26 and 28 weeks pregnant and then again within 72 hours after delivery to ensure that future pregnancies are as safe as the first.
If you undergo chorionic villus sampling (CVS) or amniocentesis, or if you experience bleeding during pregnancy or any trauma where you could be exposed to fetal cells, your doctor may give you the RhoGAM shot at another point in your pregnancy.[4]
Do I need a RhoGAM shot after a miscarriage or chemical pregnancy?
The RhoGAM shot is a good preventative measure to take any time your baby’s’ blood comes into contact with yours, which can happen if you have a miscarriage or ectopic pregnancy. You won’t, however, need a RhoGAM shot after a chemical pregnancy.
Are there side effects or risks of the RhoGAM shot?
The side effects associated with the RhoGAM shot are rare and mild. They may include:
- Soreness or rash at the infection site
- Mild fever
- Chills
- Headaches
If you’re worried about the potential side effects, talk to your doctor about any concerns.
If you’re worried about getting the RhoGAM injection because it is made from donated plasma, keep in mind there's minimal to no risk of contracting diseases like HIV or hepatitis because the donated plasma is thoroughly screened and treated. Know that the shot has saved hundreds of thousands of babies’ lives.
Finding out that you and your baby may be Rh incompatible can be a little worrying. But the RhoGAM shot is a safe, simple and effective way to stave off any potential problems — both now and for future pregnancies.
Yes 
No 
Trending On What to Expect
