Rhogam Postpartum: The Shot for Healthy Future Pregnancies

What Does it Mean to Be Rh Negative?

Blood typing is something you are probably familiar with.  You know that if you we are dealing with human blood transfusions you can’t just receive anyone’s blood.  You have to receive blood products that are compatible with your blood type, or you can experience a severe allergic reaction or other severe complications.  Our body’s immune system is built to fight off invaders to keep us healthy.  Your red blood cells have different indicators on them to tell your body what is friendly and what is foe.  

One of those identifiers is an inherited protein called the Rhesus (Rh) factor.  If your blood type is positive (such as: O+, A+. B+, or AB+), you will have the Rh protein on the surface of red blood cells.  If it is negative it will lack the Rh protein.  The presence or lack of Rh factor protein does not affect your health in any way.  It does however tell us if blood can be compatible, which is very important when it comes to pregnancy, especially for rh-negative women.  

You can easily determine your blood type and Rh factor by a simple blood test.  This will typically occur in your first prenatal appointment when your baby is between 8-10 weeks gestation.

So Why Does Rh Factor Matter During Pregnancy?

When sperm and egg meet they both contribute genetic material to the baby.  Your baby will inherit traits from both you and your partner.  Rh-positive factor is a dominate factor meaning you only need one Rh + to create an Rh+ blood type.  Where as, an Rh-negative blood type requires two Rh negative genes to create a negative blood type.  

Just like you can’t mix certain blood types together with blood transfusion the same occurs if fetal blood cells mix with mom’s blood cells during pregnancy or birth.  It can cause some problems if mom and baby have different Rh status.  This is why your medical provider will test your blood type and possibly your partner’s blood type early in your pregnancy.  

The good news is that it Rh incompatibility does not affect your first pregnancy only subsequent pregnancies and there is a reliable treatment for Rh-negative mothers. 

What is Rhogam and Why do I Need it?

Rhogam is an intramuscular injection that is given to prevent the potential Rh alloimmunization (the immune response to foreign antigens that cause antibodies to form to destroy your newborn’s foreign blood).  

So like we said this is really only necessary if you are Rh negative and your baby is Rh positive.  In the event that this is the case, like myself, if my Rh positive baby’s blood gets into my blood stream my body would recognize that the Rh-positive blood as foreign.  My body would then try to destroy it by making anti-Rh antibodies.

These antibodies can cross the placenta and attack the fetus’s blood cells, which can lead to some very serious health problems, including death.  

If you want this broken down to you in a visual format this is a really easy way to see why this happens.

Can These Antibodies my Immune System Produces Hurt my Baby?

In your first pregnancy the antibodies that your body will create will not harm your first pregnancy.  This is because typically your blood will not mix until delivery, which means rh sensitization won’t occur and buld up antibodies until after the delivery.  However, if not treated it can cause problems in future pregnancies.  

The severity of problems for your fetus in subsequent pregnancies can vary from mild to severe.  These antibodies when they see Rh + blood again will destroy those blood cells, causing hemolytic disease of the fetus (the breakdown/destruction of red blood cells quickly).  It has no negative effects on the mother, but as you can imagine that can be problematic for your fetus or newborn.  

Possible negative effects of hemolytic anemia to newborn: 

• Jaundice
• Liver failure
• Heart failure
• Still birth

If you have had Rh sensitization, your medical provider will discuss with you the severity of Rh incompatibility and what your treatment options may be.  Here are some potential treatment options: no treatment, use special lights to reduce bilirubin levels, and fetal blood transfusions are some of the options.

How Does Rhogam Work?

The Rhogam shot is an intramuscular shot that when injected suppresses the immune response of Rh-negative women to Rh-positive red blood cells.  Therefore your body will not produce the antibodies that could affect a future pregnancy.  

Rhogam is a sterilized solution made from human blood that contains a very small amount of Rh-positive antigens.  It suppresses your body’s immunes system, because the rhogam will bind to any fetal red blood cells that may circulate with maternal blood. This prevents the mothers body from creating their own anti-Rh antibodies.

You will be given a card that indicates you were given Rhogam after your shot.  It is important to carry this card with you at all times after receiving the shot in the event that your blood type is checked at another facility that may not be aware that you received Rhogam.  Your blood may test positive on an antibody screen for several months after receiving the shot.  

When do I Need Rhogam Postpartum & During Pregnancy?

The Rhogam injection is frequently given at two main intervals, 28 weeks of pregnancy and 72 hours after birth. When given at this interval the risk of Rh alloimmunization drops from 12-13% to 0.1%.  If you are an rh-negative mother and your partner is rh-positive or was not tested you will be recommended to receive Rhogam at 28 weeks, because we cannot determine the baby’s blood type at this time.  

Rhogam is effective for about 13 weeks so it should cover you for the remainder of your pregnancy when your blood and your baby’s blood are most likely to mix.  During the last trimester of your pregnancy your placenta is growing and the membranes that separate your blood from your baby’s is very thin.  That is why you will receive your first shot at 28 weeks.

When your baby is born their blood type will also be tested.  If they are rh-positive you will get another Rhogam shot within 72 hours after your birth.  If they are rh-negative you will not need an additional Rhogam shot.  

Other times you may need a Rhogam shot:

• any vaginal bleeding during pregnancy
• miscarriage, threatened miscarriage, or abortion
• evacuation of molar pregnancy
• Therapeutic termination of pregnancy
• chorionic villus sampling or amniocentesis
• injury to your abdomen (car accident or fall)
• ECV turning of the baby 
• Ectopic pregnancy

Who Doesn’t Get Rhogam?

There are some people who should not get the Rhogam injection.  First and foremost, pregnant women who are Rh positive.  Due to their blood type they do not have antibodies and will not make antibodies if your baby’s blood type is different than your own.  Newborns do not need to receive the Rhogam shot, as well.  

Additionally women who fall into these categories should not receive Rhogam:

• If you have hemolytic anemia
• Hx of allergic reaction to a shot of immune globulin
• You already have Rh sensitization

Is Rhogam Safe?  What are the Risks?

Rhogam is considered very safe.  The use of Rhogam in rh-negative women has been a part of clinical practice for about 50 years. It is made from human blood, as with any blood product there are some risks involved.  There are very low risks of infection (hepatitis and HIV), due to the rigidity of how we test blood products.  This is so rare that there are zero reports of this happening.  You could also have a risk of allergic reaction to a shot of rhogam, as with any medication.  The signs of infection include: fever, chills, shortness of breath, redness or swelling at the injection site.  

The risks of developing rh sensitization is much higher than the risks involved with the Rhogam shot that most providers will highly recommend the shot.  The potential risk to future pregnancies are often much more dangerous.    

The RhIg is small enough to potentially cross the placenta, but from what I can tell the incidence of this happening and causing poor outcomes in fetuses is insanely low. I only found one report of this coming from India. The risk is far greater when Rhogam is not given.

You of course always have a choice when it comes to any medication or treatment.  If you choose to forgo Rhogam, about 1 in 5 women will get Rh sensitization.  This cannot be reversed once it has occurred.  If you become sensitized you will have to closely monitor your baby in the future to see how your baby is handeling it.  You may have to be induced early for your baby’s safety.  

Final Thoughts

Understanding how your body works is an important part of making informed decisions for your pregnancy.  Rh negative mothers need to be aware that they could have the potential of developing rh sensitivity.  This could affect future pregnancies and cause risk to their growing fetus.  Rhogam is a safe and effective option to prevent rh sensitization.  

As an Rh negative mother, this is something that I encountered during my pregnancy.  At the time it was a lot to take in and I had to go to other sources to break it down and make sense of it all.  Not all medical professionals are great at making medical information easily digestible for the average person.  I hope that this information will help you to navigate this decision for yourself.