Rh Factor Test Before Pregnancy: A Key Step for a Healthy Pregnancy

Hey, mom-to-be! Just had your first prenatal visit and feeling a little overwhelmed by all the tests your doctor prescribed? Do not worry, you are not alone! Among those tests, you may have noticed one called the Rh factor test—a routine but crucial screening that helps ensure a smooth and healthy pregnancy.

So, what is the Rh factor, and how does it affect pregnancy? In simple terms, it is a protein found on the membrane of red blood cells. If protein is present, you are Rh-positive, and if it is absent, you are Rh-negative. While this may seem like a negligible detail, it plays a significant role in pregnancy, especially if there is an Rh incompatibility between you and your baby.

In this blog, we will break down everything you need to know about the Rh factor—its importance, potential risks, and how timely medical care can help prevent complications. Let us dive in!

What is Rh Factor?

When determining blood type, we often focus on A, B, AB, or O groups, which are classified based on the presence of specific antigens on red blood cells. However, there is another protein called Rh factor on the membrane of the red blood cells.

The Rh factor, also called as Rhesus factor, is an inherited protein found on the surface of red blood cells. If your blood cells contain this protein, you are Rh-positive; if they lack it, you are Rh-negative. This factor, combined with your ABO blood group, determines your blood type—for example, A+ (A positive) if you have the Rh protein or A− (A negative) if you do not. The Rh factor has no impact on overall health. However, during pregnancy, there is a risk of Rh incompatibility between the mother and the baby that can lead to complications.1 2

What Is Rh Incompatibility And What Causes It?

Rh protein is typically inherited from either the mother or father. However, in some cases, the fetus may not inherit the protein from either parent, resulting in a Rh-negative status. This condition, known as Rh incompatibility, can impact pregnancy and lead to serious complications if left unaddressed.5

When the blood of a Rh-positive fetus enters the bloodstream of a Rh-negative mother, her body may mistakenly recognize the fetal blood as foreign substance and release antibodies to attack it. This immune response can result in serious complications, potentially causing fetal harm or even leading to death in extreme cases.3

Quick glance on RH compatibility risk

Signs, Symptoms, and Complications of Rh Incompatibility:

If Rh incompatibility occurs, the baby may develop hemolytic disease of the newborn (HDN), which can cause: 4

• Decline in red blood count in fetus
• Jaundice 
• Enlarged liver or spleen
• Abnormal heart rate
• Breathing difficulties
• Organ damage
• Heart failure
• Miscarriage

How is Rh Incompatibility Diagnosed

During your first prenatal visit, your doctor will likely prescribe a simple yet important blood test known as the Rh factor test. This test is essential in determining your Rh factor, which plays a crucial role in your pregnancy and your baby's health. Understanding your Rh status helps ensure the best care for both you and your little one throughout the pregnancy journey.

If Rh incompatibility is suspected, doctors will recommend specific tests to confirm the diagnosis and guide treatment.1

How Can Rh Incompatibility Be Treated?

It's crucial to know whether a woman is Rh-negative or Rh-positive before pregnancy. If a woman is Rh-negative, her doctor may administer Rh immunoglobulin, which helps prevent the formation of antibodies that could harm the pregnancy. This immunoglobulin is most effective when antibodies haven't been formed yet. However, once antibodies have developed, the immunoglobulin won’t work, and this can lead to Rh incompatibility, potentially causing serious health issues for both the mother and baby. Early testing and intervention are key to preventing complications

Can Rh Incompatibility Be Prevented?

Yes, Rh incompatibility can be prevented. If a pregnant woman discovers she is Rh-negative before conception, necessary precautions and medications, such as the administration of Rh immunoglobulin, can be taken to prevent the body from forming antibodies that could harm an Rh-positive fetus. Early detection and proper medical intervention are key in ensuring a healthy pregnancy.5

Final thoughts:

For women aiming for a healthy pregnancy, determining your Rh factor before conception is crucial. If you are Rh-negative, your doctor can administer Rh immunoglobulin to protect your baby and prevent complications. Early testing and timely medical care are key to ensuring a safe pregnancy. This blog serves as a reminder for all women to understand the importance of the Rh factor. If you are planning to conceive, get tested early and give your baby the best possible start.

Frequently Asked Questions

1. Who is at risk for Rh incompatibility?

Rh incompatibility can occur if an Rh-negative mother is carrying an Rh-positive baby. This typically happens when the baby inherits the Rh-positive blood type from the father. If the mother has never been exposed to Rh-positive blood before, her immune system may react to the baby’s red blood cells, which can lead to complications in future pregnancies.3

2. Does Rh incompatibility affect a pregnant person?

Rh incompatibility itself does not harm the pregnant person, as their body does not rely on the Rh factor. However, if their immune system starts producing antibodies against the baby’s Rh-positive blood cells, it can pose risks for future pregnancies. This condition, called Rh sensitization, can be prevented with a simple Rh immunoglobulin (RhIg) shot at key stages of pregnancy and after delivery.1

3. What are the symptoms of Rh incompatibility?

Rh incompatibility doesn’t usually cause noticeable symptoms for the pregnant individual. However, if the baby is affected, symptoms may appear after birth, including jaundice (yellowing of the skin and eyes) and low muscle tone.6 

4. Can a baby inherit the Rh factor?

Yes, a baby’s Rh factor is inherited from parents. If one parent is Rh-positive and the other is Rh-negative, there’s a chance the baby could be Rh-positive. Since Rh factor is a genetic trait, doctors recommend early blood testing to determine potential risks and take necessary precautions to ensure a safe pregnancy.5