What Does a Coombs Positive Newborn Test Mean?

Key Takeaways:

• Coombs positivity is an indicator of an incompatibility of blood.
• A positive result is not your fault. You can blame it on genetics.
• It is often mild, but easily treatable.

What is a Coombs Test?

Ever heard of a Coombs’ test and wondered what it’s all about? Let’s have a friendly chat about this test, what it checks for, and why it’s sometimes a part of healthcare discussions.  there are two types of Coombs’ tests:

• The Coombs test, also known as the Direct Antiglobulin Test (DAT), is a blood test performed on newborns shortly after birth. It helps identify whether the baby’s red blood cells are coated with antibodies from the mother. These antibodies could potentially cause anemia and jaundice in the newborn.
• An Indirect Coombs test may have been done during your first trimester of pregnancy to determine if you have antibodies floating around in your blood stream that could potentially cause problems during your pregnancy if you have Rh incompatibility.  Learn More about Rh incompatibility.

Getting a Coombs’ test is like any other blood screening test. A small blood sample is taken, by a heel stick or blood draw, and then it’s sent to the lab for analysis. It’s a quick process, and you usually get the results in a short time frame.

What Does a Positive Direct Coombs Test Mean?

When you receive positive Coombs test results (DAT), it indicates that antibodies from the mother are sticking to the baby’s red blood cells. This can happen for various reasons:

• Rhesus Incompatibility:  If the mother and baby have different Rhesus (Rh) blood types, the mother’s immune system might produce antibodies against the baby’s blood cells.  This is only the case in Rh-negative blood types in mothers and Rh-positive blood in newborns. 
• ABO incompatibility: This is where the mother’s blood type is different from the baby’s, and can also lead to a positive Coombs’ test.

A Coombs’ positive result doesn’t necessarily mean immediate health issues for the baby. However, it alerts healthcare providers that the baby is at higher risk and needs to be monitored for signs of hemolytic disease of the newborn (HDN). HDN occurs when the mother’s antibodies destroy the baby’s red blood cells, potentially causing jaundice, anemia, or other complications.

What Causes a Baby to be Coombs Positive?

Coombs’ positivity happens because your blood cells and your baby’s blood cells are different. This causes your blood cells to see your baby’s blood cells as an intruder or foreign body and begins to fight against your baby’s blood cells. 

Let’s say daddy’s blood group and rhesus factor is A+ while mummy’s blood group and rhesus factor is A-. If the baby inherits daddy’s blood group which is A+, it means that while baby is A+ mummy is A-. There is a difference in the rhesus factor ( which is the plus or minus sign attached to the blood group A, or the presence or absence of a protein on the surface of red blood cells). 

During pregnancy and delivery, some quantity of baby’s blood mixes with mummy’s blood making mummy’s blood wonder where this strange A+ blood is coming from. Mummy’s blood begins making antibodies (rh sensitization).  When the maternal antibodies then come in contact with the baby’s blood they will fight and destroy the baby’s red blood cells causing the baby’s blood to reduce in number (anemia) and increase release of bilirubin causing a yellowish discoloration of baby’s eyes and skin (jaundice).

What are the Symptoms of Coombs Positive Babies?

Common symptoms seen among coomb positive babies include:

• Yellowish eyes and skin: The most noticeable symptom is a yellowish tint to the baby’s skin and the whites of their eyes. This usually starts on the face and then spreads to other parts of the body.
• Tired/fatigued Newborn: Coomb-positive babies might seem more tired or sleepy than usual. They may not be as active or alert as other babies.
• Difficulty Feeding or Sucking: If your baby is Coomb-positive, they might have difficulties with feeding or sucking. It’s important to watch for any changes in their feeding patterns or hunger cues.
• Dark Urine of Pale Stools: Jaundice can sometimes affect the color of a baby’s urine, making it darker. Stools may also appear pale.

How are Coombs Positive Babies Treated?

Treatment of Coombs positive babies involves several approaches depending on the severity and they include:

• Monitoring and Regular Check-ups:  Coombs’ positivity often doesn’t require immediate treatment. Your baby’s healthcare team will monitor their health through regular follow-up care to ensure they’re thriving.  This includes physical examination and sometimes a blood test to check for high bilirubin levels.  
• Addressing Underlying Conditions: Sometimes, Coombs’ positivity is associated with conditions like jaundice. Treating the underlying cause can help manage Coombs’ positivity. In the case of Rh incompatibility, it’s best prevented by giving Rh-negative pregnant women rhesus immunoglobulin, also called Rhogam at 28 weeks gestation and 72 hours within delivery.
• Phototherapy for Jaundice: If jaundice is present, phototherapy is a common treatment for significant jaundice. This involves exposing your baby to special lights that help break down the bilirubin causing the yellowing of the skin.
• Blood Transfusions: In rare and severe cases of severe anemia, if Coombs’ positivity leads to a significant breakdown of red blood cells, your baby might need a blood transfusion. This is done to replace damaged red blood cells with healthy ones.

Many babies with a Coombs’ positive result go on to have healthy lives. With prompt medical attention and advancements in neonatal care, healthcare professionals can effectively manage any complications associated with a positive Coombs’ test.

Final Thoughts

In my experience, telling mothers that their little one was Coombs’ positive evoked feelings of fear and uncertainty – not knowing if their baby will be fine or not.

However, I would like all mothers to remember that being Coombs’ positive is not uncommon and, in many cases, is a manageable condition. The journey ahead may involve close monitoring and possibly some medical interventions, but with the support of healthcare professionals, your little one is in good hands.

Celebrate the joy of parenthood, cherish the precious moments with your little one, and embrace the strength that comes from understanding and facing challenges together. Your baby, Coombs’ positive and all, is a beautiful addition to your family, and the journey ahead is a testament to the resilience and love that defines the adventure of parenthood.