Maternal health question: do you know your blood type? Did you know that if you’re pregnant, your blood type and the blood type of your unborn baby could affect the health of both parties?
Hemolytic disease of the fetus and newborn (HDFN) is a rare condition that affects 3 to 80 of every 100,000 people each year.1 African-Americans are the second highest ethnic group affected by HDFN.1
HDFN can be managed well with fewer complications if diagnosed early. There are preventative therapies available with early detection.2 This article will go over the types of HDFN, detection, risks, and treatment.
What is Hemolytic disease of the newborn (HDFN)?
Your red blood cells are essential to your blood and your body’s proper function; hemolysis is when your red blood cells are destroyed.2 In HDFN, an unborn baby’s blood type is not compatible with the mother’s blood type. This difference in compatibility leads to the mother’s immune system recognizing the infant’s blood as foreign and destroying the infant’s red blood cells.3-5 Normally, red blood cells last an average of 120 days in the body, but in HDFN, they are destroyed faster and this leads to swelling under the newborn’s skin. If left untreated, HDFN can be fatal to the fetus or newborn.
Causes
If your red blood cells are of a certain type, they have antigens on each cell. Antigens are substances that will cause your body to have an immune response against that substance. If you receive blood of a different type, your body will recognize the antigens on the cells of the new blood as foreign and attack the new blood. It’s the reason that you can only receive your similar blood type if you ever need a blood transfusion.
During pregnancy, the red blood cells from your unborn baby can cross into your blood. If that blood type doesn’t match yours, antibodies in your immune system will attack the antigens on your baby’s red blood cells.5 Antibodies are specific proteins made by your white blood cells in response to an antigen.
Ways that mother/baby blood types can be incompatible 5-6
Blood types A, B, AB, or O can all be positive or negative for the antigen Rh-D (Rhesus).
Who is at risk for HDFN?
If your blood type is Rh-D negative and you become pregnant with an RhD-positive child, you are at risk for HDFN.7 Your child would have inherited the Rh-D antigen from the father.
If you are at risk for HDFN with your first pregnancy, you are at a greater risk for developing HDFN in future pregnancies as long as your blood type is still incompatible with your future baby’s blood type. The antibodies in your immune system will remember the Rh-D negative antigens and attack the baby’s red blood cells faster in the future.
You are also at risk for developing HDFN if your child has an ABO blood type that is incompatible with yours. 15 to 25% of pregnancies are affected by this type of blood incompatibility. If you have blood type O, but your baby has blood type A, B, or AB the anti A, and anti B antibodies in your blood can pass through to your child and attack your baby’s red blood cells.
One study looked at live births from 1996 to 2010 and found that newborns with HDFN were more likely to be female, Black, living in the southern part of the United States, and treated at a government-owned hospital with 100 beds or more.
During your prenatal visit you will be tested to see if your baby is at risk for developing HDFN. It’s important to get prenatal care so you can be tested. If you have HDFN and it goes undiagnosed and untreated, it can lead to serious consequences for you and your baby.8
This video gives a simple explanation of the Rh-D antigen and how it can affect your pregnancy here.
What are the symptoms of HDFN?
HDFN can lead to serious pregnancy complications and symptoms seen in the fetus. Symptoms and complications include:
- Edema, or swelling under the surface of the baby’s skin
- Newborn jaundice (yellow skin) that is more severe than other cases of newborn jaundice
- Slow heart rate
- Anemia, or low blood cell count
- Abnormal metabolism
How is HDFN diagnosed?
HDFN is diagnosed with a blood test. During your first prenatal visit, you should have a screening of your blood system and antibodies. If you are Rh-positive, you won’t need additional testing. If you are Rh-negative, your physician will do an additional test. They will perform an antibody test to determine antibodies on your red blood cells. If you have antibodies named anti-D antibodies on your blood cells it indicates your baby is at risk of HDFN.8
FAQs:
Are all people at risk for HDFN?
HDFN happens when your baby has a blood type that is incompatible with yours. Specifically if you are Rh negative and your baby is Rh positive. During your prenatal visit you will be tested to see if your baby is at risk for developing HDFN. It’s important to get prenatal care so you can be tested.
Is HDFN dangerous?
HDFN can be dangerous to your baby if untreated. The sooner the risk of your baby developing HDFN is detected, there are more options for treatment.
How common is HDFN?
HDFN is considered a rare disease because it only affects 3 to 80 people out of every 100,000. If you are Rh positive, you don’t have to worry about your baby developing HDFN. If you are Rh negative and your baby is Rh positive, then your unborn baby is at risk of HDFN.
Think your newborn may be living with HDFN? We may have an opportunity for you to seek help – contact us at [email protected].
References
1. Delaney M et al. (2015) Hemolytic disease of the fetus and newborn: managing the mother, fetus, and newborn. https://ashpublications.org/hematology/article/2015/1/146/20756/Hemolytic-disease-of-the-fetus-and-newborn
2. Cleveland Clinic (2022) Hemolysis https://my.clevelandclinic.org/health/diseases/24108-hemolysis
3. Myle AK et al. (2021) Hemolytic Disease of the Newborn: A Review of Current Trends and Prospects https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8504549/
4. Yale Medicine (2024) Hemolytic Disease of the Newborn https://www.yalemedicine.org/clinical-keywords/hemolytic-disease-of-the-newborn
5. Medline Plus (2024) Hemolytic disease of the newborn https://medlineplus.gov/ency/article/001298.htm
6. Medline Plus (2024) ABO incompatibility https://medlineplus.gov/ency/article/001306.htm
7. Dean, Laura (2005) Blood Groups and Red Cell Antigens: Hemolytic Disease of the Newborn https://www.ncbi.nlm.nih.gov/books/NBK2266/
8. Hall V et al. (2024) Hemolytic Disease of the Fetus and Newborn http://www.ncbi.nlm.nih.gov/books/NBK557423/
