Aborhbldnb
A blood test performed on newborns to determine their blood type (A, B, AB, or O) and Rh factor (positive or negative), which helps identify potential blood compatibility issues between mother and baby.
{"This test determines your baby's ABO blood type and Rh factor from a small blood sample","It helps doctors check for blood type incompatibility between mother and baby","Results are important for preventing complications like jaundice or anemia in newborns","The test is routine and performed shortly after birth","No special preparation is needed for your newborn"}
Key facts at a glance
- LOINC
- 19057-9
- Short code
- ABO-Rh NB
- Synonyms
- ABO + Rh Bld NB
- Category
- chemistry
- Sample
- whole-blood
- Container
- EDTA tube (lavender/purple top) or cord blood collection tube specifically designed for blood bank testing
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 0–28 years
- Method
- Serological typing using tube agglutination or gel card methodology with anti-A, anti-B, anti-D, and reverse grouping with A1 and B reagent red cells
- CPT
- 86900
- SNOMED
- 366153006
- Specimen volume
- 1-2 mL whole blood minimum; 2-3 mL preferred for adequate testing and repeat testing if needed
- Stability
- Room temperature: 72 hours; Refrigerated (2-8°C): 7-10 days. Do not freeze whole blood specimens.
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 1–24 hours
- Order
- routine
What is this test?
The ABO and Rh group test is a blood test that determines your newborn's blood type and Rh factor. Blood is classified into different types based on the presence or absence of certain markers (antigens) on red blood cells: A, B, AB, or O. The Rh factor is another marker that can be either positive or negative. This test is performed on a small blood sample taken from your baby's heel or umbilical cord shortly after birth.
Why is this test important for my newborn?
Knowing your baby's blood type is important for several reasons. First, it helps identify if there is blood type incompatibility between you and your baby, which can cause jaundice or more serious conditions like hemolytic disease of the newborn. If the mother is Rh-negative and the baby is Rh-positive, special precautions may be needed to prevent complications in future pregnancies. This information also helps healthcare providers prepare for any potential blood transfusions your baby might need.
How is the test performed?
A healthcare professional will collect a small blood sample from your baby's heel (heel stick) or from the umbilical cord immediately after birth. The area is cleaned, and a small prick is made to collect a few drops of blood. This is similar to the routine newborn screening tests. The sample is then sent to the laboratory for analysis. The test is quick, and your baby may cry briefly during the procedure, but there are no long-term effects.
What do the results mean?
Your baby's blood type will be one of: A, B, AB, or O. The Rh factor will be either positive (+) or negative (-). For example, your baby might be A positive or O negative. If the mother is Rh-negative, the baby may be given a special injection called Rh immune globulin (Rhogam) after birth if the baby is Rh-positive, to prevent problems in future pregnancies. Your healthcare provider will discuss the results with you and explain any necessary follow-up steps.
Reference range
Results reported as ABO group (A, B, AB, or O) and Rh type (Rh-positive or Rh-negative). Reference range is not applicable as this is a qualitative test determining blood group phenotype.N/A
No special preparation required. Test may be collected alongside other newborn screening tests. Inform laboratory of recent maternal Rh immunoglobulin (Rhogam) administration as this may affect Rh typing results.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
Is this test painful for my newborn?
What happens if my baby has a different blood type than me?
Will my baby need additional tests after this?
How long does it take to get the results?
Does this test affect breastfeeding?
Sources
- 1
- 2
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy