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Abogroupbldco

Published: August 9, 2026Updated: August 16, 2026

This test determines your baby's blood type (A, B, AB, or O) using blood from the umbilical cord after birth.

Quick summary

{"The test identifies your baby's ABO blood type from cord blood collected after delivery","Knowing the baby's blood type helps healthcare providers monitor for potential blood type incompatibilities","Results are recorded in the baby's medical chart for future reference and healthcare needs","The test is quick, safe, and uses blood that would otherwise be discarded","Results can also be useful for cord blood banking decisions"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
51892-8
Short code
ABO cord
Synonyms
ABO Group BldCo
Category
chemistry
Sample
whole-blood
Container
EDTA tube (purple top) or dedicated blood bank collection tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
0–28 years
Method
Serological hemagglutination (tube, gel column, or automated platform methods)
CPT
86900 (ABO typing), 86901 (Rh typing)
SNOMED
365679008 | ABO blood group (observable entity)
Specimen volume
2-5 mL of whole blood
Stability
Room temperature: 72 hours; Refrigerated (2-8°C): up to 7 days; Do not freeze
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
1–24 hours
Order
routine

What is this test?

The ABO group test determines your baby's blood type using cord blood—the blood that remains in the umbilical cord and placenta after birth. This blood contains the same blood type information as the baby's bloodstream. The test identifies whether the baby's blood is type A, B, AB, or O, which refers to the presence or absence of specific antigens (A and B) on the surface of red blood cells.

How is the test performed?

After your baby is born, the healthcare provider clamps and cuts the umbilical cord as usual. Before or shortly after the placenta is delivered, a small sample of cord blood is collected from the clamped cord using a needle and syringe or by allowing blood to drip into a collection tube. This sample is then sent to the laboratory for analysis. The procedure does not harm the baby or the mother and uses blood that would normally be discarded.

Why is cord blood typing important?

Knowing your baby's blood type is important for several reasons. First, it provides baseline health information that may be needed throughout the child's life. Second, it helps healthcare providers identify any potential blood type incompatibility between mother and baby, which could cause jaundice in newborns. Third, cord blood contains valuable stem cells that can be collected and stored in cord blood banks for potential future medical use. Finally, the blood type information becomes part of the permanent medical record.

What do the results mean?

Blood type is determined by genes inherited from parents. Type A blood has A antigens, type B has B antigens, type AB has both A and B antigens, and type O has neither. Each type can be Rh-positive or Rh-negative, though this specific test focuses on the ABO group. Your healthcare provider will explain your baby's specific blood type and whether any follow-up is needed. In most cases, the results are simply recorded for future reference.

Reference range

Qualitative result: A, B, AB, or O (with Rh factor if ordered). No numeric reference range applies as this is a blood group determination test.N/A

Specimen: whole-blood

No fasting or special preparation required. This test is performed on cord blood collected at the time of delivery.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

Does the test hurt the baby?
No, the test uses cord blood that is collected after the cord has been clamped and cut. It does not involve the baby directly and causes no pain or risk to the newborn.
How long does it take to get results?
Results are typically available within a few hours to a day. The laboratory performs a simple blood typing procedure that involves mixing the cord blood with specific antibodies to determine the blood type.
What if my baby's blood type is different from mine?
It is common and normal for babies to have different blood types than their mothers. This is determined by genetics inherited from both parents. Your healthcare provider will explain any implications if there is a blood type incompatibility that needs monitoring.
Should I consider cord blood banking?
Cord blood contains stem cells that can be used to treat certain diseases. You may want to discuss cord blood banking options with your healthcare provider before delivery. The cord blood ABO type is one of the factors considered in the banking process.
Is this the same as the Rh factor test?
No, this specific test determines the ABO blood type (A, B, AB, or O). The Rh factor (positive or negative) is a separate test, though it is often performed together. Your healthcare provider may discuss Rh status with you separately.
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

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