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Aborhgppnlinfantbld

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

A blood test that determines your baby's blood group (A, B, AB, or O) and Rh factor (positive or negative) to help identify potential health risks.

Quick summary

{"This test identifies your baby's ABO blood type and Rh factor from a blood sample","It helps detect blood type incompatibility between mother and baby, especially Rh factor","Results are important for preventing jaundice and other complications in newborns","The test uses a small blood sample, usually taken from the baby's heel or arm","Knowing the blood type helps healthcare providers plan proper treatment if needed"}

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

Key facts at a glance

LOINC
93941-3
Short code
ABO/Rh Inf
Synonyms
ABO+Rh Gp Pnl infant Bld
Category
chemistry
Sample
serum
Container
Red top serum tube or lavender top EDTA tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
0–2 years
Method
Gel column agglutination or tube agglutination
CPT
86900 (ABO), 86901 (Rh)
SNOMED
30340000
Specimen volume
2-3 mL whole blood (minimum 1 mL for infants)
Stability
Room temperature (20-25°C): 72 hours; Refrigerated (2-8°C): 7 days. Do not freeze. Transport upright.
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
1–4 hours
Order
routine

What is this test?

The ABO and Rh blood type test is a simple blood test that determines two important things about your baby's blood: the ABO blood group (A, B, AB, or O) and the Rh factor (positive or negative). This test is routinely performed on newborns, especially during infancy, to identify potential blood type mismatches between the mother and baby that could cause health problems.

Why is it important for babies?

During pregnancy, if a mother and her baby have different blood types, it can lead to complications. The most serious concern is Rh incompatibility, which occurs when the mother is Rh negative and the baby is Rh positive. This mismatch can cause the mother's immune system to produce antibodies that attack the baby's red blood cells, leading to jaundice, anemia, or in severe cases, more serious health issues. Knowing the baby's blood type helps healthcare providers monitor and manage these risks effectively.

How is the test done?

A healthcare professional will collect a small blood sample from your baby, usually by pricking the heel (heel stick) or inserting a small needle into a vein in the arm. The blood sample is then sent to a laboratory where it is analyzed to determine the ABO group and Rh factor. The test is quick and generally causes only brief discomfort. Results are typically available within a day or two.

What do the results mean?

The test will show your baby's blood type as one of these combinations: A+, A-, B+, B-, AB+, AB-, O+, or O-. If your baby is Rh positive and you are Rh negative, your healthcare provider may recommend additional monitoring or treatments to prevent complications. In some cases, an injection called Rh immune globulin (RhIG) may be given to the mother during pregnancy to prevent Rh sensitization.

Reference range

Blood group phenotypes: A, B, AB, or O with Rh factor positive or negative. Expected antigens: A, B, AB, O; Expected Rh: D positive (Rh+) or D negative (Rh-)N/A

Specimen: serum

No special preparation required. For infants, sample may be collected via heel stick, venipuncture, or from cord blood at birth. Ensure proper identification and labeling of specimen.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

Is this test painful for my baby?
The test involves a small prick on the heel or a tiny needle insertion, which may cause brief discomfort or crying. However, the pain is usually minor and resolves quickly. Healthcare professionals are experienced in making the process as comfortable as possible for infants.
Do I need to prepare my baby for the test?
No special preparation is needed. You can feed your baby normally before the test. Bring comfort items like a favorite blanket or toy to help soothe your baby during and after the blood draw.
What happens if my baby has a different blood type than me?
If there is blood type incompatibility, your healthcare provider will monitor your baby more closely for signs of jaundice or anemia. In cases of Rh incompatibility, additional treatments such as phototherapy for jaundice or, rarely, blood transfusions may be necessary. Early detection allows for proper management.
Will my baby need this test more than once?
Typically, the blood type is determined once and remains the same throughout life. However, if there are concerns about the initial results or if the baby requires a blood transfusion, additional testing may be necessary.
Does blood type affect my baby's health long-term?
Knowing your baby's blood type is mainly important for immediate postnatal care and future pregnancies. While blood type may be associated with certain health tendencies in adults, it does not typically affect long-term health in childhood. The main concern is ensuring proper care in the newborn period if there is incompatibility.
  1. 1
    American Academy of Pediatrics - Newborn Blood Type TestingSource
  2. 2
    May Clinic - Rh IncompatibilitySource
  3. 3
    National Institutes of Health - Blood Types in PregnancySource

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.

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