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Bilirubin, Neonatal — Mass Concentration

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

This blood test measures bilirubin in newborns to help evaluate jaundice and determine whether additional monitoring or treatment is needed.

Quick summary

["Newborn bilirubin testing helps assess the severity of jaundice and the risk of bilirubin-related complications."]

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

Key facts at a glance

LOINC
47225-8
Short code
Bilirub Amn-Imp
Synonyms
Bilirub Amn-Imp
Category
liver
Sample
fluid
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
2-5 mL
Stability
Room temperature: 2h, Refrigerated: 24h
Hemolysis max
300
TAT
4–24 hours
Order
routine

What is this test?

This test measures the amount of bilirubin in a newborn's blood. Bilirubin is a yellow pigment produced as the body breaks down red blood cells.

Why might I need this test?

Newborns are commonly screened for jaundice, which can cause yellowing of the skin and eyes. Testing helps determine whether bilirubin levels may require closer monitoring, repeat testing, or treatment.

How is the test performed?

A small blood sample is usually collected from the newborn's heel, scalp, or vein. The laboratory measures bilirubin in the sample and reports the result to the newborn's care team.

How do I prepare for the test?

No special preparation is usually needed. The newborn may be gently held while the blood sample is collected, and feeding does not normally need to be stopped.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

A higher-than-expected bilirubin level may indicate newborn jaundice, which is common and often resolves on its own. The care team interprets the result using the newborn's age and other risk factors. Very high levels can pose a risk of brain injury and may require prompt treatment.

Short name

Newborn bilirubin test

Frequently asked questions

What does a bilirubin test measure?
It measures bilirubin, a yellow pigment made during the normal breakdown of red blood cells. In newborns, the test is mainly used to evaluate jaundice.
Does a high bilirubin result always mean the baby is sick?
No. Mild jaundice is common in newborns and often needs only observation. The result must be interpreted with the baby's age, feeding, health history, and other risk factors.
Will my baby need to be admitted or treated?
Some newborns need only repeat testing or close monitoring, while others may need phototherapy or other treatment. The newborn's clinician will explain what the result means and recommend the next step.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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