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Serum Choriogonadotropin (hCG) by Immunoassay, Quantitative

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

This test measures the amount of human chorionic gonadotropin (hCG) in a blood (serum) sample using an immunoassay method. It is commonly used to detect and monitor pregnancy and to help evaluate certain pregnancy-related and other conditions.

Quick summary

["A quantitative serum hCG test measures the level of the pregnancy hormone hCG in your blood, usually to confirm or monitor pregnancy."]

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

Key facts at a glance

LOINC
45003-1
Short code
C trach IgG Titr Ser IA
Synonyms
C trach IgG Titr Ser IA
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
8
Ref high
61
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
CPT
82977
SNOMED
3110003
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What This Test Measures

Human chorionic gonadotropin (hCG) is a hormone normally produced during pregnancy, beginning shortly after a fertilized egg implants in the uterus. This test measures the amount of hCG in a serum (blood) sample using an immunoassay, a method that uses antibodies to detect and quantify the hormone.

Why the Test Is Ordered

Healthcare providers commonly order a quantitative hCG test to confirm pregnancy, to see whether hCG levels are rising as expected in early pregnancy, or to follow levels after certain treatments or procedures. It may also be used when pregnancy-related complications or unusual hormone production are being evaluated.

How the Sample Is Collected

The test requires a blood draw, usually from a vein in your arm. You generally do not need special preparation, though your provider may give specific instructions if other tests are being done at the same time.

Understanding Your Results

Your result is reported as a numeric level of hCG in the blood. What counts as expected depends on many factors, including whether you are pregnant and how far along you might be. Not all laboratories use the same reference ranges or units, so your result should be interpreted together with your history and other findings by your healthcare provider.

Reference range

Adult males: 8-61 U/L; Adult females: 5-36 U/LN/A

Specimen: serum

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Quantitative serum hCG is valuable for confirming pregnancy and for monitoring how levels change over time, since the pattern of change can provide important information in early pregnancy. It is also used in evaluating suspected ectopic pregnancy, miscarriage, and some pregnancy-related growths, and occasionally in tracking certain tumors that produce hCG. Because interpretation depends on the clinical context and the specific laboratory method used, results should always be reviewed with a healthcare professional.

Short name

Quantitative hCG

Frequently asked questions

Does this test replace a home pregnancy test?
Not necessarily. A home urine test can detect pregnancy, but a quantitative serum hCG test gives a numeric measurement in the blood. Providers often use it when more precise information or monitoring over time is needed.
Do I need to fast before this test?
Typically no fasting is required for hCG testing. However, if other laboratory tests are ordered at the same time, follow any preparation instructions your provider gives you.
Can I interpret the number on my own?
A single hCG value means little without context such as your medical history and, if relevant, the stage of pregnancy. Reference ranges vary between laboratories, so it is best to discuss your result with your healthcare provider.
  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