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Chromosomal Aneuploidy Detection (Blood)

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

This test checks for irregular numbers of chromosomes in your blood cells, which may indicate conditions like Down syndrome or other genetic disorders.

Quick summary

["Determines if your cells have an unusual chromosome count that could affect your health."]

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

Key facts at a glance

LOINC
95231-7
Short code
Chromosome aneup Bld/T
Synonyms
Chromosome aneup Bld/T
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
molgen
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Is Done

Doctors may order this test if you’re pregnant and at higher risk for chromosomal issues, or if you have symptoms like developmental delays, heart problems, or other concerns that might suggest genetic abnormalities. It can also be part of prenatal screening or diagnostic testing for certain conditions.

What to Expect Before the Test

You’ll typically have a simple blood draw, similar to other routine blood tests. No special preparation is needed, but inform your healthcare provider about any medications or conditions that might affect results.

How the Test Works

Blood samples are analyzed to examine the chromosomes in your white blood cells. Advanced techniques, such as fluorescence in situ hybridization (FISH) or karyotyping, may be used to detect aneuploidy (abnormal chromosome numbers).

Possible Results and Next Steps

A normal result means your chromosome count appears typical. An abnormal result may require further testing, such as amniocentesis (if pregnant) or additional genetic evaluation to understand the cause.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Chromosomal aneuploidy can cause serious health issues, including developmental disabilities, birth defects, or increased risk of certain cancers. Early detection helps guide treatment plans and supports informed decisions about care.

Short name

Chromosomal Abnormality Screen

Frequently asked questions

What causes chromosomal aneuploidy?
Chromosomal aneuploidy often occurs due to errors during cell division, such as meiosis in reproductive cells or mitosis in somatic cells. Risk factors may include advanced maternal age (in pregnancy), certain genetic syndromes, or exposure to environmental factors.
Is this test covered by insurance?
Coverage depends on your insurance plan, medical necessity, and whether the test is part of a broader diagnostic or screening protocol. Always check with your provider or insurance company for specifics.
Can I get false results?
While rare, false results can occur due to technical errors, sample contamination, or underlying conditions affecting cell division. Your healthcare team will discuss results carefully and may recommend follow-up testing if needed.
  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