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Fetal White Blood Cell Count (Manual Differential Count)

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

This test measures the types and numbers of white blood cells in a sample taken from your fetus. It helps assess fetal health and identify potential immune or infection-related concerns.

Quick summary

["A manual fetal white blood cell count can help doctors monitor fetal well-being and detect unusual blood cell patterns early."]

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

Key facts at a glance

LOINC
66145-4
Short code
WBC Other # Bld Fetus Manual
Synonyms
WBC Other # Bld Fetus Manual
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Ref low
4.5
Ref high
11
Critical range
2 N/A – 30 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
manual-count
CPT
85004
SNOMED
900000000000003002
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 they suspect fetal infection, immune disorders, or other conditions affecting fetal blood cells. It’s often used alongside other prenatal tests to guide further care.

What to Expect Before the Test

This test involves a small blood sample collected from your placenta or umbilical cord during a prenatal procedure. The sample is examined under a microscope by a trained technician to count and classify white blood cells manually.

How the Results Are Interpreted

Results are compared to expected ranges for fetal blood cells, though reference intervals can vary by lab. Abnormal counts may signal conditions like fetal infection, immune disorders, or other health concerns that require additional evaluation.

Potential Risks and Considerations

While the procedure itself is generally safe, any invasive prenatal test carries a small risk of complications. Discuss any concerns with your healthcare provider before the test.

Reference range

Adult: 4.5-11.0 x 10^9/LN/A

Specimen: whole-blood

No special preparation required. Stay well hydrated.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Fetal WBC Count

Frequently asked questions

What does a fetal white blood cell count measure?
It measures the types (lymphocytes, neutrophils, etc.) and total number of white blood cells in fetal blood, often to check for infections, immune issues, or other conditions.
How is this test different from a standard blood test?
This test specifically targets fetal blood cells and uses manual microscopy to count and classify them, rather than automated methods for adult blood tests.
Can this test be done at home?
No, this test requires a medical procedure (like a cordocentesis) and is performed in a clinic or hospital setting by trained professionals.
  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