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Absolute Lymphocyte Count in Fetal Blood (Manual Cell Count)

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

This test measures the number of lymphocytes, a type of white blood cell, in fetal blood. It is often performed during prenatal care to assess immune system development or monitor conditions affecting fetal health.

Quick summary

["Lymphocytes help protect the fetus against infections and support immune development."]

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

Key facts at a glance

LOINC
66140-5
Short code
Lymphocytes # Bld Fetus Manual
Synonyms
Lymphocytes # Bld Fetus Manual
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
manual-count
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 Is This Test Done?

Your healthcare provider may order this test if you have concerns about fetal infection, immune system development, or certain prenatal conditions. It can also be part of routine monitoring in high-risk pregnancies.

What to Expect Before the Test

Fetal blood sampling typically occurs during a procedure called cordocentesis. You’ll receive local anesthesia, and a small amount of blood is taken from the umbilical cord. The test is usually done in a hospital setting under close supervision.

How the Results Are Interpreted

Results are compared to reference ranges for fetal age and health status. Low or high lymphocyte counts may signal potential issues, such as infections, genetic disorders, or immune deficiencies.

What Are Common Causes of Abnormal Results?

Abnormal lymphocyte counts in fetal blood may be linked to congenital infections (e.g., cytomegalovirus), chromosomal abnormalities, or immune-related disorders. Always discuss results with your healthcare provider.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Lymphocyte Count (Fetal Blood)

Frequently asked questions

Will I need to prepare for this test?
No special preparation is needed, but you may be asked to fast or avoid certain medications. Follow your healthcare provider’s instructions for the day of the procedure.
How long will it take to get my results?
Results are typically available within a few days, depending on lab processing and fetal monitoring needs. Your provider will contact you with findings promptly.
Can this test be done at home?
No, fetal blood tests like this are performed in a clinical setting, usually during a hospital procedure. Avoid self-testing for safety and accuracy.
  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