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Mononuclear Cell Count in Fetal Blood (Manual Differential)

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

This test measures the number of different types of white blood cells (mononuclear cells) in fetal blood, counted manually for detailed analysis. It helps assess fetal health and potential immune or developmental concerns.

Quick summary

["This test provides critical insights into fetal immune function and blood cell health."]

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

Key facts at a glance

LOINC
66148-8
Short code
Mononuc Cells NFr Plr Fetus Manual
Synonyms
Mononuc Cells NFr Plr Fetus Manual
Category
chemistry
Sample
fluid
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
manual-count
CPT
86430
Specimen volume
2-5 mL
Stability
Room temperature: 2h, Refrigerated: 24h
Hemolysis max
300
TAT
4–24 hours
Order
routine

Why This Test Is Done

Doctors may order this test if there are concerns about fetal health, such as suspected infections, immune disorders, or conditions affecting blood cell development. It can also be part of prenatal monitoring for high-risk pregnancies.

What to Expect Before the Test

A small sample of fetal blood is typically taken during a procedure called a cordocentesis, where a needle is inserted through the mother’s abdomen and uterus to collect blood from the umbilical cord. This is usually done in a hospital setting under sterile conditions.

What Happens During the Test

The collected blood sample is analyzed under a microscope by a trained technician to count and identify different types of mononuclear cells (e.g., lymphocytes, monocytes). Manual counting ensures high precision for detailed interpretation.

What the Results Mean

Results may indicate whether the fetal immune system or blood cell production is functioning normally. Abnormal counts could signal potential issues like immune deficiencies, infections, or genetic disorders that may require further medical evaluation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Fetal Blood Cell Count

Frequently asked questions

What does a low or high mononuclear cell count in fetal blood mean?
A low count might suggest immune suppression, infections, or genetic conditions affecting blood cell development. A high count could indicate immune activation, inflammation, or other underlying fetal health concerns that warrant further investigation.
How is this test different from a standard blood count in adults?
This test focuses specifically on mononuclear cells in fetal blood, often using manual differential counting for greater detail. Standard adult blood counts typically include automated analysis of all blood cell types, not specialized fetal assessment.
Is this test painful for the mother or fetus?
The procedure involves a small needle insertion, which may cause mild discomfort for the mother, but the fetus is protected by the amniotic sac. Most mothers report minimal pain, and the test is generally considered safe when performed 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