White Blood Cell Differential (Fetal Autoimmune Hemolytic Anemia Screen)
This test measures the types and proportions of white blood cells in your baby’s blood, sometimes performed to check for autoimmune conditions that could affect fetal health.
["Assesses fetal immune response and blood cell composition for potential autoimmune risks."]
Key facts at a glance
- LOINC
- 62251-4
- Short code
- WBC # Plr Fetus Auto
- Synonyms
- WBC # Plr Fetus Auto
- Category
- chemistry
- Sample
- fluid
- Container
- Sterile tube
- 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
- automated-count
- CPT
- 85004
- SNOMED
- 900000000000003002
- Specimen volume
- 2-5 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h
- Hemolysis max
- 300
- TAT
- 4–24 hours
- Order
- routine
What This Test Measures
The test evaluates the percentage of different white blood cell types (neutrophils, lymphocytes, monocytes, eosinophils, and basophils) in fetal blood. It may also include a qualitative assessment of red blood cell destruction (autoimmune hemolysis) using specific markers.
Why It’s Done
This screening may be recommended if you have autoimmune conditions (e.g., lupus, rheumatoid arthritis) or if your baby is at risk for conditions like autoimmune hemolytic anemia, which can impact fetal development.
Sample Collection and Process
A small blood sample is taken from your baby during a procedure like a fetal blood sampling (cordocentesis) or sometimes from a prenatal test like amniocentesis. The sample is analyzed to count and identify white blood cell types and check for signs of red blood cell destruction.
What the Results Mean
Abnormal results may indicate an immune response affecting fetal blood cells, which could require further monitoring or specialized care. Normal results suggest no immediate concerns for the tested parameters.
Reference range
Adult: 4.5-11.0 x 10^9/LN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
WBC Differential (Autoimmune Hemolysis Screen)
Frequently asked questions
If your doctor suspects autoimmune conditions or fetal complications, this test helps determine whether fetal white blood cell counts or red blood cell destruction are abnormal. It may guide decisions about additional testing or interventions.
A high or low count could signal an immune response or other fetal health concerns, but results are interpreted in the context of your medical history and overall pregnancy. Your healthcare provider will discuss findings with you.
No, this test focuses specifically on white blood cell types and red blood cell destruction markers. Other autoimmune diseases may require additional tests.
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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