Hematocrit (Fetal Red Blood Cells) via Automated Analysis
This test measures the proportion of red blood cells in fetal blood, helping assess blood volume and oxygen-carrying capacity in the fetus.
["A key indicator of fetal blood health, often checked during prenatal care or specific medical evaluations."]
Key facts at a glance
- LOINC
- 62241-5
- Short code
- Hct VFr Bld Fetus Auto
- Synonyms
- Hct VFr Bld Fetus Auto
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 36
- Ref high
- 50
- Critical range
- 18 N/A – 60 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- automated-count
- CPT
- 85014
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- 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 anemia, abnormal blood flow, or during high-risk pregnancies. It can also be part of routine monitoring in certain conditions like gestational diabetes or preeclampsia.
How the Test Works
A small blood sample is taken from the mother (or sometimes directly from the fetus via procedures like a cord blood sample). The sample is analyzed using automated technology to determine the hematocrit level in fetal red blood cells.
What to Expect Before the Test
You may need to fast for a short period before the test, depending on the procedure. For maternal blood draws, you’ll typically lie down and may feel a slight pinch. If fetal blood is drawn, it’s usually done under ultrasound guidance and may require sedation.
What the Results Mean
Results are compared to standard ranges for fetal hematocrit. Low levels may suggest anemia or other blood-related issues, while high levels could indicate dehydration or other conditions. Your healthcare provider will discuss findings in the context of your overall health and pregnancy.
Reference range
Adult males: 38-50%; Females: 36-44%N/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Fetal Hematocrit (Auto)
Frequently asked questions
What does a low fetal hematocrit level mean?
What causes high fetal hematocrit levels?
Is this test painful for the fetus?
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 17, 2026. · Read our editorial policy