Fetal Thoracic Circumference Measured via Overlay (Ultrasound)
This test measures the size of your baby’s chest during pregnancy using ultrasound imaging. It helps monitor fetal growth and development.
["Ultrasound checks fetal chest size to ensure healthy growth."]
Key facts at a glance
- LOINC
- 11989-1
- Short code
- Fet Thorax Circum by ellipse overlay
- Synonyms
- Fet Thorax Circum by ellipse overlay
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- us-measured-ellipse-overlay
- 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 Is This Test Done?
Your healthcare provider may order this test during prenatal ultrasounds to assess fetal growth patterns, detect potential developmental issues, or monitor specific conditions like fetal growth restriction or congenital anomalies. It’s often part of routine check-ups or when additional details about fetal size are needed.
How Is the Test Performed?
You’ll lie on an exam table, and a technician will apply a gel to your abdomen. A transducer (probe) is placed on your skin to send sound waves that create images of your baby’s chest. The technician measures the circumference of the fetal thorax using specialized software that overlays the image.
What Does the Result Mean?
The measurement helps determine if your baby’s chest is growing appropriately. Abnormal results may signal concerns like poor growth, structural issues, or other prenatal conditions, prompting further evaluation. Your provider will discuss findings with you.
What Are Common Reasons for This Test?
Common reasons include routine prenatal ultrasounds, monitoring high-risk pregnancies (e.g., due to maternal health conditions), or evaluating suspected fetal growth problems. It may also be part of a detailed fetal anatomy scan.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Fetal thoracic circumference is a key indicator of fetal health and growth. While it’s often used alongside other measurements (like head circumference or abdominal circumference), it can help identify deviations from expected growth trajectories. Early detection of abnormalities may allow for timely interventions or additional diagnostic testing to address potential concerns.
Short name
Fetal Chest Circumference (Ultrasound)
Frequently asked questions
When might I need this test?
How often will I need this test?
What should I expect during the procedure?
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