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Chest Diameter Measurement (Fetal)

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

This test measures the size of your baby’s chest at birth, which helps healthcare providers assess overall growth and development during pregnancy.

Quick summary

["A fetal chest measurement supports monitoring fetal health and helps identify potential growth concerns."]

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

Key facts at a glance

LOINC
11819-0
Short code
Fet Thorax Diam AP US.meas
Synonyms
Fet Thorax Diam AP US.meas
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
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 recommend this measurement during prenatal ultrasounds to track fetal development, especially if there are concerns about growth restrictions or other pregnancy-related issues. It’s often part of routine fetal monitoring.

How Is the Test Performed?

This test isn’t a blood draw or lab analysis but is conducted during an ultrasound. A technician uses sound waves to measure the circumference of your baby’s chest, typically done between 20 and 32 weeks of gestation.

What Does the Result Mean?

Results are compared to standard fetal growth charts to determine if your baby’s chest size aligns with expected ranges. While individual variations exist, consistently smaller measurements may signal potential growth delays, which can prompt further evaluation.

Common Reasons for Testing

Fetal chest circumference is checked if you have risk factors like chronic conditions (e.g., diabetes, hypertension), previous stillbirths, or if your baby shows signs of slower growth on ultrasound.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Fetal Chest Circumference

Frequently asked questions

Will I feel any discomfort during the test?
No discomfort is expected. You may feel mild pressure or a slight stretching sensation, but it’s temporary and part of the ultrasound process.
How soon will I get my results?
Results are typically reviewed immediately during the ultrasound and shared with your healthcare provider. A full report may take a few days, depending on follow-up needs.
Can I eat or drink before this test?
No special preparation is needed. You can eat and drink normally, as this test doesn’t require fasting or dietary restrictions.
  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