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Fetal Spine Length Measurement from T6 to L3

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

This test measures the length of specific vertebrae in your baby’s spine, from the sixth thoracic vertebra (T6) to the third lumbar vertebra (L3). It helps evaluate fetal development during pregnancy.

Quick summary

["This measurement supports early detection of potential spinal abnormalities in your unborn child."]

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

Key facts at a glance

LOINC
33071-2
Short code
Fet Spine Length from T6 to L3 US.meas
Synonyms
Fet Spine Length from T6 to L3 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 This Test Is Done

Your healthcare provider may recommend this test if you have a history of genetic conditions, structural birth defects, or if certain prenatal screening results suggest an increased risk. It can also be part of routine fetal ultrasound monitoring in high-risk pregnancies.

What to Expect During the Procedure

The test is performed as part of a standard ultrasound. You’ll lie on your back, and a gel is applied to your abdomen. A transducer is moved gently over your belly to capture images of your baby’s spine. The procedure is quick and painless.

Fetal Development and Monitoring

This measurement helps track fetal growth and identify any deviations from expected development. Abnormal findings may prompt further testing or closer monitoring to assess risks.

Common Uses and Benefits

Beyond early detection, this test can help guide decisions about prenatal care, such as timing for additional screenings or interventions if needed.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: This measurement is critical for assessing fetal spinal development and identifying potential congenital conditions early. While most fetuses develop normally, abnormal findings may require additional diagnostic evaluation or specialized care.

Short name

Fetal Spine Length Assessment

Frequently asked questions

When might this test be recommended?
Your healthcare provider may suggest this test if you have risk factors like a family history of spinal birth defects, prior miscarriages, or if your prenatal screening results indicate concerns about fetal anatomy.
What does an abnormal result mean?
An abnormal measurement could signal potential developmental issues, but further testing (such as additional ultrasounds or genetic counseling) would be needed to determine the cause and next steps.
Is this test painful for the baby?
No, ultrasounds are safe and do not cause pain to the baby. The procedure is non-invasive and does not involve radiation.
  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