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Estriol (Total) in Serum or Plasma

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

This test measures the total amount of estriol, a hormone produced during pregnancy, in your blood. It helps assess fetal well-being and placental function.

Quick summary

["Estriol levels can indicate how healthy your baby’s development is and how well the placenta is working."]

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

Key facts at a glance

LOINC
2257-4
Short code
Estrone Smn-mCnc
Synonyms
Estrone Smn-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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

What Is Estriol Used For?

Estriol is most commonly measured during pregnancy to monitor fetal health. Low levels may suggest potential complications, such as reduced placental function or fetal distress. Doctors may also use it in certain prenatal screenings or to evaluate conditions like preeclampsia or intrauterine growth restriction.

How Is This Test Done?

A blood sample is taken from a vein in your arm. The blood is then sent to a lab for analysis using a high-performance liquid chromatography (HPLC) method to measure estriol concentration.

Why Might You Need This Test?

Your healthcare provider may order this test if you're pregnant to check how well your baby is developing or if there are signs of possible complications. It can also be used in non-pregnant individuals under specific medical circumstances, such as hormone-related evaluations.

What Do Results Mean?

Results are not provided with specific reference ranges in this summary. Your doctor will interpret the results in the context of your medical history, symptoms, and overall health. Low or high levels may need further evaluation by a healthcare provider.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Total Estriol

Frequently asked questions

Why do some people need this test?
During pregnancy, estriol levels help assess fetal lung maturity and placental function. Outside pregnancy, it may be used in specialized hormone evaluations or research studies.
What if my results are abnormal?
Abnormal results may prompt additional testing or discussions with your doctor to determine the cause and next steps, such as further prenatal care or medical interventions.
How often is this test repeated?
Frequency depends on medical reasons—such as monitoring pregnancy progress or managing specific health conditions. Your doctor will guide you on timing.
  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