Estradiol-to-Creatinine Ratio, Urine
Measures urine estradiol relative to creatinine, helping assess estrogen status while reducing the effect of differences in urine concentration.
["This urine test helps evaluate estrogen production or excretion, particularly when a spot urine sample is used."]
Key facts at a glance
- LOINC
- 34290-7
- Short code
- u Estradiol/Creat Ur-sRto
- Synonyms
- u Estradiol/Creat Ur-sRto
- Category
- kidney
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Ref low
- 20
- Ref high
- 400
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 82670
- SNOMED
- 300919004
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
What is this test?
This test measures the amount of estradiol in urine compared with the amount of creatinine. Estradiol is a form of estrogen, and dividing by creatinine helps account for how concentrated or dilute the urine sample is.
Why might I need this test?
A clinician may use this test to evaluate estrogen status in children approaching puberty, assess hormonal patterns in adults, or investigate reproductive or fertility concerns. It may also be used to monitor certain hormonal treatments.
How is the test performed?
A urine sample is collected and tested in the laboratory. The laboratory measures estradiol and creatinine and then calculates the estradiol-to-creatinine ratio.
How do I prepare for the test?
Follow the collection instructions provided by the clinic or laboratory, including whether a first-morning spot sample or a timed collection is required. Fasting is usually unnecessary, and medicines or supplements should not be changed unless your clinician advises you to do so.
Reference range
Premenopausal: 20-400 pg/mL; Postmenopausal: <30 pg/mLN/A
For females: inform if menstrual cycle status. For certain tests, timing within menstrual cycle may matter.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
An elevated ratio may reflect increased estrogen production or excretion, while a decreased ratio may reflect lower estrogen levels or other clinical factors. Results can also be influenced by urine concentration, kidney function, medications, and the timing of the collection. The ratio should be interpreted by a clinician together with symptoms, medical history, and other hormone tests.
Short name
Urinary Estradiol/Creatinine Ratio
Frequently asked questions
Is this the same as a serum estradiol test?
Why is the result divided by creatinine?
Do I need to collect urine for a specific number of hours?
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