Urinary Estradiol-to-Creatinine Ratio
This urine test measures estradiol relative to creatinine, helping account for differences in urine concentration when evaluating estrogen excretion.
["The ratio provides a creatinine-adjusted measure of urinary estradiol, but results must be interpreted with symptoms, medications, and other tests."]
Key facts at a glance
- LOINC
- 34291-5
- Short code
- Estradiol/Creat Ur-sRto
- Synonyms
- 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, a form of estrogen, in urine relative to the amount of creatinine. Creatinine is used as a reference marker to help account for how concentrated or dilute the urine sample is.
Why might I need this test?
A clinician may order this test to evaluate estrogen production or excretion. It may be used in the assessment of hormonal symptoms, menstrual or reproductive concerns, puberty-related concerns, or monitoring of certain hormonal treatments.
How is the test performed?
A urine specimen is collected and tested in a laboratory to determine the estradiol-to-creatinine ratio. Depending on the order, it may be obtained from a single urine sample or from a timed collection, such as a 24-hour urine collection.
How do I prepare for the test?
Follow the collection instructions provided by the laboratory or clinician. For a 24-hour collection, collect all urine during the specified period, record the start and finish times, and store the container as instructed; otherwise, no special preparation is usually needed.
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.
A higher-than-expected ratio may reflect increased estrogen production, reduced estrogen clearance, medication effects, or conditions that affect hormonal balance. A lower-than-expected ratio may reflect reduced estrogen production, increased metabolism or clearance, or factors related to urine collection. The result should be interpreted with clinical findings and other hormone tests because it does not identify a specific condition by itself.
Short name
Urinary estradiol/creatinine ratio
Frequently asked questions
Is this the same as a blood estradiol test?
Why is creatinine included in the result?
Do I need to collect urine for 24 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