Estradiol (E2), Urine 17β-Estradiol, Urine

Clinical Significance:
Estradiol is one of the three main Estrogens derived from metabolism of Testosterone and also converted reversibly to Estrone.  Estradiol is the most potent Estrogen.  Estradiol is excreted into the urine in several different conjugated forms and also as unconjugated Estradiol.   This assay measures the total of the conjugated and unconjugated forms of Estradiol.  In postmenopausal women, very little glandular Estradiol is produced.  The levels found usually come from peripheral conversion of Testosterone.  Urinary Estradiol measurement offers a non-invasive method for monitoring ovarian function for such purposes as detection of ovulation.  Urinary Estradiol levels offer an advantage over blood levels when determinations are required over a long period of time and when frequent sampling is required.

Reference Ranges:
Male:                                          Up to 6.0 ug/24 hours
Female:                                      Up to  15 ug/24 hours

Urine Estradiol is measured by EIA/ELISA following hydrolysis and extraction of specimens.

Patient Preparation:
Patient should not be on any Steroid, ACTH, Gonadotropin or Estrogen medications, if possible, for at least 48 hours prior to collection of specimen.  Oral contraceptives and estrogen replacement therapy may influence Estradiol levels.

Specimen Collection:
10 ml of a 24 hour urine collection should be submitted for analysis. No special preservatives are required. Store specimen refrigerated during collection. Specimens should be frozen prior to shipping. Minimum specimen size is 5 ml.

Shipping Instructions:
Ship specimens frozen in dry ice. Provide the total volume per 24 hours.

1. CJ Munro, GH Stabenfeldt, JR Cragun, L A Addiego, JW Overstreet and BL Lasley.  Relationship of Serum Estradiol and Progesterone Concentrations to the Excretion Profiles of Their Major Urinary Profiles as Measured by Enzyme Immunoassay and EIA/ELISA.  Clinical Chemistry 37: 838-844, 1991.

2. AC Speight, KW Hancock, and RE Oakely.  Non-Protein Bound Oestrogens in Plasma and Urinary Excretion of Unconjugated Oestrogens in Non-Pregnant Women.  Journal of Endocrinology 83: 385-391, 1979.