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Test Code ESTRA Estradiol

Additional Codes

Epic: LAB523

Specimen Required

Collection Container/Tube: Serum SST
Submission Container/Tube: Plastic vial
Specimen Volume: 3.0 mL
Collection Instructions: Centrifuge and separate cells after clot formation and within 4 hours of collection.  Separate serum from gel within 24 hours.

Specimen Minimum Volume

0.5 mL

Specimen Stability

Room temperature: 24 hours
Refrigerated on gel: 24 hours
Refrigerated off gel: 7 days
Frozen: 2 weeks

Reference Range

Normal Menstruating Females:
Follicular Phase 21-251 pg/mL
Mid-Cycle Phase: 38-649 pg/mL
Luteal Phase 21-312 pg/mL 


Postmenopausal Females not on HRT: <10-28 pg/mL


Postmenopausal Females  on HRT: <10-144 pg/mL


Males: 11-44 pg/mL

Rejection Due To

Serum stored on gel >24 hours, unlabeled, mislabeled, wrong tube type, QNS, hemolysis index >500, gross lipemia (trigs >1000 mg/dl).

Report Available

Same day

Clinical Significance

Estradiol is the most potent natural estrogen in humans. It regulates reproductive function in females, and, with progesterone, maintains pregnancy. Most estradiol is secreted by the ovaries (non-pregnant women), although the testes (in men) and adrenal cortex (in men and women) secrete small amounts. During pregnancy, the placenta produces most of the circulating estradiol. Normal estradiol levels are lowest at menses and into the early follicular phase (25-75 pg/mL) and then rise in the late follicular phase to a peak of 200-600 pg/mL just before the LH surge, which is normally followed immediately by ovulation. As LH peaks, estradiol begins to decrease before rising again during the luteal phase (100-300 pg/mL). If conception does not take place, estradiol falls further to its lowest levels, and menses begins shortly thereafter. If conception occurs, estradiol levels continue to rise, reaching levels of 1,000-5,000 pg/mL during the first trimester, 5,000-15,000 pg/mL during second trimester, and 10,000-40,000 pg/mL during third trimester. At menopause, estradiol levels remain low. Because the ovaries produce most estradiol in normal women, estimation of this hormone is sometimes a gauge of ovarian function. In addition, monitoring estradiol levels is important in evaluating amenorrhea, precocious puberty, the onset of menopause, and infertility in men and women. Monitoring estradiol levels is essential during in vitro fertilization, because the timing of recovery of oocytes depends on follicular development, which in turn depends on the estradiol level.

Method Name

Chemiluminescent Micro-particle Immunoassay (CMIA)


If the estradiol results are inconsistent with clinical evidence, additional testing is suggested to confirm the result.
Heterophilic antibodies in human serum can react with reagent immunoglobulins, interfering with in vitro immunoassays.



Specimen Type


Day(s) Performed