Estriol, Serum
Also known as: E3, Pregnancy, Estriol, Unconjugated Estriol
Use
Evaluate fetal distress and placental function in the management of patients facing complications such as preëclampsia, fetal growth retardation, diabetes, Rh immunization, choriocarcinoma, and hydatidiform mole. May be elevated in hydrops fetalis in the presence of a dying fetus. May be low in the presence of a living anencephalic fetus.
Special Instructions
The test requires stating weeks of gestation on the test request form. It is typically performed as a serial measurement to observe trends over time.
Limitations
Single estriol values are challenging to interpret as trends in a series of measurements provide more reliable insights. Estriol levels can be low due to placental sulfatase deficiency, high altitude habitation, anemia, severe liver disease, or specific drugs. Levels may increase in multiple pregnancies or with oxytocin. The test is unreliable for patients with renal disease, and its sensitivity and specificity for detecting fetal distress are limited.
Methodology
Immunoassay (Immunochemiluminometric assay (ICMA))
Biomarkers
LOINC Codes
- 2251-7
- 2251-7
Result Turnaround Time
2-4 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.3 mL
Container
Red-top tube or gel-barrier tube
Collection Instructions
If a red-top tube is used, transfer separated serum to a plastic transport tube. All specimens should be drawn at the same time of day to allow comparison of values.
Patient Preparation
Patient usually in third trimester of pregnancy
Storage Instructions
Refrigerate
Causes for Rejection
Plasma specimen
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 14 days |
| Refrigerated | 14 days |
| Frozen | 14 days |