Free estriol (E3) is one of the three main naturally occurring estrogens and is primarily produced during pregnancy by the placenta through the metabolism of fetal adrenal and liver precursors. Unlike estradiol and estrone, free estriol circulates largely unbound to proteins, making it more readily available for biological activity. It plays a critical role in maintaining pregnancy and fetal development by supporting uteroplacental blood flow and preparing the body for labor. Because free estriol levels increase significantly throughout gestation, it serves as a dynamic marker of fetal and placental health.
In clinical and research settings, free estriol is commonly used as a biomarker in prenatal screening tests to assess fetal well-being and detect potential complications such as chromosomal abnormalities (e.g., Down syndrome), placental insufficiency, or fetal distress. Low levels of free estriol in maternal serum may indicate risks of adverse pregnancy outcomes, including intrauterine growth restriction or preterm labor. Additionally, free estriol measurement is valuable in monitoring pregnancies at risk and evaluating the function of the fetoplacental unit, making it a vital tool in obstetric care and research on fetal development.
This product is manufactured in USA by Eagle Biosciences.
| Size | 1 x 96 Well |
| Sensitivity | 0.058 ng/mL |
| Dynamic Range | 0.05 – 30 ng/mL |
| Incubation Time | 1 hour 20 minutes |
| Sample Type | Serum |
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| Storage | 2-8°C |
| Alternative Names | unconjugated estriol, uE3, 16 α-hydroxyestradiol, estrol, esriol |
| Instructions For Use | |
| MSDS | https://eaglebio.com/wp-content/uploads/2014/06/EagleBio-SDS-ELISA-v6.0-718.pdf |