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Estriol Unconjugated (uE3) Unit Converter
Estriol (E3) is one of the three main estrogens produced by the human body. During pregnancy, it is the dominant estrogen, synthesized in large quantities by the placenta from precursors produced by the fetal adrenal glands and liver. Because its production depends on the interplay between the fetus and the placenta, circulating levels of unconjugated estriol (uE3) serve as a marker of fetoplacental health.
Clinically, uE3 is a key component of the **second-trimester maternal serum screen** (triple or quad screen) used to assess the risk of fetal chromosomal abnormalities. Low levels of uE3 are associated with Down syndrome (Trisomy 21) and Edwards syndrome (Trisomy 18). This converter facilitates accurate switching between the standard mass unit (ng/mL) and the SI molar unit (nmol/L).
SI Units
RecommendedNanomoles per liter (Standard International).
Conventional Units
Clinical Context
Reference Values: uE3 levels rise steadily throughout pregnancy. Typical median values are:
• 15 Weeks: ≈1.5 ng/mL
• 18 Weeks: ≈3.0 ng/mL
• 20 Weeks: ≈4.5 ng/mL
In screening, results are converted to **Multiples of the Median (MoM)** to correct for gestational age, maternal weight, and other factors. An MoM < 0.7 is generally considered low. Extremely low levels (< 0.25 MoM) are highly specific for steroid sulfatase deficiency or Smith-Lemli-Opitz syndrome. The conversion factor relies on MW 288.38 g/mol: 1 ng/mL ≈ 3.47 nmol/L.
Clinical References
How to Use This Calculator
Follow these steps to get accurate clinical conversions instantly.
Enter Values
Input your laboratory results into the corresponding unit field (e.g., pg/mL). You can use either dot or comma decimals.
Automatic Conversion
The calculator works in real-time. As you type in one field, all other units (like pmol/L) are instantly updated.
Verify Units
Check the SI Units section. pmol/L is the standard unit for reproductive hormones in most of the world.
Reset
Use the Clear button to reset all fields before starting a new calculation.
Frequently Asked Questions & Tips
Yes. 1 pg/mL is exactly equal to 1 ng/L.
SI units (pmol/L) are used in most international guidelines for IVF and menopause management.