UE3 Normal Reference Range

May 23, 2022 Source: Cainiu Health

Dr. Chen Zhe

Introduction

In Down syndrome screening, UE3 refers to unconjugated estriol, an estrogen produced by the fetal-placental unit during pregnancy. The normal reference range is 0.5–2.0; however, slight variations in test results may occur due to differences in assay reagents used among laboratories. It is recommended that you consult an obstetrician-gynecologist regarding your test results and discuss whether amniocentesis is necessary to assess whether the fetus has Down syndrome.

uE3 (unconjugated estriol) is a highly pregnancy-specific biomarker, rarely detected in non-pregnant individuals or males. It is primarily synthesized by the fetal-placental unit. What, then, is the normal reference range for uE3?

Normal Reference Range for uE3

In Down syndrome screening, uE3 refers to unconjugated estriol—a form of estrogen produced by the placenta during pregnancy. The normal reference range is generally 0.5–2.0 MoM (multiples of the median), though slight variations may occur depending on the specific assay kits used by different laboratories. We recommend consulting an obstetrician-gynecologist to interpret your test results and to discuss whether amniocentesis is warranted to assess fetal risk for Down syndrome. Down syndrome screening primarily measures maternal serum concentrations of alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), and unconjugated estriol (uE3). These values, combined with the mother’s menstrual history, age, and gestational age at blood draw, are used to calculate a risk score for Down syndrome—enabling detection of approximately 80% of affected pregnancies.

Fetal serum uE3 concentration increases progressively with advancing gestational age and is approximately five times higher than maternal serum levels. Maternal serum uE3 begins to rise above non-pregnant baseline levels around gestational weeks 7–9 and continues to increase steadily, peaking near term. In pregnancies affected by Down syndrome, maternal serum uE3 levels average 29% lower than those in unaffected pregnancies. Similarly, amniotic fluid uE3 concentrations in Down syndrome pregnancies are approximately 50% lower than in normal pregnancies.

The optimal timing for Down syndrome screening is between 16 and 18 weeks of gestation, when test accuracy is highest. Pregnant women are strongly encouraged to attend scheduled prenatal visits. We hope this information is helpful. Wishing you a joyful life and good health!

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UE3 Normal Reference Range

UE3 stands for unconjugated estriol, an estrogen produced by the fetal-placental unit during pregnancy. The normal reference range is 0.5–2.0 ng/mL; however, values may vary slightly depending on the assay kit used by different laboratories. It is recommended to consult an obstetrician-gynecologist regarding your test results and to discuss whether amniocentesis is indicated to assess fetal risk for Down syndrome. Fetal serum uE3 concentration increases progressively with advancing gestational age.

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Reference range for normal hCG levels in Down syndrome screening

The reference range for the multiple of the median (MoM) of hCG in the Down syndrome screening test is 0–2.5; values above this threshold warrant special attention. Currently, the Down syndrome screening test measures the concentrations of AFP and β-hCG in maternal blood and, combined with the mother’s age, uses computerized algorithms to precisely calculate the individual risk and probability of carrying a fetus with Down syndrome.

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Reference range for normal values of 75g glucose screening

Under normal circumstances, the 75g glucose screening refers to the 75g oral glucose tolerance test (OGTT). The normal reference ranges are: fasting blood glucose ≤5.6 mmol/L, 1-hour post-glucose load blood glucose ≤10.3 mmol/L, 2-hour blood glucose ≤8.6 mmol/L, and 3-hour blood glucose ≤6.7 mmol/L.