It is a steroid hormone, a weak estrogen and a minor sex hormone. Levels of estriol in nonpregnant women are mostly not detectable. It controls the symptoms of menopause including flashes, insomnia, vaginal dryness and frequent urinary tract infections. Estriol is also involved in pregnancy. During pregnancy, it becomes the dominant estrogen. The fetal adrenal gland secretes Dehydroepiandrosterone sulphate(DHAS) which is converted into Free E3 in placenta and diffuses into maternal circulation staying in the blood for 20-30 minutes, since the maternal liver quickly conjugates it to make it water soluble for urinary excretion. E3 levels keep increasing in pregnancy peaking up at term.
Interpretation:Decreased second trimester uE3 (Free E3) has been shown to be a marker for Down and Trisomy -18 syndromes. Together with Alphafetoprotein (AFP) and Human Chorionic Gonadothropin (bHCG) and Inhibin A,uE3 is a part of a multiple marker prenatal screening. Low levels of uE3 has also been shown as a sign of pregnancy loss, Semi-Lemli-Opitz syndrome (defect in cholesterol biosynthesis), x-linked ichtiocytosis, placental sulfatase gene disorders, aromatase deficiency (enzyme converting androstenedione to estrone) and primary or secondary adrenal insufficiency.
Sample: Arm vein blood. Nonfasting
Working day: Everyday
Result Time: Next day 6:00 PM
