Unconjugated estriol (e3) Test

Estrogens are hormones responsible for sexual and reproductive developinent, especially in women. Estrogens are neemsary for germ cell maturation and in pregnancy. Also, they are linked to glom!), bone metabolism, nervous system maturation and endothelial responsiveness. Unconjugated estriol 1E3) is a biologically active form of estrogen. Unlike other estrogens, estriol isalmost exclusively produced during pregnancy, originating from a precursor synthesized by fetal adrenal glands and then converted to estriol by fetal liver and placenta. Estriol is conjugated to glucuronide in the maternal liver and excreted by the kidneys. Unconjugated estriol constitutes about 10% of the estriol in serum. This concentration rises during pregnancy, especially in the first trimester. Estimation of unoanjugatecl estriol, in conjunction with other hormones, is useful in quantifying fetal risk of developing Down’s syndrome, in the second trimester of pregnarscy.