An estrogenic metabolite of estradiol, usually the predominant estrogenic metabolite found in urine (especially during pregnancy); epimers at C-16, C-17, or both, are known as 16-epiestriol, etc. SYN: folliculin hydrate, oestriol, trihydroxyestrin.
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es·tri·ol 'es-.trī-.ȯl, e-'strī-, -.ōl or chiefly Brit oes·tri·ol 'ē-.strī-.ȯl, ē-'strī-, -.ōl n a relatively weak natural estrogenic hormone that is a glycol C18H24O3 found in the body chiefly as a metabolite of estradiol, is the main estrogen secreted by the placenta during pregnancy, and is the estrogen typically found in the urine of pregnant women
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es·tri·ol (esґtre-ol) an oxidation product of estradiol and estrone, having relatively weak estrogenic activity and detectable in high concentrations in the urine, especially human pregnancy urine.Medical dictionary. 2011.