Estriol - wikipedia Estriol This article is about estriol as a hormone. For its use as a medication, see Estriol ( medication ). Estriol Names IUPAC name ( 8R, 9S, 13S, 14S, 16R, 17R ) - 13 - methyl - 6, 7, 8, 9, 11, 12, 14, 15, 16, 17 - decahydrocyclopenta ( a ) phenanthrene - 3, 16, 17 - triol Other names Oestriol ; E3 ; Estratriol ; Theelol ; Trihydroxyestrin ; Trihydroxyoestrin ; 16α - Hydroxyestradiol ; Estra - 1, 3, 5 ( 10 ) - triene - 3, 16α, 17β - triol Identifiers CAS Number 50 - 27 - 1 1306 - 04 - 3 3D model ( JSmol ) Interactive image ChEBI CHEBI : 27974 ChEMBL ChEMBL193482 ChemSpider 5553 ECHA InfoCard 100.000. 021 KEGG C05141 PubChem CID 5756 UNII FB33469R8E InChI InChI = 1S / C18H24O3 / c1 - 18 - 7 - 6 - 13 - 12 - 5 - 3 - 11 ( 19 ) 8 - 10 ( 12 ) 2 - 4 - 14 ( 13 ) 15 ( 18 ) 9 - 16 ( 20 ) 17 ( 18 ) 21 / h3, 5, 8, 13 - 17, 19 - 21H, 2, 4, 6 - 7, 9H2, 1H3 / t13 -, 14 -, 15 +, 16 -, 17 +, 18 + / m1 / s1 Key : PROQIPRRNZUXQM - ZXXIGWHRSA - N SMILES C ( C @ ) 12CC ( C@H ) 3 ( C@H ) ( ( C @ @ H ) 1C ( C@H ) ( ( C @ @ H ) 2O ) O ) CCC4 = C3C = CC ( = C4 ) O Properties Chemical formula Molar mass 288.387 g / mol Except where otherwise noted, data are given for materials in their standard state ( at 25 ° C ( 77 ° F ), 100 kPa ). Infobox references Estriol ( E3 ), also spelled oestriol, is a steroid, a weak estrogen, and a minor female sex hormone. It is one of three major endogenous estrogens, the others being estradiol and estrone. Levels of estriol in women who are not pregnant are almost undetectable. However, during pregnancy, estriol is synthesized in very high quantities by the placenta and is the most produced estrogen in the body by far, although circulating levels of estriol are similar to those of other estrogens due to a relatively high rate of metabolism and excretion. Relative to estradiol, both estriol and estrone have far weaker activity as estrogens. In addition to its role as a natural hormone, estriol is used as a medication, for instance in menopausal hormone therapy ; for information on estriol as a medication, see the estriol ( medication ) article. Contents 1 Biological activity 2 Biochemistry 2.1 Biosynthesis 2.1. 1 In non-pregnant women 2.1. 2 In pregnant women 2.2 Distribution 2.3 Metabolism 2.4 Excretion 3 Medical use 4 Chemistry 5 History 6 Use in screening 7 References 8 Further reading Biological activity Estriol is an estrogen, specifically an agonist of the estrogen receptors ERα and ERβ. It is a far less potent estrogen than is estradiol, and as such is a relatively weak estrogen. According to one in vitro study, the relative binding affinity ( RBA ) of estriol for the human ERα and ERβ was 11.3 % and 17.6 % of that estradiol, respectively, and the relative transactivational capacity of estriol at the ERα and ERβ was 10.6 % and 16.6 % of that of estradiol, respectively. According to another in vitro study however, the RBA of estriol for the ERα and ERβ were 14 % and 21 % of those of estradiol, respectively, suggesting that unlike estradiol and estrone, estriol may have preferential affinity for ERβ. Although estriol is an efficacious agonist of the ERs, it is reported to have mixed agonist -- antagonist ( partial agonist ) activity at the ER ; on its own, it is weakly estrogenic, but in the presence estradiol, it is antiestrogenic. Relative to estradiol, the estrogenic potency of estriol and estrone have been reported to be 80 - and 12-fold lower than that of estradiol, respectively. It is notable that unlike estriol, estrone can be metabolized into estradiol, and most of its potency in vivo is in fact actually due to conversion into estradiol. In addition to acting as an agonist of the nuclear ERs, estriol also acts as an antagonist of the GPER at high concentrations, a membrane estrogen receptor where, conversely, estradiol acts as an agonist. Estradiol increases breast cancer cell growth via activation of the GPER ( in addition to the ER ), and estriol has been found to inhibit estradiol - induced proliferation of triple - negative breast cancer cells through blockade of the GPER. Biochemistry Human steroidogenesis, showing estriol at bottom right. In essence, it follows the pathway from dehydroepiandrosterone or DHEA ( at left ), but with a modified DHEA with an additional OH - group. Biosynthesis In non-pregnant women In women who are not pregnant estriol is produced in only very small quantities, and circulating levels are in fact barely detectable. Unlike estradiol and estrone, estriol is not synthesized in or secreted from the ovaries, and is instead derived mainly if not exclusively from 16α - hydroxylation of estradiol and estrone by cytochrome P450 enzymes ( e.g., CYP3A4 ) mainly in the liver. Estriol is cleared from the circulation rapidly in non-pregnant women, and so circulating levels are very low, but concentrations of estriol in the urine are relatively high. Although circulating levels of estriol are very low outside of pregnancy, parous women have been found to have levels of estriol that are to some degree higher than those of nulliparous women. In pregnant women Estriol is produced in quantities that are notable only during pregnancy. Levels of estriol increase 1,000-fold during pregnancy, whereas levels of estradiol and estrone increase 100-fold, and estriol accounts for 90 % of the estrogens in the urine of pregnant women. At term, the daily production of estriol by the placenta is 35 to 45 mg, and levels in the maternal circulation are 8 to 13 ng / dL. The placenta produces pregnenolone and progesterone from circulating cholesterol. Pregnenolone is taken up by the fetal adrenal glands and converted into dehydroepiandrosterone ( DHEA ), which is then sulfated by steroid sulfotransferase into dehydroepiandrosterone sulfate ( DHEA - S ). DHEA - S is hydroxylated by high CYP3A7 expression and activity into 16α - hydroxy - DHEA - S ( 16α - OH - DHEA - S ) in the fetal liver and to a limited extent in the fetal adrenal glands. 16α - OH - DHEA - S is then taken up by the placenta. Due to high expression of steroid sulfatase in the placenta, 16α - OH - DHEA - S is rapidly cleaved into 16α - OH - DHEA. Then, 16α - OH - DHEA is converted by 3β - hydroxysteroid dehydrogenase type I ( 3β - HSD1 ) into 16α - hydroxyandrostenedione ( 16α - OH - A4 ) and 16α - OH - A4 is converted by aromatase into 16α - hydroxyestrone ( 16α - OH - E1 ), which is subsequently converted into estriol by 17β - hydroxysteroid dehydrogenase and then secreted predominantly into the maternal circulation. Approximately 90 % of precursors in estriol formation originate from the fetus. During pregnancy, 90 to 95 % of estriol in the maternal circulation is conjugated in the form of estriol glucuronide and estriol sulfate, and levels of unconjugated estriol are slightly less than those of unconjugated estradiol and similar to those of unconjugated estrone. As such, target tissues are likely to be exposed to similar amounts of free estriol, estradiol, and estrone during pregnancy. Estrone and estradiol are also produced in the placenta during pregnancy. However, in the case of estrone and estradiol, DHEA - S is taken up by the placenta and cleaved by steroid sulfatase into dehydroepiandrosterone ( DHEA ), DHEA is converted by 3β - hydroxysteroid dehydrogenase type I into androstenedione, and androstenedione is aromatized into estrone. Then, placental 17β - hydroxysteroid dehydrogenase interconverts estrone and estradiol and the two hormones are secreted into the maternal circulation. DHEA - S that is taken up by the placenta is mainly produced by the fetal adrenal glands. Distribution Estriol is poorly bound to sex hormone - binding globulin ( SHBG ), with much lower binding affinity for this protein, relative to estradiol, and hence a greater fraction available for biological activity. Metabolism Estriol is metabolized via glucuronidation and sulfation. Excretion The main urinary metabolites of exogenous estriol administered via intravenous injection in baboons have been found to be estriol 16α - glucuronide ( 65.8 % ), estriol 3 - glucuronide ( 14.2 % ), estriol 3 - sulfate ( 13.4 % ), and estriol 3 - sulfate 16α - glucuronide ( 5.1 % ). The metabolism and excretion of estriol in these animals closely resembled that which has been observed in humans. Medical use Main article : Estriol ( medication ) Estriol is used as a medication, primarily in hormone therapy for menopausal symptoms. Chemistry See also : List of estrogens Chemical structures of major endogenous estrogens, including estrone ( E1 ), estradiol ( E2 ), estriol ( E3 ), and estetrol ( E4 ). Estriol, also known as 16α - hydroxyestradiol or as estra - 1, 3, 5 ( 10 ) - triene - 3, 16α, 17β - triol, is a naturally occurring estrane steroid with double bonds between the C1 and C2, C3 and C4, and C5 and C10 positions and hydroxyl groups at the C3, C16α, and C17β positions. The name estriol and the abbreviation E3 were derived from the chemical terms estrin ( estra - 1, 3, 5 ( 10 ) - triene ) and triol ( three hydroxyl groups ). History Estriol was discovered in 1930. It was isolated and purified from the urine of pregnant women by Marrian and colleagues. Use in screening Estriol can be measured in maternal blood or urine and can be used as a marker of fetal health and well - being. If levels of unconjugated estriol ( uE3 or free estriol ) are abnormally low in a pregnant woman, this may indicate chromosomal or congenital anomalies like Down syndrome or Edward 's syndrome. It is included as part of the triple test and quadruple test for antenatal screening for fetal anomalies. Because many pathological conditions in a pregnant woman can cause deviations in estriol levels, these screenings are often seen as less definitive of fetal - placental health than a nonstress test. Conditions which can create false positives and false negatives in estriol testing for fetal distress include preeclampsia, anemia, and impaired kidney function. References ^ Jump up to : Kuhl H ( August 2005 ). `` Pharmacology of estrogens and progestogens : influence of different routes of administration ''. Climacteric. 8 Suppl 1 : 3 -- 63. doi : 10.1080 / 13697130500148875. PMID 16112947. Jump up ^ Puri ( 1 January 2005 ). Textbook Of Biochemistry. Elsevier India. pp. 793 --. ISBN 978 - 81 - 8147 - 844 - 3. ^ Jump up to : Strauss JF, Barbieri RL ( 13 September 2013 ). Yen and Jaffe 's Reproductive Endocrinology. Elsevier Health Sciences. pp. 256 --. ISBN 978 - 1 - 4557 - 2758 - 2. ^ Jump up to : H. Maurice Goodman ( 14 March 2003 ). Basic Medical Endocrinology. Academic Press. pp. 436 --. ISBN 978 - 0 - 08 - 048836 - 3. ^ Jump up to : Roger Smith ( Prof. ) ( 1 January 2001 ). The Endocrinology of Parturition : Basic Science and Clinical Application. Karger Medical and Scientific Publishers. pp. 89 --. ISBN 978 - 3 - 8055 - 7195 - 1. ^ Jump up to : Jaouen G, Salmain M ( 20 April 2015 ). Bioorganometallic Chemistry : Applications in Drug Discovery, Biocatalysis, and Imaging. John Wiley & Sons. pp. 45 --. ISBN 978 - 3 - 527 - 33527 - 5. ^ Jump up to : Escande A, Pillon A, Servant N, Cravedi JP, Larrea F, Muhn P, Nicolas JC, Cavaillès V, Balaguer P ( May 2006 ). `` Evaluation of ligand selectivity using reporter cell lines stably expressing estrogen receptor alpha or beta ''. Biochemical Pharmacology. 71 ( 10 ) : 1459 -- 69. doi : 10.1016 / j. bcp. 2006.02. 002. PMID 16554039. ^ Jump up to : Lappano R, Rosano C, De Marco P, De Francesco EM, Pezzi V, Maggiolini M ( May 2010 ). `` Estriol acts as a GPR30 antagonist in estrogen receptor - negative breast cancer cells ''. Molecular and Cellular Endocrinology. 320 ( 1 - 2 ) : 162 -- 70. doi : 10.1016 / j. mce. 2010.02. 006. PMID 20138962. ^ Jump up to : Kenneth L. Becker ( 2001 ). Principles and Practice of Endocrinology and Metabolism. Lippincott Williams & Wilkins. pp. 932, 1061. ISBN 978 - 0 - 7817 - 1750 - 2. Jump up ^ Rubanyi GM, Kauffman R ( 2 September 2003 ). Estrogen and the Vessel Wall. CRC Press. pp. 8 --. ISBN 978 - 0 - 203 - 30393 - 1. ^ Jump up to : Susan Blackburn ( 14 April 2014 ). Maternal, Fetal, & Neonatal Physiology. Elsevier Health Sciences. pp. 39, 93. ISBN 978 - 0 - 323 - 29296 - 2. ^ Jump up to : Girgert R, Emons G, Gründker C ( December 2014 ). `` Inhibition of GPR30 by estriol prevents growth stimulation of triple - negative breast cancer cells by 17β - estradiol ''. BMC Cancer. 14 ( 1 ) : 935. doi : 10.1186 / 1471 - 2407 - 14 - 935. PMID 25496649. Jump up ^ Häggström M, Richfield D ( 2014 ), `` Diagram of the pathways of human steroidogenesis '', WikiJournal of Medicine, 1 ( 1 ), doi : 10.15347 / wjm / 2014.005, ISSN 2002 - 4436 Jump up ^ Medical Disorders in Pregnancy - An Update. Jaypee Brothers Publishers. 2006. pp. 4 --. ISBN 978 - 81 - 8061 - 711 - 9. ^ Jump up to : Henderson BE, Ponder B, Ross RK ( 13 March 2003 ). Hormones, Genes, and Cancer. Oxford University Press. pp. 25 --. ISBN 978 - 0 - 19 - 977158 - 5. Jump up ^ N.S. Assali ( 3 September 2013 ). The Maternal Organism. Elsevier. pp. 341 --. ISBN 978 - 1 - 4832 - 6380 - 9. Jump up ^ Hiroshi Yamazaki ( 23 June 2014 ). Fifty Years of Cytochrome P450 Research. Springer. pp. 385 --. ISBN 978 - 4 - 431 - 54992 - 5. Jump up ^ Vitamins and Hormones. Academic Press. 7 September 2005. pp. 282 --. ISBN 978 - 0 - 08 - 045978 - 3. Jump up ^ H.J. Buchsbaum ( 6 December 2012 ). The Menopause. Springer Science & Business Media. pp. 62 --. ISBN 978 - 1 - 4612 - 5525 - 3. Jump up ^ Lorenzo J, Horowitz M, Choi Y, Takayanagi H, Schett G ( 23 September 2015 ). Osteoimmunology : Interactions of the Immune and Skeletal Systems. Elsevier Science. pp. 216 --. ISBN 978 - 0 - 12 - 800627 - 6. ^ Jump up to : Oettel M, Schillinger E ( 6 December 2012 ). Estrogens and Antiestrogens II : Pharmacology and Clinical Application of Estrogens and Antiestrogen. Springer Science & Business Media. pp. 265 --. ISBN 978 - 3 - 642 - 60107 - 1. ^ Jump up to : Musey PI, Kirdani RY, Bhanalaph T, Sandberg AA ( December 1973 ). `` Estriol metabolism in the baboon : analysis of urinary and biliary metabolites ''. Steroids. 22 ( 6 ) : 795 -- 817. doi : 10.1016 / 0039 - 128X ( 73 ) 90054 - 8. PMID 4203562. Jump up ^ Coelingh Bennink HJ, Holinka CF, Diczfalusy E ( 2008 ). `` Estetrol review : profile and potential clinical applications ''. Climacteric. 11 Suppl 1 : 47 -- 58. doi : 10.1080 / 13697130802073425. PMID 18464023. Jump up ^ J. Elks ( 14 November 2014 ). The Dictionary of Drugs : Chemical Data : Chemical Data, Structures and Bibliographies. Springer. pp. 899 --. ISBN 978 - 1 - 4757 - 2085 - 3. Jump up ^ Index Nominum 2000 : International Drug Directory. Taylor & Francis. January 2000. pp. 407 --. ISBN 978 - 3 - 88763 - 075 - 1. ^ Jump up to : J.B. Josimovich ( 11 November 2013 ). Gynecologic Endocrinology. Springer Science & Business Media. pp. 31 --. ISBN 978 - 1 - 4613 - 2157 - 6. ^ Jump up to : Sartorelli AC, Johns DG ( 27 November 2013 ). Antineoplastic and Immunosuppressive Agents. Springer Science & Business Media. pp. 104 --. ISBN 978 - 3 - 642 - 65806 - 8. Jump up ^ Pagana TJ, Pagana KD ( 2009 ). Mosby 's Manual of Diagnostic and Laboratory Tests. St. Louis : Mosby. p. 240. ISBN 0 - 323 - 05747 - 0. Further reading Merrill RC ( July 1958 ). `` Estriol : a review ''. Physiological Reviews. 38 ( 3 ) : 463 -- 80. doi : 10.1152 / physrev. 1958.38. 3.463. PMID 13567043. Endogenous steroids Precursors Cholesterol 22R - Hydroxycholesterol 20α, 22R - Dihydroxycholesterol Pregnenolone 11β - Hydroxypregnenolone 17α - Hydroxypregnenolone 21 - Hydroxypregnenolone 17α, 21 - Dihydroxypregnenolone 11β, 17α, 21 - Trihydroxypregnenolone Corticosteroids Glucocorticoids 3α, 5α - Tetrahydrocorticosterone 5α - Dihydrocorticosterone 11 - Deoxycorticosterone 11 - Deoxycortisol 11 - Ketoprogesterone 21 - Deoxycortisol 21 - Deoxycortisone Corticosterone Cortisol Cortisone 17α - Hydroxypregnenolone 17α - Hydroxyprogesterone Pregnenolone Progesterone Mineralocorticoids 5α - Dihydroaldosterone 11 - Dehydrocorticosterone ( 11 - oxocorticosterone, 17 - deoxycortisone ) 11 - Deoxycortisol 11 - Deoxycorticosterone 11β - Hydroxyprogesterone ( 21 - deoxycorticosterone ) 18 - Hydroxy - 11 - deoxycorticosterone 18 - Hydroxycorticosterone 18 - Hydroxyprogesterone Aldosterone Corticosterone Cortisol Sex steroids Androgens 11 - Ketodihydrotestosterone 11 - Ketotestosterone 7β - Hydroxyepiandrosterone 11β - Hydroxyandrostenedione Adrenosterone ( 11 - ketoandrostenedione ) Androstenediol Androstenedione Androsterone Dehydroandrosterone DHEA DHEA sulfate Dihydrotestosterone Epiandrosterone Epitestosterone 16α - Hydroxyandrostenedione 16α - Hydroxy - DHEA 16α - Hydroxy - DHEA sulfate Testosterone Metabolites : 3α - Androstanediol 3α - Androstanediol glucuronide 3β - Androstanediol 5β - Dihydrotestosterone 3α - Etiocholanediol 3β - Etiocholanediol Androstanetriols Androstenediol sulfate Androsterone glucuronide Androsterone sulfate Dihydrotestosterone glucuronide Dihydrotestosterone sulfate Etiocholanedione Etiocholanolone Etiocholanolone glucuronide Epietiocholanolone Testosterone glucuronide Testosterone sulfate Estrogens Estranes : Estetrol Estradiol Estrone Estriol 17α - Estradiol 16β - Epiestriol ( 16β - hydroxyestradiol ) 17α - Epiestriol ( 16α - hydroxy - 17α - estradiol ) 16β, 17α - Epiestriol ( 16β - hydroxy - 17α - estradiol ) 2 - Hydroxyestradiol 2 - Hydroxyestriol 2 - Hydroxyestrone 4 - Hydroxyestradiol 4 - Hydroxyestriol 4 - Hydroxyestrone 4 - Methoxyestradiol 16α - Hydroxyestrone Others : 27 - Hydroxycholesterol 3α - Androstanediol 3β - Androstanediol 4 - Androstenedione 5 - Androstenediol DHEA DHEA sulfate 7 - Keto - DHEA 7α - Hydroxy - DHEA 16α - Hydroxy - DHEA Metabolites : 2 - Methoxyestradiol 2 - Methoxyestrone 4 - Methoxyestrone Estradiol glucuronide Estradiol sulfate Estrone glucuronide Estrone sulfate Estriol glucuronide Estriol sulfate Lipoidal estradiol ( e.g., estradiol stearate, estradiol palmitate ) Progestogens Progesterone 16α - Hydroxyprogesterone 17α - Hydroxyprogesterone 20α - Dihydroprogesterone 20β - Dihydroprogesterone 5α - Dihydroprogesterone 11 - Deoxycorticosterone 5α - DHDOC Metabolites : Allopregnanediol Pregnanediol Pregnanediol glucuronide Pregnanetriol Neurosteroids Cholestanes : 24S - Hydroxycholesterol Cholesterol Pregnanes : 3α - Dihydroprogesterone 3β - Dihydroprogesterone 5α - Dihydrocorticosterone 5α - Dihydroprogesterone 5β - Dihydroprogesterone Allopregnanolone Corticosterone DHC DHDOC 11 - Deoxycorticosterone Epipregnanolone Isopregnanolone Pregnanolone Pregnenolone Pregnenolone sulfate Progesterone THB THDOC Androstanes : 3α - Androstanediol 3α - Androstenol 7 - Keto - DHEA 7α - Hydroxy - DHEA 7β - Hydroxy - DHEA 7α - Hydroxyepiandrosterone 7β - Hydroxyepiandrosterone Androsterone DHEA DHEA sulfate Etiocholanolone Pheromones : 3α - Androstenol 3β - Androstenol Androstadienol Androstadienone Androstenone Androsterone Estratetraenol Others Vitamin D: 7 - Dehydrocholesterol Calcidiol / Calcifediol Calcitriol Cholecalciferol Others : 7α - Hydroxycholesterol 11α - Hydroxyprogesterone 11β - Hydroxyprogesterone Cholesterol sulfate Estrogen receptor modulators ER Agonists Steroidal : 2 - Hydroxyestradiol 2 - Hydroxyestrone 3 - Methyl - 19 - methyleneandrosta - 3, 5 - dien - 17β - ol 3α - Androstanediol 3α, 5α - Dihydrolevonorgestrel 3β, 5α - Dihydrolevonorgestrel 3α - Hydroxytibolone 3β - Hydroxytibolone 3β - Androstanediol 4 - Androstenediol 4 - Androstenedione 4 - Hydroxyestradiol 4 - Hydroxyestrone 4 - Methoxyestradiol 4 - Methoxyestrone 5 - Androstenediol 7 - Oxo - DHEA 7α - Hydroxy - DHEA 7α - Methylestradiol 7β - Hydroxyepiandrosterone 8, 9 - Dehydroestradiol 8, 9 - Dehydroestrone 8β - VE2 10β, 17β - Dihydroxyestra - 1, 4 - dien - 3 - one ( DHED ) 16α - Hydroxy - DHEA 16α - Hydroxyestrone 16α - Iodo - E2 16α - LE2 16β, 17α - Epiestriol ( 16β - hydroxy - 17α - estradiol ) 17α - Estradiol ( alfatradiol ) 17α - Dihydroequilenin 17α - Dihydroequilin 17α - Epiestriol ( 16α - hydroxy - 17α - estradiol ) 17β - Dihydroequilenin 17β - Dihydroequilin Abiraterone Abiraterone acetate Alestramustine Almestrone Anabolic steroids ( e.g., testosterone and esters, methyltestosterone, metandienone ( methandrostenolone ), nandrolone and esters, many others ; via estrogenic metabolites ) Atrimustine Bolandiol Bolandiol dipropionate Butolame Clomestrone Cloxestradiol Cloxestradiol acetate Conjugated estrogens Cyclodiol Cyclotriol DHEA DHEA - S Epiestriol ( 16β - epiestriol, 16β - hydroxy - 17β - estradiol ) Epimestrol Equilenin Equilin ERA - 63 ( ORG - 37663 ) Esterified estrogens Estetrol Estradiol Estradiol esters Lipoidal estradiol Polyestradiol phosphate Estramustine Estramustine phosphate Estrapronicate Estrazinol Estriol Estriol esters Estrofurate Estromustine Estrone Estrone esters Estrone methyl ether Estropipate Etamestrol ( eptamestrol ) Ethinylestradiol Ethinylestradiol 3 - benzoate Ethinylestradiol sulfonate Ethinylestriol Ethylestradiol Etynodiol Etynodiol diacetate Hexolame Hippulin Hydroxyestrone diacetate Lynestrenol Mestranol Methylestradiol Moxestrol Mytatrienediol Nilestriol Norethisterone Noretynodrel Orestrate Pentolame Prodiame Prolame Promestriene RU - 16117 Quinestradol Quinestrol Tibolone Nonsteroidal : ( R, R ) - THC ( S, S ) - THC 2, 8 - DHHHC β - LGND1 β - LGND2 ( GTx - 878 ) AC - 186 Allenestrol Allenolic acid Benzestrol Bifluranol Bisdehydrodoisynolic acid Carbestrol D - 15414 DCW234 Diarylpropionitrile Dienestrol Dienestrol diacetate Diethylstilbestrol Diethylstilbestrol esters Dimestrol ( dianisylhexene ) Doisynoestrol ( fenocycline ) Doisynolic acid Efavirenz ERB - 196 ( WAY - 202196 ) Erteberel ( SERBA - 1, LY - 500307 ) Estrobin ( DBE ) Fenestrel FERb 033 Fosfestrol ( diethylstilbestrol diphosphate ) Furostilbestrol ( diethylstilbestrol difuroate ) GTx - 758 Hexestrol Hexestrol esters ICI - 85966 ( Stilbostat ) Mestilbol Methallenestril Methestrol Methestrol dipropionate Paroxypropione Pentafluranol Phenestrol Prinaberel ( ERB - 041, WAY - 202041 ) Propylpyrazoletriol Quadrosilan SC - 4289 SERBA - 2 SKF - 82,958 Terfluranol Triphenylbromoethylene Triphenylchloroethylene Triphenyliodoethylene Triphenylmethylethylene ( triphenylpropene ) WAY - 166818 WAY - 169916 WAY - 200070 WAY - 204688 ( SIM - 688 ) WAY - 214156 Unknown / unsorted : ERB - 26 ERA - 45 ERB - 79 ZK - 283197 Xenoestrogens : Anise - related ( e.g., anethole, anol, dianethole, dianol, photoanethole ) Chalconoids ( e.g., isoliquiritigenin, phloretin, phlorizin ( phloridzin ), wedelolactone ) Coumestans ( e.g., coumestrol, psoralidin ) Flavonoids ( incl. 7, 8 - DHF, 8 - prenylnaringenin, apigenin, baicalein, baicalin, biochanin A, calycosin, catechin, daidzein, daidzin, ECG, EGCG, epicatechin, equol, formononetin, glabrene, glabridin, genistein, genistin, glycitein, kaempferol, liquiritigenin, mirificin, myricetin, naringenin, penduletin, pinocembrin, prunetin, puerarin, quercetin, tectoridin, tectorigenin ) Lavender oil Lignans ( e.g., enterodiol, enterolactone, nyasol ( cis - hinokiresinol ) ) Metalloestrogens ( e.g., cadmium ) Pesticides ( e.g., alternariol, dieldrin, endosulfan, fenarimol, methiocarb, methoxychlor, triclocarban, triclosan ) Phytosteroids ( e.g., digitoxin ( digitalis ), diosgenin, guggulsterone ) Phytosterols ( e.g., β - sitosterol, campesterol, stigmasterol ) Resorcylic acid lactones ( e.g., zearalanone, α - zearalenol, β - zearalenol, zearalenone, zeranol ( α - zearalanol ), taleranol ( teranol, β - zearalanol ) ) Steroid - like ( e.g., deoxymiroestrol, miroestrol ) Stilbenoids ( e.g., resveratrol ) Synthetic xenoestrogens ( e.g., alkylphenols, bisphenols ( e.g., BPA, BPF, BPS ), DDT, parabens, PBBs, PHBA, phthalates, PCBs ) Others ( e.g., agnuside, rotundifuran ) Mixed ( SERMs ) 2 - Phenylbenzofuran 2 - Phenylbenzothiophene 4 ' - Hydroxynorendoxifen 27 - Hydroxycholesterol Acefluranol Acolbifene Afimoxifene Anordiol Anordrin Arzoxifene Bazedoxifene Brilanestrant Broparestrol Elacestrant Chlorotrianisene Clomifene Clomifenoxide Cyclofenil D - 15413 Droloxifene Enclomifene Endoxifen Etacstil ( GW - 5638, DPC - 974 ) Ethamoxytriphetol ( MER - 25 ) Femarelle Fispemifene GW - 7604 ICI - 55548 Idoxifene Lasofoxifene Levormeloxifene LN - 1643 LN - 2299 LY - 117018 Menerba Miproxifene Miproxifene phosphate Nafoxidine Nitromifene NNC 45 - 0095 NNC 45 - 0320 NNC 45 - 0781 NNC 45 - 1506 Ormeloxifene Ospemifene Panomifene Pipendoxifene Promensil Raloxifene Rimostil ( P - 081 ) Spironolactone SS1010 Tamoxifen TAS - 108 ( SR - 16234 ) Toremifene Trioxifene TZE - 5323 Y - 134 Zindoxifene Zuclomifene Antagonists ( R, R ) - THC 7β - Hydroxy - DHEA Chloroindazole Cytestrol acetate EM - 800 Epitiostanol ERA - 90 ERB - 88 Fulvestrant ( ICI - 182780 ) Glyceollins ( I, II, III, IV ) ICI - 164384 Mepitiostane Methylepitiostanol Methylpiperidinopyrazole MIBE Oxabicycloheptene sulfonate Phenytoin PHTPP Prochloraz RU - 58668 SS1020 TAS - 108 ( SR - 16234 ) ZB716 ZK - 164015 ZK - 191703 Coregulator - binding modulators : ERX - 11 GPER Agonists 2 - Methoxyestradiol 7β - Hydroxyepiandrosterone Afimoxifene ( 4 - hydroxytamoxifen ) Atrazine Bisphenol A Daidzein DDT ( p, p ' - DDT, o ', p ' - DDE ) Equol Estradiol Ethinylestradiol Fulvestrant ( ICI - 182780 ) G - 1 Genistein GPER - L1 GPER - L2 Hydroxytyrosol Kepone Niacin Nicotinamide Nonylphenol Oleuropein PCBs ( 2, 2 ', 5 ' - PCB - 4 - OH ) Propylpyrazoletriol Quercetin Raloxifene Resveratrol Tamoxifen Tectoridin Zearalanone Zearalenol Zearalenone Zeranol ( zearalanol ) ) Antagonists CCL18 Estriol G - 15 G - 36 MIBE See also Receptor / signaling modulators Estrogens and antiestrogens Androgen receptor modulators Progesterone receptor modulators List of estrogens Retrieved from `` https://en.wikipedia.org/w/index.php?title=Estriol&oldid=854459303 '' Categories : Estranes Estrogens Hormones of the hypothalamus - pituitary - gonad axis Hormones of the pregnant female Phenols Sex hormones Triols Hidden categories : ECHA InfoCard ID from Wikidata Articles containing unverified chemical infoboxes Chembox image size set All articles with unsourced statements Articles with unsourced statements from October 2016 Talk Contents About Wikipedia تۆرکجه Bosanski Català Čeština Deutsch Español فارسی Français Galego Italiano עברית Magyar Nederlands 日本 語 Polski Português Русский Slovenčina Српски / srpski Srpskohrvatski / српскохрватски Suomi Svenska 中文 14 more Edit links This page was last edited on 11 August 2018, at 14 : 31 ( UTC ). 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Question: decreased estriol levels in pregnancy are associated with
Answer: chromosomal or congenital anomalies like Down syndrome or Edward's syndrome