A metabolite of Estradiol. It is an estrogenic steroid synthesized exclusively by the fetal liver during human pregnancy and reaching the maternal circulation through the placenta.
Estetrol is an estrogen steroid hormone exclusively produced by fetal liver from estradiol and estriol during pregnancy. It binds to estrogen receptors (ERs) with 4-fold higher affinity for ERα over ERβ and exhibits estrogenic effects in most tissues expressing ERs (bone, brain, vagina, and endometrium). In breast tumors, however, estetrol acts as an estrogen antagonist in the presence of estradiol, preventing tumor growth.
ChEBI: Estetrol is a 3-hydroxy steroid that is 17beta-estradiol which has been substituted at the 15alpha and 16alpha positions by two additional hydroxy groups. It is a natural estrogen produced exclusively during pregnancy by the fetal liver. It has a role as an estrogen, an estrogen receptor agonist, a human metabolite, a human xenobiotic metabolite and an oral contraceptive. It is a 3-hydroxy steroid, a 17beta-hydroxy steroid, a 16alpha-hydroxy steroid, a 15alpha-hydroxy steroid and a steroid hormone. It derives from a hydride of an estrane.
