Estrogen-Induced Human Luteolysis

Serum estradiol/progesterone ratio on day of embryo transfer may predict reproductive outcome following controlled ovarian hyperstimulation and in vitro fertilization

“…For normal endometrial morphology to occur, an E 2 priming phase is required followed by P. In the pre-GnRH agonist era, the alteration of the E 2 /P ratio was considered a main cause of luteal-phase inadequacy and IVF failure, possibly mediated by the luteolytic action of E 2 [12]. The action of estrogen is required for up-regulation of P receptors.…”

The human corpus luteum: life cycle and function in natural cycles

“…Estrogens inhibit the activity of luteal 3b-HSD by human luteal cells in vitro (61). Other investigators have postulated that the luteolytic action of exogenously administrated E 2 reduces the secretion of pituitary-derived LH in women (62). The reduction of luteal perfusion and other factors produced by the macrophages or leukocytes like reactive oxygen species may contribute to functional and structural luteolysis (48).…”

The role of aromatase inhibitors in ameliorating deleterious effects of ovarian stimulation on outcome of infertility treatment

“…Estrogen is thought to exert a direct luteolytic action in primates as exogenous administration of E 2 reduces progesterone concentrations during the luteal phase [191], probably via inhibiting the enzyme 3 beta-hydroxysteroid dehydrogenase, which is mandatory for progesterone synthesis [192]. Moreover, although the exact mechanism has not yet been established, estrogen may play a role in the regulation of proteins involved in the process of luteal-cell apoptosis [193].…”