The Interplay between Estrogen and Fetal Adrenal Cortex

Figure 3

Representation of how placental estrogen during gestation modulates its own production. Placental estrogen has a positive and a negative feedback mechanism to ensure that physiological levels of estrogen are established. Estrogen produced by the placenta induces a positive feedback mechanism by promoting the conversion of cortisol to its biologically inactive metabolite cortisone through upregulation of 11β-HSD expression. Serum cortisone levels stimulate the fetal pituitary gland to produce ACTH which upregulates DHEA-S production from the fetal adrenal cortical zone and leads to placental estrogen production. In contrast, if placental estrogen concentrations are too high, placental estrogen can inhibit its own production by suppressing the responsiveness of the fetal adrenal zone to ACTH and lowering its production of DHEA-S. This figure has been modified from Albrecht et al. [36].