On the regulation of fetal and maternal 16 alpha- hydroxydehydroepiandrosterone and its sulfate by cortisol and ACTH in human pregnancy at term.

In studying the mechanisms which govern estriol production in human pregnancy at term, 16 alpha OH-DHEA, 16alpha-OH-DHEA sulfate, and unbound unconjugated cortisol were measured in peripheral venous plasma of 28 healthy women and in cord venous and arterial plasms of their newborn infants at the time of elective cesarean section prior to the onset of labor. In eight cases treated with 150 mg. of cortisol, maternal and cord plasma 16alpha-OH-DHEA and its sulfate were considerably lower than in 10 control cases. Approximately 4 to 8 1/2 hours after injection of 40 I.U. of Depot-ACTH, both of these estriol precursors were also significantly decreased. It is concluded from these experiments that cortisol causes a decrease of estriol mainly by suppressing fetal 16alpha-OH-DS.