CORTICAL AND MEDULLARY ADRENAL ACTIVITY IN NORMAL LABOUR

Abstract

Activities of the adrenal cortex and medulla were investigated during and after labor in 16 normal women. Indices of activity were the plasma level of 17-hydroxy-corticosteroids and the urinary excretion of corticosteroids, 17-keto-steroids, pregnandiol and catechol amines. The plasma level of 17-hy-droxycorticosteroids was elevated in the early part of labor, rose to a maximum level at the end of labor and then decreased. The urinary excretion of corticosteroids was normal during the first period but increased to values higher than normal at the end of labor and for a few hours after parturition. There were no significant changes in the other indices during labor. It was concluded that labor and delivery are stress-promoting factors and that the adrenal cortical response in labor is of about the same magnitude as that after a major surgical operation.