SECRETION RATE OF ALDOSTERONE IN NORMAL PREGNANCY*

Abstract

All of the pregnant subjects studied had increased secretory rates of aldosterone during the third trimester of pregnancy. Our data indicate that the metabolism of aldosterone is not altered in the pregnant as compared with the nonpregnant subject. The increased secretion of aldosterone may be seen as early as week 15 of pregnancy. Wide fluctuations in secretory rate were noted among individual subjects for comparable periods of gestation. Average secretory rates suggested that from weeks 28 to 35 secretion of aldosterone was relatively uniform at about 1000 [mu]g/day. There was a further increase in the secretion from week 36 to term. The data indicate that the secretion of aldosterone in pregnancy is influenced by dietary Na. For diets containing 25 - 225 mEq. Na/day, the aldosterone secreted appears to be inversely related to the ingested Na. For diets containing less than 10 mEq., there is a marked stimulation in the secretion of aldosterone.