Abstract
Plasma epinephrine and norepinephrine were measured throughout pregnancy in an ambulatory population of normal and untreated chronically hypertensive pregnant women. There was no significant difference between trimesters for plasma epinephrine, norepinephrine, or the ratio epinephrine/norepinephrine in either the normal or chronically hypertensive group. In the first trimester of pregnancy, women with chronic hypertension demonstrated a significantly higher plasma norepinephrine and a significantly lower epinephrine/ norepinephrine ratio than normal women.