Response of ovine uterine blood flow to angiotensin II: Effect on the fetus

Abstract

The effect of intravenous infusion of angiotensin II (2 to 200 ng/kg/min) on uterine flow and cardiovascular performance was studied in the normotensive, unenesthetized pregnant owe. With low rates of infusion (2 to 4 ng/kg/min), only a transient increse in uterine blood flow, lasting 1 to 3 minutes, was observed. Higher rates (110 to 200 ng/kg/min) of infusion caused a decrease in uterine blood flow; this decrease was significantly correlated to the dose. Angiotensin II also caused a significant decrease in the maternal heart rate and an increase in mean maternal artificial blood pressure as rate of infusion was increased. A high rate of infusion resulted in decresed fetal heart rate PaO2., probably a marked reduction in uteroplacental blood flow. Am. J. Obstet. Gynecol. 141:495, 1981.)