Distribution of cardiac output in ovine pregnancy.
Cardiac output and organ blood flows were measured in 6 nonpregnant and 24 pregnant ewes from 38 to 141 days of gestation employing radionuclide-labeled microspheres. From the nonpregnant state to term increases in cardiac output, from 73.7 +/- 4.6 ml/min-kg of maternal weight to 148 +/- 2.4 ml/min-kg, and heart rate, from 88.5 +/- 10.3 to 106 +/- 4.6 beats/min, were noted, while mean arterial blood pressure was unchanged. Near term, the blood flows to the uterus and mammary gland represented approximately 18% of cardiac output. The blood flow to nonreproductive organs increased from 76.6 +/- 6.8 ml/min-kg of nonreproductive tissue in the nonpregnant state to 132 +/- 3.5 ml/min-kg at 130-140 days' gestation (P less than 0.01). No significant changes in renal blood flow were detected.
D000818:Animals; D001794:Blood Pressure; D002302:Cardiac Output; D005260:Female; D006339:Heart Rate; D008321:Mammary Glands, Animal / Q000098:blood supply; D011247:Pregnancy; D011270:Pregnancy, Animal; D012039:Regional Blood Flow; D012756:Sheep; D014599:Uterus / Q000098:blood supply