Cardiovascular changes during pregnancy in ewes

Abstract

Serial measure-ments of several cardiovascular functions were carried out on 5 pregnant and 4 nonpregnant ewes. Average values obtained in the pregnant ewes in the last 30 days of pregnancy were: cardiac output, 10.0 l/min, 33% greater than the average 0- to 30-day postpartum value (P < 0.01); heart rate, 108 beats/min, 28% greater than post partum (P 0.02); systolic arterial blood pressure, 87 mm Hg, 16% less than post partum (P < 0.1); diastolic arterial blood pressure, 76 mm Hg, 9% less (NS); blood volume 4.9 liters, 7% greater than post partum (P < 0.05); hemato-crit 30%, same as post partum. These changes were similar to those accompanying human pregnancy except for a smaller increase in blood volume and the absence of "anemia of pregnancy" in sheep.