Cardiac output distribution and uteroplacental blood flow in the pregnant XXXX : a comparative study.

@entity2175 @entity840 @entity95 @entity742
This study presents data on cardiac output distribution and uterine and placental blood flows in pregnant @entity95 under chronic steady-state conditions. Ten liters and 67 fetuses were studied at 29 days of gestation, by means of radioactive microspheres. Five nonpregnant female animals were also studied for comparison. Mean cardiac outputs were 747.16 +/- 55.7 and 613.80 +/- 63.76 ml/min in the pregnant and nonpregnant states, respectively. In the pregnant animals, uterine and mammary blood flows were 6.7% +/- 0.7% and 5.1% +/- 0.5% of cardiac output, respectively. Within litters, the highest placental blood flows occurred at the ovarian and vaginal ends of the uterine horn. Placental blood flow per gram of fetus was 0.106 +/- 0.008 ml X min-1 X gm-1. A comparison with analogous data in the @entity840 and @entity742 demonstrates that toward the end of pregnancy placental blood flow per gram of fetus is approximately 2.5-times higher in @entity742 than in @entity95 and @entity840 . Expressed as a percentage of cardiac output, near-term uterine blood flow is significantly less in @entity95 than in @entity840 and @entity742 , whereas mammary blood flow is significantly higher. These interspecies differences are related to differences in placental structure, fetal/maternal mass ratio, and @entity2175 at birth.
