Uterine Vascular Response to Hemorrhage During Pregnancy

Abstract

In response to maternal hemorrhage, vasoconstriction occurs in the uterine as well as other peripheral vascular beds of the ewe. The net effect of uterine vasoconstriction is a disproportionate decrease in uterine blood flow as compared with changes in maternal blood pressure. During oligemic shock, phenylephrine infusions improve maternal blood pressure without significantly changing uterine blood flow, whereas volume replacement of lost blood improves both parameters simultaneously. Whole blood replacement is most effective in restoring maternal and fetal homeostasis.