OBJECTIVES: Our objectives were to describe the maternal and fetal hemodynamic impact of a 1 U acute blood loss during pregnancy and to compare the hemodynamic responses of pregnant women with those of nonpregnant controls. STUDY DESIGN: With Doppler techniques cardiac output and total peripheral vascular resistance were determined in 16 pregnant women in the third trimester and in 16 nonpregnant volunteers before and during orthostatic stress, before and after donation of 450 ml of whole blood. In pregnant women the fetal umbilical artery systolic/diastolic ratio was also determined. Data were subjected to multiple logistic regression analysis. RESULTS: In both groups orthostasis provoked significant decreases in cardiac output and increases in total peripheral vascular resistance. The hemodynamic effects of blood loss were less pronounced and did not significantly change the hemodynamic response to orthostasis in either group. Neither orthostasis nor blood loss caused significant changes in the umbilical systolic/diastolic ratio. CONCLUSION: These data support the hemodynamic safety of uncomplicated autologous blood donation during late pregnancy.
OBJECTIVES: Our objectives were to describe the maternal and fetal hemodynamic impact of a 1 U acute blood loss during pregnancy and to compare the hemodynamic responses of pregnant women with those of nonpregnant controls. STUDY DESIGN: With Doppler techniques cardiac output and total peripheral vascular resistance were determined in 16 pregnant women in the third trimester and in 16 nonpregnant volunteers before and during orthostatic stress, before and after donation of 450 ml of whole blood. In pregnant women the fetal umbilical artery systolic/diastolic ratio was also determined. Data were subjected to multiple logistic regression analysis. RESULTS: In both groups orthostasis provoked significant decreases in cardiac output and increases in total peripheral vascular resistance. The hemodynamic effects of blood loss were less pronounced and did not significantly change the hemodynamic response to orthostasis in either group. Neither orthostasis nor blood loss caused significant changes in the umbilical systolic/diastolic ratio. CONCLUSION: These data support the hemodynamic safety of uncomplicated autologous blood donation during late pregnancy.