Maternal Whole Blood Viscosity in Pregnancy Hypertension

Abstract

Hemoconcentration is prominent in preeclampsia. Concomitant changes in the flow properties of maternal blood, i.e. in whole blood viscosity (WBV), might be related to the occurrence of fetal or maternal complications. To test this hypothesis, WBV was estimated in 228 pregnancies. Patients were assigned to one of four groups according to maximum diastolic blood pressure. Significantly higher WBV values were found in the more hypertensive groups throughout pregnancy. WBV data, obtained between 26 and 36 weeks of amenorrhea, contributed significantly, independently of hypertension, to the prediction of fetal outcome. With regard to maternal complications, no significant contribution of WBV data could be established independently of blood pressure. The results support the hypothesis that WBV is a determining factor in the efficacy of placental perfusion.

Haemorheological adaptation during pregnancy in a Latin American population

“…In pregnancy, there is substantial evidence that pre‐eclampsia is associated with a constriction in plasma volume (20, 21, 56–58), and increased whole‐blood (24, 59) and plasma viscosity (19). Differences in the prevalence of pre‐eclampsia have been established between different racial groups in Europe (28) and between different ethnic and racial groups in the United States (27, 59).…”

“…The importance of the changes of blood viscosity in normal pregnancy has been highlighted by several studies that demonstrated an increase in adverse pregnancy outcome with increasing haemoglobin levels (and thus whole‐blood viscosity) (16–18) and a strong correlation between the prevalence of pre‐eclampsia and plasma volume restriction and haemorheological disorders (19–24).…”

Relationship between acute fetal distress and maternal‐placental‐fetal circulations in severe preeclampsia

“…A previous study reported that increased hemoconcentration during severe preeclampsia causes increased maternal blood viscosity which predisposes to placental pathology, impairs the uteroplacental circulation, and initiates a vicious cycle ( I 5). Zondervan et al I ( 16) indicated that whole blood viscosity was a determining factor in the efficacy of placental per-fusion. For preeclampsia complicated with hemo,concentration, hypervolemic hemodilution ha!…”

The influence of maternal erythrocyte deformability on fetal growth, gestational age and birthweight

“…The increase in blood viscosity during pregnancy produces a fall in uteroplacental blood flow [6,43], retarded intrauterine growth with hypoxia and fetal lactic acidosis [9,32,42,47], reduced normal term birthweight [21,44,48] and a higher incidence of fetal death and acute fetal suffering [50].…”