Antihypertensive effect of plasma volume expansion in pregnancy-associated hypertension.

Plasma and total extracellular fluid volume expansion was confirmed in normal pregnant women in the third trimester of pregnancy. The plasma volume contraction of pregnancy-associated hypertension (pre-eclampsia) was found to be associated with an increase in the interstitial compartment of extracellular fluid volume. The infusion of a plasma volume expander produced significant amelioration of hypertension for 48 h associated with partial reversal of the disturbance of fluid distribution. This finding confirms the central place of volume contraction in maintenance of elevated blood pressure in pregnancy-associated hypertension.