Response of Blood Pressure, Plasma Volume and Prostaglandins to Volume Expanders in Pregnant Women with Chronic Hypertension

Twenty pregnant women with chronic, probably essential, hypertension experienced a significant fall in blood pressure (BP) in response to intravenous infusion of 500 ml of a volume-expanding solution. The magnitude of change in BP was unrelated to the presence or absence of peripheral edema. There was a universal rise in plasma volume and suppression of circulating prostaglandin metabolites, although only in women who had no peripheral oedema was there a stastically significant relationship between the extent of the BP change and that in plasma volume (r=-0.692, p < 0.05) or prostacyclin as measured by 6-keto-prostaglandin F10. (r=0.813, p < 0.05), The extent of change in both plasma volume and prostacyclin was greater, however, in women with peripheral oedema, suggesting the occurrence of a second factor obscuring the underlying relationship.