Renin-angiotensin-aldosterone system in pregnancy-induced hypertension.

Angiotensin-converting enzyme (ACE) and aldosterone concentration were measured in the plasma of 32 pregnant women with normal blood pressure or with pregnancy-induced hypertension (PIH). Mean arterial pressure (MAP) in PIH women was significantly higher than in normotensive pregnant women. Plasma ACE activity and aldosterone concentration in 17 PIH patients was significantly lower than their normotensive counterparts (15 cases). Mean arterial pressure was negatively correlated with the level of plasma ACE activity and with plasma aldosterone concentration in all pregnant women. Our results indicate that the circulating renin-angiotensin-aldosterone system is suppressed in pregnancy-induced hypertension.