Prorenin concentration in the hypertensive disorders in pregnancy

Objective: To evaluate the plasma prorenin levels during the three trimeste rs of normal pregnancy, their prognostic value, and their correlation with hypertensive disorders of pregnancy. Design: A prospective study in which plasma prorenin and renin levels were measured in 55 healthy pregnant women and 66 who developed gestational hype rtension or preeclampsia. The patients were classified as mild preeclampsia (mild PE), severe preeclampsia (severe PE), chronic hypertension and super imposed preeclampsia upon chronic hypertension (superimposed PE). Method: Venous blood samples were collected in the first, second and third trimesters and during delivery or cesarean. Plasma renin concentration (PRC ) was measured by radioinmmunoassay before and after incubation with trypsi n solution. The difference gave plasma prorenin concentration (PProRC). Results: PRC and PProRC were significantly higher in pregnant women compare d with healthy non-pregnant. PRC was significantly increased in the first t rimester in the chronic hypertension group and a lower value was found in t he first trimester in the superimposed PE compared with those in healthy pr egnant women. No differences in other groups were found. PProRC showed a si gnificant lower value in the first and third trimesters in the severe PE gr oup. In the superimposed PE a low value of PProRC similar to those of non-p regnant women was found. Conclusions: The results show that the different types of hypertension in p regnancy have different profiles of PProRC and PRC in relation to developme nt of preeclampsia. The absence of increase of PProRC in the first trimeste r of superimposed PE may have a prognostic value.