Maternal and umbilical cord plasma renin activity in pregnancy induced hypertension

ABSTRACT

Plasma renin activity [PRA] was determined by radioimmunoassay in maternal and cord blood of 20 women with pregnancy-induced hypertension [PIH] and in 20 normal pregnant controls. The mean maternal PRA among the group of PIH was significantly lower than that of normal pregnancy [P < 0.01]. There were significant negative relationship between maternal PRA and each of the systolic blood pressure [r = - 0.59, P < 0.05] diastolic blood pressure [r = - 0.5, P < 0.05] oedema of lower limbs [r = -0.46. P < 0.05] and proteinuria [r = - 0.61, P < 0.01]. The mean fetal PRA among PIH group was also lower than that of normal pregnancy but with no statistically significant difference [P > 0.05]. There was no significant relationship [r = 0.47, P < 0.05J between maternal and fetal PRA. No significant conelation was found between fetal PRA and any of the other parameters. PRA level is signifcantly depressed in PIH. Apparently this is the result of PIH and PRA is not involved in the pathogenesis of PIH. The trigger of PIH seems to be fetal rather than maternal in origin