GLOMERULAR AND PROXIMAL RENAL TUBULAR FUNCTION IN PREGNANCY-ASSOCIATED HYPERTENSION - PROSPECTIVE-STUDY

1. (1) 82 initially normotensive women with no past history of renal disease were studied at monthly intervals throughout pregnancy from 17 to 20 wk amenorrhea. 15 patients developed hypertension (blood pressure (BP) 135 85 mm Hg lying on the left side) in the third trimester of pregnancy, and returned to normal values post partum. Glomerular filtration rate (GFR) as measured by true endogenous creatinine clearance was elevated throughout pregnancy in both groups, while proximal renal tubular function as measured by 15-min phenolsulfonphthalein (PSP) excretion, normal in early pregnancy, was abnormally low at 33-36 wk amenorrhea in those patients who developed hypertension, prior to the rise in BP in at least 60%. PSP excretion was also found to be low in continuously normotensive women with a history of hypertension in a previous pregnancy. Uric acid clearance was elevated in all patients in early pregnancy, but showed a tendency to fall as early as 29-32 wk amenorrhea (P < 0.01) in those destined for hypertension, with a reciprocal rise in serum levels. 2. (2) It is clear that proximal renal tubular functional abnormalities appear before the onset of pregnancy-associated hypertension (P-AH), even in a mildly affected group such as the present one, and may well be involved in the initiating pathophysiological processes of the clinical syndrome. © 1979.