Renal Function Studies in Toxemia of Pregnancy

Abstract

The occurrence of proteinuria and the repeated demonstration of depression of filtration rate and renal plasma flow in toxemia of pregnancy are evidence that there is impairment of renal function. Structural abnormalities are not demonstrable in pre-eclampsia although when the stage of eclampsia supervenes morphologic abnormalities are occasionally detectable (1, 2). The invariable presence of edema attests to the fact that the functional lesion involves the mechanism of excretion of water and solutes.Attempts to define the mechanism of retention of fluid in toxemia of pregnancy have been directed mainly at the hormonal balance of toxemic subjects (3). Investigations focused specifically on the renal mechanism of water and electrolyte excretion and carried out under standard and reproducible conditions have not been reported.The present investigation was undertaken to apply some of the recently acquired knowledge of the relationship between excretion of water and solutes under the specific conditions of osmotic diuresis in hydropenia to patients with toxemia of pregnancy. The relationship between excreted loads of electrolytes and other urinary constituents, on the one hand, and water on the other, is predictable and reproducible in normal pregnant and non-pregnant subjects studied with this technique (4-6). It has been observed that the amount of water excreted under these conditions is determined solely by the osmotic pressure of the excreted solutes, that the concentrations of sodium and chloride in the urine are remarkably constant and independent of the rate of urine flow, and that the rates of excretion of sodium and

Serum cystatin C reflects glomerular endotheliosis in normal, hypertensive and pre-eclamptic pregnancies

“…Although glomerular filtration rate, defined as the plasma clearance of low molecular mass substances, is normally increased during pregnancy 13,14 , pre-eclampsia is characterised by a decrease in glomerular filtration rate 15,16 . This impairment in renal function needs to be monitored closely to ensure a timely delivery before serious renal damage occurs.…”

Serum cystatin C reflects glomerular endotheliosis in normal, hypertensive and pre‐eclamptic pregnancies

“…Although glomerular filtration rate, defined as the plasma clearance of low molecular mass substances, is normally increased during pregnancy 13,14 , pre‐eclampsia is characterised by a decrease in glomerular filtration rate 15,16 . This impairment in renal function needs to be monitored closely to ensure a timely delivery before serious renal damage occurs.…”

Aldosterone Excretion in Normal and Toxaemic Pregnancies

“…The glomerular filtration rate and renal plasma flow in toxaemia were found by Assali et al (1953) to be 70-80% of those in normal pregnancy. This reduction is insufficien-t to make an appreciable difference to the relative aldosterone values in the two groups.…”