Proteinuria in Toxaemia and Abruptio Placentae

Abstract

Differential protein clearances were carried out in 31 patients with toxaemia of pregnancy and in 21 non-toxaemic patients with abruptio placentae. In 6 patients with toxaemia and in 7 with abruptio placentae, dextran clearance determinations were also performed. Results were expressed in terms of selectivity indices relating the clearances of these macromolecules to their molecular weights. In toxaemia, protein and dextran selectivity results were in the intermediate range, dextran values being slightly higher than the values obtained for protein. In abruptio placentae, however, the values obtained for protein selectivity were very low, while those obtained for dextran selectivity were very high. These results suggest that in toxaemia the proteinuria is of glomerular origin, but that in abruptio placentae the urinary protein is post-glomerular and is derived from plasma protein passing through damaged renal tubular epithelium.

Pathophysiology of the Clinical Manifestations of Preeclampsia

“…Few investigators have used dextran-sieving techniques to elucidate the properties of the glomerular filtration barrier in women with preeclampsia. In the 1970s, MacLean et al (51) confirmed the glomerular origin of proteinuria in preeclampsia demonstrating dextran-sieving coefficients in the intermediate range. This Figure 1.…”

The Renal Lesions of Toxaemia and Abruptio Placentae Studied by Light and Electron Microscopy

“…(No. 10 in Table IT, MacLean et al, 1972), no glomerular lesion could be seen on light microscopy, the remainder showed changes similar to, but generally of a lesser degree than, those described in the toxaemic patients (Fig. 10).…”

“…( 2 ) Thirteen patients without preceding clinical evidence of toxaemia who had had abruptio placentae. Further clinical information on these patients is published elsewhere (MacLean et al, 1972).…”

Effects of Maternal Renal Dysfunction on Fetal Development

“…The study of renal physiology during pregnancy has been mainly related to glomerular function (Studd, 1971;MacLean et al, 1972). In humans, glomerular filtration rate (GFR) reaches a peak of 40-50% higher than nonpregnant values between 9 and 11 weeks of pregnancy and is sustained until at least the 36 th week (Dafnis & Sabatini, 1992).…”