Protein/creatinine ratio in the assessment of proteinuria during pregnancy.

Since the nature and the level of urinary protein excretion have considerable clinical implications in the course of pregnancy, the early detection of even minor degrees of hyperproteinuria is important. Quantitation of 24-h urinary protein excretion is the only definite method of establishing the presence of hyperproteinuria, but this method shows practical failures particularly in an outpatient setting. Dipstick analysis as a screening for hyperproteinuria also lacks reliability, since the normal rate of protein excretion in primigravid pregnancy has recently been shown to be less that 150 mg per day. In this study, therefore, we propose the determination of the protein/creatinine ratio in a single voided urine sample, obtained during normal daylight activity, as a screening test for hyperproteinuria during pregnancy which can replace the quantitation of 24-h urinary protein excretion.

Urinary excretion rates of calcium and magnesium in normal and complicated pregnancies.

In this cross-sectional study calcium and magnesium metabolism was investigated in normal pregnancies (n = 34) and pregnancies complicated by either fetal growth retardation of hypertension with or without fetal growth retardation (SGA newborns) (n = 30). Special attention has been given to the renal excretion rates of calcium and magnesium and their relationship to creatinine and sodium clearances. No differences were noted in the third trimester of pregnancy between the normal and complicated pregnancies in calcium or magnesium metabolism except for an increased serum magnesium in the SGA group. Comparing the post-partum period to normal pregnancy the following results were observed: (i) serum ionic calcium levels showed no differences; (ii) urinary calcium excretion was increased as a result of increased calcium clearance. A striking feature was the fact that the fractional calcium clearance was not increased, in contrast to the increase in relative calcium clearance. The observed results can be explained by an increased GFR and a possible dissociation between the sodium and calcium handling in the cortical thick ascending Limb of Henle's Loop.

Postpartum resolution of glomerular changes in edema-proteinuria-hypertension gestosis.

Complete resolution of glomerular changes in toxemia of pregnancy has been reported to occur as early as 4 weeks postpartum, whereas their persistence for as long as 2 years in some instances has been noted. However, the mechanism of resolution remains obscure. Percutaneous renal biopsy was performed in 22 patients between 10 and 14 days after delivery. These women fulfilled the criteria for toxemia of pregnancy (edema-proteinuria-hypertension gestosis). Biopsy specimens were examined, using light, immunofluorescence and electron microscopy. Semithin sections were studied in view of greater reliability and better relation with further electron microscopic studies. A diffuse increase in mesangial cellularity and matrix was seen in all glomeruli with varying intensity, compatible with mesangium activity, more than endothelial proliferation. So-called capillary occlusions by endothelial swelling were not observed in the biopsies taken 10 days after delivery, but expulsed mesangial cytoplasm could be observed incidentally in the capillary lumen. This phenomenon may explain the wrong interpretation of paraffin sections studied by light microscopy. The presence of immunoglobulins in the glomeruli, seen by immunofluorescence, seems to be nonspecific trapping. In view of experimental studies of mesangium function in macromolecular uptake and processing, it is possible that resolution of the characteristic renal lesions in toxemia is promoted by mesangium activity.