Glomerular ultrafiltration in normal and preeclamptic pregnancy.

Abstract

GFR and renal plasma flow (RPF) decrease in preeclampsia, a serious hypertensive complication of pregnancy. Serial data derived in late pregnancy (LP) and >5 mo postpartum (PP) in 13 healthy controls and 10 preeclamptic women (13 and 5, respectively) returning PP for theoretical analysis of neutral dextran sieving curves (theta(D)), are presented and are used to calculate the key determinants of glomerular ultrafiltration. Normal LP hyperfiltration was associated with increases in RPF and the ultrafiltration coefficient (K(f)), as well as in the nondiscriminatory shunt pathway (omega(0)) and the SD of pore size (S). Preeclamptic LP showed the largest omega(0) and S values, indicating a loss of size-selectivity, accompanying reduced K(f) and RPF, both of which are implicated in the relative hypofiltration. Despite a 100-fold increase in urinary albumin excretion (UAE), LP preeclamptic theta(D) values were reduced for the equivalent neutral dextran (36A), providing indirect evidence for a loss of glomerular barrier charge-selectivity. All the determinants of GFR and all modeled parameters were comparable across both groups PP, strong evidence that preeclamptic glomerular dysfunction resolves.