Is there a correlation between maternal venous hemodynamic dysfunction and proteinuria of preeclampsia?

ObjectivesTo evaluate in early and late preeclampsia a correlation of maternal venous Doppler flow characteristics with biochemical parameters in maternal serum and urine, or with gestational outcome.Study designIn this observational cross-sectional study, renal interlobar vein impedance index (RIVI) was measured according to a standardised protocol for combined electrocardiogram-Doppler ultrasonography in 86 women with uncomplicated pregnancy, 78 women with late onset preeclampsia (≥34 w) and 67 with early onset preeclampsia (<34 w). For each group, maternal age, pre-gestational BMI and parity were recorded together with birth weight and -percentile. For both early onset and late onset preeclampsia, maternal serum was analysed for thrombocyte count and concentrations of creatinine, ASAT, ALAT and uric acid and 24 h urine collections were analysed for creatinine clearance and proteinuria (mg/24 h). A non-parametric Mann-Whitney U-tests was performed for continuous data and a Fisher's exact tests for categorical data. Significant linear dependence between variables was identified using Pearson's correlation coefficient at nominal level a = 0.05.ResultsProteinuria was higher in early onset than in late onset preeclampsia (1756 mg [838-6116 mg] versus 877 mg [416-1696 mg], p < 0.001), and this was also true for RIVI in both left (0.45 [0.40-0.55] versus 0.41 [0.35-0.45], p = 0.001) and right kidney (0.45 [0.39-0.55] versus 0.38 [0.30-0.43], p < 0.001). In our data set, there was a significant correlation between proteinuria and RIVI of left (correlation coefficient = 0.172, p = 0.036) and right kidney (correlation coefficient = 0.218, p = 0.009) in late onset but not early onset preeclampsia.ConclusionMaternal RIVI may correlate with proteinuria of late onset preeclampsia.