Examination of Intrarenal Resistance Indices Indicate the Involvement of Renal Pathology as a Significant Diagnostic Classifier of Preeclampsia

BACKGROUND Preeclampsia (PE) is a hypertensive disorder during pregnancy with endotheliosis leading to occlusion of renal perfusion with an impact on the glomerular filtration barrier. We therefore analyzed the role of intrarenal resistance indices in the renal interlobular arteries measured by Doppler ultrasound as a diagnosis of PE. METHODS Women with preeclampsia (n = 24; mean blood pressure/24 h = 145 ± 11/ 93 ± 7 mm Hg; mean proteinuria = 5.63 ± 1.0 g/24 h) were compared against a group of healthy pregnant women (n = 24). All patients underwent a Doppler ultrasound of the intrarenal arteries between the 24th week of gestation and the 5th week postpartum. Several risk factors for PE, as well as the arterial resistive indices of the Arteriae uterinae and the Arteria umbilicalis, were monitored in parallel. RESULTS The intrarenal resistive index (mean ± SD = 0.63 ± 0.05 in women with preeclampsia vs. 0.59 ± 0.056 in healthy pregnant women; P < 0.003), the pulsatile index (mean ± SD = 1.15 ± 0.19 in women with preeclampsia vs. 0.92 ± 0.13 in healthy pregnant women; P < 0.0001), and the end diastolic flow velocity (mean ± SD = 14.16 ± 4.75 cm/s in women with preeclampsia vs. 10.67 ± 2.68 cm/s in healthy pregnant women, P < 0.006) were elevated in patients with PE, as were the arterial resistive indices of the Aa. uterinae and A. umbilicalis. The intrarenal resistive indices correctly classified 84.2% of the women as having PE. CONCLUSIONS Intrarenal resistive indices are a significant classifier of PE, providing the possibility to predict nephropathy. They could be a prognostic tool for cardiovascular comorbidity in PE patients even after delivery.