Doppler parameters of renal hemodynamics in women with preeclampsia: A systematic review and meta-analysis.

The present meta-analysis aims to compare renal arterial and venous Doppler parameters in women with preeclampsia and healthy pregnant controls. Medline, Scopus, Cochrane Central Register of Controlled Trials, Clinicaltrials.gov, and Google Scholar databases were systematically searched from inception to December 04, 2019. All observational studies reporting renal resistive index, pulsatility index, renal interlobar vein impedance, or pulse transit time among preeclamptic and healthy pregnant women were held eligible. Subgroup analysis was conducted on the basis of disease onset and side of measurement. Both pair-wise and network meta-analysis were performed using Review Manager 5.3 and R-3.4.3 software. Fourteen studies were included, with a total of 1118 women. No difference of renal resistive (MD: 0.00, 95% CI: [-0.03, 0.04]) and pulsatility index (MD: -0.01, 95% CI: [-0.14, 0.12]) was evident between the two groups. Renal interlobar vein impedance was estimated to be significantly higher in preeclampsia (MD: 0.07, 95% CI: [0.06, 0.09]), while venous pulse transit time was significantly lower (MD: -0.10, 95% CI: [-0.14, -0.05]) in women with the disease. Subgroup analysis indicated that early-onset preeclampsia was associated with significantly elevated renal interlobar vein impedance and lower venous pulse transit time than late-onset disease. The outcomes of the present meta-analysis suggest that preeclampsia is characterized by venous hemodynamic dysfunction as it is associated with significantly elevated renal interlobar vein impedance and shorter venous pulse transit time. Future large-scale prospective studies should introduce cutoff values and determine the optimal timing of measurement in order to achieve optimal predictive accuracy.