Objective: Our purpose was to evaluate central and end-organ hemodynamic effects of antepartum pyelonephritis.
Study design: Daily duplex ultrasonographic assessments of maternal cardiac output and resistive index values of the maternal renal and uterine arteries and the fetal umbilical arteries were performed in pregnant women admitted for acute pyelonephritis. For comparison, the same measures were repeated within 2 weeks after discharge.
Results: Thirty-seven women with antepartum pyelonephritis underwent serial 2-dimensional real-time and Doppler evaluation of maternal heart and duplex Doppler evaluation of maternal renal and uterine and fetal umbilical arteries. Significant differences in temperature, mean arterial pressure, and heart rate were observed during hospitalization compared with the follow-up visit. Total peripheral resistance was significantly decreased and cardiac output increased during acute infection. In women with unilateral signs and symptoms an increased resistive index was observed in the symptomatic kidney compared with the nonsymptomatic side; this difference disappeared on the follow-up study. No changes were observed in maternal uterine or fetal umbilical arteries.
Conclusions: Uncomplicated pyelonephritis is associated with measurable depression of systemic vascular resistance. This likely represents an effect of infection that in the extreme would be the septic shock syndrome. It seems reasonable to attribute the increased resistive index of the symptomatic kidney to local effects of infection.