Role of Renal Ultrasonography in the Management of Pyelonephritis in Pregnant Women

OBJECTIVE: The objective of this study was to determine the usefulness of renal ultrasonography in pregnant women with pyelonephritis. STUDY DESIGN: A retrospective review was done of hospital records of 171 consecutive pregnant women admitted to the hospital over a 7-year period with the diagnosis of pyelonephritis. RESULTS: Urine cultures were positive in all but one of the women and intravenous antibiotics were administered in all cases. Renal ultrasonography was done in 75 (43.9%) of the women and results found to be normal in 26 (34.7%) of them. The renal pelvis was dilated mildly (6 to 10 mm) in 25 (33.3%), moderately (11 to 15 mm) in 16 (21.3%), and severely (≥16 mm) in 8 (10.7%) patients. Duplicated collecting systems and renal calculi were each found in 2 (2.7%) patients. All patients were treated conservatively with no need for ureteral stents. Three of the patients with severe hydronephrosis were first seen at term and delivery was therefore induced. There was no difference in maternal characteristics and outcome of pregnancy between women who underwent renal ultrasonography and those who did not. However, the duration of hospitalization was significantly longer (p < 0.02) for women in whom renal ultrasonography was performed (mean ± SD, 5.8 ± 1.7 vs 4.1 ± 1.3 days). CONCLUSION: Renal ultrasonography is of limited benefit in pregnant women with pyelonephritis, because these imaging studies only rarely modify management and do not significantly affect pregnancy outcome.