Randomized Clinical Trial of Antibiotic Therapy for Antenatal Pyelonephritis

OBJECTIVE The aim of this study was to prospectively evaluate the efficacy of a therapeutic course of intravenous antibiotics followed by oral antibiotics vs. intravenous antibiotics alone to prevent recurrent urinary tract infection. METHODS Pyelonephritis was documented by strict criteria in 67 pregnant women who were then treated with appropriate intravenous antibiotics until afebrile and asymptomatic for 48 h. Women were then randomized to completion of a 10-day course of oral nitrofurantoin 100 mg qid or no further antibiotic therapy. Urine cultures (UC) were obtained 2 and 6 weeks after discharge, and at delivery. A positive UC or readmission for pyelonephritis was considered endpoints for participation in the study. Antibiotic suppression was not used. RESULTS Readmission for pyelonephritis prior to the 2-week follow-up visit occurred in 2/36 (5.6%) women randomized to the oral therapy group compared to 4/31 (12.9%) in the no oral treatment group (P = 0.29). At the 2-week follow-up visit, 6/31 (19.4%) women had a positive UC in the oral therapy compared to 8/26 (30.1%) in the no oral treatment group but this difference was not statistically significant (P = 0.31). CONCLUSIONS Completion of 10 days of antibiotic therapy with oral medication does not significantly reduce the risk of recurrent pyelonephritis immediately post-parenteral treatment. Women in the no oral treatment group had a non-significant increase in positive UC at the 2-week follow-up visit. The high rates of recurrent urinary tract infection during pregnancy in both groups underscore the need for regular UC and for the possible role of oral antibiotic suppression.