Single-dose antimicrobial therapy in the treatment of asymptomatic bacteriuria in pregnancy.

Fifty obstetric patients with asymptomatic bacteriuria were treated by single-dose antimicrobial therapy. The immediate cure rate was 84% and the recurrence rate was 12%. Seven of the eight patients in whom single-dose treatment failed responded to subsequent 7-day therapy with the same drug, indicating renal involvement. A 50% recurrence rate in the group of patients in whom single-dose treatment failed was compared with a 5% recurrence rate in the group cured by single-dose therapy, which indicates that failure with single-dose antimicrobial therapy can serve as a therapeutic test to identify patients at high risk for recurrent bacteriuria and its sequelae during pregnancy. It is concluded that single-dose antimicrobial therapy is a safe and effective way to treat asymptomatic bacteriuria in pregnant patients without urologic problems in their history.