Bladder versus renal bacteriuria during pregnancy: recurrence after treatment.

Localization of bacteriuria has been shown to correlate with the pattern of recurrence after treatment. The immunofluorescent technique was used to localize infection in 233 pregnant women with asymptomatic bacteriuria to determine whether this would identify those who were at greater risk for recurrence. In both an indigent and a military population, the incidence of renal bacteriuria was 42%. Regardless of the site of infection, after one course of short-term (10-day) or long-term (21-day) antimicrobial therapy, almost two thirds of these women were abacteriuric for the remainder of gestation. Women given short-term treatment were more likely to have a recurrence within 2 weeks of completion of therapy than were women given long-term therapy (P less than 0.001). Moreover, these early recurrences were more frequent in women given short-term treatment for renal bacteriuria (P less than 0.05). Conversely, recurrences 6 or more weeks after completion of therapy, and regardless of site of infection, were more common in women given long-term treatment (P less than 0.01). Although the timing of recurrence varied significantly in relation to duration of treatment and site of infection, the ultimate risk of recurrence was not related to either. The conclusion is that localization of asymptomatic bacteriuria does not contribute to the management of pregnant women, since overall recurrence rates are independent of the site of infection.