Comparison of single dose with a 5-day course of co-trimoxazole for asymptomatic (covert) bacteriuria of pregnancy.

Forty-four pregnant women with covert (asymptomatic) bacteriuria proven by suprapubic bladder aspiration were randomly allocated to treatment with either a single 1.92g dose or a standard 5-day course of co-trimoxazole. Twenty-one of 24 women were cured with a single dose. Seven of these 21 women were reinfected later in the pregnancy. All 20 women treated with a 5-day course of co-trimoxazole were cured, and 2 became reinfected later in the pregnancy. There were no side-effects of treatment, and no detrimental effects on the outcome of pregnancy. Single dose therapy should be considered as the treatment of choice for covert bacteriuria in pregnancy.