Treatment of Asymptomatic Bacteriuria in Pregnancy

This is a prospective randomized controlled day comparing the efficacy of three-day antimicrobial treatment of asymptomatic bacteriuria (ASB) in pregnancy to the standard seven-day treatment. Half the patients will receive 3-day treatment and the other half will receive 7 days of antibiotics.

The current standard of practice is to treat pregnant patients with ASB with a 7-day course of oral antimicrobial agents. If bacteriuria persists women are retreated with the same of different agent for a second course of 7 to 14 days and they may be subsequently placed on prophylaxis. In nonpregnant women, an uncomplicated lower urinary tract infection may be treated with a short course regimen from 1 to 3 days. This approach has similar rates of persistent bacteriuria or symptoms following treatment when compared to women treated with a more conventional approach. If the infection recurs or persists, the patient may then be treated with the more traditional 7 to 14 day course. The advantages of single-dose regimens are cost and patient compliance, but a major disadvantage is the failure to eradicate uropathogens from the vaginal reservoir, which results in more frequent early recurrences. The three-day regimen is advocated to maintain the advantages of lower costs and patient compliance but improving cure rates. Multiple studies have shown the advantage of even a short course of antibiotics as opposed to no treatment.

Three-day treatment with Cephalexin or Nitrofurantoin for diagnosis of asymptomatic bacteriuria in pregnancy.

Seven-day treatment with Cephalexin or Nitrofurantoin for diagnosis of asymptomatic bacteriuria in pregnancy.

Cephalexin will be prescribed for women with a positive urine culture but no symptoms of urinary tract infection.

Macrobid will be prescribed for women allergic to penicillin with a positive urine culture but no symptoms of urinary tract infection.

Evidence that 3-day treatment is as effective as 7-day treatment of asymptomatic bacteriuria in pregnancy.

Comparison of percentage of women in each group with successful treatment or asymptomatic bacteriuria with negative urine culture 2 weeks after randomized treatment.

Comparison of percentage of women in each group who develop cystitis during pregnancy and the postpartum period.

Comparison of percentage of women in each group who develop pyelonephritis during pregnancy and the postpartum period.

Inclusion Criteria: Pregnant women ≥ 18 years of age seeking prenatal care at the Academic Obstetrics and Gynecology Center at St. Joseph Mercy Hospital, Ann Arbor, Michigan Randomization will occur if the patient every has a urine culture demonstrating ≥10,000 cfu/ml of a pathogenic urinary tract organism Exclusion Criteria: Symptomatic bacteriuria (cystitis or pyelonephritis) at the time of urine collection Previously treated bacteriuria in current pregnancy Past medical history of known congenital or acquired urinary tract anomaly or abnormality (i.e. pelvic kidney, single kidney, renal transplant) Any antibiotic use within the week prior to urine sampling Urine culture revealing growth of the following organisms: Lactobacillus, coagulase-negative staphylococcus

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Patterson TF, Andriole VT. Detection, significance, and therapy of bacteriuria in pregnancy. Update in the managed health care era. Infect Dis Clin North Am. 1997 Sep;11(3):593-608. doi: 10.1016/s0891-5520(05)70375-5.

Romero R, Oyarzun E, Mazor M, Sirtori M, Hobbins JC, Bracken M. Meta-analysis of the relationship between asymptomatic bacteriuria and preterm delivery/low birth weight. Obstet Gynecol. 1989 Apr;73(4):576-82.