title: Antibiotics for asymptomatic bacteriuria in pregnancy.
abstract: BACKGROUND
  Up to 30% of mothers develop acute pyelonephritis if asymptomatic bacteriuria is untreated. Asymptomatic bacteriuria may have a role in preterm birth, or it may be a marker for low socioeconomic status and thus, low birth weight.
  
  
  OBJECTIVE
  The objective of this review was to assess the effect of antibiotic treatment for asymptomatic bacteriuria on persistent bacteriuria during pregnancy, the risk of preterm delivery and the development of pyelonephritis after delivery.
  
  
  METHODS
  I searched the Cochrane Pregnancy and Childbirth Group trials register.
  
  
  METHODS
  Randomised trials comparing antibiotic treatment with placebo or no treatment in pregnant women with asymptomatic bacteriuria found on antenatal screening.
  
  
  METHODS
  Trial quality was assessed.
  
  
  RESULTS
  Thirteen studies were included. Overall the study quality was not strong. Antibiotic treatment compared to placebo or no treatment was effective in clearing asymptomatic bacteriuria (odds ratio 0.07, 95% confidence interval 0.05 to 0.10). The incidence of pyelonephritis was reduced (odds ratio 0.25, 95% confidence interval 0.19 to 0.32). Antibiotic treatment was also associated with a reduction in the incidence of preterm delivery or low birth weight babies (odds ratio 0.60, 95% confidence interval 0.45 to 0.80).
  
  
  CONCLUSIONS
  Antibiotic treatment appears to be effective in reducing the risk of pyelonephritis in pregnancy. An apparent reduction in preterm delivery is consistent with current theories about the role of infection in preterm birth, but this association should be interpreted with caution.
authors.affiliation: Department of Pathology and Molecular Medicine, McMaster University Medical Centre, Hamilton Health Sciences Corporation, Room 2N29, 1200 Main Street West, Hamilton, Ontario, Canada, L8N 3Z5. smaill@mcmaster.ca
authors.forename: F
authors.initials: F
authors.lastname: Smaill
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001437:Bacteriuria / Q000188:drug therapy*; D005260:Female; D006801:Humans; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000188:drug therapy*
chemical_list: D000900:Anti-Bacterial Agents