Diagnosis and management of urinary tract infection in pregnancy

Urinary tract infection occurs in about 5% of pregnancies. Although usually asymptomatic, in a third of cases if untreated it progresses and causes acute pyelonephritis. Urinary tract infection is also associated with low birth weight, prematurity and other obstetric complications. Screening and treatment can reduce the incidence of these complications and are cost-effective in most populations, although there has been much debate concerning the optimal methodology for testing. Despite the investigation of rapid diagnostic methods including reagent strips, 'wet-film' microscopy, Gram staining urinary pH and the detection of bacterial catalase and ATP, in our opinion the best approach is still urine culture, which should be repeated if positive for confirmation. The antibiotics of choice for treatment are amoxycillin, cephalexin and nitrofurantoin depending on the sensitivity of the infecting organism. Single-dose therapy is effective in most women although it has not been conclusively shown to be as effective as longer courses. Patients should be followed up after treatment to ensure eradication of the infection, and preferably throughout pregnancy, to allow retreatment in the event of relapse or reinfection. The role of secondary prophylaxis has not been fully investigated. On current evidence there is no need to extend the follow-up of successfully treated women into the puerperium, although those with refractory bacteriuria or pyelonephritis should be investigated to exclude structural abnormalities of the renal tract. (C) 1999 Lippincott Williams & Wilkins.