The limited usefulness of urine and blood cultures in treating pyelonephritis in pregnancy.

Although urine cultures are performed routinely in managing acute pyelonephritis in pregnancy, little is known about the clinical usefulness of these cultures. The same is true for blood cultures. To evaluate their role in managing patients, we reviewed the records of 156 cases to determine to what extent such cultures influenced treatment. Over 90% of urine isolates were sensitive to the initial antibiotic. Most changes in therapy were based on clinical response; only 3% of pre-treatment urine cultures and 2% of blood cultures led to a change in antibiotics. On a nationwide basis, urine and blood cultures cost $10-20 million each year. Our data suggest that more limited use of cultures will simplify management and save money without compromising patient care.