The evaluation of urine pH in screening for asymptomatic bacteriuria in pregnancy.

The purpose of this prospective investigation was to determine whether an alteration in urine pH, either by itself or in combination with other rapid screening tests, could be used to identify asymptomatic bacteriuria in pregnant women. Clean catch urine specimen was used to evaluate 510 asymptomatic obstetric patients. Urine specimens were tested for pH, leukocyte esterase activity, and the presence of nitrites. The pH, leukocyte esterase activity, and nitrite reaction were evaluated singly and in combination to determine if these variables could be used to predict significant bacteriuria. Twenty-four (4.8%) patients had positive cultures for E. coli. The mean pH of the infected population was not significantly different from that of the uninfected population. The performance parameters of pH, singly and in combination with the leukocyte esteras and nitrite status, were poor. We concluded that the identification of urine pH is not of value in detecting asymptomatic bacteriuria.