Diaphragm use and urinary tract infections: analysis of urodynamic and microbiological factors.

To investigate how diaphragm use predisposes to urinary tract infection we studied 22 women who experienced 1 or more urinary tract infections while using a diaphragm and 21 who used a diaphragm and did not have a urinary tract infection. For women with and without a prior urinary tract infection the mean peak urine flow rate was significantly less with than without a diaphragm. However, the mean decrease in peak urine flow rate with a diaphragm was not significantly greater for women with a prior urinary tract infection. There also was no significant increase in time to peak flow with the diaphragm in place. Women who reported a sensation of obstruction to voiding with a diaphragm demonstrated a significant decrease in peak urine flow rate and this finding was particularly apparent in those with a history of urinary tract infection in whom the peak urine flow rate decreased by an average of 10.0 ml. per second. Current users of a diaphragm with a history of urinary tract infection had heavier growth of coliform organisms from cultures of the vagina and urethra, and significantly more episodes of infection than women without such a history (p equals 0.03 and 0.05, respectively). We conclude that use of a diaphragm can cause urinary obstruction in some women but that the obstruction is of relatively small magnitude and does not correlate with the acquisition of a urinary tract infection. Changes in vaginal flora associated with diaphragm use may be of greater importance.