Effect of the contraceptive sponge on chlamydial infection, gonorrhea, and candidiasis. A comparative clinical trial.

To investigate the effect of the nonoxynol 9-impregnated contraceptive sponge on the incidence of chlamydial infection, gonorrhea, and candidiasis, we conducted a randomized comparative study among high-risk women in Bangkok, Thailand. The first (parallel) portion of the study covered 434 woman-weeks among sponge users and 494 woman-weeks among nonusers. As compared with women not using the sponge, sponge users were found to be less likely to become infected with chlamydia (relative rate, 0.67; 95% confidence interval, 0.42 to 1.07) and gonorrhea (relative rate, 0.31 [0.16 to 0.60]) but more likely to become infected with Candida (relative rate, 2.76 [0.96 to 7.98]). Women who continued in the study were crossed over to the alternate group, with former nonusers starting to employ the sponge and vice versa. The results of this second phase were similar to those of the larger parallel study. Overall, these results suggest that women using the sponge are protected against the two most common sexually transmitted pathogens, which are also those with the most serious health consequences. However, women using the sponge should be advised they may have an increased likelihood of a vaginal infection with Candida.