The contraceptive sponge's protection against Chlamydia trachomatis and Neisseria gonorrhoeae.

To investigate the effect of the contraceptive sponge on the incidence of sexually transmitted diseases, we conducted a clinical trial among a high-risk population of women in Bangkok, Thailand. Two hundred fifty-five women were randomly assigned either to use the sponge or not and were evaluated weekly for gonorrhea and chlamydial infection. After adjustment by logistic regression for potentially confounding factors, women using the sponge were less likely to have contracted chlamydial infection (odds ratio [OR], 0.6; 90% confidence interval [CI], 0.4-1.0) and gonorrhea (OR, 0.9; CI, 0.6-1.3) as compared with women not using the sponge. These estimates probably underestimate the degree of protection because some exposure was misclassified in this pilot phase of the study. These results are consistent with other studies indicating that spermicides protect against gonorrhea and also demonstrating protection against an organism of even greater public health concern, Chlamydia trachomatis.