New spermicide protects against pregnancy and STDs?

A new acid buffering gel (BufferGel, ReProtect, Inc., Baltimore, Md.) that is supposed to be used with a diaphragm can provide safe, effective contraception. It may also help protect against sexually transmitted diseases (STDs) caused by acid-sensitive pathogens, including herpes simplex virus, chlamydia, gonorrhea, papillomavirus, and HIV-infected leukocytes, according to an 11-center, randomized, double-masked, noninferiority trial.

Researchers compared 621 women who used the new nondetergent spermicide plus diaphragm with 300 women who used nonoxynol-9 spermicide plus diaphragm for 6 months. The mean age of the participants was 25 years. In a double-masked study extension, the authors of the study followed 234 of the women for an additional 6 months.

They found pregnancy rates, as well as rates of adverse events, changes in vaginal microflora, and acceptability, to be similar between the groups. The 6-month pregnancy rate per hundred women was 10.1% (95% CI, 7.1%–13.1%) for users of the new gel versus 12.3% (95% CI, 7.7%–16.9%) for the nonoxynol-9 users. Six-month rates for those who used the products consistently and correctly were 4.7% for users of the acid gel and 6.1% for the nonoxynol-9 users.

Barnhart KT, Rosenberg MJ, MacKay HT, et al. Contraceptive efficacy of a novel spermicidal microbicide used with a diaphragm. Obstet Gynecol. 2007;110:577-586.