The Today vaginal contraceptive sponge is made of polyurethane and contains 1 gram of the spermicide nonoxynol-9. Following preclinical and phase I and II clinical trials, extensive worldwide phase III trials were conducted. These multiclinic trials were conducted according to a common protocol with regularly scheduled follow-up visits and examinations. The cumulative first year method effectiveness rate (life table) was 90 per 100 women. The second year rate was 97 per 100 women. No statistically significant difference was found in method failures between nulliparous and parous women. No serious complications occurred in over 1000 women-years of sponge use.