Sponge versus diaphragm for contraception.

The contraceptive vaginal sponge was developed as an alternative to the contraceptive diaphragm. The sponge, made of polyurethane impregnated with nonoxynol-9 (1g), releases 125 mg of the spermicide over 24 h of use. Unlike the diaphragm, the sponge can be used for more than one coital act within 24 h without the insertion of additional spermicide, and the sponge does not require fitting or a prescription from a physician. How the sponge compares with the diaphragm in terms of efficacy and continuation is not clear.