How long can a contraceptive sponge be left in place to provide protection?

A contraceptive sponge can be left in place for up to 24 hours to provide effective protection against pregnancy. This product works by releasing spermicide to immobilize sperm and also acts as a physical barrier. For optimal efficacy, it is recommended that the sponge be placed in the vagina before intercourse and should ideally be left in for at least six hours after the last act of intercourse, but not longer than 24 hours total. This is crucial because leaving it in for longer than recommended can lead to an increased risk of vaginal infections or toxic shock syndrome.

The other timeframes provided do not align with the recommended guidelines for the contraceptive sponge's use.