Spermicide nonoxynol-9 is not effective in for preventing vaginal acquisition of sexually transmitted infections and it may do harm by increasing the frequency of genital lesions .
The Prentif cervical cap may be as effective as a diaphragm in preventing pregnancy, but the FemCap may not .
The sponge is less effective than the diaphragm in preventing pregnancy, and discontinuation rates are higher at 12 months .