Both the cervical cap and the diaphragm are rubber cups that fit inside the vagina and block the entrance to the cervix.

They are barrier methods that block the sperm from swimming into the female�s reproductive system, reaching the egg and starting a pregnancy.

Both come in different sizes. The diaphragm holds spermicide against the cervix, so sperm that slip around the edge of the diaphragm are killed by the spermicidal chemicals. The cervical cap provides a tighter barrier around the cervix as it sort of suctions onto the cervix.

Both the cervical cap and diaphragm must be inserted into the vagina before intercourse and left there for six to eight hours after intercourse. They offer NO protection against sexually transmitted infections, so a condom must also be used during intercourse.

Both methods are about 80 to 85 percent effective at preventing pregnancy with typical use. If used perfectly, they prevent pregnancy about 94 percent of the time.

Sometimes, females become allergic to the spermicides. Other times, they get irritations just from having the cap or diaphragm inside them. The other downside is that in certain sexual positions, the diaphragm and cervical cap can slip out of position, which increases the chance of getting pregnant.

To get either device, you need to be fitted by a doctor or other healthcare provider. You also need a prescription. Cost varies depending on where it is fitted and purchased.