Cervical cap

The cervical cap is a small (1-1/2 inches or about 3 cm.), thimble-shaped dome made of latex or silicone rubber (it is much smaller than a diaphragm) and it fits right over the cervix. The cervical cap is used along with a spermicide. One small application of spermicide is placed inside the cap at the time of insertion. The cap plus spermicide prevent sperm from going through the cervix and entering the uterus.
A woman pushes the cervical cap up her vagina and into position over her cervix. It can remain in place for up to 48 hours. Unlike the diaphragm, fresh spermicidal jelly or foam does not need to be added each time intercourse is repeated as long as the cervical cap is correctly positioned over the cervix.
As with the diaphragm, a cervical cap requires a prescription. A woman must see a health care practitioner to determine the correct size and to ensure that she understands the proper insertion technique.
There are no known related health risks associated with using the cervical cap and spermicide method of birth control. Some women may find spermicides to be irritating, but changing brands may help. The cervical cap can be difficult to insert, but is handy for women who cannot use a diaphragm because of poor muscle tone. Women who suffer from recurring urinary tract infections related to diaphragm use may want to try using the cervical cap.
It is important to remember that using a cervical cap does not protect from sexually transmitted infections, although spermicides may give some protection against chlamydia and gonorrhea.
When the cervical cap and spermicide are used correctly, they are more than 80% effective for birth control, essentially the same reliability as the diaphragm.