The cervical cap is small and rubber barrier method that prevents sperm from entering a woman’s uterus. It is placed snugly over the cervix where it is held in place by suction. Though similar to a diaphragm, the cervical cap is smaller.

Cervical caps are available in a variety of sizes and shapes. As this method of contraception requires a precise fit to be effective, it is necessary to visit a healthcare professional for fitting. Prior to insertion, the cap may be filled with spermicidal cream or jelly. The cap can be worn for as long as 48 hours, and can be inserted long before intercourse. It must remain in place for at least six hours after intercourse for maximum effectiveness.

This method is more effective for women who have never given birth vaginally. When used with spermicidal cream or jelly, the cervical cap is 84% effective for women that have never had a vaginal delivery of a child. This statistic indicates that of 100 women using this method for one year in the real world (not in a scientific laboratory), 16 women will become pregnant during that time period. For women who have delivered a baby vaginally, the effectiveness rate is 68%, indicating that of 100 women, 32 will become pregnant.

When compared with other methods, the cervical cap has very few side effects. It is possible that the cap can become displaced during intercourse if the partner’s penis touches the ring of the cap. Some users do not like the odor that can occur as a result of the spermicide interacting with the rubber. The cervical cap should never be left in for longer than 48 hours, as it is possible to develop Toxic Shock Syndrome. However, the cap requires less spermicide than the diaphragm, and thus has a lower risk of an allergic reaction to the spermicide. In addition, the cervical cap does not alter hormone levels in a woman’s body or affect her ability to conceive children later in life.