What Is It?

A cervical cap is a small, thimble-shaped cup made of silicone that fits over the cervix (the part of the uterus that opens into the upper part of the vagina). It is considered one of the barrier methods of birth control because it provides a physical barrier between a male's sperm and a female's egg.

How Does a Cervical Cap Work?

The cervical cap keeps sperm from entering the uterus by covering the cervix. For added protection, spermicide is put into the cap before inserting the cap snugly over the cervix.

The cap is inserted at least 15 minutes before having sex and can be left in place for up to 48 hours. While the cap is in place, its position should be checked and spermicide should be added every time a couple has sex. After sex, the cap must be left in place for at least 6 hours.

Follow the manufacturer's instructions for removing the cap. Removing a cervical cap involves placing a finger in the vagina to pull the cap out. Because the cap has to be placed properly, women who use one should be comfortable feeling for their cervix deep inside the vagina.

After each time it is used, the cap must be washed with mild soap and water, rinsed, and air dried, then stored in its case. It should not be dusted with baby powder and should never be used with oil-based lubricants such as mineral oil, petroleum jelly, or baby oil. These substances can cause the material in the cap to become brittle and crack. Other vaginal creams, such as medicines for yeast infection, also can damage the cap.

How Well Does It Work?

Over the course of 1 year, about 16 out of 100 typical couples who rely on the cervical cap to prevent pregnancy will have an accidental pregnancy. For women who have had a baby, the cervical cap is less effective: about 32 out of 100 typical couples who use the cervical cap after the woman has had a baby will have an accidental pregnancy. Of course, these are average figures and the chance of getting pregnant depends on whether you use this method of birth control correctly and every time you have sex.

In general, how well each type of birth control method works depends on a lot of things. These include whether a person has any health conditions or is taking any medications that might interfere with its use. It also depends on whether the method chosen is convenient — and whether the person remembers to use it correctly every time.

Protection Against STIs

The cervical cap does not protect against sexually transmitted infections (STIs). Couples having sex must always use condoms along with the cervical cap to protect against STIs.

Abstinence (not having sex) is the only method that always prevents pregnancy and STIs.

Possible Side Effects

Most females who use the cervical cap have no problems. The few side effects some women do have include:

• Spermicides may irritate the vagina and surrounding skin or cause an allergic reaction.
• Strong odors, vaginal discharge, or infection may occur if the cervical cap is left in too long.
• The material in the cervical cap may cause an allergic reaction.
• Toxic shock syndrome (TSS) is a rare complication.
• The cap may lead to changes in the cervix because of irritation.

Who Uses It?

The cervical cap is not usually recommended for most young women since it can be very difficult to insert correctly. Inserting a cervical cap involves reaching all the way to the cervix with your fingers. It can sometimes also be knocked out of place during intercourse, which can result in pregnancy. The cervical cap cannot be used when a girl has her period.

A diaphragm works like the cervical cap, but many girls find the diaphragm easier to use.

How Do You Get It?

A doctor must fit a girl for a cervical cap. During a pelvic exam, the doctor will determine which size cap is right for her. The doctor or nurse will then teach her how to insert and remove the cap.

How Much Does It Cost?

A cervical cap costs about $70 and should be replaced every year. In addition, there is also the cost of the doctor's visit. Many health insurance plans cover these costs, and family planning clinics (such as Planned Parenthood) may charge less. In addition, the cost of spermicide is about $0.50 to $1.50 per use.

Reviewed by: Larissa Hirsch, MD
Date reviewed: June 2010