The cervical cap is a birth control (contraceptive) device that prevents sperm from entering the uterus. The cervical cap is a reusable, deep silicone cup that is inserted into the vagina and fits tightly over the cervix. The cervical cap is held in place by suction and has a strap to help with removal. The cervical cap is effective at preventing pregnancy only when used with spermicide.

Only one cervical cap — FemCap — has Food and Drug Administration (FDA) approval in the U.S. It must be fitted and prescribed by a doctor, but can be purchased online if you have a current prescription.

When used with spermicide, the cervical cap helps prevent pregnancy. Among various benefits, the cervical cap:

• Allows prompt return to fertility
• Can be used while breast-feeding beginning six weeks after delivery
• Can be inserted hours before sex and remain in place for up to 48 hours
• Doesn't require a partner's cooperation
• Poses few if any side effects

The cervical cap isn't appropriate for everyone, however. Your health care provider may discourage use of the cervical cap if you:

• Are allergic to spermicide or silicone
• Are at high risk of or have HIV/AIDS
• Are at high risk of pregnancy — you're younger than age 30; you have sex three or more times a week; you've had previous contraceptive failure with vaginal barrier methods; or you're not likely to consistently use the cervical cap
• Have vaginal or cervical abnormalities that interfere with the fit, placement or retention of the cervical cap
• Have vaginal bleeding or have a vaginal, cervical or pelvic infection
• Have a history of pelvic inflammatory disease, toxic shock syndrome, cervical cancer, third-degree uterine prolapse, uterine tract infections, or vaginal or cervical tissue tears
• Recently gave birth or had a miscarriage or an abortion
• Recently had cervical surgery

The cervical cap doesn't offer protection from sexually transmitted infections (STIs).

An estimated 16 out of 100 women who've never been pregnant or given birth vaginally will become pregnant during the first year of typical use of the cervical cap. An estimated 32 out of 100 women who've given birth vaginally will become pregnant during the first year of typical use. This difference is due to the fact that the vagina and cervix are stretched by giving birth vaginally, which means the cervical cap may not fit as well.

Inconsistent or incorrect use of the cervical cap increases your risk of pregnancy. For example, you may get pregnant when using the cervical cap if:

• The cervical cap becomes dislodged from the cervix during sex
• You don't use spermicide
• You remove the cervical cap within six hours after having sex

Spermicide applied to the cervical cap may damage the cells lining the vagina, causing:

• Increased risk of contracting STIs
• Urinary tract or vaginal infection
• Vaginal irritation

Contact your health care provider if:

• The cervical cap slips out of place when you walk, sneeze, cough or strain
• You have signs or symptoms of toxic shock syndrome, such as a sudden high fever, diarrhea, dizziness, vomiting, fainting or a rash that looks like sunburn
• You notice blood on the cervical cap after you remove it that isn't related to your period
• You notice a foul odor when the cervical cap is in place or after you remove it
• You or your partner experiences pain during or following use of the cervical cap
• Your partner has abrasions on his penis following use of the cervical cap during sex

The cervical cap comes in different sizes. Your health care provider will fit you for the cervical cap and demonstrate how to insert and remove the cap. He or she may confirm that the cervical cap is in the correct position by doing a pelvic exam.

Make sure you regularly check your cervical cap for wear, holes or discoloration and replace your cervical cap each year. You may need to have your cervical cap refitted after childbirth. Always use the cervical cap with spermicide. Don't wear the cervical cap during any kind of vaginal bleeding, including your period.

Before you use the cervical cap for the first time, practice inserting the cap and checking its placement. Use a backup method of contraception, such as a male condom, the first few times you use the cervical cap.

To use a cervical cap:

• Check the position of your cervix before inserting the cervical cap. To find your cervix, insert your finger deep into your vagina. The cervix feels like the tip of your nose. Its position will vary according to the time of the month and your body position.
• Apply spermicide. Fill the cervical cap's bowl with about 1/4 teaspoon (1.25 milliliters) of spermicide. Spread a thin layer of spermicide on the brim of the cervical cap that faces the cervix. Place 1/2 teaspoon (2.5 milliliters) of spermicide in the groove between the rim and the dome of the cervical cap. Some experts suggest using an additional dose of spermicide if you have sex a second time with the cap still in. Don't remove the cap for at least six hours after the last time you had sex.

• Insert the cervical cap. Insert the cervical cap into your vagina before sexual arousal to ensure proper placement. Find a comfortable position, such as squatting. Separate your labia with one hand. With the other hand, hold the cervical cap with the bowl facing upward and squeeze the rim of the cervical cap between your thumb and index finger.

  Slide the cervical cap into your vagina — making sure the taller brim of the cervical cap enters your vagina first. Push the cervical cap along the rear wall of your vagina as far as it will go. Use your finger to locate your cervix and press the rim of the cervical cap around the cervix until you've completely covered it.

• Always check the cervical cap's position before sex. Squat, bear down, insert your finger into your vagina and press upward on the dome to make sure your cervix is covered. If the cervical cap is not covering your cervix completely, either push it onto the cervix or remove it and reinsert it.

• Gently remove the cervical cap. After sex, leave the cervical cap in place for at least six hours and up to two days. To remove the cervical cap, squat, bear down and rotate the cap. Relax your muscles and push up on the dome of the cervical cap to break the seal.

  Grasp the removal strap and gently pull. Be careful not to scratch your vagina. After removal, wash the cervical cap with mild soap and warm water and let it air-dry. Store the cervical cap in its provided container.