Cervical cap as a barrier method of birth control

The cervical cap is a barrier method of birth control. A cervical cap, which is made of rubber and shaped like a large thimble, fits tightly over the opening to the uterus (the cervix). It is used with a spermicide. A woman should insert the cap up to 6 hours before having sexual intercourse and should leave the cap in place for 6 hours after; it can be left in place for up to 48 hours. More spermicide does not have to be inserted if the woman has sex again within that time.

Prescription method

The cap requires a prescription from a health professional. Getting a cervical cap usually requires two visits to a health professional: one visit to fit the device, and a return visit with the cap already in place to be certain the woman is using it correctly.

Effectiveness in preventing pregnancy

The cervical cap is less effective for women who have had a vaginal birth. It is a better choice for women who have not had a vaginal delivery.

• Failure rates for women who have never delivered vaginally range from 9% to 16%. In other words, when the cap is used perfectly by these women, 9 out of 100 women will become pregnant in the first year of use; with typical use, 16 of 100 will become pregnant.¹
• Failure rates for women who have had a vaginal delivery range from 20% to 32%. With perfect use, 20 out of 100 of these women will become pregnant in the first year of use; with typical use, 32 of 100 will become pregnant.¹

The difference in cervical cap failure rates for women who have borne children vaginally and those who have not may be due to changes in the cervix after vaginal delivery.

Effectiveness in preventing sexually transmitted diseases (STDs)

The cervical cap does not protect against sexually transmitted diseases (STDs), including infection with HIV. The use of spermicides with nonoxynol 9 may increase your risk of getting HIV/AIDS. So be sure to use a condom for STD protection unless you know that you and your partner are infection-free.

Advantages of cervical cap

• It does not affect future fertility for either the woman or the man.
• It is used only at the time of sexual intercourse.
• It is safe to use while breast-feeding.
• It is less expensive than hormonal methods of birth control.

Disadvantages of cervical cap

Failure rates for barrier methods are higher than for most other methods of birth control. Other disadvantages of barrier methods include the following:

• The cervical cap should not be used by a woman who has ever had toxic shock syndrome.
• The cervical cap cannot be used during a woman's period.
• Some women experience odor problems if the cervical cap is left in place longer than 24 hours.
• The cervical cap can be difficult to place properly or to remove.
• Use of the cervical cap can irritate the cervix. The cervical cap should not be used by women who currently have a vaginal or cervical infection or who have an abnormal Pap smear and the cause is not known. Use of the cervical cap may increase the risk of an abnormal Pap smear, requiring more frequent Pap test follow-up.
• The cervical cap is less effective in preventing pregnancy after a woman has had a vaginal delivery.
• Some people are embarrassed to use this method or feel the method may interrupt foreplay or intercourse.
• A couple must be comfortable with using the cap and be prepared to use it every time they have sex.
• The cap cannot be used if either person is allergic to latex.

It is important to check the cap for any cracks, holes, or other damage that would reduce its effectiveness. Avoid using any petroleum-based vaginal creams, oils, or ointments, which can damage the rubber. But water-based personal lubricants, such as Astroglide and K-Y Jelly, are safe to use.

Citations

1. Trussell J (2004). The essentials of contraception: Efficacy, safety, and personal considerations. In RA Hatcher et al., eds., Contraceptive Technology, 18th ed., pp. 221–252. New York: Ardent Media.