Cervical barrier methods
Cervical barriers, including diaphragms and cervical caps, are among the oldest known contraceptives. Ancient texts document the use of crocodile dung pessaries, lemon halves, and beeswax plugs as cervical barriers. A century ago, diaphragms and cervical caps were popular contraceptives in many European countries, and during the 1920’s and 30s, the diaphragm was the most frequently prescribed contraceptive in the United States.
Today cervical barriers are approved for use in family planning programs around the world. Distribution is limited, however, and current usage rates are low compared to other contraceptive methods.
Cervical barriers are woman-initiated and simple to use, and because they are typically durable and reusable, they can be considered low-cost contraceptive methods. Cervical barriers are also safe and effective, though contraceptive effectiveness depends on correct and consistent use, like other contraceptive methods. The diaphragm is 80-94% effective when used with spermicide, and the cervical cap is 80-91% effective (with spermicide) for women who have not given birth. The effectiveness of the cap is lower for women who have given birth; for these women, the cap is between 60-80% effective when used with spermicide. Cervical barriers may appeal to women who cannot or chose not to use hormonal contraceptive methods, such as implants, injectables, patches, and oral contraceptives.
Instructions for use of cervical barriers as contraceptives tell users to partially fill the device with spermicide and insert it before intercourse. See the Contraception Report for diaphragms or cervical caps for specific instructions. Some methods require users to apply more spermicide before additional acts of intercourse. Users must leave the method in place for six to eight hours after intercourse, but they should not wear it beyond the specified time (this time varies by method in the U.S. vs. Europe).
Spermicide use is not recommended for women at high risk of HIV infection. Information on the contraceptive efficacy of cervical barriers used without spermicide is not currently available. Given that women at high risk of HIV infection should be advised against using the diaphragm with an N-9 spermicide, research is urgently needed on whether cervical barriers used with a non-spermicidal lubricant are effective contraceptives or offer any HIV/STI protection. A few studies have examined the contraceptive effectiveness of the diaphragm with and without spermicide, however, the findings have not resulted in a definitive answer as to whether using a diaphragm with spermicide provides greater effectiveness than using the diaphragm alone or with a non-spermicidal lubricant.
Cervical barriers have characteristics that make them appealing to many women. For example, cervical barriers are female-initiated and female-controlled methods. Female-initiated methods refer to contraceptives or HIV/STI prevention methods such as the female condom that can be used by a woman or girl to protect herself from pregnancy or HIV/STI but require male cooperation. Female-controlled methods are those that do not require male cooperation, such as the diaphragm, cervical cap, and sponge.
Further, cervical barriers are a good option for women who have contraindications to hormonal methods. If inserted before sex, cervical barriers do not interrupt sexual activity, and they may be used without a partner’s knowledge. They are reusable and durable and relatively low cost. Finally, cervical barriers have a long-established safety and effectiveness track record.
In addition to offering protection from pregnancy, some research suggests that cervical barriers have the potential to protect women from some sexually transmitted infections (STIs), including HIV, the virus that causes AIDS. The possibility that cervical barriers may offer protection against pregnancy and STIs, including HIV, has sparked renewed interest in these methods. Researchers representing a range of disciplines, including the scientific, regulatory, and product-development fields, are examining the potential of existing or modified devices for HIV/STI prevention.
Sexually transmitted infections, including HIV, are a grave and growing problem for women around the world. Not only are women at greater risk of acquiring STIs than men for biological, social, economic, and cultural reasons, but, in most cases, the consequences of contracting STIs – including infertility, ectopic pregnancy, and cervical cancer – are more serious and permanent for women. Today, women are the fastest-growing population with HIV, and most become infected through heterosexual contact.
Women need products designed to protect them from HIV and other STIs. Condom use is the best known way for sexually active men and women to prevent transmission of HIV, but some women have difficulty negotiating male condom use. The only available female-initiated prevention method is the female condom. In the future, microbicides formulated as gels, creams, suppositories, or films could substantially reduce the transmission of HIV and other STIs and provide an alternative method of protection for women and couples who, for a variety of reasons, cannot or do not use condoms to prevent transmission of HIV/STIs. Cervical barriers may be able to be used in combination with a future microbicide to offer additional protection. Cervical barriers, the female condom, and microbicides may soon give women all over the world more options for protecting themselves against HIV and other STIs. Vaccines against HIV are also currently being researched and could provide another way for women to protect themselves from HIV.
Useful links on cervical barriers