Opinion: Reasons to Have Confidence in Condoms

Note: The following is a condensed version of a chapter appearing in FHI's recently published The Latex Condom -- Recent Advances, Future Directions.

By Dr. Erin T. McNeill, FHI Research Scientist

Network: Spring 1998, Vol. 18, No. 3

If used regularly and correctly, latex condoms are very reliable and effective, a powerful means to prevent pregnancy and disease. However, condoms are not being used as much as they should be, mainly because of negative perceptions among users and health-care providers alike. Here are several good reasons to have greater confidence in latex condoms:

When used correctly and consistently, condoms are an effective means of preventing pregnancy. Pregnancy rates for condoms range from 3 percent to almost 14 percent. This means three to 14 out of 100 women get pregnant in a year using only condoms for contraception. However, these pregnancies are not due primarily to condom failure. Higher pregnancy rates during typical condom use reflect inconsistent and incorrect use. If a women does not use a condom during just one fertile phase in a year, she has a four-times higher risk of becoming pregnant than if she uses condoms consistently and experiences occasional breakage. Moreover, the risk of breakage is concentrated in certain couples. This means that the majority of couples who use condoms consistently are at very low risk of pregnancy.

When used correctly and consistently, condoms are an effective means of preventing STD/HIV. A woman's fertile period is intermittent, but men and women can be at risk of contracting an STD, including HIV, at every intercourse. Study after study has shown that condoms are extremely effective against STDs if they are used consistently and correctly. In many cases, a person does not know his or her partner's STD status. In cases where partners are not infected, intermittent condom use will seem to protect against transmission in a proportion of cases since no STD was in fact present. However, if one partner is HIV-positive, then there is a guaranteed risk of exposure to infection at every unprotected intercourse, and inconsistent condom use offers little protection against HIV, compared with nonuse.

Latex condoms provide an impermeable mechanical barrier. Latex condoms are impermeable to bacteria, viruses and sperm. Therefore, unless a condom breaks or completely slips off in a clinically significant manner, i.e., during or after ejaculation, or has manufacturing defects such as pinholes (which are extremely rare), users are not exposed to semen or viral particles. (Condoms only form a barrier between the penis and vagina, yet some sexually transmitted viruses, such as human papilloma viruses, or genital warts, can be transmitted via skin-to-skin contact between the scrotal skin and the perineum. Therefore, even intact condoms cannot prevent the transmission of all organisms. The female condom, which covers more of the external genitalia, may afford greater protection.) Broken or leaky condoms certainly expose couples to risks, but not using condoms exposes people to a far higher magnitude of risk.

Most users do not break condoms, and a proportion of breakage is preventable. Most people who use condoms, especially once they gain experience with them, rarely experience breakage or slippage; condom failure is actually concentrated among a small percentage of users. Studies have identified characteristics of condom users that seem to be associated with more frequent condom breakage and slippage. A history of condom failure and inexperience in using condoms are the characteristics most strongly associated with condom failure. Some research also suggests that young age, not living with one's sexual partner, low level of education, having multiple sexual partners, low income and large penis size are correlated with increased risk of condom breakage or slippage. Studies also suggest that certain behaviors are associated with increased breakage or slippage, including: improper storage, rough handling of condoms, improper technique in putting on a condom, not encouraging natural vaginal lubrication, using excessive added lubricants (especially oil-based), lengthy or vigorous sex, anal intercourse, loss of erection prior to withdrawal, and re-use of condoms. Some failures may be prevented through counseling to avoid obvious problems like opening condom packages with sharp objects.

Today's condom is manufactured with greater precision. Latex condoms are better formulated, processed, finished and packaged than they have ever been. During formulation, there is greater control over the chemical processes of oxidation and vulcanization, which reduces the risk of condom failure due to aging. Also, current knowledge about stress and strain properties during use enables manufacturers to adjust the latex formulation in ways that optimize condom performance. In recognition of a growing concern about latex allergy from a variety of other products, condom manufacturers are making greater efforts to remove latex protein allergens during processing. Manufacturers are also aware of the potential risk posed from using talc as a dry lubricant, and many are shifting to cornstarch. However, since cornstarch may not be entirely without risk, the search for a better and safer dry finishing powder continues.

Condom use is improved by the right lubricant. Wet lubricants placed on finished condoms prior to packaging include water-based lubricants, alone or with spermicide added, and liquid silicone. The evidence suggests that using appropriate quantities of the right types of lubricant (in manufacturing and during use) decreases breakage and increases satisfaction with condoms. Use of water-based lubricants may increase slippage, but data suggest that the protective effect against breakage may outweigh any risk of increased slippage. There is no evidence that spermicidally-lubricated condoms confer any advantage by increasing efficacy against pregnancy or disease, in spite of a consumer perception that spermicidal lubricant ought to do this. Indeed, there is some preliminary evidence that spermicidal lubrication may promote leaching of latex allergens, thereby potentiating the risk of allergy. Since spermicidally-lubricated condoms also have a shorter designated shelf life, silicone is a preferable lubricant.

Condoms in intact foil packages last at least five years. Adequate packaging is crucial to the long-term integrity of latex condoms. Plastic packages expose condoms to greater and more rapid deterioration from oxidation, humidity, ozone and ultraviolet light than do foil packages. When properly sealed in foil packages, modern latex condoms are quite resistant to adverse environmental conditions and will retain their quality for at least five years and probably longer. Thus, all condoms should be packaged in aluminum foil, or foil-plastic laminate packages.

Quality control and post-production quality assurance help ensure a reliable product. In addition to many specific improvements in all aspects of latex condom manufacture, an extensive system of internal and external quality control and quality assurance is now in place to ensure high quality of condoms. In the era of AIDS, the condom is considered a potentially life-saving medical device, and as such is subject to strict quality standards. Through both worldwide and regional standards bodies, minimum acceptable quality levels are enforced, some by law and others through consensus guidelines. The wide net cast by current standards bodies ensures that the great majority of condoms (including condoms supplied by international donors) are manufactured to high standards.

While it is not yet clear how well the test standards predict results during human use, a combination of tests can provide clear guidance on the quality of condoms in the field. The current battery of tests -- condom dimensions, package integrity, lubricant quantity, water leakage, tensile properties, and air-burst properties -- assure that newly manufactured condoms conform to international standards and specifications. But uncertainty still surrounds the validity of these tests in assessing condom deterioration over time and predicting performance in human use. For the time being, a combination of condom age and relevant tests (air-burst, package integrity and lubricant quantity) should be used to assess possible condom deterioration. No single laboratory test is an adequate surrogate for condom performance during use.

In time, condoms made of non-latex, synthetic materials may replace latex condom use in part or altogether. Synthetic condoms made from thermoplastic elastomers have several advantages over latex condoms. They have more controllable physical properties such as strength and can be fashioned in any shape and size. They may transmit heat better than latex, allowing for greater sensitivity during intercourse. However, only two synthetic condoms are being sold: the Avanti male condom (London International Group) and the female condom (Female Health Company). Unfortunately, the limited availability and relatively high cost of synthetic condoms mean that most consumers will need to rely on latex condoms for the foreseeable future.