Condom
A condom is a sheath-shaped barrier device primarily used during sexual intercourse to reduce the probability of pregnancy or a sexually transmitted infection. There are both external condoms, also called male condoms, and internal condoms.
The external condom is rolled onto an erect penis before intercourse and works by forming a physical barrier which limits skin-to-skin contact, exposure to fluids, and blocks semen from entering the body of a sexual partner. External condoms are typically made from latex and, less commonly, from polyurethane, polyisoprene, or lamb intestine. External condoms have the advantages of ease of use, ease of access, and few side effects. Individuals with latex allergy should use condoms made from a material other than latex, such as polyurethane. Internal condoms are typically made from polyurethane and may be used multiple times.
With proper use—and use at every act of intercourse—women whose partners use external condoms experience a 2% per-year pregnancy rate. With typical use, the rate of pregnancy is 18% per-year. Their use greatly decreases the risk of gonorrhea, chlamydia, trichomoniasis, hepatitis B, and HIV/AIDS. To a lesser extent, they also protect against genital herpes, human papillomavirus, and syphilis.
Condoms as a method of preventing STIs have been used since at least 1564. Rubber condoms became available in 1855, followed by latex condoms in the 1920s. It is on the World Health Organization's List of Essential Medicines. As of 2019, globally around 21% of those using birth control use the condom, making it the second-most common method after female sterilization. Rates of condom use are highest in East and Southeast Asia, Europe and North America.
Medical uses
Birth control
The effectiveness of condoms, as of most forms of contraception, can be assessed two ways. Perfect use or method effectiveness rates only include people who use condoms properly and consistently. Actual use, or typical use effectiveness rates are of all condom users, including those who use condoms incorrectly or do not use condoms at every act of intercourse. Rates are generally presented for the first year of use. Most commonly the Pearl Index is used to calculate effectiveness rates, but some studies use decrement tables.The typical use pregnancy rate among condom users varies depending on the population being studied, ranging from 10 to 18% per year. The perfect use pregnancy rate of condoms is 2% per year. Condoms may be combined with other forms of contraception for greater protection.
Sexually transmitted infections
Condoms are widely recommended for the prevention of sexually transmitted infections. They have been shown to be effective in reducing infection rates in both men and women. While not perfect, the condom is effective at reducing the transmission of organisms that cause AIDS, genital herpes, cervical cancer, genital warts, syphilis, chlamydia, gonorrhea, and other diseases. Condoms are often recommended as an adjunct to more effective birth control methods in situations where STI protection is also desired.According to a 2000 report by the National Institutes of Health, consistent use of latex condoms reduces the risk of HIV transmission by approximately 85% relative to risk when unprotected, putting the seroconversion rate at 0.9 per 100 person-years with condom, down from 6.7 per 100 person-years. Analysis published in 2007 from the University of Texas Medical Branchand the World Health Organization found similar risk reductions of 80–95%.
The 2000 NIH review concluded that condom use significantly reduces the risk of gonorrhea for men. A 2006 study reports that proper condom use decreases the risk of transmission of human papillomavirus to women by approximately 70%. Another study in the same year found consistent condom use was effective at reducing transmission of herpes simplex virus-2, also known as genital herpes, in both men and women.
Although a condom is effective in limiting exposure, some disease transmission may occur even with a condom. Infectious areas of the genitals, especially when symptoms are present, may not be covered by a condom, and as a result, some diseases like HPV and herpes may be transmitted by direct contact. The primary effectiveness issue with using condoms to prevent STIs, however, is inconsistent use.
Condoms may also be useful in treating potentially precancerous cervical changes. Exposure to human papillomavirus, even in individuals already infected with the virus, appears to increase the risk of precancerous changes. The use of condoms helps promote regression of these changes. In addition, researchers in the UK suggest that a hormone in semen can aggravate existing cervical cancer, condom use during sex can prevent exposure to the hormone.
Causes of failure
Condoms may slip off the penis after ejaculation, break due to improper application or physical damage, or break or slip due to latex degradation. The rate of breakage is between 0.4% and 2.3%, while the rate of slippage is between 0.6% and 1.3%. Even if no breakage or slippage is observed, 1–3% of women will test positive for semen residue after intercourse with a condom. Failure rates are higher for anal sex, and until 2022, condoms were only approved by the FDA for vaginal sex. The One Male Condom received FDA approval for anal sex on 23 February 2022.Different modes of condom failure result in different levels of semen exposure. If a failure occurs during application, the damaged condom may be disposed of and a new condom applied before intercourse begins – such failures generally pose no risk to the user. One study found that semen exposure from a broken condom was about half that of unprotected intercourse; semen exposure from a slipped condom was about one-fifth that of unprotected intercourse.
Standard condoms will fit almost any penis, with varying degrees of comfort or risk of slippage. Many condom manufacturers offer "snug" or "magnum" sizes. Some manufacturers also offer custom sized-to-fit condoms, with claims that they are more reliable and offer improved sensation/comfort. Some studies have associated larger penises and smaller condoms with increased breakage and decreased slippage rates, but other studies have been inconclusive.
It is recommended for condoms manufacturers to avoid very thick or very thin condoms, because they are both considered less effective. Some authors encourage users to choose thinner condoms "for greater durability, sensation, and comfort", but others warn that "the thinner the condom, the smaller the force required to break it".
Experienced condom users are significantly less likely to have a condom slip or break compared to first-time users, although users who experience one slippage or breakage are more likely to suffer a second such failure. An article in Population Reports suggests that education on condom use reduces behaviors that increase the risk of breakage and slippage. A Family Health International publication also offers the view that education can reduce the risk of breakage and slippage, but emphasizes that more research needs to be done to determine all of the causes of breakage and slippage.
Among people who intend condoms to be their form of birth control, pregnancy may occur when the user has sex without a condom. The person may have run out of condoms, or be traveling and not have a condom with them, or dislike the feel of condoms and decide to "take a chance". This behavior is the primary cause of typical use failure.
Another possible cause of condom failure is sabotage. One motive is to have a child against a partner's wishes or consent. Some commercial sex workers from Nigeria reported clients sabotaging condoms in retaliation for being coerced into condom use. Using a fine needle to make several pinholes at the tip of the condom is believed to significantly impact on their effectiveness. Cases of such condom sabotage have occurred.
Use of multiple condoms ("double bagging")
"Double bagging", the practice of using two condoms at once, might increase or decrease the risk of sperm leaking through; expert opinions are divided, and it may depend on additional factors. Using two condoms may increase the risk of slippage, though the condoms often become stuck together after use. It may also increase the chance of tearing or breaking if there is friction between the condoms. However, lubricant can be added between the condoms to decrease friction. If multiple condoms are used, an exposure break only occurs if all of the condoms are broken.A literature review in Contraceptive Technology Update recommends that "When clinicians see women and men who have experienced multiple breaks or slippages, it would be wise to encourage them to use two condoms." A literature review by Planned Parenthood concludes that "It seems that there is no evidence-based information to support advising against double bagging. On the other hand, the evidence to support double bagging is limited, but positive. It may be best to advise that if double bagging increases a person's sense of comfort and security, there is no harm in using more than one condom, and there may be benefits."
With two latex condoms, heat and friction can cause them to disintegrate; however, layering a lambskin condom and a latex condom can be helpful if one of the partners is allergic to latex. For sex workers, presenting clients with a leading question, such as the choice between one or two condoms, or between a male or a female condom, is often easier than directly requesting that they use a condom, and makes it more likely that a condom will be used. Using multiple condoms, especially more than two, may decrease pleasure, prolong intercourse, and/or cause irritation to a woman's vagina. The use of multiple condoms is a behavioral therapy for treating premature ejaculation, though it is not always sufficient.
In summary, the consensus seems to be that using two condoms instead of one usually decreases risk if properly lubricated but increases risk if not, and that using more condoms generally results in less sexual stimulation for men.