Essay:Effectiveness of birth control
The following is simply a list of various forms of birth control and their effectiveness. They are arranged by their approximate strengths. If one of my claims are unstated or something, just send me a message and I'll fix it. Feel free to do cleanup on this article to improve it, etc., but remember that the reason we have this here is because some of us find "very effective" or "somewhat effective" too vague and need percents. And some of the pro-lifers say that condoms fail a lot and stuff like that, so knowing the actual numbers helps.
DISCLAIMER: This is not a guide to help you choose what type(s) of birth control you should use, even though we have included percentages and such. Understanding how effective different birth control methods are is simply included to help dispel Focus on the Family's myths on condoms and such.
Grade-A (~100% effectiveness)
Abstinence is completely refraining from sexual intercourse. It works by depositing no sperm within the vagina to fertilize the egg cell. This method is almost 100% effective in preventing pregnancy, with a few exceptions in mythology. Generally, abstinence carries no risks, but may cause a degree of psychological frustration and short sightedness. This method also may lead to more pregnancies since abstinence only education, most often supported by the religious right, provides no education regarding preventing pregnancy or disease if passion unexpectedly gets the upper hand. These "education" programs often actively discourage the use of contraception that is known to be effective, particularly by twisting or quote mining the data on effectiveness or even by outright lying about it. Other sex education programs, ones which aren't endorsed by the religious right, teach abstinence in combination with conventional contraceptives and disease prevention methods.
However, saying that abstinence is 100% effective in preventing pregnancy is a bit like saying that condoms are 100% effective when they do not fail. When abstinence does fail (which happens a lot, due to human nature), there is absolutely nothing preventing pregnancy or STDs - unless some form of contraception is used, which it often isn't due to the narrow scope of sex education provided within abstinence movements.
Abortion is not a form of contraception, since it is carried out in response to a pregnancy rather than to prevent one, but is still a highly effective method of preventing a live birth, although in a few exceptionally rare cases, a child aborted late in a pregnancy has survived. Abortion laws and methods vary around the world, as do social and ethical attitudes towards abortion. In a few countries, such as Russia, Turkey and parts of Eastern Europe, abortion is seen as an accepted choice for birth control, and women in former Soviet States have been quoted that state paid abortions were easier to get than prescription birth control adding to a culture of "abortion as birth control". In China abortions are often mandated to enforce the one-child rule. In most other countries, the emphasis is placed on the prevention of pregnancies and abortion is used as only as a last resort to terminate an unwanted pregnancy when other alternatives were unavailable or failed.
Vasectomy is a procedure in which the vas deferens (the ducts that carry sperm from the testes to the prostate gland in the male) are cut, a small section removed, and the resulting ends sealed off with small stainless steel clips. It is nearly 100% effective. This method prevents sperm from entering the semen, but carries the obvious risk of (usually) irreversible sterility. If performed by a completely incompetent doctor, however, sperm can still reach the prostate, and thus escape the male's body to potentially impregnate a woman. Also, vasectomies have been known to reverse themselves.
Tubal Ligation is a similar method of sterilization for females. The oviducts are cut and sealed, preventing eggs from reaching the uterus. Although having nearly a 100% effectiveness, as with a vasectomy, if performed incorrectly, an egg can still pass through. Unlike a sperm count after a vasectomy, there is no real test to determine the success or failure of a tubal ligation other than the lack or presence of future pregnancies. For couples comparing, it's worth noting that tubal ligation is an invasive abdominal surgery, with high risk factors, while vasectomy is a much simpler and cheaper outpatient procedure.
Some methods exist which don't serve to prevent a birth in the sense of keeping sperm from reaching the egg or keeping the egg from implanting, but rather to distract the sexual participants. These include:
Masturbation is giving oneself sexual pleasure by manual stimulation of one's own genitalia. Like abstinence, it is almost 100% effective in preventing pregnancy. Risks of blindness and hairy palms have been greatly exaggerated. (Please be sure to dispose of your batteries in an environmentally friendly manner.) It should be noted that masturbation is not exclusively a solo activity, and it is possible to stimulate another person's genitalia. When two or more more people stimulate each other with this method, it is called "mutual masturbation."
Oral sex is the simulation of the genitalia of another person (or, for the incredibly flexible, oneself) using the lips, tongue, and, if they actually enjoy it, teeth. It is nearly 100% effective in preventing pregnancy; however, as with abstinence, passions can spin out of control, causing the couple to actually do the deed without a proper means of artificial contraception.
Anal sex is the insertion of a penis or dildo into the anus. It is almost 100% effective, but there is a theoretical possibility (when the receptive partner is female) that the sperm will migrate out of the woman's anus and into her vagina. Also, it's really painful the first few times. Or so we've heard. Anal sex is riskier than vaginal sex because of the thinner, capillary-rich, walls of the anus, compared to the thick muscular walls of the vagina. This increases the likelihood of disease transmission when unprotected. If you do engage in anal sex, make sure to wash before engaging in vaginal sex to prevent possible infection of the vagina with rectal flora or fauna. Also note that unlike the vagina, the anus cannot produce its own lubrication, you must provide this yourself with appropriate products.
It should be noted that both oral and anal sex can be performed with a male condom to minimise the likelihood of disease transmission.
Grade-B (>90% effective)
A contraceptive implant is a set of capsules of progestogen implanted into the upper arm using a needle-like applicator. The hormones function similarly to oral contraception, but without the need for daily pill ingestion. Because there is no action on the woman's part, human error is not an issue, making the implant the single most effective hormonal birth control. Unlike the oral pill, it is not affected by antibiotics or sickness; however some HIV and epilepsy medications can reduce its effectiveness. The implant lasts for three years, and is over 99% effective ("Less than one woman in 1,000 will get pregnant in one year.")
The intrauterine device, or IUD, is essentially a plastic-and-copper coil inserted into the uterus by a doctor. The device itself generally acts to prevent sperm from reaching the egg. However, as the constant light abrasion of the device irritates the uterus it triggers an immune system response that prevents implantation of any fertilized eggs. This method of contraception carries a slight risk of uterine infection, and is about 99% successful in preventing pregnancy. And as Dr. House explained, the patient may become sensitized to copper and develop a full-blown allergy to it.
Oral contraception is a hormone-based female contraception pill. The hormones prevent the anterior pituitary from releasing follicle stimulation hormones, thus preventing the ovary from preparing the egg for release into the Fallopian tubes. The drug is taken daily for three weeks then one week of placebo or nothing for the body to expel the built up blood lining the uterine wall. This method is around 99% effective if the medication is taken as prescribed (important note: it clashes with some antibiotics, rendering it ineffective). Furthermore, you may have to shell out like 300 bucks for mifepristone if this shit doesn't work.
Depo Provera is a injection of a progesterone-like steroid for women which lasts at least 3 months, and is therefore given 4 times a year. The hormone functions like the other hormonal methods mentioned above. This method is also about 99% effective.
It should be noted that even when the odds of getting pregnant on correctly used hormone contraceptions are 1 in 1000 (99% effective), with over 50,000,000 American women using birth control each year, 50,000 women in the United States will still face an unwanted pregnancy when they've done "everything right".
The condom is the best known form of non-hormone based contraception, which is a latex (or "lambskin", or other synthetic plastic) sheath rolled over an erect penis, which traps sperm before it can reach the vagina. Since latex condoms also trap most bacteria and viruses, the condom is highly effective (and very recommended) in preventing the transmission of STD/STI. The usage of sheepskin condoms, although still effective at preventing sperm from reaching the vagina, have pores large enough to allow viruses, such as HIV, to pass through. Condoms carry around a 98% success rate against pregnancy when used correctly.
The female condom is a liner fitted into the vagina before intercourse which prevents the sperm from progressing past the cervix. Like latex condoms, the "female condom" prevents STD/STIs. Female Condoms should not be used in conjunction with a male condom, as the two latex surfaces will stick together and increase the risk of tearing, thus removing all protection. As with a male condom, this method carries about a 98% success rate. Modern sex ed courses that are not based on Right Wing fear tactics suggest that either the female or male condom should be used at all times even if the woman is on another form of birth control, since this is the only known method of birth control that prevents STD/STI.
Another female method for preventing pregnancy is the diaphragm, which is a latex cover for the cervix inserted into the vagina before intercourse. The diaphragm prevents sperm from entering the uterus. Combined with an application of spermicidal jelly, mentioned later, the effectiveness is around 90%. An oddity worth mentioning is that lemons were used in the 1700's as a diaphragm, and modern science has discovered they are effective at killing sperm and the HIV virus. However, other studies have concluded that lemon juice can damage vaginal tissue, so lemons are probably not a wise choice for the educated woman.
Grade-C (>80% effective)
Emergency contraceptive pills (ECPs) also known as the "morning after pill" or the "Plan B pill" is a special class of contraception that is designed to prevent a pregnancy resulting from a single act of unprotected sex. There is a very short window (generally 48 hours) in which it is effective.  The pills act to prevent both the fertilization and implantation of the embryo. It is distinct from abortion as abortions are by performed on a pregnancy which is by medical definition, after implantation. Examples of these pills include levonorgestrel (progestin) which are 89% effective, and mifepristone (These are used only at selected countries as ECPs) which are about 83% effective at ECP dosage (10 mg).
Taking the diaphragm a step further is the cervical cap, which is a cap held by suction to the cervix, also buttressed with use of a spermicide. This 85% efficient method has a possible link to cancer of the cervix, owing to the application of cell destroying chemicals right onto the cervix.
Spermicides, as mentioned above, are products designed to create a hostile environment for sperm, which kills a large enough number to prevent the egg from being fertilized. Presently, there is no significant risk known, save for the aforementioned possible link to cervical cancer. Spermicides are usually used in conjunction with the various barrier methods such as condoms and diaphragms. In typical use, the most common spermicide, nonoxynol-9, has an 80-90% rate of effectiveness.
Grade-F (<80% effective)
Withdrawal of the penis before ejaculation, also known as coitus interruptus, is self-explanatory, and is intended to prevent sperm from even entering the vagina. If done correctly, this method is still only 80%  effective since even before ejaculation, sperm can enter the woman's vagina from the pre-ejaculate. Even though there are only a few drops of seman before ejaculation, with the high number of sperm in semen, that small amount in the pre-ejaculate is enough cause a pregnancy. The greater problem is the difficulty in "doing it correctly", since it depends on good timing on the part of the male at a moment when he is least likely to be thinking about timing. The withdrawal method is often jokingly associated with Catholicism, although the Catholic Church regards it as a mortal sin (See Onanism). Apart from its problems as a birth control method, withdrawal may also detract somewhat from the joy of the occasion (unless you're a bukkake enthusiast).
The rhythm method (a.k.a. "Vatican roulette") involves keeping track of the day of ovulation, and limiting intercourse to certain days of the month. It is the only method other than abstinence that is approved by the Catholic Church. There are two serious problems with this method of birth control. The first is that sperm can survive within the fallopian tubes for up to five days, and in some cases, up to seven. The second is that women can and do get pregnant while they are on their period, it is in fact, an urban legend that this time of the month is "safe", though it is somewhat "safer". Not to mention cases where people think "rhythm method" means something totally different. Done correctly (which is very difficult to do, as it requires calendars, thermometers, and calculations that would make a rocket scientists pull out his hair) is about 70% effective.
A douche is a method of washing out the vagina and uterus with water or other substances after intercourse, and is the least effective method of birth control, if it can even be considered a method at all. By inserting a liquid medium into the vagina, you have actually propelled the sperm closer to their target. Although this does remove some sperm, not enough is removed to make this a useful form of birth control. A product known as Dr. Bronner's Soap is essentially a woo flavoured douche based around altering the pH of the vagina, but this could be actively dangerous. Alternatively if the aim is prevent implantation of the embryo into the womb, it may have to be continued for prolonged periods of time. Douching is less than 60% effective.
Herbal contraception is worth mentioning, more for historical interest than practical use. Various herbs, fruits and vegetables, including pomegrate, neem oil, marijuana, and wild carrot seeds are known to lower male or female fertility to some extent, and have been used for contraceptive purposes in the past, or in societies which do not have access to modern birth control products. However, their effectiveness is highly unreliable and does not compare favourably with modern contraceptive methods.
In the Hunter Davies novel Here We Go 'Round the Mulberry Bush, it was suggested that the radioactivity from a luminous watch placed by the testes for several hours would kill any sperm, and thus prevent conception. Unfortunately, modern luminous watches are no longer radioactive -- and even if they were, hanging a lump of radioactive material around one's genitals would not be recommended.
- (see Johnston, Levi)
- http://www.rferl.org/content/Abortion_Remains_Top_Birth_Control_Option_Russia/1145849.html Russian Birth Control options
- If you don't know why this qualification is necessary, read Myra Breckinridge, or just see Wikipedia's article on pegging. "I don't want to hurt you; I only want to teach you..."
- NHS UK patient information, retrieved July 18 2011
- Sadly, the single most common reason for unwanted pregnancies as determined by the CDC, is not taking the pill as prescribed. Called in non-medical circles "Opps, I forgot". 
- See the Wikipedia article on Emergency contraception.
- The effectiveness rate is more difficult to calculate, since not all acts of sexual activity will result in a pregnancy, and these are "one off" pills.
- Planned Parenthood onemergency contraception
- Elizabeth G. Raymond, Pai Lien Chen, Joanne Luoto, for the Spermicide Trial Group. "Contraceptive Effectiveness and Safety of Five Nonoxynol-9 Spermicides: A Randomized Trial" Obstetrics & Gynecology. 2004; 103:430-439. available online
- American pregnancy association
- see Monty Python's Every sperm is sacred for a detailed and clearly historically accurate discussion of the Catholic view
- Perhaps in terms of several 24-hour days, continuously.
- See Herbal Contraception for more information, but please don't consider this as a serious contraceptive option!