Birth control


Birth control is a regimen of one or more actions, devices, or medications followed in order to deliberately prevent or reduce the likelihood of a woman becoming pregnant or giving birth. For many people, birth control is an integral component of family planning. Mechanisms which are intended to reduce the likelihood of the fertilisation of an ovum by a spermatozoon may more specifically be referred to as contraception.

History

Probably the oldest methods of contraception (aside from sexual abstinence) are coitus interruptus, certain barrier methods, and herbal methods (emmenagogues and abortifacients).

Coitus interruptus (withdrawal of the penis from the vagina prior to ejaculation) probably predates any other form of birth control. Once the relationship between the emission of semen into the vagina and pregnancy was known or suspected, some men began to use this technique. This is not a particularly reliable method of contraception, as few men have the self-control to correctly practice the method at every single act of sexual intercourse. Although it is commonly believed that pre-ejaculate fluid can cause pregnancy, modern research has shown that pre-ejaculate fluid does not contain viable sperm.[1][2]

There are historic records of Egyptian women using a pessary (a vaginal suppository) made of various acidic substances (crocodile dung is alleged) and lubricated with honey or oil, which may have been somewhat effective at killing sperm. However, it is important to note that the sperm cell was not discovered until Anton van Leeuwenhoek invented the microscope in the late 17th century, so barrier methods employed prior to that time could not know of the details of conception. Asian women may have used oiled paper as a cervical cap, and Europeans may have used beeswax for this purpose. The condom appeared sometime in the 17th century, initially made of a length of animal intestine. It was not particularly popular, nor as effective as modern latex condoms, but was employed both as a means of contraception and in the hopes of avoiding syphilis, which was greatly feared and devastating prior to the discovery of antibiotic drugs.

Various abortifacients have been used throughout human history, although many do not associate induced abortion with the term "birth control". Some of them were effective, some were not; those that were most effective also had major side effects. One abortifacient reported to have low levels of side effects — silphium — was harvested to extinction around the 1st century.[3]The ingestion of certain poisons by the female can disrupt the reproductive system; women have drunk solutions containing mercury, arsenic, or other toxic substances for this purpose. The Greek gynaecologist Soranus in the 2nd century suggested that women drink water that blacksmiths had used to cool metal. The herbs tansy and pennyroyal are well-known in folklore as abortive agents, but these also "work" by poisoning the woman. Levels of the active chemicals in these herbs that will induce a miscarriage are high enough to damage the liver, kidneys, and other organs, making them very dangerous. However, in those times where risk of maternal death from postpartum complications was high, the risks and side effects of toxic medicines may have seemed less onerous. Some herbalists claim that black cohosh tea will also be effective in certain cases as an abortifacient.[4]

The fact that various effective methods of birth control were known in the ancient world sharply contrasts with a seeming ignorance of these methods in wide segments of the population of early modern Christian Europe. This ignorance continued far into the 20th century, and was paralleled by eminently high birth rates in European countries during the 18th and 19th centuries.[5] Some historians have attributed this to a series of coercive measures enacted by the emerging modern state, in an effort to repopulate Europe after the population catastrophe of the Black Death, starting in 1348. According to this view, the witch hunts were the first measure the modern state took in an attempt to eliminate knowledge about birth control within the population, and monopolize it in the hands of state-employed male medical specialists (gynecologists). Prior to the witch hunts, male specialists were unheard of, because birth control was naturally a female domain.[6]

Presenters at a family planning conference told a tale of Arab traders inserting small stones into the uteruses of their camels in order to prevent pregnancy, a concept very similar to the modern IUD. Although the story has been repeated as truth, it has no basis in history and was meant only for entertainment purposes.[7]The first interuterine devices (which occupied both the vagina and the uterus) were first marketed around 1900. The first modern intrauterine device (contained entirely in the uterus) was described in a German publication in 1909, although the author appears to have never marketed his product.[8]

The Rhythm Method (with a rather high method failure rate of ten percent per year) was developed in the early 20th century, as researchers discovered that a woman only ovulates once per menstrual cycle. Not until the 1950s, when scientists better understood the functioning of the menstrual cycle and the hormones that controlled it, were oral contraceptives and modern methods of fertility awareness (also called natural family planning) developed.

Methods

Physical methods

Barrier methods

Barrier methods place a physical impediment to the movement of sperm into the female reproductive tract.

The most popular barrier method is the male condom, a latex or polyurethane sheath placed over the penis. The condom is also available in a female version, which is made of polyurethane. The female condom has a flexible ring at each end — one secures behind the pubic bone to hold the condom in place, while the other ring stays outside the vagina.

Cervical barriers are devices that are contained completely within the vagina. The contraceptive sponge has a depression to hold it in place over the cervix. The cervical cap is the smallest cervical barrier. It stays in place by suction to the cervix or to the vaginal walls. The Lea's shield is a larger cervical barrier, also held in place by suction. The diaphragm fits into place behind the woman's pubic bone and has a firm but flexible ring, which helps it press against the vaginal walls.

The SILCS diaphragm is a new diaphragm design which is still in clinical testing and is not yet available.

Hormonal methods

There are variety of delivery methods for hormonal contraception.

Combinations of synthetic oestrogens and progestins (synthetic progestogens) are commonly used. These include the combined oral contraceptive pill ("The Pill"), the Patch, and the contraceptive vaginal ring ("NuvaRing"). Not currently available for sale in the United States is Lunelle, a monthly injection.

Other methods contain only a progestin (a synthetic progestogen). These include the progestin only pill (the POP or 'minipill'), the injectables Depo Provera (a depot formulation of medroxyprogesterone acetate given as an intramuscular injection every three months) and Noristerat (norethisterone acetate given as an intramuscular injection every 8 weeks), and contraceptive implants. The progestin-only pill must be taken at more precisely remembered times each day than combined pills. The first contraceptive implant, the original 6-capsule Norplant, was removed from the market in the United States in 1999, though a newer single-rod implant called Implanon was approved for sale in the United States on July 17, 2006. The various progestin-only methods may cause irregular bleeding during use.

Ormeloxifene (Centchroman)

Ormeloxifene (Centchroman) is a selective oestrogen receptor modulator, or SERM. It causes ovulation to occur asynchronously with the formation of the uterine lining, preventing implantation of a zygote. It has been widely available as a birth control method in India since the early 1990s, marketed under the trade name Saheli®. Centchroman is legally available only in India.

Intrauterine methods

These are contraceptive devices which are placed inside the uterus. They are usually shaped like a "T" — the arms of the T hold the device in place. There are two main types of intrauterine contraceptives: those that contain copper (which has a spermicidal effect), and those that release a progestogen (in US the term progestin used).

The terminology used for these devices differs in the United Kingdom and the United States. In the US, all devices which are placed in the uterus to prevent pregnancy are referred to as Intra-Uterine Devices (IUDs). In the UK, only copper-containing devices are called IUDs, and hormonal intrauterine contraceptives are referred to with the term Intra-Uterine System (IUS). This may be because there are seven types of copper IUDs available in the UK, compared to only one in the US.

Emergency contraception

Some combined pills and POPs may be taken in high doses to prevent pregnancy after a birth control failure (such as a condom breaking) or after unprotected sex. Hormonal emergency contraception is also known as the "morning after pill," although it is licensed for use up to three days after intercourse.

Copper intrauterine devices may also be used as emergency contraception. For this use, they must be inserted within five days of the birth control failure or unprotected intercourse.

Because emergency contraception may prevent a fertilized egg from developing, some people consider it a form of abortion.

Induced abortion

Abortion can be done with surgical methods, usually suction-aspiration abortion (in the first trimester) or dilation and evacuation (in the second trimester). Medical abortion uses drugs to end a pregnancy and is approved for pregnancies of less than 8 weeks gestation.

Some herbs are believed to cause abortion (abortifacients). Peer-reviewed research has proven the efficacy of some of these substances, but the use of herbs to induce abortion is not recommended, due to the risk of serious side effects.[9][4]

Abortion is subject to ethical debate.

Sterilization

Surgical sterilization is available in the form of tubal ligation for women and vasectomy for men.

A non-surgical sterilization procedure, Essure, is also available for women.

Behavioral methods

Fertility awareness methods

Fertility awareness (FA) methods involve a woman's observation and charting of one or more of her body's primary fertility signs, to determine the fertile and infertile phases of her cycle. Unprotected sex is restricted to the least fertile period. During the most fertile period, barrier methods may be availed, or she may abstain from intercourse. Different methods track one or more of the three primary fertility signs:[10] changes in basal body temperature, in cervical mucus, and in cervical position, though cervical position is most frequently used as a cross-reference with one or both of the others. If a woman tracks both basal body temperature and another primary sign, the method is referred to as symptothermal. Other bodily cues such as mittelschmerz are considered secondary indicators. A woman may chart these events on paper or with software.

The term natural family planning (NFP) is sometimes used to refer to any use of FA methods. However, this term specifically refers to the practices which are permitted by the Roman Catholic Churchbreastfeeding infertility, and periodic abstinence during fertile times. FA methods may be used by NFP users to identify these fertile times.

Statistical methods

Statistical methods such as the Rhythm Method and Standard Days Method are dissimilar from observational fertility awareness methods, in that they do not involve the observation or recording of bodily cues of fertility. Instead, statistical methods estimate the likelihood of fertility based on the length of past menstrual cycles. Statistical methods are much less accurate than fertility awareness methods, and are considered by many fertility awareness teachers to have been obsolete for at least 20 years.

Coitus interruptus

Coitus interruptus (literally "interrupted sex"), also known as the withdrawal method, is the practice of ending sexual intercourse ("pulling out") before ejaculation. The main risk of coitus interruptus is that the man may not make the maneuver in time. Although concern has been raised about the risk of pregnancy from sperm in pre-ejaculate, several small studies[11][12] have failed to find any viable sperm in the fluid.

Avoiding vaginal intercourse

The risk of pregnancy from non-vaginal sex, such as outercourse (sex without penetration), anal sex, or oral sex is low. (A very small risk comes from the possibility of semen leaking onto the vulva (with anal sex) or coming into contact with an object, such as a hand, that later contacts the vulva). However, with this method, discipline is required to prevent the progression to intercourse.

Abstinence

Sexual abstinence is the practice of refraining from all sexual activity.

Lactational

Most breastfeeding women have a period of infertility after the birth of their child. The Lactational Amenorrhea Method, or LAM, gives guidelines for determining the length of a woman's period of breastfeeding infertility.

Methods in development

For females

* Praneem is a polyherbal vaginal tablet being studied as a spermicide, and a microbicide active against HIV.[13]* BufferGel is a spermicidal gel being studied as a microbicide active against HIV.[14]* Duet is a disposable diaphragm in development that will be pre-filled with BufferGel.[15] It is designed to deliver microbicide to both the cervix and vagina. Unlike currently available diaphragms, the Duet will be manufactured in only one size and will not require a prescription, fitting, or a visit to a doctor.[14]

For males

Other than condoms and withdrawal, there are currently no available methods of reversible contraception which males can use or control. Several methods are in research and development:

Misconceptions

Modern misconceptions and urban legends have given rise to a great deal of false claims:

Effectiveness

<span class="boilerplate seealso">See also the table at: Comparison of birth control methods</span>

Effectiveness is measured by how many women become pregnant using a particular birth control method in a year. Thus, if 100 women use a method that has a 12 percent failure rate, then sometime during that year, 12 of the women should become pregnant.

The most effective methods in typical use are those that do not depend upon regular user action. Surgical sterilization, Depo-Provera, implants, and intrauterine devices (IUDs) all have failure rates of less than one percent per year for perfect use. Depo-Provera, or the shot, has a typical failure rate of three percent, while sterilization, implants, and IUDs still have a typical failure use under one percent.

Other methods may be highly effective if used consistently and correctly, but can have typical use failure rates that are considerably higher due to incorrect or ineffective usage by the user. Hormonal contraceptives, fertility awareness methods, and ecological breastfeeding, if used strictly, have failure rates of less than 1% per year.[23][24][25][26] Typical use failure rates of hormonal contraceptives are as high as eight percent per year. Fertility awareness methods as a whole have typical-use failure rates as high as 25 percent per year; however, as stated above, perfect use of these methods reduces the failure rate to less than 1%.[27]

Condoms and cervical barriers such as the diaphragm have similar typical use failure rates (15 and 16 percent, respectively), but perfect usage of the condom is more effective (two percent failure vs six percent) and condoms have the additional feature of helping to prevent the spread of sexually transmitted diseases such as the HIV virus. The withdrawal method, if used consistently and correctly, has a failure rate of four percent. Due to the difficulty of consistently using withdrawal correctly, it has a typical use failure rate of 27 percent[27] and is not recommended by some medical professionals,[28] although others believe it deserves more support.

Protection against sexually transmitted infections

Not all methods of birth control offer protection against sexually transmitted infections. Abstinence from all forms of sexual behavior will protect against the sexual transmission of these infections. The male latex condom offers some protection against some of these diseases with correct and consistent use, as does the female condom, although the latter has only been approved for vaginal sex. The female condom may offer greater protection against sexually transmitted infections that pass through skin to skin contact, as the outer ring covers more exposed skin than the male condom, and can be used during anal sex to guard against sexually transmitted infections. However, the female condom can be difficult to use. Frequently a woman can improperly insert it, even if she believes she is using it correctly.

The remaining methods of birth control do not offer significant protection against the sexual transmission of these diseases.

However, so-called sexually transmitted infections may also be transmitted non-sexually, and therefore, abstinence from sexual behavior does not guarantee 100 percent protection against sexually transmitted infections. For example, HIV may be transmitted through contaminated needles which may be used in intravenous drug use, tattooing, body piercing, or injections. Health-care workers have acquired HIV through occupational exposure to accidental injuries with needles.[29]

Religious and cultural attitudes

Religious views on birth control

Religions vary widely in their views of the ethics of birth control. In Christianity, the Roman Catholic Church accepts only Natural Family Planning,[30] while Protestants maintain a wide range of views from allowing none to very lenient.[31] Views in Judaism range from the stricter Orthodox sect to the more relaxed Reformed sect.[32] In Islam, contraceptives are allowed if they do not threaten health or lead to sterilty, although their use is discouraged.[33] Hindus may use both natural and artificial contraceptives.[34]

Birth control education

Many teenagers, most commonly in developed countries, receive some form of sex education in school. What information should be provided in such programs is hotly contested, especially in the United States and Great Britain. Possible topics include reproductive anatomy, human sexual behavior, information on sexually transmitted diseases (STDs), social aspects of sexual interaction, negotiating skills intended to help teens follow through with a decision to remain abstinent or to use birth control during sex, and information on birth control methods.

One type of sex education program, called abstinence-only education, promotes abstinence until marriage and does not provide information on birth control, or heavily emphasizes negative information such as failure rates. Because abstinence offers better protection against pregnancy and disease than sexual activity with even the best birth control methods, advocates of abstinence-only education believe they will result in decreased rates of teenage pregnancy and STD infection. However, some studies have found that abstinence-only sex education programs actually increase the rates of pregnancy and STDs in the teenage population.[35][36]

See also

External links

Citations