Abortion

An abortion is the termination of a pregnancy associated with the death of an embryo or a fetus. This can occur spontaneously, in the form of a miscarriage, or be intentionally induced through chemical, surgical, or other means. Generally, abortions are performed by gynaecologists or obstetricians. All mammalian pregnancies can be aborted; however, this article focuses exclusively on the abortion of human pregnancy.

There have been various methods of inducing an abortion throughout the centuries. In the 20th century, the ethics and morality of abortion became the subject of intense political debate in many areas of the world.

Definitions
Pregnancy is defined by the medical community as beginning at the implantation of the embryo. Others differ, however, placing this initiation at conception. The following medical terms are used to define an abortion:


 * Spontaneous abortion (miscarriage): An abortion due to accidental trauma or natural causes.
 * Induced abortion: An abortion deliberately caused. Induced abortions are further subcategorized into therapeutic abortions and elective abortions:
 * Therapeutic abortion
 * To save the life of the pregnant woman.
 * To preserve the woman's physical or mental health.
 * To terminate a pregnancy that would result in the birth of a child with defects which would be incompatible with life or associated with significant morbidity.
 * To selectively reduce the number of fetuses in a multiple pregnancy to lessen health risks involved.
 * Elective abortion: An abortion performed for any other reason.

Methods of birth control that prevent implantation, such as emergency contraception, are not considered to be abortion; however, emergency contraception is generally considered equivalent to abortion by those who reject the medical definition of pregnancy.

A pregnancy that ends earlier than 37 completed weeks of gestation, and where an infant is born and survives, is termed a premature birth. A pregnancy that ends with an infant dead upon birth at any gestational stage, due to causes including spontaneous abortion or complications during delivery, is termed a stillbirth.

In common parlance, the term "abortion" is synonymous with induced abortion of a human fetus.

Incidence
The incidence of and reasons for induced abortion vary in regions in which abortion is generally permitted.

It has been estimated that the total number of induced abortions performed globally is approximately 46 million per year. 26 million of these are said to occur in places in which abortion is legal; the other 20 million happen where it is illegal. Some countries, such as Belgium and the Netherlands, experience a low rate of induced abortion, while others like Russia and Vietnam have a comparatively high rate.

A 1998 study aggregated data from studies in 27 countries on the reasons women seek to terminate their pregnancies. It concluded that common factors cited to have influenced the abortion decision were the desire to delay or end childbearing, concern over the interruption of work or education, issues of financial or relationship stability, and perceived immaturity. In Finland and the United States, concern for the health risks posed by pregnancy in individual cases was not a factor commonly given, whereas in Bangladesh, India, and Kenya such a concern was found to be more prevalent. A 2004 study in which American women at clinics answered a questionnaire yielded similar results.

Some abortions are undergone as the result of societal pressures, such as eugenics, the stigmatization of disabled persons, preference for children of a specific sex, disapproval of single motherhood, insufficient economic support for families, lack of access to or rejection of contraceptive methods, or efforts toward population control (such as China's one-child policy). A combination of these factors can sometimes result in forced abortion, forced sterilization, infanticide, child abandonment, or sex-selective abortion and infanticide — which is illegal in most countries, but difficult to stop. In many areas, especially in developing nations or where abortion is illegal, women sometimes resort to "back-alley" or self-induced procedures. The World Health Organization suggests that there are 19 million terminations annually which fit its criteria for an unsafe abortion. See social issues for more information on these subjects.

Spontaneous abortion
Spontaneous abortions, generally referred to as miscarriages, occur when an embryo or fetus is lost due to natural causes. A miscarriage is spontaneous loss of the embryo or fetus before the 20th week of development. Spontaneous abortions after the 20th week are generally considered to be preterm deliveries. Most miscarriages occur very early in a pregnancy. Approximately 10-50% of pregnancies end in miscarriage, depending upon the age and health of the pregnant woman.

The risk for spontaneous abortion is greater in those with a history of more than three previous (known) spontaneous abortions, those who have had a previous induced abortion, those with systemic diseases, and in women over age 35.

Other causes can be infection (of either the woman or the fetus), immune responses, or serious systemic diseases of the woman.

A spontaneous abortion can also be caused by accidental trauma; intentional trauma to cause miscarriage is considered an induced abortion. Some governments have laws increasing the criminal liability of a person who causes a miscarriage during an assault or other violent crime.

Induced abortion
A pregnancy can be intentionally aborted in a number of ways. The manner selected depends chiefly upon the gestational age of the fetus, in addition to the legality, regional availability, and/or doctor-patient preference for specific procedures.

Surgical abortion


In the first fifteen weeks, suction-aspiration or vacuum abortion is the most common method. Manual vacuum aspiration, or MVA abortion, consists of removing the fetus or embryo by suction using a manual syringe, while the Electric vacuum aspiration or EVA abortion method uses an electric pump. These techniques are equivalent, differing only in the mechanism use to apply suction. From the fifteenth week up until around the twenty-sixth week, a surgical dilation and evacuation (D &amp; E) is used. D &amp; E consists of opening the cervix of the uterus and emptying it using surgical instruments and suction.

Dilation and curettage (D &amp; C) is a standard gynaecological procedure performed for a variety of reasons, including examination of the uterine lining for possible malignancy, investigation of abnormal bleeding, and abortion. Curettage refers to the cleaning of the walls of the uterus with a curette. The World Health Organization recommends this sort of procedure, also called Sharp Curettage, only when MVA is unavailable. Sharp curettage only accounted for 2.4% of abortion procedures in the US in 2002. The term "D and C" can more generally be used to refer to the first trimester abortion procedure, irrespective of the method used to perform the procedure.

Other techniques must be used to induce abortion in the third trimester. Premature delivery can be induced with prostaglandin; this can be coupled with injecting the amniotic fluid with caustic solutions containing saline or urea. Very late abortions can be brought about by intact dilation and extraction (intact D &amp; X), which requires the surgical decompression of the fetus's head before evacuation, and is sometimes termed "partial-birth abortion." A hysterotomy abortion, similar to a caesarian section but resulting in a terminated fetus, can also be used at late stages of pregnancy. It can be performed vaginally, with an incision just above the cervix, in the late mid-trimester.

Chemical abortion


Effective in the first trimester of pregnancy, chemical (also referred to as a medical abortion), or non-surgical abortions comprise 10% of all abortions in the United States and Europe. The process begins with the administration of either methotrexate or mifepristone, followed by misoprostol. When appropriately used, 98% of women undergoing medical termination of pregnancy will experience completed abortion without surgical intervention. The Food and Drug Administration currently approves the use of mifepristone up to 49 days gestation (7 weeks), though evidence based regimens exist for its use up to 61 days gestation with similar success rates. Misoprostol alone can also be used, though it is not FDA approved for this purpose. Misoprostol (Cytotec) alone has the advantage of costing less than one dollar for an effective dose, as opposed to several hundred dollars for an effective dose of mifepristone. In cases of failure of medical abortion, vacuum or manual aspiration is used to complete the abortion surgically.

Other means of abortion
Historically, a number of herbs reputed to possess abortifacient properties have been used in folk medicine: tansy, pennyroyal, black cohosh, and the now-extinct silphium (see history of abortion). The use of herbs in such a manner can cause serious — even lethal — side effects, such as multiple organ failure, and is not recommended by physicians.

Abortion is sometimes attempted through means of trauma to the abdomen. The degree of force applied, if severe, can cause serious internal injuries without necessarily succeeding in inducing miscarriage. Both accidental and deliberate abortions of this kind can be subject to criminal liability in many countries. In Burma, Indonesia, Malaysia, the Philippines, and Thailand, there is an ancient tradition of attempting abortion through forceful abdominal massage.

Reported methods of unsafe, self-induced abortion include the misuse of the ulcer drug Misoprostol and the insertion of non-surgical implements such as knitting needles and clothes hangers into the uterus.

Health effects
Early-term surgical abortion is a simple procedure, and when performed by competent doctors (and in some states, nurse practitioners, nurse midwives and physician assistants) in first-world nations (before the 16th week), is safer than carrying the pregnancy to term.

As with most surgical procedures, the most common surgical abortion methods carry the risk of potentially serious complications. These risks include: a perforated uterus, perforated bowel or bladder, septic shock, sterility, and death. The risk of complications occurring can increase depending on how far the pregnancy has progressed, but may be counterbalanced by complications that would occur from carrying the pregnancy to term.

It is difficult to accurately assess the risks of induced abortion due to a number of factors. These factors include wide variation in the quality of abortion services in different societies and among different socio-economic groups, a lack of uniform definitions of terms, and difficulties in patient follow-up and after-care. The degree of risk is also dependent upon the skill and experience of the practitioner; maternal age, health, and parity; gestational age; pre-existing conditions; methods and instruments used; medications used; the skill and experience of those assisting the practitioner; and the quality of recovery and follow-up care. A highly-skilled practitioner, operating under ideal conditions, will tend to have a very low rate of complications; an inexperienced practitioner in an ill-equipped and ill-staffed facility, on the other hand, will often have a higher incidence of complications.

In the United Kingdom, the number of deaths due to legal abortion between the years of 1991 and 1993 was 5, as compared to the 9 deaths caused by ectopic pregnancy during the same time frame. In the United States, during the year 1999, there were a total of 4 deaths due to legal abortion.

Some practitioners advocate using minimal anesthesia so that the patient can alert them to possible complications. Others recommend general anesthesia, in order to prevent patient movement, which might cause a perforation. General anesthesia carries its own risks, including death, which is why public health officials recommend against its routine use.

Dilation of the cervix carries the risk of cervical tears or perforations, including small tears that might not be apparent and might cause cervical incompetence in future pregnancies. Most practitioners recommend using the smallest possible dilators, and using osmotic rather than mechanical dilators after the first trimester of pregnancy.

Instruments are placed within the uterus to remove the fetus. These can, on rare occasions, cause perforation or laceration of the uterus, and damage to structures surrounding the uterus. Laceration or perforation of the uterus or cervix can, again on rare occasions, lead to even more serious complications.

Incomplete emptying of the uterus can cause hemorrhage and infection. Use of ultrasound verification of the location and duration of the pregnancy prior to abortion, with immediate follow-up of patients reporting continuing pregnancy symptoms after the procedure, will virtually eliminate this risk. The sooner a complication is noted and properly treated, the lower the risk of permanent injury or death.

In rare cases, the abortion will be unsuccessful and the pregnancy will continue. An unsuccessful abortion can also result in the delivery of a live neonate, or infant. This, termed a failed abortion, is more likely to occur if the procedure is carried out later in the pregnancy. Some doctors faced with this situation have voiced concerns about the ethical and legal ramifications of then letting the neonate die. As a result, recent investigations have been launched in the United Kingdom by the Confidential Enquiry into Maternal and Child Health (CEMACH) and the Royal College of Obstetricians and Gynecologists, in order to determine how widespread the problem is and what an ethical response in the treatment of the infant might be.

Use of other methods (e.g., overdose of various drugs, insertion of various objects into uterus) for abortion is potentially dangerous, carrying a significantly elevated risk for permanent injury or death compared to abortions done by physicians.

Suggested effects
There is controversy over a number of proposed risks and effects of abortion. Evidence, whether in support of or against such claims, might in part be influenced by the political and religious beliefs of the parties behind it.

Breast cancer
The abortion-breast cancer (ABC) hypothesis posits a causal relationship between having an induced abortion and a higher risk of developing breast cancer in the future. An increased level of estrogen in early pregnancy helps to initiate cellular differentiation (growth) in the breast in preparation for lactation. If this process is terminated, through abortion, before full differentiation in the third trimester, then more "vulnerable" undifferentiated cells will be left than there were prior to the pregnancy. It is proposed that this might result in an elevated risk of breast cancer. The majority of interview-based studies have indicated a link, and some have been demonstrated to be statistically significant, but there remains debate as to their reliability because of possible response bias.

Larger and more recent record-based studies, such as one in 1997 which used data from two national registries in Denmark, found the correlation to be negligible to non-existent after statistical adjustment. The National Cancer Institute conducted an official workshop with dozens of experts on the issue, between February 24-February 26, 2003, which concluded from its examination of various evidence that it is "well established" that "induced abortion is not associated with an increase in breast cancer risk." These findings and how the Denmark study statistically adjusted their overall results have been disputed by Dr. Joel Brind, an invitee to the workshop and the leading scientific advocate of the abortion-breast cancer hypothesis. Nevertheless, gaps and inconsistencies remain in the research, and the subject continues to be one of political and scientific contention.

Fetal pain
The experience of the fetus during abortion is a matter of medical, ethical and public policy concern. Evidence is conflicting, with some authorities holding that the fetus is capable of feeling pain from the first trimester, and others maintaining that the neuro-anatomical requirements for such experience do not exist until the second or third trimester.

Pain receptors begin to appear in the seventh week of pregnancy. The thalamus, the part of the brain which receives signals from the nervous system and then relays them to the cerebral cortex, starts to form in the fifth week. However, other anatomical structures involved in the nociceptic process are not present until much later in gestation. Links between the thalamus and cerebral cortex aren't forged until around the 23rd week.

Researchers have observed changes in the heart rates and hormonal levels of newborn infants after circumcision, blood tests, and surgery — effects which were alleviated with the administration of anesthesia. Others suggest that the human experience of pain, being more than just physiological, cannot be measured in such reflexive responses.

Mental health
Some women will experience negative feelings as a result of elective abortion. However, whether this phenomenon is significant enough to warrant a general diagnosis, or even classification as an independent syndrome (see post-abortion syndrome), is a subject that is debated among members of the medical community.

Data on the incidence of clinical depression, mental illness, post-traumatic stress disorder, and suicide in association with abortion remain inconclusive. A comparative analysis of the suicide rates among postpartum and post-abortive women in Finland found a  statistical correlation between abortion and suicide.

Other studies have suggested a link between the elective termination of an unwanted pregnancy and an improvement in reported mental well-being. Elective abortion may reduce the occurrence of depression in cases of unwanted pregnancy, as compared to cases in which the pregnancy has been carried to completion, but it is also sometimes reported as an additional stressor (ibid.). The majority of evidence would seem to indicate that adverse emotional reactions to the procedure are most strongly influenced by pre-existing psychological conditions and other negative factors (ibid.).

Spontaneous abortion, or miscarriage, is known to present an increased risk of depression in women.

History of abortion


The practice of induced abortion, according to some anthropologists, can be traced to ancient times. There is evidence to suggest that, historically, pregnancies were terminated through a number of methods, including the administration of abortifacient herbs, the use of sharpened implements, the application of abdominal pressure, and other techniques.

Soranus, a 2nd century Greek physician, suggested in his work Gynecology that women wishing to abort their pregnancies should engage in violent exercise, energetic jumping, carrying heavy objects, and riding animals. He also prescribed a number of recipes for herbal bathes, pessaries, and bloodletting, but advised against the use of sharp instruments to induce miscarriage due to the risk of organ perforation. It is also known that the ancient Greeks relied upon the herb silphium as both a contraceptive and an abortifacient. The plant, as the chief export of Cyrene, was driven to extinction, but it is suggested that it might have possessed the same abortive properties as some of its closest extant relatives in the Apiaceae family.

Such folk remedies, however, varied in effectiveness and were not without risk. Tansy and pennyroyal, for example, are two poisonous herbs with serious side effects that have at times been used to terminate pregnancy.

19th-century medicine saw advances in the fields of surgery, anaesthesia, and sanitation, in the same era that doctors with the American Medical Association lobbied for bans on abortion in The United States and the British Parliament passed the Offences Against the Person Act. Demand for the procedure continued, however, as the disguised, but nonetheless open, advertisement of abortion services in Victorian times would seem to suggest.

Social issues
A number of of complex issues exist in the debate over abortion. These, like the suggested effects upon health listed above, are a focus of research and a fixture of discussion among members on all sides the controversy.

Effect upon crime rate
A controversial theory attempts to draw a correlation between the unprecedented nationwide decline of the overall crime rate witnessed in the United States during the 1990s and the decriminalization of abortion 20 years prior.

The suggestion was brought to widespread attention by a 1999 academic paper, The Impact of Legalized Abortion on Crime, authored by the economists Steven D. Levitt and John Donohue. They attributed the drop in crime to a reduction in individuals said to have a higher statistical probability of committing crimes: unwanted children, especially those born to mothers who are African-American, impoverished, adolescent, uneducated, and single. The change coincided with what would've been the adolescence, or peak years of potential criminality, of those who had not been born as a result of Roe v. Wade and similar cases. Donohue and Levitt's study also noted that states which legalized abortion before the rest of the nation experienced the lowering crime rate pattern earlier and that those with higher abortion rates had more pronounced reductions.

Fellow economists Christopher Foote and Christopher Goetz criticized the methodology in the Donahue-Levitt study, noting a lack of accommodation for statewide yearly variations such as cocaine use, and recalculating based on incidence of crime per capita; they found no statistically significant results. Levitt and Donohue responded to this by presenting an adjusted data set which took into account these concerns but, they claim, maintained the statistical significance of their initial paper.

Such research has been criticized by some as being utilitarian, discriminatory as to race and socioeconomic class, and as promoting eugenics as a solution to crime. Levitt states in his book, Freakonomics, that they are neither promoting nor negating any course of action – merely reporting data as economists.

Sex-selective abortion
The advent of both ultrasound and amniocentesis has allowed parents to determine sex before birth. This has lead to the occurrence of sex-selective abortion or the targeted termination of a fetus based upon its gender.

It is suggested that sex-selective abortion might be partially responsible for the noticeable disparities between the birth rates of male and female children in some places. The preference for male children is reported in many areas of Asia, and the use of abortion to limit female births has been reported in Mainland China, Taiwan, South Korea, and India.

In India, the economic role of men, the costs associated with dowries, and a Hindu tradition which dictates that funeral rites must be performed by a male relative have lead to a  cultural preference for sons. The widespread availability of diagnostic testing, during the 1970s and '80s, lead to advertisements for services which read, "Invest 500 rupees [for a sex test] now, save 50,000 rupees [for a dowry] later." In 1991, the male-to-female sex ratio in India was skewed from its biological norm of 105 to 100, to an average of 108 to 100. Researchers have asserted that between 1985 and 2005 as many as 10 million female fetuses may have been selectively aborted. The Indian government passed an official ban of pre-natal sex screening in 1994 and moved to pass a complete ban of sex-selective abortion in 2002.

In the People's Republic of China, there is also a historic son preference. The implementation of the one-child policy in 1979, in response to population concerns, lead to an increased disparities in the sex ratio as parents attempted to circumvent the law through sex-selective abortion or the abandonment of unwanted daughters. Sex-selective abortion might be a part of what is behind the shift from the baseline male-to-female birth rate to an elevated national rate of 117:100 reported in 2002. The trend was more pronounced in rural regions: as high as 130:100 in Guangdong and 135:100 in Hainan. A ban upon the practice of sex-selective abortion was enacted in 2003.

Unsafe abortion
Where and when access to safe abortion has been barred, due to explicit sanctions or general unavailability, women seeking to terminate their pregnancies have sometimes resorted to unsafe methods.

"Back-alley abortion" is a slang term for any abortion not practiced under ideal conditions of sanitation and professionalism. The World Health Organization defines an unsafe abortion as being, "a procedure...carried out by persons lacking the necessary skills or in an environment that does not conform to minimal medical standards, or both." This can include a person without medical training, a professional health provider operating in sub-standard conditions, or the woman herself.

Unsafe abortion remains a public health concern today due to the higher incidence and severity of its associated complications, such as incomplete abortion, sepsis, hemorrhage, and damage to internal organs. WHO estimates that 19 million unsafe abortions occur around the world annually and that 68,000 of these result in the death of a woman. Complications of unsafe abortion are said to account, globally, for approximately 13% of all maternal mortalities, with regional estimates including 12% in Asia, 25% in Latin America, and 13% in sub-Saharan Africa. Health education, access to family planning, and improvements in healthcare during and after abortion have been proposed to address this phenomenon.

Abortion debate


Over the course of the history of abortion, induced abortions have been a source of considerable debate and controversy regarding the morality and legality of this practice. An individual's position on the complex ethical, moral, philosophical, biological, and legal issues have a strong relationship with that individual's value system. A person's position on abortion may be best described as a combination of their personal beliefs on the morality of abortion, and that person's beliefs on the ethical scope and responsibility of legitimate governmental and legal authority. Another factor for many individuals is religious doctrine (see religion and abortion).

Abortion debates, especially pertaining to abortion laws, are often spearheaded by advocacy groups belonging to one of two camps. Most often those in favor of legal prohibition of abortion describe themselves as pro-life while those against legal restrictions on abortion describe themselves as pro-choice. Both are used to indicate the central principles in arguments for and against abortion: "Is the fetus a human being with a fundamental right to life?" for pro-life advocates, and, for those who are pro-choice, "Does a woman have the right to choose whether or not to have an abortion?"

In both public and private debate, arguments presented in favor of or against abortion focus on either the moral permissibility of an induced abortion, or justification of laws permitting or restricting abortion. Arguments on morality and legality tend to collide and combine, complicating the issue at hand.

Debate also focuses on whether the pregnant woman should have to notify and/or have the consent of others in distinct cases: a minor her parents; a legally-married or common-law wife her husband; or a pregnant woman the biological father. In a 2003 Gallup poll in the United States, 72% of respondents were in favor of spousal notification, with 26% opposed; of those polled, 79% of males and 67% of females responded in favor.

Public opinion
Political sides have largely been divided into absolutes. The abortion debate, as such, tends to center around individuals who hold strong positions. However, public opinion varies from poll to poll, country to country, and region to region:


 * Australia: In a February 2005 AC Nielsen poll, as reported in The Age, 56% thought the current abortion laws, which generally allow abortion for the sake of life or health, were "about right," 16% want changes in law to make abortion "more accessible," and 17% want changes to make it "less accessible." A 1998 poll, conducted by Roy Morgan Research, asked, "Do you approve of the termination of unwanted pregnancies through surgical abortion?" 65% of the  Australians polled stated that they approved of surgical abortion and 25% stated that they disapproved of it.


 * Canada: A recent poll of Canadians, conducted in April 2005 by Gallup, found that 52% of those polled want abortion laws to "remain the same," 20% want the laws to be "less strict," and 24% would prefer that the laws become "more strict." An earlier Gallup poll, from December 2001, asked, "Do you think abortions should be legal under any circumstances, legal only under certain circumstances or illegal in all circumstances and in what circumstances?" 32% of Canadians responded that they believe abortion should be legal in all circumstance, 52% that it should be legal in certain circumstances, and 14% that it should be legal in no circumstances. See Abortion in Canada.


 * Ireland: A 1997 Irish Times/MRBI poll of the Republic of Ireland's electorate found that 18% believe that abortion should never be permitted, 35% that one should be allowed in the event that the woman's life is threatened, 18% if her health is at risk, 28% that "an abortion should be provided to those who need it," and 5% were undecided.


 * The United Kingdom: An online YouGov/Daily Telegraph poll in August 2005 found that 30% of Britons would back a measure to reduce the legal limit for abortion to 20 weeks, 19% support a limit of 12 weeks, 9% support a limit of less than 12 weeks, and 25% support maintaining the current limit of 24 weeks. 6% responded that abortion should never be allowed while 2% said it should be permitted throughout the entirety of pregnancy.


 * The United States: In a January 2006 CBS News poll, which asked, "What is your personal feeling about abortion?", 27% said that abortion should be "permitted in all cases," 15% that it should be "permitted, but subject to greater restrictions than it is now," 33% that it should be "permitted only in cases such as rape, incest or to save the woman's life," 17% that it should "only be permitted to save the woman's life," and 5% that it should "never" be permitted. A November 2005 Pew Research Center poll asked "In 1973 the Roe versus Wade decision established a woman's constitutional right to an abortion, at least in the first three months of pregnancy. Would you like to see the Supreme Court completely overturn its Roe versus Wade decision, or not?", with 29% indicating they want it overturned, and 65% that they do not.

Abortion law
The Soviet Union (1920) and Iceland (1935) were some of the first countries to generally allow abortion. The second half of the twentieth century saw the liberalization of abortion laws in many other countries. In 1973, the U.S. Supreme Court struck down state laws banning abortion, ruling that such laws violated an inferred right to privacy in the U.S. Constitution. The Supreme Court of Canada, similarly, discarded its criminal code regarding abortion in 1988, after ruling that such restrictions violated the security of person guaranteed to women under in the Canadian Charter of Rights and Freedoms in the case of R. v. Morgentaler. Canada later struck down provincial regulations of abortion in the case of R. v. Morgentaler (1993). Ireland, on the other hand, added an amendment to its Constitution in 1983 by popular referendum, recognizing "the right to life of the unborn" (see Abortion in Ireland).

Current laws pertaining to abortion are diverse. Religious, moral, and cultural sensibilities continue to influence abortion laws throughout the world. The right to life, the right to liberty, and the right to security of person are major issues of human rights that are sometimes used as justification for the existence or the absence of laws controlling abortion. Many countries in which abortion is legal require that certain criteria be met in order for an abortion to be obtained, often, but not always, using a trimester-based system to regulate the window in which abortion is still legal to perform:

Other countries, in which abortion is illegal, will allow one to be performed in the case of rape, incest, or danger to the pregnant woman's life or health. A handful of nations ban abortion entirely, such as Chile, El Salvador, and Malta.
 * In the United States, some states impose a 24-hour waiting period before the procedure, prescribe the distribution of information on fetal development, or require that parents be contacted if their minor daughter requests an abortion.
 * In the United Kingdom, as in some other countries, two doctors must first certify that an abortion is medically or socially necessary before it can be performed.