An abortion is when a pregnancy is ended early, without the natural birth of the child.

A developing human usually takes about thirty-nine weeks to grow and be born. Normally, this occurs about forty weeks after the mother's last menstrual period. This developing human is called an embryo for the first eight weeks of the pregnancy, and fetus for the rest of the pregnancy. Abortion causes the embryo or fetus to die.

When an abortion occurs naturally, it is often called a miscarriage. Humans can also choose to end the pregnancy before birth takes place. This is called an induced abortion.  Often, the term abortion often refers only to an induced abortion.

In both types of abortion, the embryo or fetus usually comes out of the womb. This is called a complete abortion. In some cases, the embryo or fetus remains inside the womb. This is called a missed abortion. Surgery is needed to remove the embryo or fetus from the womb so the woman does not get an infection.

Different countries have different laws regarding induced abortion. While abortion is illegal in many countries, there are often exceptions that permit it in cases such as family incest, rape, the fetus having severe disabilities or the mother's health being at risk.

Spontaneous abortions

Names 
People speak of spontaneous abortion or miscarriage when the embryo or fetus is lost due to natural causes before the 20th week of pregnancy. A pregnancy that ends this way, but that is between 20 and 37 weeks old is known as "premature birth" if the baby is born alive. If the fetus dies in the womb after 20 weeks, or while it is born, this is known as "stillbirth". Premature births and stillbirths are generally not considered to be miscarriages.

How common they are 
Spontaneous abortions (miscarriages) are common. About fifteen percent of pregnancies end in spontaneous abortion. In many cases, the woman is not even aware she was pregnant. The pregnancy is only a few days or weeks old and the woman believes the miscarriage is just her menses. About twenty-five percent of all women will have a spontaneous abortion during their lives.

Most miscarriages occur very early. Between ten and fifty percent of pregnancies end with a miscarriage,
where the mother or the doctors are aware of it. These figures depend on the age and health of the pregnant woman. Most spontaneous abortions occur so early in the pregnancy that the woman is not even aware that she was pregnant. One particular study showed that 61.9% of pregnancies end in miscarriage before 12 weeks. In 91.7% of these miscarriages, the woman did not know she was pregnant.

The risk of spontaneous abortion decreases sharply after the 10th week of pregnancy, with a loss rate between 8.5 weeks LMP and birth of about two percent; pregnancy loss is “virtually complete by the end of the embryonic period."

Some people are more likely to have a spontaneous abortion 
Those people who have already had several spontaneous or induced abortions run a greater risk of having a spontaneous one. Those with certain diseases, and those over the age 35 also run a greater risk. Other causes for abortions can be the infection of either the woman or embryo/fetus, or their immune response. Certain diseases or  an accidental trauma can also cause a spontaneous abortion.  Putting the woman under trauma or stress to cause miscarriage is considered induced abortion. Some countries call this feticide.

Cause of spontaneous abortions 
Most miscarriages are due to problems with the copying of chromosomes, but some are caused by environmental factors. When a human is conceived, it gets 23 chromosomes from its mother and 23 from its father. If it does not get the right number its development happens wrong (it does not grow right.) It may have many bad birth defects.

Most embryos and fetuses with chromosome problems will not live for a long time. They die very early. There are a few chromosome problems that babies can sometimes be born with. For example, Down syndrome happens when there are three copies of chromosome #21. (Usually people have 2 of every chromosome.) This is called trisomy 21 (tri- means 3.)

Symptoms of spontaneous abortions 
The most common symptom is bleeding from the vagina. This can be very little blood (less blood than a normal menses.) It can be very much blood (much more than a normal menses.)
Some women have bad pains in their low abdomen when they have a miscarriage. This is sometimes like the pain of menses. It can be much worse. Or a woman may have no pain at all. If the pregnancy is many weeks old, the woman may see the embryo or fetus when it comes out. But if it is less than 12 weeks old a woman may not see anything but blood.

Treatment of spontaneous abortions 
Usually, no treatment is needed for a miscarriage. However, sometimes some pregnancy tissue remains in the womb after the miscarriage and must be removed. Sometimes doctors do a surgical abortion. This is the same kind of surgery that is done for induced abortions. Doctors can also prescribe women medicines that can help the miscarriage finish without needing surgery.

Induced abortions 
An induced abortion is when things are done to end the pregnancy on purpose. These things are normally done by doctors. In countries where abortion can be done legally, it is often done by specialists who know a lot about women's bodies (gynecologists). Abortions done illegally are often performed by people without this special knowledge. This makes them more dangerous. Such abortions are usually called unsafe abortions, back-alley abortions or DIY abortions, mainly because the risk to the health of the mother is much higher than with abortions carried out by skilled doctors.

Reasons for an induced abortion 
There can be medical reasons why an abortion is performed. These include:
 saving the life of the pregnant woman
 preserving the woman's physical or mental health
 ending a pregnancy that would result in a child being born with severe birth defects, which would be fatal, or which would increase the risk of the child dying at an early age.
 reducing the number of fetuses to lower the health risks associated with a multiple pregnancy (like twins)

Kinds of induced abortions 
There are two different kinds of induced abortions. The type of abortion that is done depends on a few different things, like what the woman wants, what her doctor thinks is best, and how far along a woman is in her pregnancy (how long she has been pregnant).

One type of induced abortion is called a "medical abortion" or a "medication abortion". In this type of abortion, a doctor gives the woman one or two medications that will end her pregnancy. A medication abortion can only be done early on in the pregnancy. This is because the medications that are used work best when they are started as early as possible, and after a woman has been pregnant for about two months, the medications usually do not work very well. Because of this, medication abortion usually is not used after a woman has been pregnant for 9 weeks. Some of the benefits (or reasons why some women choose this type of abortion) are that it can be started as soon as a woman realizes she is pregnant; it does not require anesthesia; and the woman does not have to have a procedure in a hospital or clinic to have the fetus removed, like with the other kind of abortion that is done. After a woman is given the medication or medications that end her pregnancy, the abortion happens like a "spontaneous" abortion or a miscarriage. (The woman passes the fetus, along with the blood and tissue that have built up in the uterus, from her vagina.)

The most common medications that are used for medication abortions are mifepristone and misoprostol. First, a doctor gives the woman mifepristone, which is sometimes also called "RU-468" or "the abortion pill". This drug blocks the hormone progesterone in the body. Without progesterone, the embryo cannot survive. The lining of the uterus becomes thinner, and the embryo cannot grow or stay attached to the lining of the uterus. After a few days, a doctor gives the woman misoprostol. This makes the uterus contract (or get smaller) and the embryo is expelled from (or pushed out of) the uterus through the woman's vagina. Sometimes, another medication, called methotrexate, is used along with misoprostol in medication abortions. A woman is given methotrexate, usually as a shot in a doctor's office, and the drug stops the embryo from staying attached to the lining of the uterus. Then misoprostol is given a few days later.

With the second type of abortion - called "surgical abortion" or "in-office abortion" - a doctor does a procedure that removes an embryo or fetus from the woman's uterus. This kind of abortion can be done in different ways, depending on how long the woman has been pregnant. Surgical abortion is simpler, and there are fewer problems that can happen, if it is done earlier on in the pregnancy. The most common form is called an "aspiration abortion" or a "suction curettage." This can be done in a doctor's office or clinic. First the woman's cervix (the top part of the uterus) is dilated (or made bigger).  A medical tool is used to suction out everything inside the woman's uterus, including the fetus. If the woman has been pregnant for more than 12 weeks, the doctor first has to dilate the cervix (or make the cervix bigger), usually by putting small sticks into the cervix to help it open up. If another tool, called a curette, has to be used to scrape out tissue that is still inside the uterus, then this form of abortion is sometimes called a "dilation and curettage" (or "D&C").

Risks and complications 
A pregnancy that ends without a child being born also may cause some problems to the woman this happens to. There are two broad groups of things that can happen:
 It affects the mental health of the mother
 It affects the physical health of the mother
The mother will feel depression from ending the life of her child

Physical problems 
Abortion is safer than childbirth if it is done before the 16th week of pregnancy and it is done by a professional. Certain methods of abortion are pretty safe, and complications are rare. Generally, stopping a pregnancy that has gone on longer is riskier.

Women usually feel a small amount of pain during first-trimester abortion. In a 1979 study of 2,299 patients, 97% reported having some amount of pain. Patients rated the pain as being less than earache or toothache, but more than headache or backache.

Local and general anesthesias are used during the abortion.

Psychological problems 
Few studies have been done to see if an abortion affects the woman psychologically, or mentally. Those that have been done give contradictory results. One study looked at 13.000 women who had become pregnant even though they did not want to. The study found that having an induced abortion does not increase the risk of getting mental health problems; the group that was compared were women who also did not want to have a baby, but who did not have an abortion.  Other studies showed similar results: women who had an abortion did better in school or at work after the abortion. Another study showed that women who had an abortion had a higher self-esteem and felt better than those who did not.

Many women who had an abortion felt better afterwards, they also felt relieved. They would do it again in a similar situation.

A study done in New Zealand in 2006 showed that many women who had an abortion developed severe depression up to 4 years after they had the abortion. They were also more likely to have problems with alcohol and illegal drugs than those women who did not have an abortion. The person who oversaw the study later told media that given these results it would be very hard to say that having an abortion has no psychological effects on the woman who has it. He called the abortion "a traumatic experience".

Other problems 
Both spontaneous and induced abortions have some risk for the woman.

If a bad thing happens because of a surgery or medicine that a doctor gives, or because of a miscarriage, it is called a complication. Complications of abortions can be infection, bleeding, pain. There may or may not be problems getting pregnant again; this is still being researched. In places where induced abortions are legal less than 1% of induced abortions have a bad complication. If doctors do induced abortions, the risk to the woman is less than the risk of complications of childbirth (giving birth to a baby). In places where induced abortions are legal, less women have complications of induced abortion than in places where induced abortion is illegal. This is because induced abortions that are not done by doctors have much more risks. For example, after induced abortions became legal in the United States in 1973, less women died from having abortions. In the United States in 2000, 11 women died from the complications of legal abortion. The risk of death from a legal abortion is 1/100 of the risk of an appendectomy. The risk of death from an injection (shot) of penicillin (an antibiotic) is bigger than the risk of death from a legal abortion.

There can be emotional problems for the woman after a spontaneous or induced abortion. She may feel sad, angry, or guilty that she had a miscarriage or asked for an abortion. She may think she has done something that made the miscarriage happen, or that having an abortion was the wrong thing to do, and because of this she may feel intense grief. There are many places where women can get help dealing with these feelings.

Some women who have induced abortions may get criticism from friends or family who have different beliefs. When scientists look at this in research studies, however, they do not usually see that women have emotional problems after induced abortions. In 1987, President Ronald Reagan told the Surgeon General of the US to look at this question. Both president Reagan and the Surgeon General C. Everett Koop did not think abortion was right. Dr Koop looked at 250 papers that scientists wrote in scientific journals. Dr Koop said that the science we know does not show that induced abortions cause emotional problems for women who have them.

Numbers and reasons for induced abortions 
The number of induced abortions done are different for different parts of the world. This is also true for the reasons why women decide to have an abortion. Estimates are that about 46 million induced abortions are done worldwide, every year. 26 million of them occur in places where abortion is legal, 20 million happen in countries where it is illegal to have an abortion. Some countries, like Belgium (11.2 per 100 known pregnancies) and the Netherlands (10.6 per 100) have a low rate of induced abortion. Others, like Russia (62.6 per 100) and Vietnam (43.7 per 100) have a comparatively high rate. Overall, there are 26 induced abortions per 100 known pregnancies.

WHO estimated in 2001 that every year, about 210 million women get pregnant, and that there are about 135 mililon live births. The remaining 75 million cases are miscarriages or induced abortions. About forty percent of pregnancies are unplanned, and about a fifth of the pregnant women decide to end the pregnancy early. This results in about 42 million abortions per year. About 20 million of these are legal, the rest are against the law. Most of the illegal abortions are performed by those who are not medically qualified, often with poor hygiene, which often threaten the lives of the women.  The WHO estimated that about 47.000 women died in 2008 because of illegal abortions. This number was lower than the estimate of 1990, mainly because in South America, women opted to take drugs to end the pregnancy.

Methods used for abortions; times when abortions are done 

Abortion rates vary. The length the pregnancy has gone on, and the method used to do the abortion influence these rates. According to data collected in the United States, 88.2% of abortions were done in the first twelve weeks of pregnancy, 10.4% between week 13 and week 20 of the pregnancy. The remaining 1.4% were done in week 21 or later.

90.9% were done by curettage, 7.7% were medical abortions (using drugs, mifepristone in most  cases), 0.4% by "intrauterine instillation" (saline or prostaglandin), and 1.0% by "other" (including hysterotomy and hysterectomy).  The Guttmacher Institute estimated there were 2,200 intact dilation and extraction procedures in the U.S. during 2000 -  0.17% of the total number of abortions performed that year. The Guttmacher Institute estimated that "most abortions in the United States are obtained by minority women" because minority women "have much higher rates of unintended pregnancy."

Some women have an abortion because the society they live in pressures them to.
 In certain parts of the world, disabled people have problems to fit into society.
 The sex of the child might influence the status of the mother; often, mothers who bear boys have a higher social status than those who bear girls.
 In many parts of the world, raising a child is a very difficult task for a single (unmarried) mother.
 Certain countries, like China have measures to control their population growth.
Any of these factors might force a pregnant woman to have an abortion.

Abortion and the law 

Induced abortion is not legal in every place. In some countries, a doctor who does an induced abortion is committing a crime. In the United States, Canada, and many countries in Europe abortion is legal (not a crime). In some countries like Ireland and Somalia it is legal only to save the life of the woman. In some countries like Chile and El Salvador, abortion is never legal, including in cases where the woman risks dying from continuing the pregnancy.

In countries where induced abortion is not legal many more women die from abortion. Women still get induced abortions, but they cannot get them in safe hospitals and clinics. These induced abortions have more complications than abortions done by doctors.

Women who live in places where abortion is illegal, or heavily frowned upon sometimes travel to other places where an abortion can be done legally, so they can have an abortion. This is a form of medical tourism.

Spontaneous abortion in other mammals 
Spontaneous abortions occur in various mammals. In sheep, it may be caused by crowding through doors, or by being chased by dogs. In cows, abortion may be caused by contagious diseases, such as Brucellosis or Campylobacter. This can often be controlled by vaccination, though.

Abortion may also be induced in animals, in the context of animal husbandry.  For example, abortion may be induced in mares that have been mated improperly, or that have been purchased by owners who did not realize the mares were pregnant, or that are pregnant with twin foals.

Feticide can occur in horses and zebras. Usually this is done because males harass pregnant mares or force copulation. Scientists have raised the question, how often this occurs in the wild, though. Male Gray langur monkeys may attack females following male takeover, causing miscarriage.

Opinions about induced abortions 
Induced abortion is a subject that is controversial. Each person has a system of moral values. Based on their system of morals, people have different opinions about it. Religion can also influence this opinion.

Different opinions around the world 
A number of opinion polls have been carried out around the world. They have tried to find out what people think about abortion. Results were different for different countries, but also varied with the questions that were asked.

In May 2005, a survey was done in ten European countries. The people were asked, if they could agree with the statement: "If a woman does not want children, she should be allowed to have an abortion". The highest level of approval was 81% in the Czech Republic; the lowest was 47% in Poland.

A poll was done in November 2001. The poll asked people in Canada in what circumstances they believed an abortion should be permitted. 32% responded that they believe abortion should be legal in all circumstances, 52% that it should be legal in certain circumstances, and 14% that it should never be legal. A similar poll in April 2009 surveyed people in the United States about abortion; 18% said that abortion should be "legal in all cases", 28% said that abortion should be "legal in most cases", 28% said abortion should be "illegal in most cases" and 16% said abortion should be "illegal in all cases". In a Gallup poll taken in July of 2011, however, 47% of Americans identified themselves as pro-life and the same percentage of Americans identified themselves as pro-choice. A November 2005 poll in Mexico found that 73.4% think abortion should not be legalized while 11.2% think it should.

Of attitudes in South America, a December 2003 survey found that 30% of Argentines thought that abortion should be allowed in Argentina "regardless of situation", 47% that it should be allowed "under some circumstances", and 23% that it should not be allowed "regardless of situation". A March 2007 poll about abortion in Brazil found that 65% of Brazilians believe that it "should not be modified", 16% that it should be expanded "to allow abortion in other cases", 10% that abortion should be "decriminalized", and 5% were "not sure". A July 2005 poll in Colombia found that 65.6% said they thought that abortion should remain illegal, 26.9% that it should be made legal, and 7.5% that they were unsure.

Pro-life and pro-choice 

Some people have strong feelings about abortion. People who think that the law should let women choose to have abortions are called pro-choice. People who think that abortion is wrong and that the law should not allow it are called pro-life.

People who are pro-choice believe that women should be allowed to have control over their own bodies when it comes to ending or continuing a pregnancy. They believe that, because the embryo or fetus is inside the woman's body and does not have developed enough organs to survive on its own until later in the pregnancy, it is not yet a person with rights. Pro-choice people also make the argument that abortion needs to be legal in order to protect women, because when abortion is illegal, it does not completely stop abortions from happening, but makes it so that women try to do abortions on themselves or get them done by people who are not trained doctors, which puts those women in danger of death or injury. Pro-choice people believe the way to prevent abortion is to make sure women only get pregnant when they want to. In addition to advocating the legality of abortion, pro-choice groups like Planned Parenthood often try to improve people's access to things used to prevent pregnancy (called contraception), and try to teach young people about sex to reduce the number of teen pregnancies.

People who are pro-life believe that all humans, including the unborn, have a right to life. For this reason, they believe abortion is wrong and that it is murder. They think the law should make abortion a crime in order to protect innocent life within the womb. However, though pro-life people think abortion is wrong, there are rare cases in which some pro-life people would allow an abortion to happen, like if the pregnancy puts the woman's life at risk or if she got pregnant from rape. Pro-life people think women who are pregnant and do not want to raise a child should look for alternatives to abortion such as giving the baby up for adoption. There are many crisis pregnancy centers pro-life people have started to discourage women from having abortions. They have also started advocacy groups, like the American Life League, Feminists for Life and Live Action, to try to convince more people to believe that abortion is wrong and to try to get governments to make laws to restrict abortion. Some pro-life people have used violence to try to stop abortions from happening. However, most people who are against abortion do not do such wrong things and so they try to stop abortions from happening through peaceful activism.

Religious views 
Many religions have a view on abortion. These views span a broad spectrum from acceptance to rejection. Most religions generally oppose abortion.

Selected issues of the debate 
Generally, when there is a debate about whether abortion laws should be changed in a country, there are advocacy groups. Some of the arguments these groups often have are outlined below.

Breast cancer hypothesis 
There is a hypothesis that induced abortion raises the risk of getting breast cancer. People who support this, call it a link, rather than a hypothesis.
The subject has been controversial, but currently, scientists agree that there is no link between abortion in the first trimester, and increasing the risk to get breast cancer.

In early pregnancy, levels of estrogen increase. This causes the breast to grow, and to prepare for lactation. In the 1890s, studies were done on rats, before this hypothesis was put forward.

Can the embryo or fetus feel pain? 
It is currently unclear from what moment the embryo or fetus can feel pain. This is also used in the debate about abortion. Many researchers think that a fetus is unlikely to feel pain until after the seventh month of pregnancy. Others disagree. At about twenty-six weeks of pregnancy, certain connections are made in the thalamus of the growing fetus. Developmental neurobiologists suspect that these connections may be critical to perception of pain by the fetus. However, legislation has been proposed by pro-life advocates requiring abortion providers to tell a woman that the embryo or fetus may feel pain during an abortion procedure.

Researchers from the University of California, San Francisco published a study in the Journal of the American Medical Association. The study analyzed data  from dozens of medical reports and other studies. The researchers concluded that fetuses are unlikely to feel pain until the third trimester of pregnancy. However a number of medical critics have since disputed these conclusions.  There are certain connections in the thalamus of the fetuse. These connections develop at about twenty-six weeks of pregnancy. At the end of the 20th century there was an emerging consensus among developmental neurobiologists that these connections are very important when it comes to the perception of pain in the fetus. Other researchers such as Anand and Fisk have challenged this late date, positing that pain can be felt around twenty weeks.
Pain can have many different aspects: It might be purely relying on sensory input, but it might also involve emotions and thought. For this reason, it is perhaps impossible to know exactly when the embryo or fetus feels pain, even if it has developed the links in the thalamus.

References 

  Phillip G. Stubblefield & David A. Grimes, “Septic Abortion.” NEW ENG. J. MED. 310 (1994).
  Strauss L, et al. “Abortion Surveillance --- United States, 2001.” MMWR. 53(SS09) (2004).
  Warren M. Hern, Abortion Practice 23‐24 (1984), citing JE Wennberg et al. “The Need for Assessing the Outcome of Common Medical Practices.” 1 Ann Rev Pub Health 291 (1980).
  Nancy Felipe Russo. “Unwanted Childbearing, Abortion, and Women’s Mental Health: Research Findings, Policy Implications.” Rocky Mountain Psych. 9 (1992).
  March of Dimes information about miscarriages
  Letter from C. Everett Koop, Surgeon General Dep’t of Health & Human Services, to Ronald Reagan, President of the United States (Jan. 9, 1989).

 
Women's rights