An abortion (an event or procedure that terminates or brings a pregnancy to an end) can be spontaneous (unplanned) or induced (planned). The spontaneous abortion of a fetus (name given to unborn young from the end of the eighth week of development to the moment of birth) is called a miscarriage, and occurs in about twenty-four percent of all pregnancies. In the case of miscarriage, there is usually some problem with the fetus, or with the ability of the woman's uterus to support the fetus's development. The most common cause of miscarriage is a low level of prenatal hormones. A planned abortion occurs when, for personal or medical reasons, the embryo (name given to unborn young up to the beginning of the eighth week of development) or fetus is removed before gestation (the carrying or development of young in the uterus from conception to birth) is complete. Planned abortions are considered medical procedures and are usually performed in a hospital, clinic, or doctor's office under the supervision of trained staff.
Most miscarriages and planned abortions occur during the first trimester (months one through three) of a woman's pregnancy, when the embryo is just beginning to develop. A much smaller number of abortions and miscarriages occur in the second trimester (months four through six), when the fetus has developed further. Abortions are rarely performed in the third trimester (months seven through nine), because the fetus may be viable (able to survive outside the uterus) with intensive hospital care. Viability generally occurs at the twenty-fourth week of pregnancy when the fetus weighs at least 21 ounces.
Procedures for conducting a planned abortion vary according to the trimester of the pregnancy. In the first trimester, uterine aspiration (the suctioning and cutting of fetal material from the womb) under local anesthe- sia is most common. Aspiration is also used to remove any lingering tissues from a miscarriage.
A recent and more controversial first trimester abortion method is RU 486. Known as the "abortion pill," RU 486 was created by French biochemist Etienne-Emile Baulieu (1926-; cofounder of the International Society for Research in Biology and Reproduction) and introduced in France in 1988. RU 486 works by changing the hormonal environment of the uterus so that it interferes with the development of the fertilized egg. Once this interference occurs, the fertilized egg and lining separate from the uterine wall and are expelled through bleeding.
For pregnancies that occur in the second trimester, two other methods are utilized. In the first method, a saline (salt water) solution is injected into the uterus, which kills the fetus. The woman then has induced (brought on) labor, which expels the fetal tissue. The second—and more common—method is to inject prostaglandins (hormone-like substances) into the uterus to kill the fetus, followed by the induction of labor and expulsion of fetal material.
Legal and Moral Issues
There is great debate in the United States about legalized abortion. In its 1973 Roe vs. Wade decision, the United States Supreme Court held that a woman has the right to end a pregnancy for any reason during the first trimester. States may regulate the use of abortions during the second trimester as long as the woman's health is not threatened. During the third trimester, individual states may forbid abortion unless the life or health of the mother is threatened.
The abortion issue has such emotional power that it has influenced political elections and led to protests against clinics, offices, and hospitals where abortions are performed. Pro-life advocates view abortion as the killing an unborn child, while pro-choice supporters believe that women should be free to make their own decisions about pregnancy termination. Recent developments concerning abortion—such as President Bill Clinton's 1996 veto of a bill that would have overturned rarely performed partial birth abortions—have only added fuel to the debate.
Complications from a properly performed abortion are rare, but illegal abortions done by nonprofessionals or attempted by the woman herself can cause many problems, including infection, uncontrolled hemorrhaging (bleeding), and can even result in death.
[See also Hormone ]