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abortion The end of a PREGNANCY before the
FETUSis viable (capable of independent life). Abor-
tion may occur spontaneously (commonly called
miscarriage) or be induced to end a pregnancy. In
the United States, federal law mandates the avail-
ability of induced abortion, and state laws regulate
the definition of viability as it applies to induced
abortion. The range of legal viability is 20 weeks
to 24 weeks of gestational age. The clinical border
for viability is generally 20 weeks or a fetal weight
of 500 grams (about 1 pound). It is uncommon for
a fetus delivered between 24 and 20 weeks and
unlikely for a fetus born before 20 weeks of gesta-
tional age to survive. A full-term pregnancy is 42
weeks.

Spontaneous Abortion
Numerous factors may initiate spontaneous abor-
tion. The most vulnerable period of pregnancy for
spontaneous abortion is between 7 and 12 weeks.
Doctors believe that most abortions that occur
within this early stage of pregnancy occur because
the conceived EMBRYOhas congenital or chromoso-
mal defects that are not survivable. About 15 per-
cent of known pregnancies end in spontaneous
abortion before the 12th week of pregnancy.
Regardless of the cause and the stage of preg-
nancy, spontaneous abortion is often a traumatic
loss for the woman and her partner.

Induced Abortion
An induced abortion is a procedure a woman
chooses to undergo to end a pregnancy and may
be therapeutic (medically necessary for the
woman’s health or because the fetus has known,
nonsurvivable defects such as anencephaly) or
elective termination of pregnancy. An induced
abortion may be a surgical procedure called dila-

tion and evacuation (D&E), performed under

ANESTHESIAin a hospital operating room or in an

AMBULATORY SURGICAL FACILITY, in which the doctor

dilates the CERVIXand withdraws the contents of

the UTERUSvia suction (also called vacuum aspira-

tion abortion). Before seven weeks an induced

abortion may be a medical procedure, brought

about by taking medications such as mifepristone

(RU486), methotrexate, or misoprostol. These

drugs, called abortifacients, prevent cell division

(methotrexate, a CHEMOTHERAPY DRUGused to treat

cancer) or implantation, or initiate uterine con-

tractions (mifepristone and misoprostol).

Complications of Abortion

Uncontrolled bleeding (hemorrhage) and INFECTION

are risks with either spontaneous or induced abor-

tion. The abortion may be incomplete (some of

the contents of CONCEPTIONremain in the uterus),

causing persistent or occasionally heavy bleeding.

Persistent or heavy bleeding often requires DILA-

TION AND CURETTAGE(D&C), a surgical procedure in

which the doctor dilates the cervix and uses a

curette to gently scrape the interior walls of the

uterus. Undiagnosed GONORRHEA and CHLAMYDIA

are the most common causes of postabortion

infection. Infection requires treatment withANTIBI-

OTIC MEDICATIONS. Either bleeding or infection may

be life threatening; both require immediate med-

ical evaluation and appropriate treatment. Rarely,

abortion results in complications that can affect

future FERTILITY.

Abortion, whether spontaneous or induced, is

often an emotional experience for the woman and

her partner. Guilt, sadness, and anger are common

feelings that may persist for some time or

reemerge years later. Induced abortion often has

additional religious or philosophical implications.

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