Your Family Physician

Introduction

Abortion is the termination of pregnancy prior to viability of the fetus. Viability is the ability of the fetus to live independently from the mother and is defined as occurring at 24 weeks of gestation. Induced abortion can be elective (performed for nonmedical indications) or therapeutic (performed for medical indications). Abortion can be performed by surgical or medical means. This article is confined to a discussion of surgical methods of abortion.
History of the Procedure

All cultures have practiced abortion, and the practice of abortion has been documented as early as ancient times. Abortion is controversial and has been subject to an ongoing debate focused on 3 central questions: (1) When should abortion be allowed? (2) Who should make the decision about abortion, the individual or society? and (3) When does the fetus become human?

The answers to the 3 central questions have varied with time, place, and culture. In the United States, the modern debate about abortion began in the 1820s with antiabortion legislation targeted against high maternal mortality rates associated with abortion. Notable in the 20th century was Roe v Wade, the 1973 Supreme Court ruling that guaranteed the fundamental right of a woman to decide whether to terminate her pregnancy. The 1973 Supreme Court ruling did not end the controversy surrounding abortion, and it continues today with legislation and legal intervention at the state and federal levels.
Problem

Abortion is one of the most common surgical procedures performed for American women. Based on estimated lifetime risk, each American woman is expected to have 3.2 pregnancies, of which 2 will be a live birth, 0.7 will be an induced abortion, and 0.5 will be a miscarriage. Using 1996 data, this translates into 3.89 million live births, 1.37 million abortions, and 0.98 million miscarriages.
Frequency

The Centers for Disease Control and Prevention (CDC) data are based upon information on legally induced abortions voluntarily submitted by states and by 2 areas of occurrence (ie, District of Columbia, New York City). The most current figures were compiled in 2001; this information does not include statistics from the states of Alaska, California, or New Hampshire.

The Alan Guttmacher Institute (AGI) is a private organization that is not subject to the reporting limitations of state health departments. AGI contacts abortion providers directly and provides abortion data every 4-5 years. A previous report documented a discrepancy of approximately 12% between statistical figures presented by the CDC compared with those of AGI (the latter generally having higher estimates). CDC figures were used for this article.

A total of 853,485 legal induced abortions were reported to the CDC for 2001 from the 49 reporting areas. This reflects a decline of 0.5% from the number of legal induced abortions reported for 2000 from the same reporting areas.

The abortion rate in the United States has steadily declined from a peak of 29.4 per 1000 women aged 15-44 years in 1990 to a low of 16 per 1000 women in 2001. The decline in the abortion rate has been attributed to a decrease in the number of unintended pregnancies, increased use of condoms and long-acting hormonal contraceptives in young women, reduced or limited access to abortion services, including the passage of abortion laws that affect adolescents (eg, parental consent, notification laws and mandatory waiting periods), and a shift in the age distribution of women toward the older and less fertile ages.

The abortion rates reported for the United States were higher than those reported for Canada and Western European countries but lower than the rates reported for China, Cuba, most of Eastern European countries, and certain newly independent states of the former Soviet Union.

Most abortions in the United States were performed in the first trimester: 59% of abortions were performed at less than 8 weeks' gestation and 88% of abortions were performed at less than 13 weeks' gestation. Few abortions were performed in the second trimester: 4.3% at 16-20 weeks and 1.4% at more than 21 weeks. In 2000 (the most recent year for which data are available), as in previous years, deaths related to legally induced abortions occurred rarely at less than one death per 100,000 abortions, making surgical abortion one of the safest surgical procedures performed in the United States.

The trend over the last reported years (1992-1997) has been toward abortions performed earlier in gestation. From 1992 (when detailed data on early abortions were first available) through 2001, data have indicated steady increases in procedures performed at less than 6 weeks' gestation with decreases occurring in the percentage of abortions performed at 8-12 weeks' gestation. The proportion of abortions performed at more than 13 weeks has varied little since 1992. Abortions performed early in pregnancy are associated with lower risks of mortality and morbidity. Early surgical abortions ( <6 wk) has been shown to be safe and effective with complication rates comparable with that of mifepristone and vaginal misoprostol.

For the abortions reported in the United States, the vast majority are performed using surgical methods. For women whose type of procedure was adequately reported, 95% of abortions were performed by curettage (which includes dilatation and evacuation [D&E]) and 0.5% were performed by intrauterine instillation. The percentage of abortions performed by D&E (curettage) at more than 13 weeks' gestation increased from 31% in 1974 (the first year for which these data were available) to 96% in 2001, while the percentage of abortions performed by intrauterine instillation at more than 13 weeks' gestation decreased from 57% to 0.5%. The increase in D&E (and the associated decrease in intrauterine instillation) is likely attributable to the lower risk of complications associated with D&E. Hysterotomy and hysterectomy were used in less than 0.01% of all abortions.
Etiology

Abortion is by definition a reproductive failure. The failure can be the result of the mother's lack of access to care, failure of the contraceptive method, failure to use contraceptives, or failure of the normal reproductive process (eg, fetal anomalies, fetal death, maternal illness).

Data from 1987 documented that 50% of all pregnancies in the United States were unintended. The large number of unintended pregnancies accounts for the bulk of pregnancy terminations in the United States.
Presentation

The decision to end a pregnancy may be made prior to the diagnosis of pregnancy. Many women present for pregnancy diagnosis with a simultaneous request for abortion. Women should be encouraged to have early diagnosis of pregnancy for the following reasons:

* The earlier the diagnosis of pregnancy, the greater the number of abortion methods available.
* Earlier diagnosis of pregnancy allows a greater chance for early abortion and lower complication rates.
* Earlier diagnosis of pregnancy allows earlier diagnosis of possible ectopic pregnancy and lower complication rates.
* Earlier diagnosis of pregnancy enables earlier entry into prenatal care and earlier diagnosis of indications for therapeutic abortion.

Obtain medical, surgical, and obstetric/gynecological history to help differentiate healthy pregnancies from abnormal pregnancies. Symptoms of normal pregnancy include anorexia, nausea, vomiting, breast tenderness, amenorrhea, and lethargy. Symptoms of abnormal pregnancy include abdominal pain, vaginal bleeding, passage of tissue, and near syncope or syncope.

Most elective abortions are performed in women aged 20-24 years. Most therapeutic abortions are performed in women older than 35 years. The most likely profile of patient requesting an elective abortion is that of an unmarried white woman who is younger than 25 years. Females younger than 15 years comprise fewer than 1% of all abortion patients.

Many patients who present with an abortion request are upset and frightened. Adequate counseling with discussion of all options available for the pregnancy and explanation of abortion options, risks, and complications is mandatory.
Indications

Elective abortion is the termination of pregnancy for nonmedical indications as determined by the patient.

Therapeutic abortion is termination of pregnancy for medical indications, including the following:

* Medical illness in the mother in which continuation of the pregnancy has the potential to threaten the life or health of the mother: Consider the present medical condition and a reasonable prediction of future circumstances because few medical indications are absolute.
* Rape or incest
* Fetal anomalies when pregnancy outcome is likely to be birth of a child with significant mental or physical defects or high likelihood of intrauterine or neonatal death
* Fetal death

Relevant Anatomy

Adequate evaluation of uterine size is mandatory. Physical examination may be inadequate for uterine sizing. Common causes of inadequate sizing by physical examination are obesity, uterine fibroids, patient apprehension with voluntary guarding, retroverted uterus, and firm abdominal musculature in young patients.

* Obtaining ultrasound confirmation of gestational age prior to abortion in the second trimester is common practice.
* A small or stenotic cervical os may prevent adequate dilatation for a surgical abortion.
* Uterine leiomyoma may make uterine sizing by physical examination erroneous, dilatation of the cervix difficult or impossible, and introduction of suction tips and curets into the uterine cavity difficult or impossible. Ultrasound prior to abortion is recommended, and ultrasound guidance during the abortion procedure may be helpful.
* Previous uterine surgery may increase the risk of perforation during surgical abortion.
* Previous uterine surgery and high parity are associated with greater likelihood of placenta praevia, placenta accreta, and placenta percreta. Surgical abortion should be performed in a setting where blood transfusion and access to laparotomy are available.
* Scarring of the cervix caused by cone biopsy or delivery may increase the risk of cervical stenosis and damage to cervix at dilatation. Consider passive dilatation with osmotic dilators (eg, laminaria, Dilapan).
* Uterine anomalies (eg, uterine septum, double uterus) may make entry into and emptying of the uterus complicated. Ultrasound guidance during abortion procedures is recommended.
* Multiple gestations may make surgical abortion more technically challenging. Adequate cervical dilatation and equipment appropriate to uterine size (not dates) is recommended.
* For an adnexal mass, the physician must obtain an ultrasound to exclude ectopic pregnancy and to determine the nature of the mass.
* Selection of the surgical abortion procedure primarily depends on the gestational age of the pregnancy.
* Careful consideration of choice of anesthesia must be based on the medical, psychiatric, and emotional condition of the patient. Local anesthesia affords greatest safety. General anesthesia is associated with greater risk of anesthesia complications and hemorrhage.

Contraindications

Absolute contraindications are virtually unknown. If abortion presents a medical risk to the patient, then continuation of the pregnancy presents an even greater risk. The type and timing of an abortion procedure or method may be contraindicated based on the medical, surgical, or psychiatric condition of the patient.

* Medical abortion is contraindicated in patients with clotting disorders, severe liver disease, renal disease, cardiac disease, and chronic steroid use.
* Surgical abortion is contraindicated in patients with hemodynamic instability, profound anemia, and/or profound thrombocytopenia.
* The rare instance of placenta accreta and percreta in the second trimester may necessitate laparotomy with hysterotomy or hysterectomy.

Source : http://emedicine.medscape.com/article/266626-overview