According to the U.S. Centers for Disease Control and Prevention, 1.18 million legal abortions were performed in the United States in 1997. The risk of death from legal abortion is 0.4 per 100,000 induced abortions. Most abortions are performed surgically by vacuum curettage. Medical abortion (abortion induced by the use of medications) has recently become an option in this country. In most medical abortions, expulsion of the pregnancy occurs at home. About 1% of women require surgical evacuation to complete the process.
TECHNIQUE FOR SURGICAL ABORTION
Surgical abortion can be performed in an office or hospital setting. The success rate of surgical termination is 99%. It is usually a single-step process that requires one visit to the practitioner. In early pregnancy (less than 7 weeks), a small flexible plastic cannula (5–6 mm) is inserted into the uterus under sterile conditions. Plastic syringes (50 ml) are used as the vacuum source and the uterine contents are suctioned out. Adequate pain relief is provided by injecting local anesthetic into the cervix and administering intravenous sedation and analgesics. After 7 weeks, a larger rigid plastic cannula (8–10 mm) is used with an electric pump as the vacuum source. After 18 weeks, a dilation and evacuation (using larger bore cannulae) usually must be performed undergeneral anesthesia.
Typically, seaweed (laminaria) or a synthetic version is inserted into the cervix to prepare it for the procedure. The seaweed absorbs water, swells, and gently dilates the cervix over a 24-hour period. This facilitates the use of a cannula to extract the fetus and placenta at the time of the procedure.
The risks associated with pregnancy termination increase with gestational age and the use of general anesthesia. Risks include hemorrhage, infection, and perforation of the uterus if a surgical instrument slips through the uterine wall. Uterine perforation can cause bladder, bowel, or vascular injury necessitating further surgery for repair. The most common complication is
uterine infection (0.1–4.7%).
Medical termination requires the close observation of a practitioner. It usually requires two or more visits, and there is a potential need for emergency intervention during the process. Finally, it requires close follow-up to ensure that the process of abortion is complete. The earlier the gestational age is, the higher the complete abortion rate. The complete abortion rate ranges from 92 to 96% if medication is begun before 56 days. The pregnancy age should be confirmed by clinical evaluation and/or ultrasonography. Most medication regimens require patients to be no more than 50 days pregnant (as calculated from the first day of the last menstrual period).
The bleeding resulting from a medical abortion is heavier than that experienced during a normal menses and is accompanied by severe cramping. Most patients require pain medication. In rare instances, women who are having a medical abortion require an emergency dilation and curettage because of heavy bleeding (1%). Postabortion follow-up with a practitioner is extremely important because not all women are able to determine whether they have completely aborted based on their symptoms. In some studies, only half of the women who thought they had aborted actually had done so. Medical abortion is contraindicated in women on long-term systemic corticosteroid therapy or anticoagulant therapy and in those with chronic
kidney, liver, or respiratory disease, severe anemia, a known coagulopathy, uncontrolled hypertension, angina, valvular disease, cardiac arrhythmias, or cardiac failure.
Three medications are currently used in medical abortion: misoprostol, mifepristone (RU 486), and methotrexate. Misoprostol is the most common medication used in medical abortion. It was originally approved to prevent gastric ulcers in persons taking anti-inflammatory drugs. It causes softening of the cervix and uterine contractions, resulting in the termination of a pregnancy. Because misoprostol is potentially teratogenic (it can cause physical malformations of the fetus), a surgical abortion must be performed in the event of a continuing pregnancy.
Mifepristone is a progestin-like structure that occupies the progesterone receptor and prevents its activation (antiprogesterone effect). This may cause an alteration in the lining of the uterus (decidua) resulting in termination of the pregnancy. It also softens the cervix so the pregnancy can be expelled. Methotrexate blocks DNA synthesis by blocking enzymes. This halts the process of implantation (attachment of the embryo to the uterine wall). All three medications can cause side effects including pain, nausea, blee ding, vomiting, diarrhea, warmth or chills, dizziness, headache, and fatigue. Repeated use of medical termination has not been well studied in the medical lecture. However, there is no medical basis to believe that repeated medical abortion has an untoward effect on fertility.