Compared with other contraceptive methods, voluntary female steriliza tion is highly effective and convenient. It is also popular, being the most widely used contraceptive method worldwide with more than 150 million users.1
Sterilization is free from the side effects associated with most temporary methods, does not interfere with sexual intercourse, and does not require routine follow-up care or prescription refills. Yet, because this method is permanent and involves surgery, it is not appropriate for every client. Long-term reversible methods, such as the intrauterine device (IUD), injectables or implants, allow couples the opportunity to have children in the future and may be just as desirable or convenient for some women. Clients interested in sterilization should compare this permanent method with reversible options and be encouraged to select the most appropriate method for their circumstances from a range of contraceptive choices.
Sterilization counseling must be done carefully and may require more time than counseling for other contraceptive methods. Young women, in particular, may need extra time considering future life goals and alternative contraceptive options to avoid the possibility of regret later in life. Young women are more likely than older women to be unhappy later about their decision to terminate fertility.2
"Each case has to be taken on an individual basis," says Dr. Sangeeta Pati, medical associate at AVSC International (AVSC), a New York-based nonprofit organization that works worldwide to improve reproductive health care, with extensive experience in helping providers to maintain quality sterilization services. "If you look at the data, women sterilized at a younger age have much higher rates of regret and pregnancy. Now, knowing what we know, AVSC is recommending that in counseling women under 35, one has to think seriously about whether another long-term method, such as the IUD, is a better option. The most important thing is that the client has choices."
Long-term effectiveness
While female sterilization is generally very effective, a few sterilization clients experience unintended pregnancies. New data show this method is slightly less effective than previously thought.
Scientists once thought that the risk of pregnancy virtually disappeared within a year or two after sterilization, but a recent study sponsored by the U.S. Centers for Disease Control and Prevention (CDC) shows the risk of pregnancy continues for years. The combined 10-year pregnancy rate for various methods of tubal occlusion used by 10,685 women in the United States was 1.8 per 100 women,3 comparable to the 10-year pregnancy rate for the copper T IUD of 2.0 pregnancies per 100 women.4
However, long-term effectiveness differs among specific categories of sterilized women. For women 34 and older, sterilization is one of the most effective of all contraceptive methods, with a 0.7 percent failure rate over 10 years. But younger women, ages 18 to 33, have more than three times that pregnancy risk, at 2.6 percent over 10 years of use, according to the CDC study. Also, among six ways to perform a tubal occlusion that were followed in the study, the use of spring clips (like the Hulka clip) showed the highest pregnancy rates after 10 years, at about 3.7 percent for all women. The study noted that the higher failure rate underscored the need for proper technique in applying clips on the fallopian tubes.
"We have been underestimating the likelihood that pregnancy will occur years after sterilization. It does not change our understanding that this is a very safe and effective procedure," says Dr. Herbert Peterson, principal investigator of the long-term efficacy analysis and chief of women's health and fertility at CDC in Atlanta. "It does tell us that failures, including ectopic pregnancies, can occur many years after sterilization."
While the long-term pregnancy rate for female sterilization is higher than previously believed, this method is at least as effective as most reversible long-term contraceptives. About one in 200 sterilized women become pregnant during the first year after the procedure, or 0.55 pregnancies per 100 women. This compares favorably with the under 1 percent one-year pregnancy rates for the subdermal implant Norplant, the three-month injectable depot-medroxyprogesterone acetate (DMPA) and the copper T 380 intrauterine device.
Risks
When sterilized women do get pregnant, there is a high risk that pregnancies may be ectopic. Counseling should encourage sterilized women to seek medical attention promptly if they suspect they have become pregnant, since an ectopic pregnancy can be fatal. Signs of ectopic pregnancy include missed menstrual periods, reduced menstrual flow, fainting, or lower abdominal pain. Women sterilized under age 30 are at least twice as likely as women over 30 to have an ectopic pregnancy, probably because their fecundity leads to more method failures.5
While female sterilization is generally very safe, rare fatalities or long-term injuries occur due to surgery. About five per 100,000 sterilized women die in developing countries.
The primary causes of death are cardiac or respiratory arrest resulting from anesthesia problems or unintended injury during surgery. In a retrospective study examining female sterilization services in 50 countries from 1973 to 1988, general anesthesia was found to be the most common cause of sterilization-related mortality, followed closely by deaths from intestinal injuries and deaths from infection. Other leading causes were deaths from abdominal hemorrhage, dehydration or allergic reactions to sedatives.6
"To improve safety, the emphasis should be on using local anesthesia whenever appropriate, instead of general anesthesia," says Dr. David Sokal of FHI, who has analyzed sterilization research data extensively. "Local anesthesia minimizes the potential for complications." However, local anesthesia is not appropriate for all women. Some women are allergic to local anesthetics, and obese women typically require general anesthesia because the operation is more difficult to perform on them.
The increased use of local anesthesia and improved infection control in many countries during the 1980s significantly reduced fatality rates associated with sterilization. Other improvements have included the establishment of safe upper limits of the dose for common anesthetics, better ways to monitor vital signs, and increased training in the management of cardiorespiratory depression.
However, local anesthesia can also involve complications. A sedative used with local anesthesia to reduce pain or discomfort may be incompatible with a patient's medical history or may be given in too large an amount. Risks are lower when local anesthesia is used without additional sedatives and providers closely monitor vital signs.
As with all surgery, tubal ligation exposes patients to a slight risk of unintended injury to nearby organs. For female sterilization, bowel injury is one of the most serious, since injuring the bowels allows bacteria to enter the abdominal cavity, causing severe infection (peritonitis). Fortunately, the rate of bowel injury has decreased in recent years due to improved surgical techniques and training. For example, unipolar coagulation, which uses electrical current to burn the tubes closed, is rarely performed because this procedure increases the risk of bowel injury. It has been replaced by the safer bipolar technique.
Other injuries that can occur during female sterilization are perforation of the uterus or the accidental cutting of a major vessel. If severed, the vessel can cause internal hemorrhaging. If not treated, hemorrhaging can lead to shock or death. If the uterus itself is punctured, the organ will normally heal on its own. Profuse bleeding can result if a provider fails to close the fallopian tubes securely.
Infections of the abdomen, pelvic area or wound can be prevented by screening clients for pre-existing infections and using good hygiene in the operating room. When infections do occur, most can be treated with antibiotics. Patients should see their doctor if they have serious abdominal pain, fever or foul-smelling discharge from the wound soon after surgery or if they start bleeding or swelling around the incision site.
Female sterilization offers at least one substantial health benefit -- protection against ovarian cancer. One large-scale prospective study that followed more than 396,000 women for nine years found that women with tubal ligations had 30 percent less risk of developing ovarian cancer than women who were not sterilized.7 Precisely why sterilization protects women against ovarian cancer is not well understood.
Sterilization should be considered permanent because reversal surgery is difficult, expensive and not widely available. Reversal involves a major abdominal incision and delicate surgery on damaged fallopian tubes.
Restrictions
Most international family planning organizations oppose regulations that deny sterilization to clients below a certain age or with fewer than a specified number of children, since such blanket restrictions may limit access to some who could benefit from sterilization. "Although a couple may be young, age does not matter if the decision is correct in their case," says Dr. Marta Durand-Carbajal of the Instituto Nacional de la Nutrición Salvador Zubirán in Mexico City, who has performed sterilizations and helped conduct research on regret. "It's not the age, it's how the decision is made. As a provider, I can help young couples think about the future."
Women who might be interested in sterilization may hesitate to use this method due to a number of misunderstandings and myths. Some women fear that sterilization will cause them to be less feminine, gain weight or lose their sexual desire. Providers should explain that sterilization does not affect normal sexual function, weight or femininity in any way, and can even improve a couple's attitudes toward sexual intercourse by reducing anxieties about unwanted pregnancies.8
"Many women think they will gain weight," says Dr. Kamal Hazari, assistant director at the Institute for Research in Reproduction in Bombay, India, who has studied the medical sequelae of female sterilization. "Because they come to get sterilized in their late 30s or early 40s, they are likely to gain weight anyway. We need to explain to them that this is part of the normal process of aging, rather than the procedure." Other misunderstandings are that eggs build up in the body, or that the tubes are simply "tied" and can easily be "untied" to restore fertility. Providers should explain that the tubes are generally cut as well as tied, and that reversal is a very complex procedure that often fails.
Other questions surrounding the health effects of sterilization stem from scientific debates. Some scientists believe that sterilized women are more likely to experience menstrual irregularities, sometimes termed "poststerilization syndrome." But recent research does not show any difference in menstrual disorders between sterilized women and those who are not. Researchers hypothesize that it is not sterilization, but the normal aging process or the discontinuation of cycle-regulating contraceptives, such as oral contraceptives, that cause some sterilized women to experience more menstrual irregularities.9
Others have questioned whether hysterectomy (the surgical removal of the uterus) is more common among sterilized women. A 1990 study found no difference in hysterectomy rates between sterilized and non-sterilized women over age 30, but younger sterilized women were three times more likely to have hysterectomies than their non-sterilized peers.10 Researchers postulated that young women who are sterilized may be more likely to consider having hysterectomies to cure menstrual irregularities because they are not worried about losing their fertility and have completed their childbearing.
Few contraindications
Unlike hormonal contraceptive methods that are contraindicated for women with certain health conditions, sterilization is safe for women with nearly any medical condition, as long as providers treat or stabilize the condition prior to surgery. For example, providers must try to be sure a woman is not pregnant before performing sterilization. If they suspect pregnancy, the procedure should be delayed.
The postpartum period is often a convenient time to perform sterilization, since many women are rarely in contact with health services except when giving birth. Care should be taken to counsel pregnant women about sterilization in advance of labor or delivery (see related article, page 18).
Postpregnancy procedures are safe, as long as the client's most recent delivery or abortion proceeded smoothly. Pregnancy-related conditions that warrant a delay in the procedure include severe pre-eclampsia; prolonged rupture of the membranes prior to delivery; infection; fever; severe hemorrhage or acute hematometra -- a collection of blood in the uterus. Women who experience severe trauma to the genital tract, uterine rupture or perforation during delivery should also wait.
Postpartum women must have time to receive counseling and think over their decision. If the decision delays a procedure by more than seven days after delivery, the World Health Organization (WHO) recommends waiting at least six weeks to perform the procedure, until the uterus returns to its normal size.
Voluntary female sterilization is safe for women with a wide range of health conditions, according to WHO. There is no reason to deny sterilization to women with malaria; abnormal changes in cervical cells; tuberculosis (without pelvic infection); simple goiters; or an HIV infection. The sterilization procedure is still safe, but requires extra preparation and precautions, when performed on women with mild hypertension (blood pressure between 140-159/90-99); non-vascular diabetes; mild valvular heart disease; sickle cell disease; or thalassaemia, an inherited disorder of hemoglobin metabolism. Providers should take precautions when clients have kidney disease; benign or malignant liver tumors; mild cirrhosis; or complicated schistosomiasis. Precautions should also be used with women who are obese or malnourished because they have an increased risk of wound infection.
Some women can safely be sterilized, but require special care, says WHO. Sterilization should only be undertaken in a hospital setting, with an experienced surgeon and staff, access to general anesthesia services and back-up medical support, if women have the following conditions: severe hypertension (above 160/100); vascular diabetes; coagulation disorders; pelvic conditions, such as endometriosis or an immobile uterus; or chronic respiratory problems, such as lung infections, asthma, bronchitis or emphysema. AIDS-related complications, severe cirrhosis, hyperthyroid condition, and abdominal wall or umbilical hernias also require special care.
Other women need to delay sterilization until their current health conditions stabilize or improve. This category includes women with deep venous thrombosis; pulmonary embolism; ischemic heart disease; pelvic inflammatory disease; current STDs (other than HIV); abdominal infections; systemic infections; gastroenteritis; active hepatitis; acute respiratory disease; severe iron deficiency anemia; and current biliary tract disease. Women with cervical, endometrial or ovarian cancers may not need to have the procedure because the treatment regimens for these cancers often render women infertile. Unexplained vaginal bleeding, a common sign of cervical cancer, should be evaluated prior to sterilization.
-- Sarah Keller
References
- United Nations. Department of Economic and Social Resources. World Contraceptive Use, 1994, poster. New York: United Nations, 1995.
- Hardy E, Bahamondes L, Osis MJ, et al. Risk factors for tubal sterilization regret, detectable before surgery. Contraception 1996;54:159-62.
- Peterson HB, Xia Z, Hughes JM, et al. The risk of pregnancy after tubal sterilization: findings from the U.S. Collaborative Review of Sterilization. Am J Obstet Gynecol 1996;174:1161-70.
- World Health Organization. Special Programme of Research, Development and Research Training in Human Reproduction. The TCu 380A IUD and the frameless IUD "FlexiGard": interim three-year data from an international multicenter trial. Contraception 1995;52(2):77-83.
- Peterson HB, Xia Z, Hughes JM, et al. The risk of ectopic pregnancy after tubal sterilization. N Engl J Med 1997;336(11):762-67.
- Khairullah Z, Huber DH, Gonzáles B. Declining mortality in international sterilization services. Int J Gynecol Obstet 1992;39(1):41-50.
- Miracle-McMahill HL, Calle EE, Kosinski AS, et al. Tubal ligation and fatal ovarian cancer in a large prospective cohort study. Am J Epidemiol 1997;145(4):349-57.
- Shain RN, Miller WB, Holden AE, et al. Impact of tubal sterilization and vasectomy on female marital sexuality: results of a controlled longitudinal study. Am J Obstet Gynecol 1991;164(3):763-71.
- Rulin MC, Davidson AR, Philliber SG, et al. Long-term effect of tubal sterilization on menstrual indices and pelvic pain. Obstet Gynecol 1993;82(1):118-21.
- Stergachis A, Shy KK, Grothaus LC, et al. Tubal sterilization and the long-term risk of hysterectomy. J Am Med Assoc 1990;264:2893-98.
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