Carolyn Westhoff, M.D., and Anne Davis, M.D. INCIDENCE AND PREVALENCE

Transcription

1 FERTILITY AND STERILITY VOL. 73, NO. 5, MAY 2000 Copyright 2000 American Society for Reproductive Medicine Published by Elsevier Science Inc. Printed on acid-free paper in U.S.A. CONTRACEPTION Tubal sterilization: focus on the U.S. experience Carolyn Westhoff, M.D., and Anne Davis, M.D. Department of Obstetrics and Gynecology, College of Physicians and Surgeons, Columbia University, New York, New York Received March 12, 1999; revised and accepted May 26, Supported by the Contraception and Reproductive Health branch of the National Institute of Child Health and Human Development. Presented in part at the conference entitled Male and Female Sterilization: Medical Effects and Behavioral Issues, which was held in Bethesda, Maryland, on June 11 12, Reprint requests: Carolyn Westhoff, M.D., Department of Obstetrics and Gynecology, PH-16, College of Physicians and Surgeons, Columbia University, 630 West 168th Street, New York, New York (FAX: ; /00/$20.00 PII S (00) Objective: To review the frequency, effectiveness, and clinical sequelae of tubal sterilization with a focus on the U.S. experience. Design: A review of U.S. health care statistics and English-language literature using a MEDLINE search, bibliographies of key references, and U.S. government publications. Patient(s): Women seeking tubal sterilization. Intervention: Tubal sterilization. Main Outcome Measure(s): Effectiveness and long-term risks and benefits. Result(s): Half of the 700,000 annual bilateral tubal sterilizations (TS) are performed postpartum and half as ambulatory interval procedures. Eleven million U.S. women years of age rely on TS for contraception. Failure rates vary by method with one third or more resulting in ectopic pregnancy. Reversal is most successful after use of methods that destroy the least tube. Evidence of menstrual or hormonal disturbance after TS is weak, although some studies find higher rates of hysterectomy among previously sterilized women. Decreased risk of subsequent ovarian cancer has been observed among sterilized women. Conclusion(s): Tubal sterilization is highly effective and safe. Failures, although uncommon, occur at higher rates than previously appreciated. Evidence for hormonal or menstrual changes due to TS is weak. Tubal sterilization is associated with decreased risk of ovarian cancer. (Fertil Steril 2000;73: by American Society for Reproductive Medicine.) Key Words: Tubal sterilization, bilateral tubal ligation, female sterilization, sterilization failure, sterilization reversal, ovarian cancer INCIDENCE AND PREVALENCE Because most tubal sterilizations, at least through the 1970s, were performed during hospitalization, their numbers have been estimated from the National Hospital Discharge Survey (NHDS), which covers a sample of all nonfederal short-stay hospitals in the United States and reports on numbers and rates of discharges by diagnosis and by procedures performed. The NHDS data regarding tubal sterilization are currently available from 1970 through 1995 (Fig. 1) (1 16). The number of procedures coded as bilateral occlusion or destruction of the fallopian tubes increased during the 1970s from 201,000 in 1970 to a peak of 702,000 by The number of cases reported by this survey has decreased since then. In 1987 the NHDS estimated that 414,000 tubal sterilizations were performed (9). An ad hoc Centers for Disease Control and Prevention (CDC) survey for the same year identified 415,000 cases performed in the inpatient hospital setting, which gives excellent agreement with the NHDS estimate; however, including tubal ligations performed in all settings, the CDC estimated that 640,000 cases were performed in 1987, demonstrating the magnitude of cases missed by the NHDS as surgery moves to the outpatient setting (17). Analyses of NHDS data of postpartum sterilization from 1988 to 1994 indicate that there were 350,000 such procedures reported each year (18). This finding indicates that nearly all of the sterilizations recently captured by the NHDS are postpartum sterilizations and that sterilization immediately follows nearly 10% of all births. To increase the coverage of outpatient surgical procedures, the NHDS has instituted a survey of surgery performed in ambulatory facilities; however, these data are 913

2 FIGURE 1 Annual number of tubal sterilizations in the U.S. (1 17). National Hospital Discharge Survey, except as noted for 1987 and Procedure codes bilateral destruction or occlusion of fallopian tubes. Westhoff. Tubal sterilizations. Fertil Steril available only for recent years. The combined ambulatory and outpatient data indicate a total of 687,000 tubal sterilizations performed in the United States in 1995 (16). This number is similar to the peak of inpatient cases that were enumerated in 1977 and 1978; thus, the large apparent decreases since 1977 may be due entirely to changes in the location of care. Because of the large recent shifts to outpatient surgical care, we will never know exactly how many interval tubal sterilizations have been performed in the United States during the last decade. Figure 1 estimates total tubal sterilizations based on annual inpatient information and extrapolates from the outpatient data that are available only for 1987 and The NHDS obtains information about the age, race, marital status of women undergoing tubal sterilization, and information about the type and timing of the surgical procedure, and a few detailed analyses of these variables have been published (2, 17, 18). The number and rate of sterilizations increased for all subgroups of women during the 1970s. Women aged had the highest incidence in every year from 1970 to 1978, but younger and older women increased their rates of tubal sterilization even more, narrowing the age differences somewhat. Similarly, black women had higher rates of sterilization than white women from 1970 to 1978, but because the rates increased more among white women, the gap was smaller by 1978 than previously. Most of the women undergoing sterilization are married, but the proportion of currently married women decreased from 89% to 83% from 1970 to In 1970, 70% of all tubal sterilizations reported by the NHDS were pregnancy related. During the period from 1970 to 1978, the number of pregnancy-related tubal sterilizations doubled to 308,000, and the number of interval sterilizations increased fivefold to 345,000 (1). Most inpatient sterilizations follow vaginal delivery; however, the rate per delivery is higher after cesarean section than vaginal delivery (18). The number of sterilizations after other pregnancy outcomes, such as abortion, was only 3.5% in 1978 and has not been reported since (2). Annual age-specific rates for interval tubal sterilization are not now and may never be available. Counts of cases have been incomplete because the operation is performed in various settings, and it is even more difficult to determine the number of women at risk of sterilization because we do not have counts in each age group of those who are candidates for sterilization (i.e., with a uterus and not previously sterilized). Because of these difficulties, large changes in the number or incidence rate of tubal sterilizations could be easily missed. Despite serious gaps in the available incidence data, there are a stable 700,000 tubal sterilizations per year in the United States; about half of these follow delivery, and half of these are performed as outpatient interval procedures. The prevalence of tubal sterilization among women aged is estimated periodically by the National Survey of Family Growth (NSFG), which was first conducted in Earlier data from the National Fertility Surveys in 1960, 1965, and 1970 are also helpful (Table 1) (19). Until 1982, the surveys only included married or ever-married women. Because most sterilizations, especially in those earlier years, were performed among currently or ever-married women, the estimates are essentially complete. Increases in prevalence were dramatic until 1982 and have not increased since. Age-specific prevalence rates (Table 2) show constant TABLE 1 Percentage of U.S. contraceptive users relying on tubal sterilization by age. Variable Percentage of contraceptive users who relied on tubal sterilization Age group (y) Percentage who used tubal sterilization Percentage using any method Percentage using tubal sterilization of all women y No. using tubal sterilization ( 10 6 ) No. of women y ( 10 6 ) Note: Data were adapted from the National Survey of Family Growth. Westhoff. Tubal sterilizations. Fertil Steril Westhoff and Davis Tubal sterilization in the United States Vol. 73, No. 5, May 2000

3 TABLE 2 Relative frequency of use of various laparoscopic sterilization techniques in the United States, Relative frequency of use of laparoscopic techniques by year Percentage who responded Percentage of respondents using indicated method Clip Ring Bipolar Unipolar Note: Data were adapted from American Association of Gynecologic Laparoscopists Surveys (21, 22). Westhoff. Tubal sterilizations. Fertil Steril patterns with sterilization uncommon in women younger than age 25. The 1995 data showed that the percent sterilized was higher for Hispanic women (21%) and black women (25%) than for white women (16%) and others (11%) (20). This pattern has been relatively stable and agrees with the NHDS incidence data. The NSFG data do not distinguish postpartum and interval sterilization. Both the incidence and the prevalence data indicate increasing levels of tubal sterilization during the 1970s with fairly stable levels since then. What factors have led to this dramatic increase? The direct medical factors include increased safety of anesthesia and surgery, which led to greater tolerance for elective surgery among gynecologists. The development of laparoscopic approaches to sterilization led to quicker operations, shorter hospital stays, and more acceptable cosmetic results; these are factors that appeal to both doctors and patients. The indirect medical factors included controversy about the safety of oral contraception in the early 1970s, which led to abandonment of the pill by many women in their older reproductive years. In the 1980s, the withdrawal of most intrauterine devices (IUDs) from the U.S. market may have pushed some additional women to tubal sterilization. Finally, insurance coverage for sterilization, but not for reversible contraceptives, may have encouraged some women to choose sterilization. In the U.S., data on sterilization procedures by method have been collected by the American Association of Gynecologic Laparoscopists (AAGL). Since 1976, the Association has surveyed its members regarding sterilization procedures. The survey was sent to 1,300 members in 1976 and, with increases in every round, was sent in 1993 to 7,322 members; however, response rates declined from a high of 50% in the initial survey to 13% in 1993 (21). Results from the survey indicate that from 1976 to 1982, the use of unipolar cautery decreased dramatically, and bipolar cautery became the most common method of laparoscopic sterilization among respondants (Table 3). Since 1985, use of other methods reported by respondents has remained stable (22). Respondents to this survey are a select group whose choice of sterilization methods may differ from other gynecologists, but no other estimates of technique choice are available. SURGICAL CONSIDERATIONS Key elements of preoperative counseling include the permanent nature of sterilization, the risks of surgery and anesthesia, the risk of intrauterine and ectopic pregnancy after sterilization, and the effectiveness of reversible methods of contraception and of male sterilization. Until the 1970s, most sterilizations included laparotomy incisions, often in conjunction with cesarean section. TABLE 3 Tubal ligation and ovarian cancer. Study (reference) No. of cases Year of study Percentage of controls reporting TS OR (95% CI) Irwin et al. (82) ( ) Whittemore et al. (83) 2, Hospital-based 0.59 ( ) Population-based 0.87 ( ) Hankinson et al. (84) (Nurses Health Study) ( ) Cramer et al. (85) /1984/ ( ) Rosenblatt et al. (86) ( ) Greene et al. (87) ( ) Miracle et al. (88) (ACS cohort) 800 deaths ( ) Note: TS tubal sterilization. Westhoff. Tubal sterilizations. Fertil Steril FERTILITY & STERILITY 915

4 Smaller, minilaparotomy incisions gradually were adapted for sterilization. Postpartum, before uterine involution, tubes are better accessed through periumbilical minilaparotomy. Distant from delivery, when the uterus is small, 2- to 5-cm minilaparotomy incisions near the pubic symphysis are used. In the 1960s, fiber-optic technology was adapted to laparoscopic surgery (23). Laparoscopic sterilization can be accomplished with local or general anesthesia, one- or twopuncture techniques, and various insufflating gases. Unlike minilaparotomy, laparoscopy permits inspection of pelvic and abdominal structures. Use of laparoscopic techniques enabled shorter hospital stays with eventual outpatient, same-day procedures (24). Open laparoscopy was developed with the aim of reducing penetrating injuries associated with blind instrument placement (25). This technique uses a small incision extending into the peritoneum and placement of instruments under direct visualization. Vaginal approaches to sterilization had some popularity before the uptake of laparoscopic sterilization (23), but infectious complications, inability to complete the procedure vaginally, and the ease of the laparoscopic approach led to decreased use. The transcervical approach for delivery of plugs, thermal energy, or sclerosing agents remains investigational (26). Timing of sterilization can be puerperal, interval, or associated with abortion. Complications of pregnancy can postpone puerperal sterilization. According to the American College of Obstetricians and Gynecologists (ACOG), among patients who have had medical or obstetric complications of pregnancy, the procedure should be deferred unless there are overriding medical indications for proceeding (27). Important advantages of puerperal sterilization include tubal access through umbilical minilaparotomy using regional anesthesia (at times initiated during delivery), superior long-term success of postpartum procedures (28) and, for many women, secure medical insurance. In 1978, 3.4% of sterilizations were performed concurrent with induced abortion (2). A combined procedure that includes hysterectomy or hysterotomy as the surgical approach is not justified because of risk (29), but a combined suction curettage and laparoscopic sterilization may be efficient and safe for the patient. The frequency of concurrent sterilization and abortion since 1978 is unknown. Whether effective sterilization counseling can be provided at the time of an abortion is also unknown. Thirty-day waiting periods for elective sterilization, which are required for women obtaining sterilization with public funding, are not compatible with the need for quick care for a woman seeking pregnancy termination as well. Dilatation and curettage concurrent with surgical sterilization has been performed for diagnostic screening and to interrupt undiagnosed luteal phase pregnancy. Lichter et al. (30) report a series of 272 surgical sterilization patients of whom two thirds also underwent dilatation and curettage. Pathologic examination revealed curettings in the luteal phase (37%), follicular phase (39%), and during menstruation (7.0%). Only two unsuspected pregnancies (0.8%) were identified by immature villi. Preoperative contraception, timing of surgery in the follicular phase, and use of highly sensitive pregnancy tests are efficient approaches to prevent or detect luteal phase pregnancy. Routine dilatation and curettage increases cost, adds surgical morbidity, and can be ineffective in early pregnancy termination (31). Both general and local anesthesia are effective for tubal sterilization. In the U.S., general anesthesia is more often used for interval sterilization and regional anesthesia for postpartum procedures. Worldwide, 75% of sterilizations are performed under local anesthesia. In the 1991 Membership Survey of Gynecologic Laparoscopists, 78% of respondents always used general anesthesia, 22% sometimes used local or regional, with only 1% using local exclusively (32). A randomized trial compared local and general anesthesia in 100 women having tubal sterilization. Those having general anesthesia experienced higher heart rates and blood pressures (33). Advantages of local anesthesia with or without conscious sedation include decreased cost, increased safety, simplified technique, shorter recovery, patients ability to report symptoms indicating complication, and decreased nausea and vomiting. Potential disadvantages to local anesthesia include increased patient anxiety, need for surgeon experience enabling decisive, gentle technique, and the need for attention to conscious sedation by the surgeon, if used. Sterilization by electrocautery may be less painful than clips or rings in the immediate postoperative period (34, 35). To decrease postoperative pain after any of the techniques, various regimens using application of local anesthesia to the tubes have been evaluated (36 39) without compelling evidence of benefit. MORTALITY AND SHORT-TERM MORBIDITY In 1977 and 1978, the AAGL and the Royal College of Obstetricians and Gynaecologists (RCOG) reported casefatality rates after laparoscopic sterilization of 2 and 10 deaths per 100,000 procedures, respectively (21, 40). Around the same time, the CDC reported 4 deaths per 100,000 procedures of various types (41). A CDC report identified 1 2 deaths per 100,000 procedures during 1979 and 1980 (42). Subsequently, AAGL members reported 1 death in 40,337 procedures in 1991 and 1 death in 22,966 procedures in 1993 (22, 32). Although the response rates were low in the AAGL surveys, the mortality rates are similar to those identified elsewhere. In an international survey (43), there were 6 deaths per 100,000 procedures. The 916 Westhoff and Davis Tubal sterilization in the United States Vol. 73, No. 5, May 2000

5 highest mortality rate of 19 per 100,000 was reported from temporary sterilization camps in rural India (44). Anesthetic complications account for most tubal sterilization mortality. In the United States, the leading cause of death attributable to surgical sterilization reported between 1977 and 1981 was cardiopulmonary arrest during general anesthesia (45). Hypoventilation is a major cause of anesthesiarelated death, being implicated in 6 of 11 cases undergoing general anesthesia in one series (46). Additional causes of death related to surgical sterilization include sepsis, hemorrhage after vessel laceration, myocardial infarction, and pulmonary embolus. Preexisting medical conditions increase risk of death. In the U.S. 10 of 27 sterilization-related deaths occurred in women with underlying medical conditions (46). Method-specific morbidity and mortality for electrocautery, rings, and interruptive methods have been described. In 1973, Wheeless and Thompson (47) reported 11 cases of severe bowel burns in 3,600 cases of surgical sterilization with unipolar coagulation. Two deaths directly attributed to bowel injury during unipolar coagulation occurred in 1978 and 1979 (48). These deaths, in conjunction with 100 previously reported cases of bowel injury during unipolar coagulation led the CDC to advise reconsideration of the use of unipolar coagulation. These injuries led to preferential use of bipolar coagulation and a lower injury rate (27). Because of the sharp grasping forcep, use of a ring applicator has been associated with tubal transection and associated hemorrhage in 0.1% 6.7% of cases (49, 50). Interruptive methods, both interval and postpartum, have also been associated with bleeding from improperly ligated vessels. In addition to these problems, morbidity after sterilization can be measured by rates of hospital readmission, prolonged hospital stay, and conversion to laparotomy secondary to failure of laparoscopy (51, 52). Surgeon experience may be related to the complication rate. On the basis of self-report in the 1976 AAGL survey, surgeons who had performed fewer than 100 laparoscopic sterilizations experienced a combined total of 14.7 complications per 1,000 procedures compared to 3.8 complications per 1,000 procedures among surgeons with more experience (21). Many safety modifications of laparoscopic technique have been described (21). In 1971, Hasson introduced open laparoscopy, which might improve safety by preventing penetrating injuries or conversion to laparotomy (25). In a clinical trial conducted by Family Health International, four experienced laparoscopists conducted 100 consecutive conventional laparoscopic sterilizations followed by 300 consecutive open laparoscopic sterilizations using Falope rings under local anesthesia (53). Slightly more surgical difficulties were encountered in the open group (2.9% vs. 2.1%), but these were related to entering the abdomen and dropped dramatically after the first 100 open cases. Minor complications in both groups were similar (1.4%), and no serious complications occurred. This report indicates that the open technique can be safely and quickly learned by experienced operators but does not indicate compelling superiority of the open technique. Much larger studies would be needed to detect differences in risk of rare serious injuries. Only 8% of respondents in the 1993 AAGL survey reported use of the open technique (22). EFFECTIVENESS Effectiveness of surgical sterilization is measured by pregnancy rates. Luteal phase pregnancy is defined as conception occurring immediately before surgery, and method failures are defined as conceptions subsequent to sterilization. Failure rates vary by method, timing of surgery, and age of woman. Pregnancies after sterilization are more often ectopic, and ectopic rates also vary by sterilization method. Many early studies reported failure rates of 1%. Follow-up was limited because of the assumption that any failures would occur soon after surgery. A U.S. report on contraceptive failure in 1990 estimated probability of 1st year failure to lie between 0 and 0.4% across all types of sterilization (54). When the intensity of patient surveillance is limited, then the failure rates are underestimated. The AAGL found that of 478 sterilization failures reported in their survey, 190 were identified and reported by the physician who performed the procedure, but 288 were identified by a different physician who responded to the survey (21). Because of brief or incomplete follow-up, the low failure rates reported by many investigators (55, 56) are now recognized to be underestimates. A prospective comparison of 365 women randomized to receive either Hulka clips or Falope rings who were then followed for a mean of 16 months revealed much higher failure rates. Pregnancy rates were 4.5% for clips and 2.6% for rings (57), indicating that previous case series were missing even early sterilization failures. In 1996, the CDC published the findings of the U.S. Collaborative Review of Sterilization (CREST) (28). As a large, multicenter, observational prospective study, CREST provides the only available long-term failure rates in a large group of women. Data were collected on procedures performed between 1978 and 1986 at 16 U.S. hospital centers. Women were interviewed before sterilization, 1 month after surgery, and annually thereafter. Follow-up included 10,685 women, with participation of 89% at 1 year, 81% at 3 years, 73% at 5 years, and 58% at 8 14 years. Follow-up rates were lower in minority and younger women. The CREST study identified a 10-year cumulative failure rate of 18.5 per 1,000 for all methods combined. At 10 years, the most effective methods were postpartum partial salpingectomy and laparoscopic unipolar coagulation, with failure rates of 7.5 per 1,000, followed by Falope rings 17.7 per 1,000, interval partial salpingectomy 20.1 per 1,000, bipolar coagulation 24.8 per 1,000, and spring clips 36.5 per 1,000. FERTILITY & STERILITY 917

6 The 10-year probability of pregnancy was affected by age at the time of sterilization, with women 28 years more likely to become pregnant than those age 34 for all methods except interval partial salpingectomy. Among women sterilized after age 34, none of the differences between method effectiveness were significant. Sterilization failures were more likely to occur in minority women with a relative risk (RR) for black women of 2.53 (95% confidence interval [CI] ) and a RR of 1.24 (95% CI ) in other nonwhite women compared with white women. The investigators point out that even these unexpectedly high failure rates may be underestimates because the subgroups of women more likely to fail sterilization (young and nonwhite) were also more likely to be lost to follow-up in this study. Pregnancies occurring after sterilization are more likely to be ectopic than pregnancies occurring in an unsterilized population. In Denmark, 76% of pregnancies poststerilization were ectopic (58). In that study, ectopic pregnancies in the sterilized women were more likely to rupture than ectopic pregnancies in the nonsterilized women. Ectopic pregnancy rates in a nonsterilized group depend on contraceptive practices. A case-control study comparing ectopic cases to control women using various types of contraception or no contraception found those undergoing interval sterilization had 3.7 ( ) times the risk of ectopic pregnancy compared with current oral contraceptive users, 0.8 ( ) times the risk of IUD users, and 0.2 ( ) times the risk of noncontraceptive users (59). Hence, for women using no contraception, sterilization will protect them against ectopic pregnancy, but for women using oral contraceptives correctly and consistently, sterilization will actually increase their risk of a future ectopic pregnancy. The CREST study demonstrated a 10-year cumulative probability of ectopic pregnancy of 7.3 per 1,000 women for all methods combined (60). Ectopic pregnancy followed bipolar coagulation in 17.1 per 1,000 women compared to 1.5 per 1,000 after postpartum salpingectomy. Of all subsequent pregnancies, 65% were ectopic in the bipolar coagulation group compared to 17% and 15% for unipolar and clip sterilization. Later pregnancies were more likely to be ectopic. The proportion of ectopic gestations were three times greater 4 10 years after sterilization than during the first 3 years. REVERSAL Some women undergoing tubal sterilization will express regret and eventually request reversal. The incidence of regret or seeking reversal among 7,000 women interviewed annually for up to 5 years after sterilization was about 6% (61, 62). Women sterilized at years were twice as likely to report regret as those sterilized after age 30 (62). Also, women 30 at sterilization were twice as likely to seek information about reversal (61). A case-control study of 360 U.S. women found that women requesting reversal started and finished childbearing 5 years earlier and underwent sterilization 9 years earlier than sterilized women not requesting reversal (63). Gomel (64) reported that 25% of couples interested in reversal did not pursue surgery after initial counseling about cost, success rates, and other related issues. Studies of the success of sterilization reversal are difficult to compare because of small numbers and because of major differences in preoperative exclusion criteria, in duration of postoperative follow-up, and in the definition of success (i.e., conceptions vs. births). Despite these limitations, it seems that success of reversal is mainly related to the amount of undamaged tube available for anastomosis (65). The amount of remaining tube is, of course, strongly correlated to the sterilization method that was used. The greater success reported with microsurgical techniques may be due, in part, to its use in women whose original sterilization was performed with less destructive techniques, leaving them with a better prognosis (64 67). Results from the largest series that reported term pregnancy rates, mainly from the United States, are considered here. After bipolar cautery, term pregnancies were reported in 42% (65), 52% (66), and 48% (67) of the 33, 58, and 46 patients who underwent surgery. After a Pomeroy-type procedure, 57% of 47 patients (66), 41% of 27 patients (67), and 74% of 124 patients (68) had a term pregnancy. There is less information about reversal of rings; the only large report indicates term pregnancy among 19 of 22 reversals (65); this degree of success supports Henderson s earlier results (66) with five successes after 6 ring reversals. A combination of several small series show high conception rates after reversal of sterilization using the Hulka clip, with a total of 74 pregnancies after 85 reversals (69), but term pregnancy rates were not reported. There are not yet any large series of reversals after use of the Filshie clip. Time since sterilization and patient age may affect reversal success. In scanning electron microscopic studies, Vasquez et al. (70) noted progressive changes in tubal epithelium after sterilization, suggesting a histologic basis for lower success rates with time. Clinical studies, however, do not provide strong support for decreased success with passing time (67, 71). Although advancing age is associated with decreasing female fertility, conflicting results have been found regarding how age affects reversal success (68, 71). The expected age-related decline in success may have been obscured by exclusion of older women with low fertility based on preoperative testing before a reversal procedure. Ectopic pregnancy is common after reversal of sterilization, and this is the main reason that reporting conception rates (rather than birth rates) is inadequate. After reversal of cautery, 8 of 46 pregnancies (17%), 3 of 20 pregnancies (15%), and 1 of 29 pregnancies (3%) were ectopic (65 67). After reversal of Pomeroy procedures, 2 of 35 pregnancies 918 Westhoff and Davis Tubal sterilization in the United States Vol. 73, No. 5, May 2000

7 (6%) and 8 of 92 pregnancies (9%) were ectopic (66, 68). Finally, after reversal of ring sterilizations, 2 of 19 pregnancies (11%) and 1 of 18 pregnancies (5%) were ectopic (65, 70). Ectopic rates after reversal of clip sterilizations have not been reported. MENSTRUAL DISTURBANCES The notion of a still ill-defined posttubal sterilization syndrome has stimulated studies ever since tubal sterilization incidence started to increase. A recent review that covered the English language literature comparing sterilized and control women found no consistent differences in objective end points, such as hormone levels, and little difference in menstrual cycle characteristics (72). There is an increase in menstrual flow among those women who discontinue oral contraceptives for sterilization (73). A marker for those menstrual disorders that might be more severe or persistent or bothersome is hospital admission. In a U.S. cohort study with 6 years of follow-up, sterilized women were more likely to be hospitalized (RR 2.4) in relation to a menstrual disorder, usually for a curettage (74). Compared with women whose husbands had a vasectomy, the risk was more modest (RR 1.6). The risk was highest among women sterilized at a young age (RR 5.0 for women aged 25 29) and for women of greater higher parity. In a United Kingdom cohort, there was no difference in hospital referral rates for sterilized women compared with women whose husbands had a vasectomy (75). In the CREST study, the subgroup of women sterilized before age 30 who have menstrual dysfunction before sterilization subsequently experienced more menstrual changes (76) and ultimately more hysterectomy (77). LONG-TERM OUTCOMES AMONG STERILIZED WOMEN Large prospective studies in the United States (78 80), United Kingdom (75), and Canada (81) assessed the risk of hysterectomy subsequent to tubal sterilization. Although the cohort analyses vary in analytic approaches, they were able to look for increased risk at various lengths of follow-up up to 17 years after sterilization, and some were able to consider past gynecologic history and indication for hysterectomy. Increased risks of hysterectomy were identified in two U.S. cohorts when sterilized women were compared with women receiving care in the same health care system (78, 79). In both of these cohorts the increased risks were concentrated among the women who underwent sterilization before age 30 with little or no risks among women sterilized later. In the Canadian cohort, there was no overall increase in risk; however, there was a modest increase among the women aged at sterilization (RR 1.6). In the U.K. cohort there was no overall increase, and risk estimates for age subgroups were not provided. In three of the studies (69, 75, 81), analyses compared sterilized women to women whose husbands had undergone vasectomy; in two of these analyses there was no increased risk of hysterectomy among the sterilized women (75, 78). All of these studies compared risks by type of tubal sterilization, and no differences emerged. The concern that sterilized women might have a higher risk of hysterectomy was based on the possible consequences of increased menstrual complaints among these women. Particularly in the U.S. where hysterectomy rates are highest, many women who undergo hysterectomy do so for relief of menstrual complaints in the absence of anatomic abnormalities of the uterus. The Kaiser cohort (79) was able to estimate relative risks for hysterectomy by indication and found increased risks among sterilized women associated with hysterectomy for menstrual disorders (RR 1.65), pelvic pain (RR 2.4), and pelvic inflammatory disease (RR 1.5). No increased risk was found in those analyses using wives of vasectomized men as a comparison group except in the CREST analysis (81); also, no increased risk was found in Canada and the United Kingdom where hysterectomy is less common. No analyses found a relation between hysterectomy and type of sterilization. Where examined, a history of gynecologic complaints was most strongly associated with risk of hysterectomy (77). Taken together, these findings do not support a biological explanation for the association between hysterectomy and sterilization that was observed in some of the studies. An alternative explanation is that women (or couples) who find surgery an acceptable approach to fertility control may also find surgery an acceptable approach to gynecological problems. In the same vein, the comparison women may avoid elective hysterectomy for gynecological problems either because they generally want to avoid surgery or because they specifically want to retain their potential for childbearing. Recent studies in the United States and other countries agree that women have a decreased risk of ovarian cancer after tubal sterilization (Table 3) (82 88). Some of the individual analyses listed (82, 85) are also included in part in the Whittemore combined analysis, which includes 12 studies altogether (83). In addition to the results shown in Table 3, a record linkage analysis from Ontario obtained similar relative risks despite having no information about confounding variables (89). Taken together, these studies provide a consistent picture of a protective effect. Proposed mechanisms for this protection include the possibility that tubal sterilization (and similarly hysterectomy) might protect against cancer by preventing the ascent of environmental carcinogens and the possibility that inspection of the ovaries at the time of surgery might lead to the removal of those ovaries with suspicious characteristics, leading to decreased risk in the future, a sort of screening effect. If screening occurs, one would expect the level of protection to be greatest early. If FERTILITY & STERILITY 919

8 blockage of ascending carcinogens is the mechanism of protection, one would expect to observe greater risk reductions over time. Although these proposals seem to be distinguishable hypotheses, the available data are generally too sparse to address whether the magnitude of protection changes with time since tubal sterilization. Most of these studies did not identify any clear temporal relationships. In the CASH analyses (82) and the ASC cohort analyses (88), the investigators identified a waning of the protective effect in subjects whose sterilization occurred more than two decades before the ovarian cancer. In Cramer s combined case-control analysis (85), there was a suggestion of increased risk two decades after tubal sterilization. All of these differences are based on a small number of subjects in the sterilization-more-than-two-decades-ago subgroup. Because tubal sterilization was rarely performed two decades before the 1980s (when these studies were performed), it is likely that those few women were different in other ways from the rest of the subjects. Now that tubal sterilization has become more prevalent, current studies will probably be able to address this question more successfully. Although talc is the favorite putative environmental carcinogen for the ovary, the protection observed in these studies is not limited to or greater in talc users. The identity of any environmental carcinogens remains to be determined. The CASH study also permitted an analysis of the association between tubal sterilization and breast cancer; no association was observed (90). These findings are all reassuring, but a possible concern is that women undergoing sterilization may decrease their visits for the routine health care that is often associated with contraceptive care in this age group. If sterilized women have fewer Pap smears, their risk for cervical cancer may increase. In a series of 214 women with cervical cancer in the Bronx, New York, the screening history of those with a history of sterilization was inferior to those without tubal sterilization (91). Similarly, in Brooklyn, New York, women with a previous tubal sterilization had fewer subsequent Pap smears than nonsterilized women (92). No analyses at this time assess whether sterilized women change their patterns of obtaining preventive services. DISCUSSION Tubal sterilization has been an extremely common operation for 20 years in the United States. Its popularity demonstrates that women want highly effective family planning methods. Direct complications are rare, particularly in women without medical problems. Because pregnancy itself is more dangerous for women with medical problems, it is reasonable for them to undergo the small risks of sterilization to avoid the larger risks of a pregnancy. Long-term follow-up of sterilized women has clarified many issues that should be communicated to women considering sterilization. First, the cumulative failure rates over 10 years are higher than previously believed, particularly after interval procedures. Many physicians are unaware of these failures because their patients have moved to another source of care by the time the failure occurs. In addition, many failures are ectopic pregnancies. Women who are seeking sterilization primarily because of its presumed effectiveness need to be informed that the highly effective reversible methods may be just as effective for them. This is particularly relevant for younger women requesting an interval sterilization because they will be most likely to experience a sterilization failure. The difficulty, expense, and poor success of reversal should also be clearly expressed to all women who seek sterilization. Clinicians need to communicate that reversible contraceptives such as IUDs and long-acting hormonal methods are often just as effective as sterilization. Second, there is no evidence to support the existence of a specific posttubal sterilization syndrome; however, some sterilized women experience increased menstrual symptoms over time, and some seek hysterectomy to relieve these symptoms. Data from several studies indicate that the excess risk is concentrated among women who completed their families early and sought sterilization by age 30 or earlier. There is no evidence that this finding is biologically mediated. Women who have heavy or irregular periods, dysmenorrhea, and even endometriosis before sterilization may benefit more by using oral contraceptives to suppress these symptoms and to provide contraception. This seems most important for women under 30 seeking an interval sterilization. These younger women are most likely to experience not only these symptoms but also are more likely than women who are sterilized later to experience a failure or to request a reversal. Third, the reduced risk of ovarian cancer in sterilized women reported by many investigators does not yet have a biological explanation but is consistent enough to be considered as a possible noncontraceptive benefit of sterilization. Similarly, reduced risk of PID after tubal sterilization may be another noncontraceptive benefit deserving further attention (93, 94). Finally, because women no longer require direct reproductive health care after sterilization, they may need encouragement to seek out routine preventive services in the following years. References 1. DeStefano F, Greenspan JR, Ory HW, Peterson HB, Maze JM, Smith JC. Demographic trends in tubal sterilization: United States, Am J Public Health 1982;72: Centers for Disease Control, Center for Health Promotion and Education. Surgical Sterilization Surveillance: Tubal Sterilization U.S. Department of Health and Human Services, Public Health Service, Atlanta, GA, March Pokras R. Surgical and non-surgical procedures in short-stay hospitals, United States, Vital and Health Statistics. Series 13, No. 70. DHHS Pub. No. (PHS) National Center for Health Statistics. Public Health Service. Washington. U.S. Government Printing Office, February Westhoff and Davis Tubal sterilization in the United States Vol. 73, No. 5, May 2000

9 4. Graves E, Haupt B. Utilization of short-stay hospitals, United States, Annual summary. Vital and Health Statistics. Series 13, No. 72. DHHS Pub. No. (PHS) National Center for Health Statistics. Public Health Service. Washington: U.S. Government Printing Office, September Graves E. Utilization of short-stay hospitals, United States Annual summary. Vital and Health Statistics. Series 13, No. 78. DHHS Pub. No. (PHS) National Center for Health Statistics. Public Health Service. Washington: U.S. Government Printing Office, August Graves E. Utilization of short-stay hospitals, United States Annual summary. Vital and Health Statistics. Series 13, No. 83. DHHS Pub. No. (PHS) National Center for Health Statistics. Public Health Service. Washington: U.S. Government Printing Office, May Lawrence L. Detailed diagnoses and procedures for patients discharged from short-stay hospitals, United States, Vital and Health Statistics. Series 13, No. 86. DHHS Pub. No. (PHS) National Center for Health Statistics. Public Health Service. Washington: U.S. Government Printing Office, April National Center for Health Statistics Summary: National Hospital Discharge Survey. Advance Data from Vital and Health Statistics No. 145 DHHS Pub. No. (PHS) Hyattsville (MD): Public Health Service, National Center for Health Statistics, Hospital Care Statistics Branch summary: National Hospital Discharge Survey. Advance Data from Vital and Health Statistics. No. 159 (Rev.) DHHS Pub. No. (PHS) Hyattsville (MD): Public Health Service, Gillum BS, Graves EJ, Kozak LJ. Trends in hospital utilization: United States National Center for Health Statistics. Vital Health Stat 1996;13: Graves EJ summary: National Hospital Discharge Survey. Advance data from vital and health statistics (no. 199). Hyattsville (MD): National Center for Health Statistics, Graves EJ summary: National Hospital Discharge Survey. Advance data from vital and health statistics (no. 210). Hyattsville (MD): National Center for Health Statistics, Graves EJ summary: National Hospital Discharge Survey. Advance data from vital and health statistics (no. 249). Hyattsville (MD): National Center for Health Statistics, Graves EJ. Detailed diagnoses and procedures. National Hospital Discharge Survey, National Center for Health Statistics. Vital Health Stat 1995;13: Graves EJ, Gillum BS. Detailed diagnoses and procedures. National Hospital Discharge Survey, National Center for Health Statistics. Vital Health Stat 1997;13: Graves EJ, Gillum BS. Detailed diagnoses and procedures. National Hospital Discharge Survey, National Center for Health Statistics. Vital Health Stat 1997;13: Schwartz DB, Wingo PA, Antarsh L, Smith JC. Female sterilizations in the United States, Fam Plann Perspect 1989;21: Pollack AE, Koonin LM, Haws JM, Kieke BA, MacKay AP, Peterson HB. Postpartum tubal sterilization in the United States, (Abstract). Presented at the 1997 APHA Annual Meeting, Indianapolis, IN. 19. Chandra A. Surgical sterilization in the United States: prevalence and characteristics, National Center for Health Statistics. Vital Health Stat 1998;20: Abra J, Chandra A, Mosher W, Peterson L, Piccinino L. Fertility, family planning, and women s health: new data from the 1995 National Survey of Family Growth. National Center for Health Statistics. Vital Health Stat 1997;19: Phillips J, ed. Membership Surveys and Complication Reports. American Association of Gynecologic Laparoscopists, Santa Fe, CA, Hulka JF, Phillips JM, Peterson HB, Surrey MW. Laparoscopic sterilization: American Association of Gynecologic Laparoscopists 1993 Membership Survey. J Am Assoc Gynecol Laparosc 1995;2: Wilson EW. The evolution of methods for female sterilization. Int J Gynecol Obstet 1995;51(Suppl):S Peterson HB, Greenspan JR, DeStefano F, Ory HW, Layde PM. The impact of laparoscopy on tubal sterilization in United States hospitals, 1970 and 1975 to Am J Obstet Gynecol 1981;140: Hasson HM. A modified instrument and method for laparoscopy. Am J Obstet Gynecol 1971;110: Neuwirth RS. Update on transcervical sterilization. Int J Gynecol Obstet 1995;51(Suppl 1):S American College of Obstetricians and Gynecologists. Sterilization: Technical Bulletin number 222. Washington, DC: American College of Obstetricians and Gynecologists, April Peterson HB, Xia Z, Hughes JM, Wilcox LS, Tylor LR, Trussel J, for the US Collaborative Review of Sterilization Working Group. The risk of pregnancy after tubal sterilization: findings from the US collaborative review of sterilization. Am J Obstet Gynecol 1996;174: Atrash HK, Peterson HB, Cates W, Grimes DA. The risk of death from combined abortion and sterilization procedures: can risk of hysterectomy or hysterotomy be justified? Am J Obstet Gynecol 1982;142: Lichter ED, Scott PL, Freidman EA. Value of routine dilatation and curettage at the time of interval sterilization. Obstet Gynecol 1986;67: Grimes DA, Peterson HB. Should dilatation and curettage be performed routinely at the time of laparoscopy? J Reprod Med 1982;27: Peterson HB, Hulka JF, Phillips JM, Surrey MW. Laparoscopic sterilization: American Association of Gynecologic Laparoscopists 1991 membership survey. J Reprod Med 1993;38: Peterson HB, Hulka JF, Speilman FJ, Lee S, Marchbanks PA. Local versus general anesthesia for laparoscopic sterilization: a randomized study. Obstet Gynecol 1987;70: Baggish MS, Lee WK, Miro SJ, Dacko L, Cohen G. Complications of laparoscopic sterilization: a comparison of two methods. Obstet Gynecol 1979;54: Chi IC, Cole LP. Incidence of pain among women undergoing laparoscopic sterilization by electrocoagulation, the spring-loaded clip, and the tubal ring. Am J Obstet Gynecol 1979;135: Eriksson H, Tenhunen A, Korttila K. Balanced analgesia improves recovery and outcome after outpatient tubal ligation. Acta Anesthesiol Scand 1996;40: Ezeh UD, Shoulder VS, Martin JL, Breeson AJ, Lamb MD, Vellcott ID. Local anesthesia on Filshie clips for pain relief after tubal sterilization: a randomized double-blind controlled trial. Lancet 1995;346: Bordahl PE, Raeder JC, Nordentott J, Kirste U, Refsdal A. Laparoscopic sterilization under local or general anesthesia? A randomized study. Obstet Gynecol 1993;81: Forgach L, Ong BY. Failure of meperidine wound infiltration to reduce pain after laparoscopic tubal ligation. Can J Anesthesia 1995;42: Chamberlain G, Brown JC, editors. The Report of the Working Party of Confidential Enquiry into Gynecological Laparoscopy. London: The Royal College of Obstetricians and Gynecologists, 1978: Peterson HB, DeStefano F, Greenspan JR, Ory HW. Mortality risk associated with tubal sterilization in United States hospitals. Am J Obstet Gynecol 1981;143: Escobedo LG, Peterson HB, Grubb GS, Franks AL. Case-fatality rates for tubal sterilization in U.S. hospitals, 1979 to Am J Obstet Gynecol 1989;160: Aubert JM, Lubell I, Schima M. Mortality risk associated with female sterilization. Int J Gynecol Obstet 1980;18: Bhatt R, Pachauri S, Pathak N, Chauchan L. Female sterilization in small camp settings in rural India. Stud Fam Plann 1978;9: Peterson HB, Greenspan JR, DeStefano F, Ory HW. Deaths associated with laparoscopic sterilization in the United States, J Reprod Med 1982;27: Peterson HB, DeStefano F, Rubin GL, Greenspan JR, Lee NC, Ory HW. Deaths attributable to tubal sterilization in the United States, Am J Obstet Gynecol 1983;146: Wheeless CR, Thompson BH. Laparoscopic sterilization: review of 3,600 cases. Obstet Gynecol 1973;42: Peterson HB, Ory HW, Greenspan JR, Tyler CW. Deaths associated with laparoscopic sterilization by unipolar electrocoagulating devices, 1978 and Am J Obstet Gynecol 1981;139: Levinson CJ, Daily HI, Marko MW, Richardson DC. Non-electric laparoscopic sterilization: experience with a silastic band. Obstet Gynecol 1976;48: Beck P, Gal D, Tancer ML. Silicone band sterilization with radiographic and laparoscopic evaluation. Obstet Gynecol 1979;53: Peterson HB, Lubell I, DeStefano F, Ory HW. The safety and efficacy of tubal sterilization: an international overview. Int J Gynecol Obstet 1983;21: DeStefano F, Greenspan JR, Dicker RC, Peterson HB, Strauss LT, Rubin GL. Complications of interval laparoscopic tubal sterilization. Obstet Gynecol 1983;61: Bhiwandiwala PP, Mumford SD, Kennedy KI. Comparison of the safety of open and conventional laparoscopic sterilization. Obstet Gynecol 1985;66: Trussel J, Hatcher RA, Cates W Jr, Stewart FH, Kost K. Contraceptive failure in the United States: an update. Stud Fam Plann 1990;21: Yoon I, Wheeless C, King T. A preliminary report on a new laparoscopic sterilization technique: the silicone rubber band technique. Am J Obstet Gynecol 1974;120: Rubin G, Lian A, DeStefano F. Failure rate after electrocoagulation and silastic band sterilization. Presented at the annual meeting of American FERTILITY & STERILITY 921