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Hormone levels before and after tubal sterilization
Contraception 73 (2006) 507 – 511
Original research article
Hormone levels before and after tubal sterilization Gwen P. Gentilea, Donald W. Helbiga, Howard Zacurb, Taesung Parkc, Young Jack Leed,e, Carolyn L. Westhoff f,g,4 a
Department of Obstetrics and Gynecology, State University of New York–Downstate, Brooklyn, NY 11203, USA b Department of Obstetrics and Gynecology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA c Department of Statistics, Seoul National University, Seoul 151-742, South Korea d Division of Biostatistics, National Institute of Child Health and Human Development, Bethesda, MD, USA e Hanyang University, Seoul 122-791, South Korea f Department of Obstetrics and Gynecology, Columbia University School of Medicine, New York, NY 10032, USA g The Mailman School of Public Health, Columbia University School of Medicine, New York, NY 10032, USA Received 1 November 2005; revised 21 November 2005; accepted 14 December 2005
Abstract Objective: The aim of this study was to determine whether women experience significant luteal phase hormonal changes following interval tubal sterilization. Design: This is a partly randomized, prospective clinical study. Setting: This study involved healthy volunteers in an academic research environment. Patients: This study involved 118 fertile women seeking tubal sterilization and 57 fertile controls with at least three normal cyclic menstrual periods before entry into the study. Interventions: The patients were randomized to bipolar cautery or Hulka clip as sterilization methods. Barrier contraception or abstinence was used by controls. Main Outcome Measures: The main outcome measures are serum estradiol and progesterone levels and urinary estradiol and pregnanediol levels obtained during the luteal phase before, 1 year and 2 years after sterilization. Results: The women randomized to the bipolar cautery group had higher midluteal progesterone levels measured between Days 5 and 11 postovulation (15.5 ng/mL before sterilization, 14.5 ng/mL at 1 year and 14.5 ng/mL at 2 years) than did the other two groups. The clip group had progesterone levels of 14.1, 12.0 and 12.5 ng/mL at baseline, 1 year and 2 years, respectively, and the control group had levels of 12.0, 11.9 and 11.3 ng/mL for the same periods. Serum estradiol and progesterone and urinary pregnanediol and estradiol were not significantly changed over the 2-year period, nor were there significant differences between the two groups. Conclusions: There were no significant hormonal changes in sterilized women over a period of 2 years when compared with their baseline levels or when compared with unsterilized age-matched controls. D 2006 Elsevier Inc. All rights reserved. Keywords: Laparoscopic tubal sterilization; Posttubal sterilization syndrome; Estradiol level; Progesterone level; Bipolar tubal cauterization; Hulka clip sterilization; Luteal phase hormonal levels
1. Introduction In the United States, over 600,000 women have a tubal sterilization each year and 10 million women in the reproductive ages have been sterilized for contraceptive purposes. The number worldwide is estimated to be
4 Corresponding author. Department of Obstetrics and Gynecology, Columbia University School of Medicine, New York, NY 10032, USA. E-mail address: [email protected] (C.L. Westhoff ). 0010-7824/$ – see front matter D 2006 Elsevier Inc. All rights reserved. doi:10.1016/j.contraception.2005.12.002
140 million. Forty-two percent of U.S. women between 30 and 44 years of age have undergone a tubal sterilization [1]. Since Williams et al [2] in 1951 reported that sterilized women had more menstrual abnormalities than other gynecologic or obstetric patients, numerous studies have addressed this issue. Some looked at menstrual history alone; others, at the incidence of surgery after sterilization; and still others, at hormonal evidence of menstrual changes. A literature review concluded that no one study adequately looked at all the variables [3]. A recent large-scale study concluded that sterilized women were no more likely to
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G.P. Gentile et al. / Contraception 73 (2006) 507–511
have menstrual abnormalities than women who had not undergone sterilization [4]. This prospective longitudinal study was undertaken with nonsterilized fertile women as controls in an attempt to look at all the relevant parameters affecting sterilized women as they age and to correlate these with hormone levels and menstrual changes. This analysis focuses on the hormonal levels in women before and during the 2 years after a tubal sterilization. We compared bipolar cautery and the Hulka clip to determine if there are more changes in ovarian hormone production after using a technique that destroys a large segment of the fallopian tube and mesosalpinx (bipolar cautery) than after a sterilization technique that destroys only a small section of the tube (Hulka clip).
2. Materials and methods 2.1. Patients Women were recruited into this study from the Family Planning Clinic at the State University of New York– Downstate Medical Center. One hundred eighteen women who sought voluntary tubal sterilization and 57 controls were enrolled. Institutional review board approval was obtained, and the women signed an informed consent. Eligibility criteria included age between 21 and 35 years, at least one prior pregnancy and a history of regular cyclic menses with an interval between 23 and 38 days and a moderate flow lasting between 2 and 7 days. If a woman had recently completed a pregnancy, stopped breast-feeding or used an oral contraceptive or an intrauterine device, she was required to wait at least 3 months and until she had at least three regular menstrual periods prior to enrollment in the study. At the initial history and physical examination, she had to have no evidence of endocrine or gynecologic pathology that might adversely affect her menstrual pattern. In addition, control participants needing contraception had to use barrier methods or practice fertility awareness during the study. 2.2. Study design Subjects answered standardized questions at enrollment regarding medical, surgical, obstetric and contraceptive history; socioeconomic factors; use of controlled and illicit substances and sexual practices. They also completed a life stress instrument [5] and the Moos menstrual distress questionnaire [6]. A physical examination, including thyroid, breast and pelvic examinations, was performed at the time of enrollment. During the month after enrollment, subjects measured their basal body temperature (BBT) and collected first-voided morning urine specimens daily. The urines were kept in the patient’s freezer, collected by the study staff and stored at 208C until being assayed for pregnanediol and estradiol. They also underwent phlebotomy every 3 to 4 days during the luteal phase of that
menstrual cycle. The bloods were centrifuged, and the serum was stored at 208C until being assayed for progesterone and estradiol. Sterilizations took place after completion of the baseline study cycle. We used simple randomization with a 1:1 allocation ratio to assign the 118 women seeking sterilization either to the Hulka clip (n = 62) or to the bipolar cautery (n =56) technique. Randomization took place after completion of consent and all other enrollment procedures. A single clinician (GPG) performed all examinations and all tubal sterilizations. Subjects completed questionnaires and underwent a physical examination annually for 2 years. In addition, sterilized patients completed a questionnaire about reactions to the sterilization and feelings of regret. Subjects also repeated the BBT measurements, urine collection and blood collection for one additional menstrual cycle at 1 year and 2 years after study entry. Blood collection stopped after Year 2, but urine specimens were collected again 3 years after entry. Of the 175 women enrolled in this study, 102 (58.6%) were followed for 2 years or longer. Women in the control group who became pregnant resumed follow-up after pregnancy termination, followed by three spontaneous cyclic menstrual periods. In all study cycles, both at baseline and during follow-up, we assigned a cycle day to each urine and blood specimen by using menstrual diaries and BBT charts. A single author (GPG) made all assignments of menstrual cycle day. 2.3. Assay methods Pregnanediol 3-a glucuronide and estradiol glucuronide were measured by radioimmunoassay in unextracted urine. Urine samples were thawed and centrifuged at 1000g for 10 min at 88C. The supernatant was then diluted 1:1000 for pregnanediol 3-a glucuronide and 1:10 for estradiol glucuronide in 0.1 M, pH 7 phosphate buffered saline with 0.1% gelatin prior to assay. Tritiated [3H]-pregnanediol 3-a glucuronide and estradiol glucuronide and antisera were added, and the samples were successively incubated at 378C for 30 min. Free and antibody-bound steroid conjugates were separated by the addition of dextran-coated charcoal. Samples were then centrifuged, and the supernatant was counted. All samples were analyzed in duplicate. Pregnanediol 3-a glucuronide, estradiol glucuronide, antisera to pregnanediol 3-a glucuronide and estradiol glucuronide and tritiated [3H]-pregnanediol 3-a glucuronide and estradiol glucuronide were obtained from Samarajeewa (Courtauld Institute of Biochemistry, Middlesex Hospital Medical School, London, UK). Assay sensitivity for pregnanediol 3-a glucuronide was 15 pg/100 AL; intra-assay coefficient of variation was 6.6% with an interassay coefficient of variation of 15.7%. Assay sensitivity for estradiol glucuronide was 7.5 pg/100 AL, intra-assay coefficient of variation was 5.3% and interassay was 13.2%. Urinary creatinine levels were originally measured, but we found that the use of creatinine as a means of adjusting urinary steroid values was not valid [7].
G.P. Gentile et al. / Contraception 73 (2006) 507–511 Table 1 Characteristics of study participants Characteristic
Table 3 Serum progesterone levels: Days 5 to 11 of luteal phase
Study group Total
Total enrolled Mean Age Ethnic group (%) Black White Hispanic Other Education (years) Marital status (%) Never married Currently married Legally separated Divorced Widowed Religion (%) Protestant Catholic Other None Working at enrollment (%) Median household income (US$) Mean no. of pregnancies Mean weight at enrollment
Clip
Cautery
Control
174 29.8
61 29.6
56 29.5
57 30.2
59.8 17.8 20.7 1.7 13.3
60.7 9.8 27.9 1.6 12.5
62.5 14.3 23.2
56.1 29.8 10.5 3.5 15.1
32.2 56.3 2.9 7.5 1.1
32.8 60.7
46.6 33.3 11.5 8.6 61.5
49.2 31.1 11.5 8.2 59.0
22,500 3.4 150.6
8.6
18,050
12.3 23.2 58.9 7.1 8.9 1.8
40.4 49.1 1.8 8.8
50.0 37.5 7.1 5.4 46.4
40.4 31.6 15.8 12.3 78.9
14,800
3.9 154.5
3.9 146.9
30,000 2.4 150.1
All specimens were retained for laboratory analysis until specimen collection was completed. All specimens from a single subject were included in the same run. In order to avoid the introduction of drift or other bias in the hormonal measurements, equal numbers of controls and subjects in both sterilization groups were included in each assay run. 2.4. Statistical analysis The goal of the analysis was to compare each hormone level (serum estradiol and progesterone, pregnanediol 3-a glucuronide and estradiol glucuronide) between the study groups (clip, cautery, control) over time (baseline, Year 1, Year 2). Linear regression analyses were carried out using the log-transformed hormone values. These analyses also included age, weight, age at menarche and smoking (yes or no) as covariates [8]. Each subject had multiple hormone measurements both during a single menstrual cycle as well as during cycles one or more years apart. These repeated measures within the study subjects are not completely independent; therefore, several statistical models were fitted Table 2 Urinary pregnanediol levels: Days 5 to 11 of luteal phase Clip Baseline Year 1 Year 2 Year 3
954 836 848 901
(59) (45) (32) (23)
509
Cautery
Control
1072 933 868 1109
1015 863 884 710
(56) (42) (36) (19)
(54) (45) (31) (15)
Values are in picograms per milliliter. Values in parentheses are n. p = .29.
Baseline Year 1 Year 2
Clip
Cautery
Control
14.1 (57) 12.0 (43) 12.5 (36)
15.5 (55) 14.5 (43) 14.5 (34)
12.0 (54) 11.9 (41) 11.3 (26)
Values are in nanograms per milliliter. Values in parentheses are n. p = .04 based on higher serum progesterone levels in cautery group at baseline.
to the data that incorporated varying assumptions about the correlations of each hormone level within individual subjects. The p values presented here are from the spatial covariance model, which assumes partial covariance of hormone levels from adjacent study days. Alternative models that assumed greater or lesser autocorrelations were also evaluated and gave similar results (data not shown) [9]. 3. Results A total of 175 women were enrolled in this study, 118 of whom were seeking voluntary tubal sterilization and 57 of whom were controls. One woman was dropped from the study at the time of surgery because significant tubal abnormalities precluded performing the type of sterilization to which she had been randomly assigned. The characteristics of the participants are summarized in Table 1. The two groups were similar in age, menstrual cycle length, age at menarche and weight. The controls were more likely to work outside the home, to be white, to have more education and to have a higher household income. The controls, who were required to use barrier contraception during the study, most often chose the diaphragm. The women seeking sterilization had higher parity, were more likely to smoke and were more likely to be Hispanic. These differences between the controls and the women seeking sterilization were unrelated to their hormone levels. Participants were ovulatory for nearly all study cycles, and their general hormonal pattern was normal [8]. There were no differences in baseline characteristics between the women who participated throughout all 3 years of the study and those who withdrew or were lost to followup (data not shown). Urinary pregnanediol 3-a glucuronide was evaluated from postovulation Days 5 to 11; the mean for each group was obtained (Table 2). There were no significant differences between the clip, the cautery or the control groups nor between the baseline values and the values in subsequent years. The p value from the spatial covariance model was 0.29. Similar results were obtained when pregnanediol 3-a Table 4 Urinary estradiol levels: Days 5 to 11 of luteal phase Baseline Year 1 Year 2
Clip
Cautery
Control
51.7 (59) 48.3 (45) 53.3 (32)
52.0 (56) 54.2 (42) 50.0 (36)
54.6 (54) 58.2 (45) 60.0 (31)
Values are in picograms per milliliter. Values in parentheses are n. p = .82.
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Table 5 Estradiol levels: Days 5 to 11 of luteal phase Baseline Year 1 Year 2
Clip
Cautery
Control
120.4 (57) 120.7 (42) 122.4 (35)
140.5 (46) 122.3 (41) 124.8 (32)
120.1 (41) 111.8 (35) 125.2 (23)
Values are in picograms per milliliter. Values in parentheses are n. p = .96.
glucuronide values were evaluated for the area under the curve or for peak values (data not shown). Serum progesterone levels during the postovulatory Day 5 through 11 interval were significantly higher in the cautery group at baseline than they were in either the clip group or the controls (Table 3). This elevated level persisted through the years of the study and continued to be significantly higher than the other two groups. There were, however, no significant changes in progesterone level over time in this group or in the other two groups. The p value of .04 reflects the higher progesterone level in the cautery group. In all groups, there was a slight decrease in progesterone values over time, but this was not statistically significant. There were no significant changes in midluteal serum estradiol or urinary estradiol glucuronide levels (Tables 4 and 5) either between groups or over time, with p values of .82 for the serum estradiol and .96 for the urinary estrogen metabolite. Results were similar for analyses limited to women who participated throughout all cycles of the study (data not shown).
4. Discussion This report provides the results of a comprehensive and controlled study of the effects of tubal sterilization on ovarian hormone levels in women during early to middle reproductive years. Women who sought sterilization were studied prior to sterilization and were randomly assigned to one of two sterilization types (Hulka clip or bipolar cautery). They were then followed for 2 years after sterilization along with a group of controls who were of similar age, weight and menstrual regularity. Our findings confirm reports of smaller studies that sterilization does not cause major changes in ovarian hormones [10–14]. This was true whether the operator used the clip technique, which has minimal effect on tubal and vascular architecture, or used bipolar cautery, with its demonstrably greater destruction of the tube and mesosalpinx and possibly of ovarian blood supply. The strengths of this investigation are its large size, the randomization of women to two different sterilization techniques and the prospective longitudinal collection of urine and blood for the hormonal assays. There are limitations to this study. We did not collect follicular phase estradiol levels; these might have allowed a more complete analysis of the possibility of hormone changes in sterilized women. Specifically, this would have identified if an adequate follicular phase preceded the demonstrably adequate luteal phase. Even more helpful
would have been a longer follow-up period. Data from the Walnut Creek Contraceptive Drug Study showed significant menstrual aberrations only when following women for longer than 2 years after sterilization [15]. Luteal phase hormone levels were the focus of this analysis. Urine for estradiol and pregnanediol determinations was obtained daily and blood for serum progesterone levels was obtained every third day during the luteal phase in all women at enrollment and every year for 2 years. No statistically significant differences in these levels within and between groups were seen. There were also no significant changes in urinary or serum estradiol levels in the luteal phase. The higher serum progesterone level in the cautery group that persisted over the course of the study was present at baseline and thus appears to be due to a chance imbalance between the groups. Study participants had not been on oral contraceptives, had not used an intrauterine device, had not been pregnant within 3 months of enrollment and had had at least three normal cyclic menstrual periods prior to the performance of the sterilization. Therefore, normal menstrual cycle description was based on current records rather than on distant memory. The cycle immediately preceding the sterilization was tracked by BBTs, urinary and blood hormone measures, a day-by-day description of the amount and duration of flow and the presence or absence of dysmenorrhea. Analyses from the Collaborative Review of Sterilization [16] suggest that the women who had menstrual problems prior to sterilization were most likely to have subsequent menstrual complaints. These complaints and problems led to further gynecological surgery, including hysterectomy. We excluded women with irregular cycles or significant menstrual complaints from this study. This study confirms that women with normal cycles prior to sterilization will maintain normal ovarian function, as defined by luteal phase hormone levels, during the 2 years following sterilization. Acknowledgments The authors thank Barbara Driscoll, R.N., for her assistance in data collection, drawing blood samples and maintaining patient follow-up. This project was funded, in part, with federal funds from the National Institute of Child Health and Human Development, National Institutes of Health, under Contract Number NO1HD052908. The content of this publication does not necessarily reflect the views or policies of the Department of Health and Human Services, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. government. References [1] Abma JC, Chandra A, Mosher WD, Peterson LS, Piccinino LJ. Fertility, family planning and women’s health: new data from the 1995 National Survey of Family Growth. Vital Health Stat 1997 series 23 No. 19, CDC, NCHS. p. 62 – 4.
G.P. Gentile et al. / Contraception 73 (2006) 507–511 [2] Williams EL, Jones HE, Merrill RE. Subsequent course of patients sterilized by tubal ligation. Am J Obstet Gynecol 1951;61:423 – 6. [3] Gentile GP, Kaufman SC, Helbig DW. Is there any evidence for a post-tubal sterilization syndrome? Fertil Steril 1998;69:179 – 86. [4] Peterson HB, Ling G, Folger SG, Hillis SA, Marchbanks PA, Wilcox LS. The risk of menstrual abnormalities after tubal sterilization. N Engl J Med 2000;343:1681 – 7. [5] Saranson IG, Johnson JH, Siegel JM. Development of life experiences survey. J Clin Psychol 1978;46:932 – 46. [6] Moos RH. Menstrual distress questionnaire manual. Palo Alto (CA)7 Dept Psychiatry, Stanford Univ/Veterans Admin; 1977. [7] Zacur H, Kaufman SC, Smith B, Westhoff C, et al. Does creatinine adjustment of urinary pregnanediol glucuronide reduce or introduce measurement error? Gynecol Endocrinol 1997;11:29 – 33. [8] Westhoff C, Gentile G, Lee J, Zacur H, Helbig D. Predictors of ovarian steroid secretion in reproductive-age women. Am J Epidemiol 1996;144:381 – 8. [9] Park T, Park JK, Davis CS. Effects of covariance model assumptions on hypothesis tests for repeated measurements: analysis of ovarian hormone data and pituitary-pteromaxillary distance data. Stat Med 2001;20:2441 – 53.
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[10] Helm G, Sjoberg NO. Corpus luteal function after tubal sterilization using endothermic coagulation. Acta Obstet Gynecol Scand 1986;65: 741 – 4. [11] Alvarez F, Faundes A, Braebe V, Tejada AS, Segal SJ. Prospective study of the pituitary function after tubal sterilization by the Pomeroy or Uchida techniques. Fertil Steril 1989;51:604 – 8. [12] Garza-Flores J, Vasquez-Estrada L, Reyes A, et al. Assessment of luteal function after surgical tubal sterilization. Adv Contracept 1991;7:371 – 7. [13] Thranov I, Herz JB, Kjer JJ, Anderson A, Misic S, Nielsen J, et al. Hormonal and menstrual changes after laparoscopic sterilization by Falope-rings or Filshie clips. Fertil Steril 1992;57:751 – 5. [14] Fagundes M, Mendes M, Patta M, et al. Hormonal assessment of women submitted to tubal ligation. Contraception 2005;71: 309 – 14. [15] DeStefano F, Perlman JA, Peterson HB, Diamond EL. Long-term risk of menstrual disturbances after tubal sterilization. Am J Gynecol 1985;152:835 – 41. [16] Wilcox LS, Martinez-Schnell B, Peterson HB, Ware JH, Hughes JM. Menstrual function after tubal sterilization. Am J Epidemiol 1992;135: 1368 – 81.
Original research article
Hormone levels before and after tubal sterilization Gwen P. Gentilea, Donald W. Helbiga, Howard Zacurb, Taesung Parkc, Young Jack Leed,e, Carolyn L. Westhoff f,g,4 a
Department of Obstetrics and Gynecology, State University of New York–Downstate, Brooklyn, NY 11203, USA b Department of Obstetrics and Gynecology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA c Department of Statistics, Seoul National University, Seoul 151-742, South Korea d Division of Biostatistics, National Institute of Child Health and Human Development, Bethesda, MD, USA e Hanyang University, Seoul 122-791, South Korea f Department of Obstetrics and Gynecology, Columbia University School of Medicine, New York, NY 10032, USA g The Mailman School of Public Health, Columbia University School of Medicine, New York, NY 10032, USA Received 1 November 2005; revised 21 November 2005; accepted 14 December 2005
Abstract Objective: The aim of this study was to determine whether women experience significant luteal phase hormonal changes following interval tubal sterilization. Design: This is a partly randomized, prospective clinical study. Setting: This study involved healthy volunteers in an academic research environment. Patients: This study involved 118 fertile women seeking tubal sterilization and 57 fertile controls with at least three normal cyclic menstrual periods before entry into the study. Interventions: The patients were randomized to bipolar cautery or Hulka clip as sterilization methods. Barrier contraception or abstinence was used by controls. Main Outcome Measures: The main outcome measures are serum estradiol and progesterone levels and urinary estradiol and pregnanediol levels obtained during the luteal phase before, 1 year and 2 years after sterilization. Results: The women randomized to the bipolar cautery group had higher midluteal progesterone levels measured between Days 5 and 11 postovulation (15.5 ng/mL before sterilization, 14.5 ng/mL at 1 year and 14.5 ng/mL at 2 years) than did the other two groups. The clip group had progesterone levels of 14.1, 12.0 and 12.5 ng/mL at baseline, 1 year and 2 years, respectively, and the control group had levels of 12.0, 11.9 and 11.3 ng/mL for the same periods. Serum estradiol and progesterone and urinary pregnanediol and estradiol were not significantly changed over the 2-year period, nor were there significant differences between the two groups. Conclusions: There were no significant hormonal changes in sterilized women over a period of 2 years when compared with their baseline levels or when compared with unsterilized age-matched controls. D 2006 Elsevier Inc. All rights reserved. Keywords: Laparoscopic tubal sterilization; Posttubal sterilization syndrome; Estradiol level; Progesterone level; Bipolar tubal cauterization; Hulka clip sterilization; Luteal phase hormonal levels
1. Introduction In the United States, over 600,000 women have a tubal sterilization each year and 10 million women in the reproductive ages have been sterilized for contraceptive purposes. The number worldwide is estimated to be
4 Corresponding author. Department of Obstetrics and Gynecology, Columbia University School of Medicine, New York, NY 10032, USA. E-mail address: [email protected] (C.L. Westhoff ). 0010-7824/$ – see front matter D 2006 Elsevier Inc. All rights reserved. doi:10.1016/j.contraception.2005.12.002
140 million. Forty-two percent of U.S. women between 30 and 44 years of age have undergone a tubal sterilization [1]. Since Williams et al [2] in 1951 reported that sterilized women had more menstrual abnormalities than other gynecologic or obstetric patients, numerous studies have addressed this issue. Some looked at menstrual history alone; others, at the incidence of surgery after sterilization; and still others, at hormonal evidence of menstrual changes. A literature review concluded that no one study adequately looked at all the variables [3]. A recent large-scale study concluded that sterilized women were no more likely to
508
G.P. Gentile et al. / Contraception 73 (2006) 507–511
have menstrual abnormalities than women who had not undergone sterilization [4]. This prospective longitudinal study was undertaken with nonsterilized fertile women as controls in an attempt to look at all the relevant parameters affecting sterilized women as they age and to correlate these with hormone levels and menstrual changes. This analysis focuses on the hormonal levels in women before and during the 2 years after a tubal sterilization. We compared bipolar cautery and the Hulka clip to determine if there are more changes in ovarian hormone production after using a technique that destroys a large segment of the fallopian tube and mesosalpinx (bipolar cautery) than after a sterilization technique that destroys only a small section of the tube (Hulka clip).
2. Materials and methods 2.1. Patients Women were recruited into this study from the Family Planning Clinic at the State University of New York– Downstate Medical Center. One hundred eighteen women who sought voluntary tubal sterilization and 57 controls were enrolled. Institutional review board approval was obtained, and the women signed an informed consent. Eligibility criteria included age between 21 and 35 years, at least one prior pregnancy and a history of regular cyclic menses with an interval between 23 and 38 days and a moderate flow lasting between 2 and 7 days. If a woman had recently completed a pregnancy, stopped breast-feeding or used an oral contraceptive or an intrauterine device, she was required to wait at least 3 months and until she had at least three regular menstrual periods prior to enrollment in the study. At the initial history and physical examination, she had to have no evidence of endocrine or gynecologic pathology that might adversely affect her menstrual pattern. In addition, control participants needing contraception had to use barrier methods or practice fertility awareness during the study. 2.2. Study design Subjects answered standardized questions at enrollment regarding medical, surgical, obstetric and contraceptive history; socioeconomic factors; use of controlled and illicit substances and sexual practices. They also completed a life stress instrument [5] and the Moos menstrual distress questionnaire [6]. A physical examination, including thyroid, breast and pelvic examinations, was performed at the time of enrollment. During the month after enrollment, subjects measured their basal body temperature (BBT) and collected first-voided morning urine specimens daily. The urines were kept in the patient’s freezer, collected by the study staff and stored at 208C until being assayed for pregnanediol and estradiol. They also underwent phlebotomy every 3 to 4 days during the luteal phase of that
menstrual cycle. The bloods were centrifuged, and the serum was stored at 208C until being assayed for progesterone and estradiol. Sterilizations took place after completion of the baseline study cycle. We used simple randomization with a 1:1 allocation ratio to assign the 118 women seeking sterilization either to the Hulka clip (n = 62) or to the bipolar cautery (n =56) technique. Randomization took place after completion of consent and all other enrollment procedures. A single clinician (GPG) performed all examinations and all tubal sterilizations. Subjects completed questionnaires and underwent a physical examination annually for 2 years. In addition, sterilized patients completed a questionnaire about reactions to the sterilization and feelings of regret. Subjects also repeated the BBT measurements, urine collection and blood collection for one additional menstrual cycle at 1 year and 2 years after study entry. Blood collection stopped after Year 2, but urine specimens were collected again 3 years after entry. Of the 175 women enrolled in this study, 102 (58.6%) were followed for 2 years or longer. Women in the control group who became pregnant resumed follow-up after pregnancy termination, followed by three spontaneous cyclic menstrual periods. In all study cycles, both at baseline and during follow-up, we assigned a cycle day to each urine and blood specimen by using menstrual diaries and BBT charts. A single author (GPG) made all assignments of menstrual cycle day. 2.3. Assay methods Pregnanediol 3-a glucuronide and estradiol glucuronide were measured by radioimmunoassay in unextracted urine. Urine samples were thawed and centrifuged at 1000g for 10 min at 88C. The supernatant was then diluted 1:1000 for pregnanediol 3-a glucuronide and 1:10 for estradiol glucuronide in 0.1 M, pH 7 phosphate buffered saline with 0.1% gelatin prior to assay. Tritiated [3H]-pregnanediol 3-a glucuronide and estradiol glucuronide and antisera were added, and the samples were successively incubated at 378C for 30 min. Free and antibody-bound steroid conjugates were separated by the addition of dextran-coated charcoal. Samples were then centrifuged, and the supernatant was counted. All samples were analyzed in duplicate. Pregnanediol 3-a glucuronide, estradiol glucuronide, antisera to pregnanediol 3-a glucuronide and estradiol glucuronide and tritiated [3H]-pregnanediol 3-a glucuronide and estradiol glucuronide were obtained from Samarajeewa (Courtauld Institute of Biochemistry, Middlesex Hospital Medical School, London, UK). Assay sensitivity for pregnanediol 3-a glucuronide was 15 pg/100 AL; intra-assay coefficient of variation was 6.6% with an interassay coefficient of variation of 15.7%. Assay sensitivity for estradiol glucuronide was 7.5 pg/100 AL, intra-assay coefficient of variation was 5.3% and interassay was 13.2%. Urinary creatinine levels were originally measured, but we found that the use of creatinine as a means of adjusting urinary steroid values was not valid [7].
G.P. Gentile et al. / Contraception 73 (2006) 507–511 Table 1 Characteristics of study participants Characteristic
Table 3 Serum progesterone levels: Days 5 to 11 of luteal phase
Study group Total
Total enrolled Mean Age Ethnic group (%) Black White Hispanic Other Education (years) Marital status (%) Never married Currently married Legally separated Divorced Widowed Religion (%) Protestant Catholic Other None Working at enrollment (%) Median household income (US$) Mean no. of pregnancies Mean weight at enrollment
Clip
Cautery
Control
174 29.8
61 29.6
56 29.5
57 30.2
59.8 17.8 20.7 1.7 13.3
60.7 9.8 27.9 1.6 12.5
62.5 14.3 23.2
56.1 29.8 10.5 3.5 15.1
32.2 56.3 2.9 7.5 1.1
32.8 60.7
46.6 33.3 11.5 8.6 61.5
49.2 31.1 11.5 8.2 59.0
22,500 3.4 150.6
8.6
18,050
12.3 23.2 58.9 7.1 8.9 1.8
40.4 49.1 1.8 8.8
50.0 37.5 7.1 5.4 46.4
40.4 31.6 15.8 12.3 78.9
14,800
3.9 154.5
3.9 146.9
30,000 2.4 150.1
All specimens were retained for laboratory analysis until specimen collection was completed. All specimens from a single subject were included in the same run. In order to avoid the introduction of drift or other bias in the hormonal measurements, equal numbers of controls and subjects in both sterilization groups were included in each assay run. 2.4. Statistical analysis The goal of the analysis was to compare each hormone level (serum estradiol and progesterone, pregnanediol 3-a glucuronide and estradiol glucuronide) between the study groups (clip, cautery, control) over time (baseline, Year 1, Year 2). Linear regression analyses were carried out using the log-transformed hormone values. These analyses also included age, weight, age at menarche and smoking (yes or no) as covariates [8]. Each subject had multiple hormone measurements both during a single menstrual cycle as well as during cycles one or more years apart. These repeated measures within the study subjects are not completely independent; therefore, several statistical models were fitted Table 2 Urinary pregnanediol levels: Days 5 to 11 of luteal phase Clip Baseline Year 1 Year 2 Year 3
954 836 848 901
(59) (45) (32) (23)
509
Cautery
Control
1072 933 868 1109
1015 863 884 710
(56) (42) (36) (19)
(54) (45) (31) (15)
Values are in picograms per milliliter. Values in parentheses are n. p = .29.
Baseline Year 1 Year 2
Clip
Cautery
Control
14.1 (57) 12.0 (43) 12.5 (36)
15.5 (55) 14.5 (43) 14.5 (34)
12.0 (54) 11.9 (41) 11.3 (26)
Values are in nanograms per milliliter. Values in parentheses are n. p = .04 based on higher serum progesterone levels in cautery group at baseline.
to the data that incorporated varying assumptions about the correlations of each hormone level within individual subjects. The p values presented here are from the spatial covariance model, which assumes partial covariance of hormone levels from adjacent study days. Alternative models that assumed greater or lesser autocorrelations were also evaluated and gave similar results (data not shown) [9]. 3. Results A total of 175 women were enrolled in this study, 118 of whom were seeking voluntary tubal sterilization and 57 of whom were controls. One woman was dropped from the study at the time of surgery because significant tubal abnormalities precluded performing the type of sterilization to which she had been randomly assigned. The characteristics of the participants are summarized in Table 1. The two groups were similar in age, menstrual cycle length, age at menarche and weight. The controls were more likely to work outside the home, to be white, to have more education and to have a higher household income. The controls, who were required to use barrier contraception during the study, most often chose the diaphragm. The women seeking sterilization had higher parity, were more likely to smoke and were more likely to be Hispanic. These differences between the controls and the women seeking sterilization were unrelated to their hormone levels. Participants were ovulatory for nearly all study cycles, and their general hormonal pattern was normal [8]. There were no differences in baseline characteristics between the women who participated throughout all 3 years of the study and those who withdrew or were lost to followup (data not shown). Urinary pregnanediol 3-a glucuronide was evaluated from postovulation Days 5 to 11; the mean for each group was obtained (Table 2). There were no significant differences between the clip, the cautery or the control groups nor between the baseline values and the values in subsequent years. The p value from the spatial covariance model was 0.29. Similar results were obtained when pregnanediol 3-a Table 4 Urinary estradiol levels: Days 5 to 11 of luteal phase Baseline Year 1 Year 2
Clip
Cautery
Control
51.7 (59) 48.3 (45) 53.3 (32)
52.0 (56) 54.2 (42) 50.0 (36)
54.6 (54) 58.2 (45) 60.0 (31)
Values are in picograms per milliliter. Values in parentheses are n. p = .82.
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Table 5 Estradiol levels: Days 5 to 11 of luteal phase Baseline Year 1 Year 2
Clip
Cautery
Control
120.4 (57) 120.7 (42) 122.4 (35)
140.5 (46) 122.3 (41) 124.8 (32)
120.1 (41) 111.8 (35) 125.2 (23)
Values are in picograms per milliliter. Values in parentheses are n. p = .96.
glucuronide values were evaluated for the area under the curve or for peak values (data not shown). Serum progesterone levels during the postovulatory Day 5 through 11 interval were significantly higher in the cautery group at baseline than they were in either the clip group or the controls (Table 3). This elevated level persisted through the years of the study and continued to be significantly higher than the other two groups. There were, however, no significant changes in progesterone level over time in this group or in the other two groups. The p value of .04 reflects the higher progesterone level in the cautery group. In all groups, there was a slight decrease in progesterone values over time, but this was not statistically significant. There were no significant changes in midluteal serum estradiol or urinary estradiol glucuronide levels (Tables 4 and 5) either between groups or over time, with p values of .82 for the serum estradiol and .96 for the urinary estrogen metabolite. Results were similar for analyses limited to women who participated throughout all cycles of the study (data not shown).
4. Discussion This report provides the results of a comprehensive and controlled study of the effects of tubal sterilization on ovarian hormone levels in women during early to middle reproductive years. Women who sought sterilization were studied prior to sterilization and were randomly assigned to one of two sterilization types (Hulka clip or bipolar cautery). They were then followed for 2 years after sterilization along with a group of controls who were of similar age, weight and menstrual regularity. Our findings confirm reports of smaller studies that sterilization does not cause major changes in ovarian hormones [10–14]. This was true whether the operator used the clip technique, which has minimal effect on tubal and vascular architecture, or used bipolar cautery, with its demonstrably greater destruction of the tube and mesosalpinx and possibly of ovarian blood supply. The strengths of this investigation are its large size, the randomization of women to two different sterilization techniques and the prospective longitudinal collection of urine and blood for the hormonal assays. There are limitations to this study. We did not collect follicular phase estradiol levels; these might have allowed a more complete analysis of the possibility of hormone changes in sterilized women. Specifically, this would have identified if an adequate follicular phase preceded the demonstrably adequate luteal phase. Even more helpful
would have been a longer follow-up period. Data from the Walnut Creek Contraceptive Drug Study showed significant menstrual aberrations only when following women for longer than 2 years after sterilization [15]. Luteal phase hormone levels were the focus of this analysis. Urine for estradiol and pregnanediol determinations was obtained daily and blood for serum progesterone levels was obtained every third day during the luteal phase in all women at enrollment and every year for 2 years. No statistically significant differences in these levels within and between groups were seen. There were also no significant changes in urinary or serum estradiol levels in the luteal phase. The higher serum progesterone level in the cautery group that persisted over the course of the study was present at baseline and thus appears to be due to a chance imbalance between the groups. Study participants had not been on oral contraceptives, had not used an intrauterine device, had not been pregnant within 3 months of enrollment and had had at least three normal cyclic menstrual periods prior to the performance of the sterilization. Therefore, normal menstrual cycle description was based on current records rather than on distant memory. The cycle immediately preceding the sterilization was tracked by BBTs, urinary and blood hormone measures, a day-by-day description of the amount and duration of flow and the presence or absence of dysmenorrhea. Analyses from the Collaborative Review of Sterilization [16] suggest that the women who had menstrual problems prior to sterilization were most likely to have subsequent menstrual complaints. These complaints and problems led to further gynecological surgery, including hysterectomy. We excluded women with irregular cycles or significant menstrual complaints from this study. This study confirms that women with normal cycles prior to sterilization will maintain normal ovarian function, as defined by luteal phase hormone levels, during the 2 years following sterilization. Acknowledgments The authors thank Barbara Driscoll, R.N., for her assistance in data collection, drawing blood samples and maintaining patient follow-up. This project was funded, in part, with federal funds from the National Institute of Child Health and Human Development, National Institutes of Health, under Contract Number NO1HD052908. The content of this publication does not necessarily reflect the views or policies of the Department of Health and Human Services, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. government. References [1] Abma JC, Chandra A, Mosher WD, Peterson LS, Piccinino LJ. Fertility, family planning and women’s health: new data from the 1995 National Survey of Family Growth. Vital Health Stat 1997 series 23 No. 19, CDC, NCHS. p. 62 – 4.
G.P. Gentile et al. / Contraception 73 (2006) 507–511 [2] Williams EL, Jones HE, Merrill RE. Subsequent course of patients sterilized by tubal ligation. Am J Obstet Gynecol 1951;61:423 – 6. [3] Gentile GP, Kaufman SC, Helbig DW. Is there any evidence for a post-tubal sterilization syndrome? Fertil Steril 1998;69:179 – 86. [4] Peterson HB, Ling G, Folger SG, Hillis SA, Marchbanks PA, Wilcox LS. The risk of menstrual abnormalities after tubal sterilization. N Engl J Med 2000;343:1681 – 7. [5] Saranson IG, Johnson JH, Siegel JM. Development of life experiences survey. J Clin Psychol 1978;46:932 – 46. [6] Moos RH. Menstrual distress questionnaire manual. Palo Alto (CA)7 Dept Psychiatry, Stanford Univ/Veterans Admin; 1977. [7] Zacur H, Kaufman SC, Smith B, Westhoff C, et al. Does creatinine adjustment of urinary pregnanediol glucuronide reduce or introduce measurement error? Gynecol Endocrinol 1997;11:29 – 33. [8] Westhoff C, Gentile G, Lee J, Zacur H, Helbig D. Predictors of ovarian steroid secretion in reproductive-age women. Am J Epidemiol 1996;144:381 – 8. [9] Park T, Park JK, Davis CS. Effects of covariance model assumptions on hypothesis tests for repeated measurements: analysis of ovarian hormone data and pituitary-pteromaxillary distance data. Stat Med 2001;20:2441 – 53.
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[10] Helm G, Sjoberg NO. Corpus luteal function after tubal sterilization using endothermic coagulation. Acta Obstet Gynecol Scand 1986;65: 741 – 4. [11] Alvarez F, Faundes A, Braebe V, Tejada AS, Segal SJ. Prospective study of the pituitary function after tubal sterilization by the Pomeroy or Uchida techniques. Fertil Steril 1989;51:604 – 8. [12] Garza-Flores J, Vasquez-Estrada L, Reyes A, et al. Assessment of luteal function after surgical tubal sterilization. Adv Contracept 1991;7:371 – 7. [13] Thranov I, Herz JB, Kjer JJ, Anderson A, Misic S, Nielsen J, et al. Hormonal and menstrual changes after laparoscopic sterilization by Falope-rings or Filshie clips. Fertil Steril 1992;57:751 – 5. [14] Fagundes M, Mendes M, Patta M, et al. Hormonal assessment of women submitted to tubal ligation. Contraception 2005;71: 309 – 14. [15] DeStefano F, Perlman JA, Peterson HB, Diamond EL. Long-term risk of menstrual disturbances after tubal sterilization. Am J Gynecol 1985;152:835 – 41. [16] Wilcox LS, Martinez-Schnell B, Peterson HB, Ware JH, Hughes JM. Menstrual function after tubal sterilization. Am J Epidemiol 1992;135: 1368 – 81.