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Effect of hysterectomy or LNG-IUS on serum inhibin B levels and ovarian blood flow
Maturitas 57 (2007) 279–285
Clinical trial paper
Effect of hysterectomy or LNG-IUS on serum inhibin B levels and ovarian blood flow Karoliina H. Halmesm¨aki a,∗ , Ritva A. Hurskainen a,b , Bruno Cacciatore a , Aila Tiitinen a , Jorma A. Paavonen a a
Department of Obstetrics and Gynecology, University of Helsinki, Haartmaninkatu 2, 00290 Helsinki, Finland b Health Services Research Unit, Stakes, Finland Received 2 December 2006; received in revised form 9 January 2007; accepted 19 January 2007
Abstract Objectives: Nearly one third of women complain of heavy menstrual bleeding during their reproductive years. Hysterectomy and levonorgestrel-releasing intrauterine system (LNG-IUS) are effective treatment options for menorrhagia. However, the influence of these two treatment modalities on ovarian function remains unclear. The aim of the study was to evaluate the effect of hysterectomy or LNG-IUS on ovarian function. Methods: Of 107 women, aged 35–49 years, referred for menorrhagia to the University of Helsinki, Finland, 54 were randomised to hysterectomy group and 53 to LNG-IUS group. Serum concentrations of inhibin B were measured at baseline, at 6-month, and at 12-month follow-up visits. The pulsatility indeces (PI) of ovarian and intraovarian arteries were measured by transvaginal ultrasound on the same visits. Changes in outcome measures between the groups were tested by Student’s t-test for independent samples and within the group by Wilcoxon signed rank test. To test association between outcome variables and explaining factors a multiple linear regression model was used. Results: Serum inhibin B concentrations decreased after the first 6 months in both groups (P < 0.05). No change was observed in PI of the ovarian arteries in either group. PI of the intraovarian arteries decreased at 6 and 12 months (P < 0.05) in the hysterectomy group, which was not seen among LNG-IUS users. Change in PIs between the treatment arms was also significant (P < 0.05). In multiple linear regression model treatment modality explained the change in serum inhibin B concentration and the change in PI of intraovarian artery (P < 0.05). Conclusions: Hysterectomy but not LNG-IUS alters intraovarian blood flow and may impair ovarian function. © 2007 Elsevier Ireland Ltd. All rights reserved. Keywords: Hysterectomy; LNG-IUS; Menorrhagia; FSH; Inhibin B; Blood flow
1. Introduction ∗ Corresponding author. Tel.: +358 40 5632794; fax: +358 9 47175550. E-mail address: [email protected] (K.H. Halmesm¨aki).
Nearly one-third of women complain of heavy menstrual bleeding during their reproductive years [1]. There are several treatment modalities available,
0378-5122/$ – see front matter © 2007 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.maturitas.2007.01.007
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of which hysterectomy and levonorgestrel—releasing intrauterine system (LNG-IUS) are the most effective [2]. However, hysterectomy may impair ovarian function and cause early menopausal symptoms [3]. LNG-IUS releases levonorgestrel (LNG) and low serum concentrations of LNG have only weak effect on ovarian function [3,4]. After the first year of use, about 85% of menstrual cycles are ovulatory and systemic side-effects are rare [4]. Ovarian reserve can be estimated by measuring serum concentrations of FSH, inhibin B or anti-M¨ullerian hormone and by antral follicle count [5,6]. Folliculogenesis is a complex process regulated by several endocrine and paracrine signals. Adequate vascular supply is needed to regulate follicle growth [7]. Ovarian stromal blood flow can be measured by colour Doppler using pulsatility index (PI) or by threedimensional (3D) power Doppler and vascularization index (VI). Aging is also associated with vascular changes and age-related reduction in ovarian artery blood flow has been detected in several studies [8,9]. Antral follicles secrete inhibin B, a dimeric glycoprotein, which reflects antral follicle count [10]. Therefore, serum inhibin B concentration is considered as a direct marker of ovarian reserve. The decrease in serum inhibin B concentration precedes the rise in serum FSH and is a more sensitive marker of ovarian aging than FSH [11]. The influence of hysterectomy and LNG-IUS on ovarian function is unclear. Some studies suggest that ovarian artery flow and serum inhibin B concentration decrease after hysterectomy [12,13]. We have previously shown that menopausal symptoms develop earlier and serum FSH concentrations rise earlier among hysterectomised women than among LNG-IUS users [3]. Therefore, we conducted a substudy, in which serum inhibin B concentration, ovarian and intraovarian artery pulsatility indeces were analysed to evaluate the ovarian function after hysterectomy or LNG-IUS more thoroughly.
2. Materials and methods A detailed description of the original study design and characteristics of the study population have been reported elsewhere [2]. Of 107 women referred for menorrhagia to the University Hospital, Helsinki, Fin-
land, between November 1994 and 1997, 54 were randomly assigned to hysterectomy and 53 to LNGIUS use. Randomly varying clusters of numbered, opaque, sealed envelopes were used for randomisation. The women were 35–49 years old, were menstruating, had completed their family size, and were eligible for hysterectomy (with no plans for oophorectomy). At the randomisation visit all women completed a questionnaire including information on body mass index (BMI), smoking, parity, method of contraception and history of medications. Women with submucousal fibroids, endometrial polyps, urinary or bowel symptoms due to large fibroids (>5 cm) or ovarian pathology were excluded. Women originally randomised to the LNG-IUS group, but hysterectomised were excluded. Also women, who underwent bilateral oophorectomy or were on estrogen replacement therapy were excluded. LNG-IUS (Mirena, Leiras Co., Turku, Finland) was inserted during the randomisation visit. Hysterectomy was performed abdominally, vaginally or laparoscopically at the discretion of the physician. The follow-up visits took place 6 and 12 months after the treatment. The study was approved by the Ethics Committees of all university hospitals and STAKES (National Research and Development Center for Welfare and Health). 2.1. Laboratory investigations Serum inhibin B concentrations were measured at baseline, at 6 and 12 months. Baseline samples were drawn in the early follicular phase (period days 1–7) and other samples at follow-up visits. Serum FSH concentrations were measured as previously described [3]. To document the time of the cycle, serum progesterone levels were measured at 6 and 12 months. Inhibin B levels were measured by enzyme-linked immunosorbent assay (ELISA from Diagnostic System Laboratories, Inc., Webster, TX, USA). For inhibin B measurement the limit of detection was 7 pg/mL. Inhibin B concentrations between 0.01 and 7 pg/mL were given a value of 3.5 pg/mL. The concentrations over 300 pg/mL were excluded from the analysis according to manufacturer’s instructions (one in hysterectomy group at baseline and one in the LNG-IUS at 1 year). Serum progesterone concentrations were measured by using 125 I-RIA kit (DPC Corporation, Los Angeles, CA, USA).
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2.2. Blood flow measurements
Table 1 Baseline characteristics of the study population
Transvaginal ultrasound (TVS) with blood flow measurements was performed (n = 60) by a same experienced gynaecologic sonographer (B.C.) at baseline in the beginning of the cycle at 6 and 12 months after the treatment. TVS was performed (between 10:00 and 12:00 h to reduce the effect of circadian variation) by 9.5-MHz broadband probe (ATL, HDI 3000, Bothell, WA, USA). Colour Doppler was used for imaging ovarian and intraovarian arteries. The pulsatility index (PI) was measured from representative flow velocity waveforms of each of these vessels including three cardiac cycles by the following formula: PI = (A − B)/mean, where A is the peak systolic Doppler shift frequency, and B is the end-diastolic shift frequency over the cardiac cycle [14]. A mean value from the right and left side intraovarian artery values was calculated for statistical analysis. If a unilateral ovarian cyst (>3 cm) was present, only the value from the side without the cyst was used. The reproducibility of the PI was tested in 10 patients by measuring variables three times at 10 min intervals.
Charasteristic
Hysterectomy (n = 54)
LNG-IUS (n = 53)
P-value
Age (years) Parity Body-mass index (kg/m2 ) Tubal ligation (%) Smoking (%) Ovarian cysts (>3 cm) (%) FSH (IU/L) Inhibin B (pg/mL)
43.7 (3.3) 1.9 (1.4) 25.4 (4.5)
43.3 (3.5) 1.9 (1.0) 25.6 (4.8)
0.51 0.57 0.85
25 (46.3) 10 (18.5) 3 (5.6)
25 (47.2) 13 (24.5) 10 (18.9)
1.0 0.60 0.03
7.9 (5.2) 52.3 (50.6)
7.8 (3.5) 44.7 (52.3)
0.34 0.61
2.3. Statistical analyses Power calculations were performed. The study had at 5% ␣-level a power of 80% to detect a 32% difference in serum inhibin B concentrations, 24% difference in ovarian blood flow, and 13% difference in intraovarian blood flow. Data was analysed by SPSS 11.0 version for Windows (SPSS Inc., Chicago, IL, USA). Differences in categorical variables in baseline characteristics were tested by χ2 -test or by Fischer’s exact test if expected frequency in the cell was under five. Changes in outcome measures between the groups following normal distribution were tested by Student’s t-test for independent variables and those not following normal distribution by Mann–Whitney U-test. Changes within the groups in repeated measurements were analysed by Wilcoxon’s signed rank test. In multivariate linear regression model change in inhibin B concentration and change in intraovarian artery flow the effect of treatment modality was adjusted with serum FSH concentrations, age, BMI, tubal ligation and smoking either as a dichotomised variable or a continuous variable defined as amount of cigarettes smoked per day. Values ≤ 0.05 were considered significant.
Pulsatility indexa Ovarian artery Intraovarian artery
2.21 (0.90) 0.99 (0.35)
2.01 (0.81) 0.87 (0.2)
0.76 0.09
Data are presented as mean values (standard deviation). a Pulsatility index given as a mean of the right and the left side.
3. Results Selected characteristics of the study population are shown in Table 1. At baseline, ovarian cysts were more common in LNG-IUS users. Otherwise the groups were comparable. After 1 year, 50 women in the hysterectomy group were hysterectomised (10 abdominally, 14 vaginally, and 26 laparoscopically), 2 women cancelled the operation, one woman had LNG-IUS inserted and one was lost to follow-up. Two (4%) women had bilateral oophorectomy, and altogether four (7%) women used estrogen replacement therapy. Four (8%) women had ovarian cysts in their ovaries. Three women had serum progesterone concentration above 14 nmol/L indicating luteal phase. Thus, 46 women were included in the analyses (Fig. 1). After 1 year LNG-IUS was in situ in 36 (68%) women in the LNG-IUS group. Twelve (23%) women were hysterectomised, including two (4%) with bilateral oophorectomy. Altogether four (8%) of the hysterectomised women, and none of the women using LNG-IUS, used estrogen replacement therapy. One woman underwent endometrial ablation, three women had LNG-IUS removed and one was lost to followup. Twelve (24%) women had ovarian cysts. Four women had serum progesterone concentration above 14 nmol/L indicating luteal phase. Thus, 36 women were included in the analyses (Fig. 1).
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Fig. 1. The flow-chart of the trial profile.
In the hysterectomy group (n = 46) serum inhibin B concentrations decreased from 48.62 pg/mL (S.D. 46.34) at baseline to 25.78 pg/mL (S.D. 36.16) at 6 months, and to 18.86 pg/mL (S.D. 29.21) at 12 months (P = 0.02 for the first 6 months versus baseline) (Fig. 2). In the LNG-IUS group (n = 36) serum inhibin B concentrations decreased from 55.10 pg/mL (S.D. 57.07) at the baseline, to 25.63 pg/mL (S.D. 38.85) at 6 months, and to 14.52 pg/mL (S.D. 22.73) at 12 months (P = 0.001 for the first 6 months versus baseline) (Fig. 2). Women, whose serum inhibin B concentration was below 7 pg/mL at baseline (n = 26) had significantly higher serum FSH level (P = 0.01) and tended to smoke (P = 0.06) more often than those whose serum inhibin B concentrations were above 7 pg/mL. In the multiple linear regression model decrease in inhibin B concentration associated with treatment modality (P = 0.05) and serum FSH concentration (P = 0.01) (Table 2).
In the hysterectomy group, PI of the ovarian arteries did not change during the follow up (Fig. 3). However, PI of the intraovarian arteries decreased significantly (Fig. 4). The measurements were successful in 28, 20 and 13 women at baseline, at 6 months, and at 12 months, respectively. The women, whose PI measurements were successful at baseline were younger
Fig. 2. Serum inhibin B (pg/mL) concentrations by study group.
Fig. 4. Intraovarian artery pulsatility indeces (PI) by the study group.
Fig. 3. Ovarian pulsatility indeces (PI) by the study group.
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Table 2 Multivariate linear regression model Standadized coefficients (β)
95% Confidence interval
P-value
Change in serum inhibin B concentration Treatment modality Serum FSH concentration (IU/L) Age Body mass index Smoking
−0.38 −0.60 0.02 0.28 −0.02
−43.00 to −0.10 −5.44 to −1.09 −5.69 to 6.25 −1.10 to 8.30 −2.80 to 2.48
0.05 0.01 0.92 0.13 0.90
Change in intraovarian artery blood flow Treatment modality Serum FSH concentration (IU/L) Age Body mass index Smoking
0.49 0.17 0.23 −0.28 −0.06
0.02 to 0.35 −0.01 to 0.02 −0.02 to 0.08 −0.06 to 0.01 −0.46 to 0.35
0.03 0.37 0.24 0.19 0.78
Significant values are in bold.
(P = 0.04) and had higher serum inhibin B concentrations (P = 0.03) than those, whose PI measurements were unsuccessful. The PI of the intraovarian arteries decreased from 0.99 (S.D. 0.37) at baseline to 0.67 (S.D. 0.16) at 6 months and 0.66 (S.D. 0.18) at 12 months (P = 0.01) (Fig. 4). Among LNG-IUS users, the PI of the ovarian arteries did not change (Fig. 3). The PI measurements of the intraovarian arteries were successful in 18, 12 and 16 women at baseline, at 6 months and at 12 months, respectively. At 6-months the PI of the intraovarian arteries increased from 0.91 (S.D. 0.19) at baseline to 1.00 (S.D. 0.33) (P = 0.04), but this change was no more evident at 12-months (Fig. 4). The PI change of the intraovarian arteries differed significantly between the groups both at 6 months (P = 0.0001) and 12 months (P = 0.004). Multiple regression analysis showed significant association between change in PI of intraovarian artery and treatment modality (P = 0.03) (Table 2).
4. Discussion We performed a substudy within a large randomised controlled trial comparing the cost-effectiveness of hysterectomy or LNG-IUS in the treatment of idiopathic menorrhagia [2]. The aim of this substudy was to evaluate the effect of these two treatments of menorrhagia on ovarian function. The PI of intraovarian arteries decreased in the hysterectomy group,
and serum inhibin B concentrations decreased in both groups. In the multivariate linear regression model hysterectomy explained both changes. The results suggest that hysterectomy, but not LNG-IUS, alters intraovarian blood flow, which may impair ovarian function. Inhibin B is a dimeric glycoprotein belonging to the family of transforming growth factor  (TGF-). It is composed of an alpha subunit and a -B subunit linked with disulphide bonds [10]. Inhibin B is secreted by granulosa cells of developing antral follicles and it controls secretion of FSH by negative feedback loop [15]. As inhibin B represents antral follicle pool of the ovaries, its decrease may be the earliest marker of declining of ovarian reserve [11]. In a case–control study, Nahas et al. [12] reported decreased serum inhibin B concentrations 12 months after total abdominal hysterectomy, but no change in serum FSH concentration. In our study, serum inhibin B concentrations declined rapidly in both groups. According to power calculations a small risk of type II error exists. However, it is more likely that the rapid changes seen in both groups are true changes explained by the women’s age. Women in our study were 8 years older than in the study by Nahas et al., and serum inhibin B concentration is detectable until 2 years before cessation of menses [16] both of which explain the decline seen in our study. Even if the multiple regression analysis did not reveal age as an significant covariate, the effect of age may have been masked by other factors, i.e. FSH and treatment modality. Perhaps a more frequent
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sampling in the beginning of the follow-up might have helped. The mechanism causing impaired ovarian function after hysterectomy remains unclear. Impaired blood flow to the ovaries after hysterectomy may explain it. This is supported by histological findings showing congestion and oedema, which result in stromal cell hyperplasia, thickening of the tunica albuginea, a significant decrease in follicular reserve and endocrinological disturbances [17]. It is wellknown that ovarian dysfunction occurs after uterine artery embolisation and tubal ligation [18,19]. Even if hysterectomy decreased PI of ovarian arteries in a recent study [13], such a change was not seen in our population. The PI of intraovarian arteries decreased, however. As decreased PI means increased blood flow in intraovarian artery, it is possible that ovaries try to compensate posthysterectomy ischemia by vasodilatation. The effect of LNG-IUS on PIs of gynecological organs has not been well studied. The PI of uterine arteries is known to rise [20], but change in PIs of the ovarian or intraovarian arteries is not known. It would have been useful to have additional control groups to compare outcomes among LNG-IUS users to outcomes among other groups such as users of intrauterine contraceptive device not releasing LNG. Respectively, the outcomes of hysterectomised women could have been compared to the outcomes of those women whose uterus is preserved. Since the study population consisted of women referred for menorrhagia to the University Hospital, it would have been difficult to justify no treatment. In multiple regression analysis the change of intraovarian artery PI was explained by treatment modality. In addition to treatment modality, serum FSH concentrations also explained decreasing inhibin B concentrations. The baseline samples were taken in the beginning of the cycle, whereas other samples were not adjusted by the menstrual cycle. However, ovulatory serum progesterone concentrations were as common in both groups. Even if the blood flow in the dominant ovary increases during luteal phase [21], systematic bias is avoided by our randomised study design and by the fact ovulation was equally common in both groups. Since hysterectomy was performed either abdominally, vaginally, or laparoscopically, it is possible that technique used had influence on outcome. This is unlikely, however, since increased hot flushes and rise in serum
FSH concentrations were unrelated to the technique used [3]. Considerable population of women randomised to the LNG-IUS group were hysterctomised during the follow-up period. This is not surprising, since discontinuation of LNG-IUS is multifactorial and difficult to predict [22]. There were slightly more ovarian cysts among LNG-IUS users both in the beginning of the study and during the follow-up. Benign ovarian cysts may have some effect on intraovarian flow [23]. Therefore, we excluded flow values obtained from cyst sides. Tobacco smoke is known to be a potent vasoconstrictor and smoking impairs ovarian function. Ever-smokers are 30% more likely to be menopausal at age of 45–54 compared to never-smokers [24]. In our study the effect of smoking was adjusted in the multiple regression model. Interestingly, both smoking and hysterectomy seem to affect the ovaries by altering blood flow [25]. Smoking diminishes inhibin B concentrations directly [26]. Antim¨ullerian hormone (AMH) is a novel marker of ovarian aging [27]. It would have been interesting to evaluate also serum AMH concentrations. However, since the mean age of women of our study was 43 years in the beginning of the study, it is unlikely, that measuring serum AMH concentration would have given additional information. As it is relatively difficult to measure PIs from small intraovarian vessels it would have been more accurate to use three-dimensional power Doppler rather than classic two-dimensional transvaginal ultrasound. However, the PIs were always measured by the same expert sonographer. Intraobsever coefficient of variation for intraovarian artery PIs is between 10 and 15% [28]. The difference in intraovarian artery PIs between the study groups exceeded this variation significantly. It is not known how well intraovarian artery PI actually represents the blood flow in the whole ovary. Perhaps isotopic angiography would have been better in measuring ovarian stromal circulation [29]. In conclusion, this is the first randomised controlled trial comparing the effects of hysterectomy or LNGIUS on serum inhibin B concentrations and blood flow measurements. The results suggest that hysterectomy alters intraovarian blood flow, which in turn may decrease serum inhibin B concentrations. This is important to consider when planning treatment for menorrhagia among fertile aged women.
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Acknowledgements We thank Mika Kortesniemi for his excellent help in evaluating the clinical significance of the results and Eira Halenius and Teija Karkkulainen for their skilful assistance.
[15]
[16]
References [1] Shapley M, Jordan K, Croft PR. An epidemiological survey of symptoms of menstrual loss in the community. Br J Gen Pract 2004;54:359–63. [2] Hurskainen R, Teperi J, Rissanen P, et al. Clinical outcomes and costs with the levonorgestrel-releasing intrauterine system or hysterectomy for treatment of menorrhagia: Randomized trial 5-year follow-up. JAMA 2004;291:1456–63. [3] Halmesmaki K, Hurskainen R, Tiitinen A, et al. A randomized controlled trial of hysterectomy or levonorgestrel-releasing intrauterine system in the treatment of menorrhagia-effect on FSH levels and menopausal symptoms. Hum Reprod 2004;19:378–82. [4] Barbosa I, Bakos O, Olsson SE, Odlind V, Johansson ED. Ovarian function during use of a levonorgestrel-releasing IUD. Contraception 1990;42:51–66. [5] Vladimirov IK, Tacheva DM, Kalinov KB, Ivanova AV, Blagoeva VD. Prognostic value of some ovarian reserve tests in poor responders. Arch Gynecol Obstet 2005;272:74–9. [6] van Rooij IA, Tonkelaar I, Broekmans FJ, et al. Anti-mullerian hormone is a promising predictor for the occurrence of the menopausal transition. Menopause 2004;11:601–6. [7] McGee EA, Hsueh AJ. Initial and cyclic recruitment of ovarian follicles. Endocr Rev 2000;21:200–14. [8] Kurjak A, Kupesic S. Ovarian senescence and its significance on uterine and ovarian perfusion. Fertil Steril 1995;64:532–7. [9] Ng EH, Chan CC, Yeung WS, Ho PC. Effect of age on ovarian stromal flow measured by three-dimensional ultrasound with power doppler in chinese women with proven fertility. Hum Reprod 2004;19:2132–7. [10] Kline J, Kinney A, Kelly A, Reuss ML, Levin B. Predictors of antral follicle count during the reproductive years. Hum Reprod 2005;20:2179–89. [11] Muttukrishna S, Child T, Lockwood GM, Groome NP, Barlow DH, Ledger WL. Serum concentrations of dimeric inhibins, activin A, gonadotrophins and ovarian steroids during the menstrual cycle in older women. Hum Reprod 2000;15:549–56. [12] Nahas E, Pontes A, Traiman P, NahasNeto J, Dalben I, De Luca L. Inhibin B and ovarian function after total abdominal hysterectomy in women of reproductive age. Gynecol Endocrinol 2003;17:125–31. [13] Petri Nahas EA, Pontes A, Nahas-Neto J, Borges VT, Dias R, Traiman P. Effect of total abdominal hysterectomy on ovarian blood supply in women of reproductive age. J Ultrasound Med 2005;24:169–74. [14] Gosling R. Extraction of physiological information from spectrum analysed doppler-shifted continuous wave ultrasound
[17]
[18]
[19]
[20]
[21]
[22]
[23] [24]
[25]
[26]
[27]
[28]
[29]
285
signals obtained noninvasively from the arterial tree. In: Hill D, Watson B, editors. Medical Electronic Monographs, vol. 13–22. London: Peter Peregrinus; 1976. p. 73–125. Muttukrishna S, Sharma S, Barlow DH, Ledger W, Groome N, Sathanandan M. Serum inhibins, estradiol, progesterone and FSH in surgical menopause: A demonstration of ovarian pituitary feedback loop in women. Hum Reprod 2002;17: 2535–9. Overlie I, Morkrid L, Andersson AM, Skakkebaek NE, Moen MH, Holte A. Inhibin A and B as markers of menopause: a five-year prospective longitudinal study of hormonal changes during the menopausal transition. Acta Obstet Gynecol Scand 2005;84:281–5. Souza AZ, Fonseca AM, Izzo VM, Clauzet RM, Salvatore CA. Ovarian histology and function after total abdominal hysterectomy. Obstet Gynecol 1986;68:847–9. Tulandi T, Sammour A, Valenti D, Child TJ, Seti L, Tan SL. Ovarian reserve after uterine artery embolization for leiomyomata. Fertil Steril 2002;78:197–8. Kelekci S, Yilmaz B, Yasar L, Savan K, Sonmez S, Kart C. Ovarian reserve and ovarian stromal blood supply after tubal ligation by the pomeroy technique: comparison with controls. Gynecol Endocrinol 2005;20:279–83. Jarvela I, Tekay A, Jouppila P. The effect of a levonorgestrelreleasing intrauterine system on uterine artery blood flow, hormone concentrations and ovarian cyst formation in fertile women. Hum Reprod 1998;13:3379–83. Jokubkiene L, Sladkevicius P, Rovas L, Valentin L. Assessment of changes in volume and vascularity of the ovaries during the normal menstrual cycle using three-dimensional power doppler ultrasound. Hum Reprod 2006;21:2661–8. Hurskainen R, Teperi J, Aalto AM, et al. Levonorgestrelreleasing intrauterine system or hysterectomy in the treatment of essential menorrhagia: predictors of outcome. Acta Obstet Gynecol Scand 2004;83:401–3. Kurjak A, Kupesic S, Simunic V. Ultrasonic assessment of the peri- and postmenopausal ovary. Maturitas 2002;41:245–54. Cramer DW, Harlow BL, Xu H, Fraer C, Barbieri R. Cross-sectional and case-controlled analyses of the association between smoking and early menopause. Maturitas 1995;22:79–87. Motejlek K, Palluch F, Neulen J, Grummer R. Smoking impairs angiogenesis during maturation of human oocytes. Fertil Steril 2006;86:186–91. Lambert-Messerlian GM, Harlow BL. The influence of depression, body mass index and smoking on serum inhibin B levels in late reproductive aged women. J Clin Endocrinol Metab 2006;91:1496–500. Ficicioglu C, Kutlu T, Baglam E, Bakacak Z. Early follicular antimullerian hormone as an indicator of ovarian reserve. Fertil Steril 2006;85:592–6. Tekay A, Jouppila P. Intraobserver reproducibility of transvaginal doppler measurements in uterine and intraovarian arteries in regularly menstruating women. Ultrasound Obstet Gynecol 1996;7:129–34. Janson PO, Jansson I. The acute effect of hysterectomy on ovarian blood flow. Am J Obstet Gynecol 1977;127:349–52.
Clinical trial paper
Effect of hysterectomy or LNG-IUS on serum inhibin B levels and ovarian blood flow Karoliina H. Halmesm¨aki a,∗ , Ritva A. Hurskainen a,b , Bruno Cacciatore a , Aila Tiitinen a , Jorma A. Paavonen a a
Department of Obstetrics and Gynecology, University of Helsinki, Haartmaninkatu 2, 00290 Helsinki, Finland b Health Services Research Unit, Stakes, Finland Received 2 December 2006; received in revised form 9 January 2007; accepted 19 January 2007
Abstract Objectives: Nearly one third of women complain of heavy menstrual bleeding during their reproductive years. Hysterectomy and levonorgestrel-releasing intrauterine system (LNG-IUS) are effective treatment options for menorrhagia. However, the influence of these two treatment modalities on ovarian function remains unclear. The aim of the study was to evaluate the effect of hysterectomy or LNG-IUS on ovarian function. Methods: Of 107 women, aged 35–49 years, referred for menorrhagia to the University of Helsinki, Finland, 54 were randomised to hysterectomy group and 53 to LNG-IUS group. Serum concentrations of inhibin B were measured at baseline, at 6-month, and at 12-month follow-up visits. The pulsatility indeces (PI) of ovarian and intraovarian arteries were measured by transvaginal ultrasound on the same visits. Changes in outcome measures between the groups were tested by Student’s t-test for independent samples and within the group by Wilcoxon signed rank test. To test association between outcome variables and explaining factors a multiple linear regression model was used. Results: Serum inhibin B concentrations decreased after the first 6 months in both groups (P < 0.05). No change was observed in PI of the ovarian arteries in either group. PI of the intraovarian arteries decreased at 6 and 12 months (P < 0.05) in the hysterectomy group, which was not seen among LNG-IUS users. Change in PIs between the treatment arms was also significant (P < 0.05). In multiple linear regression model treatment modality explained the change in serum inhibin B concentration and the change in PI of intraovarian artery (P < 0.05). Conclusions: Hysterectomy but not LNG-IUS alters intraovarian blood flow and may impair ovarian function. © 2007 Elsevier Ireland Ltd. All rights reserved. Keywords: Hysterectomy; LNG-IUS; Menorrhagia; FSH; Inhibin B; Blood flow
1. Introduction ∗ Corresponding author. Tel.: +358 40 5632794; fax: +358 9 47175550. E-mail address: [email protected] (K.H. Halmesm¨aki).
Nearly one-third of women complain of heavy menstrual bleeding during their reproductive years [1]. There are several treatment modalities available,
0378-5122/$ – see front matter © 2007 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.maturitas.2007.01.007
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of which hysterectomy and levonorgestrel—releasing intrauterine system (LNG-IUS) are the most effective [2]. However, hysterectomy may impair ovarian function and cause early menopausal symptoms [3]. LNG-IUS releases levonorgestrel (LNG) and low serum concentrations of LNG have only weak effect on ovarian function [3,4]. After the first year of use, about 85% of menstrual cycles are ovulatory and systemic side-effects are rare [4]. Ovarian reserve can be estimated by measuring serum concentrations of FSH, inhibin B or anti-M¨ullerian hormone and by antral follicle count [5,6]. Folliculogenesis is a complex process regulated by several endocrine and paracrine signals. Adequate vascular supply is needed to regulate follicle growth [7]. Ovarian stromal blood flow can be measured by colour Doppler using pulsatility index (PI) or by threedimensional (3D) power Doppler and vascularization index (VI). Aging is also associated with vascular changes and age-related reduction in ovarian artery blood flow has been detected in several studies [8,9]. Antral follicles secrete inhibin B, a dimeric glycoprotein, which reflects antral follicle count [10]. Therefore, serum inhibin B concentration is considered as a direct marker of ovarian reserve. The decrease in serum inhibin B concentration precedes the rise in serum FSH and is a more sensitive marker of ovarian aging than FSH [11]. The influence of hysterectomy and LNG-IUS on ovarian function is unclear. Some studies suggest that ovarian artery flow and serum inhibin B concentration decrease after hysterectomy [12,13]. We have previously shown that menopausal symptoms develop earlier and serum FSH concentrations rise earlier among hysterectomised women than among LNG-IUS users [3]. Therefore, we conducted a substudy, in which serum inhibin B concentration, ovarian and intraovarian artery pulsatility indeces were analysed to evaluate the ovarian function after hysterectomy or LNG-IUS more thoroughly.
2. Materials and methods A detailed description of the original study design and characteristics of the study population have been reported elsewhere [2]. Of 107 women referred for menorrhagia to the University Hospital, Helsinki, Fin-
land, between November 1994 and 1997, 54 were randomly assigned to hysterectomy and 53 to LNGIUS use. Randomly varying clusters of numbered, opaque, sealed envelopes were used for randomisation. The women were 35–49 years old, were menstruating, had completed their family size, and were eligible for hysterectomy (with no plans for oophorectomy). At the randomisation visit all women completed a questionnaire including information on body mass index (BMI), smoking, parity, method of contraception and history of medications. Women with submucousal fibroids, endometrial polyps, urinary or bowel symptoms due to large fibroids (>5 cm) or ovarian pathology were excluded. Women originally randomised to the LNG-IUS group, but hysterectomised were excluded. Also women, who underwent bilateral oophorectomy or were on estrogen replacement therapy were excluded. LNG-IUS (Mirena, Leiras Co., Turku, Finland) was inserted during the randomisation visit. Hysterectomy was performed abdominally, vaginally or laparoscopically at the discretion of the physician. The follow-up visits took place 6 and 12 months after the treatment. The study was approved by the Ethics Committees of all university hospitals and STAKES (National Research and Development Center for Welfare and Health). 2.1. Laboratory investigations Serum inhibin B concentrations were measured at baseline, at 6 and 12 months. Baseline samples were drawn in the early follicular phase (period days 1–7) and other samples at follow-up visits. Serum FSH concentrations were measured as previously described [3]. To document the time of the cycle, serum progesterone levels were measured at 6 and 12 months. Inhibin B levels were measured by enzyme-linked immunosorbent assay (ELISA from Diagnostic System Laboratories, Inc., Webster, TX, USA). For inhibin B measurement the limit of detection was 7 pg/mL. Inhibin B concentrations between 0.01 and 7 pg/mL were given a value of 3.5 pg/mL. The concentrations over 300 pg/mL were excluded from the analysis according to manufacturer’s instructions (one in hysterectomy group at baseline and one in the LNG-IUS at 1 year). Serum progesterone concentrations were measured by using 125 I-RIA kit (DPC Corporation, Los Angeles, CA, USA).
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2.2. Blood flow measurements
Table 1 Baseline characteristics of the study population
Transvaginal ultrasound (TVS) with blood flow measurements was performed (n = 60) by a same experienced gynaecologic sonographer (B.C.) at baseline in the beginning of the cycle at 6 and 12 months after the treatment. TVS was performed (between 10:00 and 12:00 h to reduce the effect of circadian variation) by 9.5-MHz broadband probe (ATL, HDI 3000, Bothell, WA, USA). Colour Doppler was used for imaging ovarian and intraovarian arteries. The pulsatility index (PI) was measured from representative flow velocity waveforms of each of these vessels including three cardiac cycles by the following formula: PI = (A − B)/mean, where A is the peak systolic Doppler shift frequency, and B is the end-diastolic shift frequency over the cardiac cycle [14]. A mean value from the right and left side intraovarian artery values was calculated for statistical analysis. If a unilateral ovarian cyst (>3 cm) was present, only the value from the side without the cyst was used. The reproducibility of the PI was tested in 10 patients by measuring variables three times at 10 min intervals.
Charasteristic
Hysterectomy (n = 54)
LNG-IUS (n = 53)
P-value
Age (years) Parity Body-mass index (kg/m2 ) Tubal ligation (%) Smoking (%) Ovarian cysts (>3 cm) (%) FSH (IU/L) Inhibin B (pg/mL)
43.7 (3.3) 1.9 (1.4) 25.4 (4.5)
43.3 (3.5) 1.9 (1.0) 25.6 (4.8)
0.51 0.57 0.85
25 (46.3) 10 (18.5) 3 (5.6)
25 (47.2) 13 (24.5) 10 (18.9)
1.0 0.60 0.03
7.9 (5.2) 52.3 (50.6)
7.8 (3.5) 44.7 (52.3)
0.34 0.61
2.3. Statistical analyses Power calculations were performed. The study had at 5% ␣-level a power of 80% to detect a 32% difference in serum inhibin B concentrations, 24% difference in ovarian blood flow, and 13% difference in intraovarian blood flow. Data was analysed by SPSS 11.0 version for Windows (SPSS Inc., Chicago, IL, USA). Differences in categorical variables in baseline characteristics were tested by χ2 -test or by Fischer’s exact test if expected frequency in the cell was under five. Changes in outcome measures between the groups following normal distribution were tested by Student’s t-test for independent variables and those not following normal distribution by Mann–Whitney U-test. Changes within the groups in repeated measurements were analysed by Wilcoxon’s signed rank test. In multivariate linear regression model change in inhibin B concentration and change in intraovarian artery flow the effect of treatment modality was adjusted with serum FSH concentrations, age, BMI, tubal ligation and smoking either as a dichotomised variable or a continuous variable defined as amount of cigarettes smoked per day. Values ≤ 0.05 were considered significant.
Pulsatility indexa Ovarian artery Intraovarian artery
2.21 (0.90) 0.99 (0.35)
2.01 (0.81) 0.87 (0.2)
0.76 0.09
Data are presented as mean values (standard deviation). a Pulsatility index given as a mean of the right and the left side.
3. Results Selected characteristics of the study population are shown in Table 1. At baseline, ovarian cysts were more common in LNG-IUS users. Otherwise the groups were comparable. After 1 year, 50 women in the hysterectomy group were hysterectomised (10 abdominally, 14 vaginally, and 26 laparoscopically), 2 women cancelled the operation, one woman had LNG-IUS inserted and one was lost to follow-up. Two (4%) women had bilateral oophorectomy, and altogether four (7%) women used estrogen replacement therapy. Four (8%) women had ovarian cysts in their ovaries. Three women had serum progesterone concentration above 14 nmol/L indicating luteal phase. Thus, 46 women were included in the analyses (Fig. 1). After 1 year LNG-IUS was in situ in 36 (68%) women in the LNG-IUS group. Twelve (23%) women were hysterectomised, including two (4%) with bilateral oophorectomy. Altogether four (8%) of the hysterectomised women, and none of the women using LNG-IUS, used estrogen replacement therapy. One woman underwent endometrial ablation, three women had LNG-IUS removed and one was lost to followup. Twelve (24%) women had ovarian cysts. Four women had serum progesterone concentration above 14 nmol/L indicating luteal phase. Thus, 36 women were included in the analyses (Fig. 1).
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Fig. 1. The flow-chart of the trial profile.
In the hysterectomy group (n = 46) serum inhibin B concentrations decreased from 48.62 pg/mL (S.D. 46.34) at baseline to 25.78 pg/mL (S.D. 36.16) at 6 months, and to 18.86 pg/mL (S.D. 29.21) at 12 months (P = 0.02 for the first 6 months versus baseline) (Fig. 2). In the LNG-IUS group (n = 36) serum inhibin B concentrations decreased from 55.10 pg/mL (S.D. 57.07) at the baseline, to 25.63 pg/mL (S.D. 38.85) at 6 months, and to 14.52 pg/mL (S.D. 22.73) at 12 months (P = 0.001 for the first 6 months versus baseline) (Fig. 2). Women, whose serum inhibin B concentration was below 7 pg/mL at baseline (n = 26) had significantly higher serum FSH level (P = 0.01) and tended to smoke (P = 0.06) more often than those whose serum inhibin B concentrations were above 7 pg/mL. In the multiple linear regression model decrease in inhibin B concentration associated with treatment modality (P = 0.05) and serum FSH concentration (P = 0.01) (Table 2).
In the hysterectomy group, PI of the ovarian arteries did not change during the follow up (Fig. 3). However, PI of the intraovarian arteries decreased significantly (Fig. 4). The measurements were successful in 28, 20 and 13 women at baseline, at 6 months, and at 12 months, respectively. The women, whose PI measurements were successful at baseline were younger
Fig. 2. Serum inhibin B (pg/mL) concentrations by study group.
Fig. 4. Intraovarian artery pulsatility indeces (PI) by the study group.
Fig. 3. Ovarian pulsatility indeces (PI) by the study group.
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Table 2 Multivariate linear regression model Standadized coefficients (β)
95% Confidence interval
P-value
Change in serum inhibin B concentration Treatment modality Serum FSH concentration (IU/L) Age Body mass index Smoking
−0.38 −0.60 0.02 0.28 −0.02
−43.00 to −0.10 −5.44 to −1.09 −5.69 to 6.25 −1.10 to 8.30 −2.80 to 2.48
0.05 0.01 0.92 0.13 0.90
Change in intraovarian artery blood flow Treatment modality Serum FSH concentration (IU/L) Age Body mass index Smoking
0.49 0.17 0.23 −0.28 −0.06
0.02 to 0.35 −0.01 to 0.02 −0.02 to 0.08 −0.06 to 0.01 −0.46 to 0.35
0.03 0.37 0.24 0.19 0.78
Significant values are in bold.
(P = 0.04) and had higher serum inhibin B concentrations (P = 0.03) than those, whose PI measurements were unsuccessful. The PI of the intraovarian arteries decreased from 0.99 (S.D. 0.37) at baseline to 0.67 (S.D. 0.16) at 6 months and 0.66 (S.D. 0.18) at 12 months (P = 0.01) (Fig. 4). Among LNG-IUS users, the PI of the ovarian arteries did not change (Fig. 3). The PI measurements of the intraovarian arteries were successful in 18, 12 and 16 women at baseline, at 6 months and at 12 months, respectively. At 6-months the PI of the intraovarian arteries increased from 0.91 (S.D. 0.19) at baseline to 1.00 (S.D. 0.33) (P = 0.04), but this change was no more evident at 12-months (Fig. 4). The PI change of the intraovarian arteries differed significantly between the groups both at 6 months (P = 0.0001) and 12 months (P = 0.004). Multiple regression analysis showed significant association between change in PI of intraovarian artery and treatment modality (P = 0.03) (Table 2).
4. Discussion We performed a substudy within a large randomised controlled trial comparing the cost-effectiveness of hysterectomy or LNG-IUS in the treatment of idiopathic menorrhagia [2]. The aim of this substudy was to evaluate the effect of these two treatments of menorrhagia on ovarian function. The PI of intraovarian arteries decreased in the hysterectomy group,
and serum inhibin B concentrations decreased in both groups. In the multivariate linear regression model hysterectomy explained both changes. The results suggest that hysterectomy, but not LNG-IUS, alters intraovarian blood flow, which may impair ovarian function. Inhibin B is a dimeric glycoprotein belonging to the family of transforming growth factor  (TGF-). It is composed of an alpha subunit and a -B subunit linked with disulphide bonds [10]. Inhibin B is secreted by granulosa cells of developing antral follicles and it controls secretion of FSH by negative feedback loop [15]. As inhibin B represents antral follicle pool of the ovaries, its decrease may be the earliest marker of declining of ovarian reserve [11]. In a case–control study, Nahas et al. [12] reported decreased serum inhibin B concentrations 12 months after total abdominal hysterectomy, but no change in serum FSH concentration. In our study, serum inhibin B concentrations declined rapidly in both groups. According to power calculations a small risk of type II error exists. However, it is more likely that the rapid changes seen in both groups are true changes explained by the women’s age. Women in our study were 8 years older than in the study by Nahas et al., and serum inhibin B concentration is detectable until 2 years before cessation of menses [16] both of which explain the decline seen in our study. Even if the multiple regression analysis did not reveal age as an significant covariate, the effect of age may have been masked by other factors, i.e. FSH and treatment modality. Perhaps a more frequent
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sampling in the beginning of the follow-up might have helped. The mechanism causing impaired ovarian function after hysterectomy remains unclear. Impaired blood flow to the ovaries after hysterectomy may explain it. This is supported by histological findings showing congestion and oedema, which result in stromal cell hyperplasia, thickening of the tunica albuginea, a significant decrease in follicular reserve and endocrinological disturbances [17]. It is wellknown that ovarian dysfunction occurs after uterine artery embolisation and tubal ligation [18,19]. Even if hysterectomy decreased PI of ovarian arteries in a recent study [13], such a change was not seen in our population. The PI of intraovarian arteries decreased, however. As decreased PI means increased blood flow in intraovarian artery, it is possible that ovaries try to compensate posthysterectomy ischemia by vasodilatation. The effect of LNG-IUS on PIs of gynecological organs has not been well studied. The PI of uterine arteries is known to rise [20], but change in PIs of the ovarian or intraovarian arteries is not known. It would have been useful to have additional control groups to compare outcomes among LNG-IUS users to outcomes among other groups such as users of intrauterine contraceptive device not releasing LNG. Respectively, the outcomes of hysterectomised women could have been compared to the outcomes of those women whose uterus is preserved. Since the study population consisted of women referred for menorrhagia to the University Hospital, it would have been difficult to justify no treatment. In multiple regression analysis the change of intraovarian artery PI was explained by treatment modality. In addition to treatment modality, serum FSH concentrations also explained decreasing inhibin B concentrations. The baseline samples were taken in the beginning of the cycle, whereas other samples were not adjusted by the menstrual cycle. However, ovulatory serum progesterone concentrations were as common in both groups. Even if the blood flow in the dominant ovary increases during luteal phase [21], systematic bias is avoided by our randomised study design and by the fact ovulation was equally common in both groups. Since hysterectomy was performed either abdominally, vaginally, or laparoscopically, it is possible that technique used had influence on outcome. This is unlikely, however, since increased hot flushes and rise in serum
FSH concentrations were unrelated to the technique used [3]. Considerable population of women randomised to the LNG-IUS group were hysterctomised during the follow-up period. This is not surprising, since discontinuation of LNG-IUS is multifactorial and difficult to predict [22]. There were slightly more ovarian cysts among LNG-IUS users both in the beginning of the study and during the follow-up. Benign ovarian cysts may have some effect on intraovarian flow [23]. Therefore, we excluded flow values obtained from cyst sides. Tobacco smoke is known to be a potent vasoconstrictor and smoking impairs ovarian function. Ever-smokers are 30% more likely to be menopausal at age of 45–54 compared to never-smokers [24]. In our study the effect of smoking was adjusted in the multiple regression model. Interestingly, both smoking and hysterectomy seem to affect the ovaries by altering blood flow [25]. Smoking diminishes inhibin B concentrations directly [26]. Antim¨ullerian hormone (AMH) is a novel marker of ovarian aging [27]. It would have been interesting to evaluate also serum AMH concentrations. However, since the mean age of women of our study was 43 years in the beginning of the study, it is unlikely, that measuring serum AMH concentration would have given additional information. As it is relatively difficult to measure PIs from small intraovarian vessels it would have been more accurate to use three-dimensional power Doppler rather than classic two-dimensional transvaginal ultrasound. However, the PIs were always measured by the same expert sonographer. Intraobsever coefficient of variation for intraovarian artery PIs is between 10 and 15% [28]. The difference in intraovarian artery PIs between the study groups exceeded this variation significantly. It is not known how well intraovarian artery PI actually represents the blood flow in the whole ovary. Perhaps isotopic angiography would have been better in measuring ovarian stromal circulation [29]. In conclusion, this is the first randomised controlled trial comparing the effects of hysterectomy or LNGIUS on serum inhibin B concentrations and blood flow measurements. The results suggest that hysterectomy alters intraovarian blood flow, which in turn may decrease serum inhibin B concentrations. This is important to consider when planning treatment for menorrhagia among fertile aged women.
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Acknowledgements We thank Mika Kortesniemi for his excellent help in evaluating the clinical significance of the results and Eira Halenius and Teija Karkkulainen for their skilful assistance.
[15]
[16]
References [1] Shapley M, Jordan K, Croft PR. An epidemiological survey of symptoms of menstrual loss in the community. Br J Gen Pract 2004;54:359–63. [2] Hurskainen R, Teperi J, Rissanen P, et al. Clinical outcomes and costs with the levonorgestrel-releasing intrauterine system or hysterectomy for treatment of menorrhagia: Randomized trial 5-year follow-up. JAMA 2004;291:1456–63. [3] Halmesmaki K, Hurskainen R, Tiitinen A, et al. A randomized controlled trial of hysterectomy or levonorgestrel-releasing intrauterine system in the treatment of menorrhagia-effect on FSH levels and menopausal symptoms. Hum Reprod 2004;19:378–82. [4] Barbosa I, Bakos O, Olsson SE, Odlind V, Johansson ED. Ovarian function during use of a levonorgestrel-releasing IUD. Contraception 1990;42:51–66. [5] Vladimirov IK, Tacheva DM, Kalinov KB, Ivanova AV, Blagoeva VD. Prognostic value of some ovarian reserve tests in poor responders. Arch Gynecol Obstet 2005;272:74–9. [6] van Rooij IA, Tonkelaar I, Broekmans FJ, et al. Anti-mullerian hormone is a promising predictor for the occurrence of the menopausal transition. Menopause 2004;11:601–6. [7] McGee EA, Hsueh AJ. Initial and cyclic recruitment of ovarian follicles. Endocr Rev 2000;21:200–14. [8] Kurjak A, Kupesic S. Ovarian senescence and its significance on uterine and ovarian perfusion. Fertil Steril 1995;64:532–7. [9] Ng EH, Chan CC, Yeung WS, Ho PC. Effect of age on ovarian stromal flow measured by three-dimensional ultrasound with power doppler in chinese women with proven fertility. Hum Reprod 2004;19:2132–7. [10] Kline J, Kinney A, Kelly A, Reuss ML, Levin B. Predictors of antral follicle count during the reproductive years. Hum Reprod 2005;20:2179–89. [11] Muttukrishna S, Child T, Lockwood GM, Groome NP, Barlow DH, Ledger WL. Serum concentrations of dimeric inhibins, activin A, gonadotrophins and ovarian steroids during the menstrual cycle in older women. Hum Reprod 2000;15:549–56. [12] Nahas E, Pontes A, Traiman P, NahasNeto J, Dalben I, De Luca L. Inhibin B and ovarian function after total abdominal hysterectomy in women of reproductive age. Gynecol Endocrinol 2003;17:125–31. [13] Petri Nahas EA, Pontes A, Nahas-Neto J, Borges VT, Dias R, Traiman P. Effect of total abdominal hysterectomy on ovarian blood supply in women of reproductive age. J Ultrasound Med 2005;24:169–74. [14] Gosling R. Extraction of physiological information from spectrum analysed doppler-shifted continuous wave ultrasound
[17]
[18]
[19]
[20]
[21]
[22]
[23] [24]
[25]
[26]
[27]
[28]
[29]
285
signals obtained noninvasively from the arterial tree. In: Hill D, Watson B, editors. Medical Electronic Monographs, vol. 13–22. London: Peter Peregrinus; 1976. p. 73–125. Muttukrishna S, Sharma S, Barlow DH, Ledger W, Groome N, Sathanandan M. Serum inhibins, estradiol, progesterone and FSH in surgical menopause: A demonstration of ovarian pituitary feedback loop in women. Hum Reprod 2002;17: 2535–9. Overlie I, Morkrid L, Andersson AM, Skakkebaek NE, Moen MH, Holte A. Inhibin A and B as markers of menopause: a five-year prospective longitudinal study of hormonal changes during the menopausal transition. Acta Obstet Gynecol Scand 2005;84:281–5. Souza AZ, Fonseca AM, Izzo VM, Clauzet RM, Salvatore CA. Ovarian histology and function after total abdominal hysterectomy. Obstet Gynecol 1986;68:847–9. Tulandi T, Sammour A, Valenti D, Child TJ, Seti L, Tan SL. Ovarian reserve after uterine artery embolization for leiomyomata. Fertil Steril 2002;78:197–8. Kelekci S, Yilmaz B, Yasar L, Savan K, Sonmez S, Kart C. Ovarian reserve and ovarian stromal blood supply after tubal ligation by the pomeroy technique: comparison with controls. Gynecol Endocrinol 2005;20:279–83. Jarvela I, Tekay A, Jouppila P. The effect of a levonorgestrelreleasing intrauterine system on uterine artery blood flow, hormone concentrations and ovarian cyst formation in fertile women. Hum Reprod 1998;13:3379–83. Jokubkiene L, Sladkevicius P, Rovas L, Valentin L. Assessment of changes in volume and vascularity of the ovaries during the normal menstrual cycle using three-dimensional power doppler ultrasound. Hum Reprod 2006;21:2661–8. Hurskainen R, Teperi J, Aalto AM, et al. Levonorgestrelreleasing intrauterine system or hysterectomy in the treatment of essential menorrhagia: predictors of outcome. Acta Obstet Gynecol Scand 2004;83:401–3. Kurjak A, Kupesic S, Simunic V. Ultrasonic assessment of the peri- and postmenopausal ovary. Maturitas 2002;41:245–54. Cramer DW, Harlow BL, Xu H, Fraer C, Barbieri R. Cross-sectional and case-controlled analyses of the association between smoking and early menopause. Maturitas 1995;22:79–87. Motejlek K, Palluch F, Neulen J, Grummer R. Smoking impairs angiogenesis during maturation of human oocytes. Fertil Steril 2006;86:186–91. Lambert-Messerlian GM, Harlow BL. The influence of depression, body mass index and smoking on serum inhibin B levels in late reproductive aged women. J Clin Endocrinol Metab 2006;91:1496–500. Ficicioglu C, Kutlu T, Baglam E, Bakacak Z. Early follicular antimullerian hormone as an indicator of ovarian reserve. Fertil Steril 2006;85:592–6. Tekay A, Jouppila P. Intraobserver reproducibility of transvaginal doppler measurements in uterine and intraovarian arteries in regularly menstruating women. Ultrasound Obstet Gynecol 1996;7:129–34. Janson PO, Jansson I. The acute effect of hysterectomy on ovarian blood flow. Am J Obstet Gynecol 1977;127:349–52.