Dexamethasone attenuates the embryotoxic effect of endometriotic peritoneal fluid in a murine model

Purpose

The in vitro fertilization (IVF) pregnancy rate of women with advanced stage endometriosis is nearly half that of the general population, suggesting incomplete targeting of the pathophysiology underlying endometriosis-associated infertility. Compelling evidence highlights inflammation as the etiologic link between endometriosis and infertility and a potential target for adjunctive treatment. The objective of this study was to examine the effect of dexamethasone on murine embryos exposed to human endometriotic peritoneal fluid (PF) using the established murine embryo assay model.

Methods

PF was obtained from women with and without severe endometriosis. Murine embryos were harvested and randomly allocated to five groups of culture media conditions: (1) human tubal fluid (HTF), (2) HTF and 10 % PF from women without endometriosis, (3) HTF and 10 % PF from women with endometriosis (PF-E), (4) HTF with PF-E and 0.01 mcg/mL dexamethasone, and (5) HTF with PF-E and 0.1 mcg/mL dexamethasone. Embryos were cultured in standard conditions and evaluated for blastocyst development.

Results

A total of 266 mouse embryos were cultured. Baseline blastulation rates were 63.6 %. The addition of peritoneal fluid from women with endometriosis decreased the blastocyst development rate to 38.9 % (P = 0.008). The addition of 0.1 mcg/mL of dexamethasone to the culture media restored the blastulation rate to near baseline levels (61.2 %; P = 0.019).

Conclusions

The results of our in vitro study demonstrate the capacity of dexamethasone to mitigate the deleterious impact of endometriotic PF on embryo development. If confirmed in vivo, dexamethasone may prove a useful adjunct for the treatment of endometriosis-associated infertility.     

Effect of peritoneal fluid on in vitro cleavage of 2-cell mouse embryos: possible role in infertility associated with endometriosis

The purpose of this study was to evaluate the effect of peritoneal fluid (PF) on in vitro cleavage of 2-cell mouse embryos. PF was aspirated from the posterior cul-de-sac at laparoscopy and centrifuged, and the cell-free supernatant was heat-inactivated at 56 degrees C for 30 minutes and filtered (0.22 micron). Five percent PF in Ham's F-10 media was prepared and eight to ten 2-cell mouse embryos cultured for 72 hours. There were two study groups, one consisting of 10 PF samples from infertile patients with no endometriosis (PF-NE) and 18 from infertile patients with endometriosis (PF-E). Each sample was assayed along with a control consisting of media only. At 72 hours, greater than 50% of the embryos in the control groups reached the blastocyst and hatching stages. Individual PF samples in both study groups were classified as toxic if less than 50% of the embryos reached the blastocyst and hatching stages at 72 hours. Eight of the 10 samples in the PF-NE group were nontoxic and 14 of the 18 samples in the PF-E group were toxic (P less than 0.01). For evaluation of the overall effect of PF, all results in the PF-E group were pooled (162 embryos) and compared by the Mann-Whitney U test to pooled results in the PF-NE group (100 embryos). The embryonic stages in the PF-NE group were significantly more advanced than those in the PF-E group (P less than 0.001) at 24, 48, and 72 hours.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of cytokine levels and embryo toxicity in peritoneal fluid in infertile women with untreated or treated endometriosis.

OBJECTIVE: Our aim was to examine the relationship between the levels of cytokines in peritoneal fluid and its embryo toxicity. STUDY DESIGN: The levels of interleukin-1 and tumor necrosis factor were measured in peritoneal fluid from infertile women who did not have endometriosis (n = 21), who had untreated endometriosis (n = 19), and who had undergone medical treatment for endometriosis (n = 10). Embryo toxicity was investigated in mouse two-cell embryos cocultured with the oviducts in culture media that contained various concentrations of peritoneal fluid. RESULTS: The levels of cytokines were significantly higher in the peritoneal fluid from women who had untreated endometriosis than in women who did not have endometriosis, but they were extremely low in women who had undergone medical treatment with either danazol or buserelin. The peritoneal fluid from women who had untreated endometriosis adversely affected the cleavage of mouse two-cell embryos. After medical treatment the embryo toxicity of the peritoneal fluid was almost undetectable. CONCLUSION: These results offer some theoretic bases in support of medical treatment to improve reproductive performance in infertile women who have endometriosis.     

子宫内膜异位症并不孕患者腹腔液淋巴细胞及其白细胞介素-2的变化

目的探讨腹腔液中淋巴细胞转化活性及其释放白细胞介素－２（ＩＬ－２）的含量与子宫内膜异位症患者不孕的关系。方法采集１５例子宫内膜异位症不孕患者（异位症组）及１３例健康生育妇女（对照组）的腹腔液,用形态学观察法测定腹腔液中淋巴细胞转化活性,以生物活性检测法测定腹腔液、腹腔液中淋巴细胞培养上清液的ＩＬ－２含量。结果异位症组淋巴细胞转化率较对照组明显增高（Ｐ＜０．００１）;异位症组腹腔液及淋巴细胞培养上清液中ＩＬ－２的活性明显高于对照组（Ｐ＜０．０１,Ｐ＜０．００１）。异位症组淋巴细胞转化率与淋巴细胞培养上清液中ＩＬ－２活性有明显的直线正相关（Ｐ＜０．００１）。结论ＩＬ－２的含量增加可能是异位症不孕的重要因素。     

Increased nitric oxide in peritoneal fluid from women with idiopathic infertility and endometriosis.

OBJECTIVE: To verify whether nitric oxide in peritoneal fluid is associated with endometriosis and infertility. STUDY DESIGN: Twenty-five women with idiopathic infertility and 38 with endometriosis were recruited, and 18 cases of uterine myomata and 2 cases of ovarian cyst served as controls. Peritoneal fluid samples were aspirated from the pouch of Douglas during laparoscopy or laparotomy. Metabolites of nitric oxide (nitrite and nitrate) in peritoneal fluid were determined by a method using nitrate reductase and the Griess reaction. RESULTS: Peritoneal concentrations of nitrate/nitrite in both infertile women (42.02 +/- 12.98 mmol/L) and patients with endometriosis (41.75 +/- 16.42 mmol/L) were significantly higher than that in controls (33.96 +/- 13.07, P < .05 for both). No significant difference in peritoneal nitrate/nitrite level was found between infertile women and patients with endometriosis (P > .5). Peritoneal levels of nitrate/nitrite were comparable among patients with endometriosis at different stages (P > .5). Patients with endometriosis had more peritoneal fluid than controls and idiopathic infertile women, while controls and idiopathic infertile women had comparable amounts of peritoneal fluid. CONCLUSION: An increased peritoneal level of nitric oxide is a common alteration in endometriosis, endometriosis-associated infertility and idiopathic infertility and may be associated with the pathogenesis of these diseases.     

Total antioxidant status of peritoneal fluid in infertile women

OBJECTIVE: To determine whether impairment of the antioxidant systems of peritoneal fluid might be a factor responsible for infertility. STUDY DESIGN: Total antioxidant status was measured in peritoneal fluid obtained from 18 infertile women suffering from minimal or mild endometriosis, 23 patients with unexplained infertility, 12 women with tubal infertility and 13 fertile women. RESULTS: Total antioxidant status was significantly lower in peritoneal fluid from women with unexplained infertility (0.49+/-0.21 mmol/l) compared to both fertile patients (0.67+/-0.24 mmol/l, P=0.02) and women with tubal infertility (0.76+/-0.26 mmol/l, P=0.001). Peritoneal fluid total antioxidant status did not differ significantly between patients with endometriosis (0.61+/-0.2 mmol/l), tubal infertility and the fertile group (P>0.05). CONCLUSIONS: Our results suggest that low antioxidant status in peritoneal fluid may play a role in the pathogenesis of infertility.     

Marked elevation of macrophage migration inhibitory factor in the peritoneal fluid of women with endometriosis

OBJECTIVE: To evaluate the presence of macrophage migration inhibitory factor (MIF) in the peritoneal fluid of normal fertile women and patients with endometriosis and its growth-promoting activity toward human endothelial cells. DESIGN: Retrospective study using ELISA to measure peritoneal fluid MIF, and [3H]-thymidine incorporation into the DNA of human endothelial cells to assess its mitogenic activity. SETTING: Gynecology clinic and human reproduction research laboratory. PATIENT(S): Thirty-six healthy women and 57 women with endometriosis. INTERVENTION(S): Peritoneal fluid samples were obtained at laparoscopy. MAIN OUTCOME MEASURE(S): Macrophage migration inhibitory factor concentrations in the peritoneal fluid samples and [3H]-thymidine incorporation into the DNA of human microvascular endothelial cells to assess proliferation. RESULT(S): This study demonstrated the presence of MIF in the peritoneal fluid and a 238% increase of MIF levels in women with endometriosis as compared with healthy women. Both fertile and infertile women with endometriosis had significantly higher MIF concentrations than did fertile women with normal gynecological status, but the difference was more significant in infertile endometriosis patients. Anti-MIF antibody significantly inhibited proliferation of human microvascular endothelial cells in response to peritoneal fluids from healthy women and women with endometriosis stages I-II and III-IV, as assessed by [3H]-thymidine incorporation. CONCLUSION(S): This study revealed the presence of MIF in the peritoneal fluid and its increased levels in endometriosis and suggests that MIF may be involved in endometriosis-associated infertility and angiogenesis.     

子宫内膜异位症不孕患者腹腔液淋巴细胞转化活性及可溶性白细胞介素-2受体的含量

本文采集了15例子宫内膜异位症不孕患者及13例健康生育妇女的腹腔液，分别测定腹腔液淋巴细胞转化活性及淋巴细胞培养上清液中可溶性白细胞介素-2受体（SIL－2R的含量。结果表明，子宫内膜异位症不孕患者淋巴细胞转化活性增强，SIL－2R含量增加。这些变化可能与异位症不孕的发生密切相关。     

Cytokine profiles in serum and peritoneal fluid from infertile women with and without endometriosis

OBJECTIVE: To study the serum and peritoneal fluid cytokine profiles in infertile women with minimal/mild active endometriosis. METHODS: Fifty-seven consecutive infertile women undergoing laparoscopy for unexplained infertility had peritoneal fluid and serum samples obtained at the time of laparoscopy. The levels of interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-1 beta (IL-1 beta), vascular endothelial growth factor (VEGF), tumor necrosis factor-alpha (TNF-alpha), monocyte chemotatic protein-1 (MCP-1), RANTES, platelet derived growth factor (PDGF), soluble Fas (sFas), and soluble Fas Ligand (sFasL) in peritoneal fluid and serum were measured to compare the concentration in both biological fluids, in women who have minimal/mild red endometriosis using women with no endometriosis as controls. RESULTS: Peritoneal fluid levels of MCP-1, IL-8 and IL-6 were significantly higher in the endometriosis group (P < 0.012, P = 0.003, and P = 0.015, respectively). There was no significant difference in the peritoneal fluid levels of IL-1 beta, TNF-alpha, RANTES, VEGF, PDGF, sFas and sFasL in the two groups. Although serum levels of IL-8 were higher in women with endometriosis, the difference was not significant (P = 0.07). Serum levels of PDGF, IL-6, RANTES, IL-1 beta, TNF-alpha, and sFas, were not significantly different in the two groups. CONCLUSION: The elevated levels of MCP-1, IL-6, and IL-8 in peritoneal fluid but not serum may indicate the importance of local macrophage activating factors in the pathogenesis of endometriosis.     

达那唑体外对子宫内膜异位症患者腹腔巨噬细胞释放细胞因子 …

目的 了解达那唑体外对子宫内膜异位症（内异症）患者腹腔巨噬细胞释放细胞因子的影响及与胞浆游离钙（「Ｃａ＾２＋」）浓度的关系。方法 将浓度分别为１０μｇ／Ｌ、１００μｇ／Ｌ、１０００μｇ／Ｌ的达那唑加入１４例内异症不孕患者和１１例盆腔正常的不孕患者（对照）的腹腔液中进行培养，用双抗体夹心法检测腹腔巨噬细胞培养上清液中肿瘤坏死因子α（ＴＮＦ－α）和白细胞介素６（ＩＬ－６）的水平。同时，应用Ｆｒｕａ２测     

Alterations in expression of endometrial endothelial nitric oxide synthase and alpha(v)beta(3) integrin in women with endometriosis

OBJECTIVE: To determine the expression of endometrial endothelial nitric oxide synthase (eNOS) protein and alpha(v)beta(3) integrin in patients with and without endometriosis. DESIGN: Case-control cohort study. SETTING: University-based tertiary care center. PATIENT(S): Endometrial biopsy samples were obtained from 9 fertile women with regular cycles and 30 infertile women with varying severity of endometriosis. Peritoneal fluid levels of nitric oxide were determined in 13 infertile women with a normal pelvis and 12 infertile women with endometriosis. MAIN OUTCOME MEASURE(S): Expression of eNOS and alpha(v)beta(3) integrin protein in the endometrium and peritoneal fluid levels of nitric oxide. RESULTS: In patients with endometriosis, expression of eNOS was significantly increased in the glandular and luminal epithelium, with no significant changes in the stroma. Peritoneal fluid levels of nitric oxide were unchanged, and expression of alpha(v)beta(3) integrin expression in glandular and luminal epithelium was significantly decreased compared with controls. A significant negative correlation was observed between luminal expression of eNOS and alpha(v)beta(3) integrin and between glandular expression of eNOS and luminal expression of alpha(v)beta(3) integrin. CONCLUSION(S): The nitric oxide pathway may play a role in the pathogenesis of endometriosis.     

子宫内膜异位症不孕妇女腹腔液前列腺素水平

本文测定子宫内膜异位症不孕妇女23例(异位症组)、不明原因不孕妇女11例(不孕对照组)和正常妇女11例(正常对照组)腹腔液前列腺素水平,结果提示:异位症不孕妇女腹腔液中,PGE_2、PGF_(2α)、TXB_2、6-Keto-PGF_(1α)的浓度均高于正常对照组;PGE_2、PGF_(2α)、6-Keto-PGF_(1α)的浓度也高于不孕对照组。四种前列腺素,不孕对照组与正常对照组无区别。表明:腹腔液中前列腺素水平增高可能与异位症引起不孕的机制有关,而不孕对照组的不孕可能是前列腺素以外的其它原因所致。     

Elevated soluble Fas ligand levels may suggest a role for apoptosis in women with endometriosis

OBJECTIVE: To evaluate soluble Fas ligand concentrations in serum and peritoneal fluid from women with endometriosis and from fertile controls without endometriosis, and to study levels of soluble Fas ligand in conditioned media of cultured endometrial stromal cells. DESIGN: Prospective, experimental trial. SETTING: Two academic IVF centers. PATIENT(S): Twenty-nine fertile women without endometriosis and 57 infertile women with endometriosis (32 with stage I or II disease and 25 with stage III or IV disease). MAIN OUTCOME MEASURE(S): Enzyme-linked immunosorbent assay was used to measure soluble Fas ligand concentrations in paired samples of serum and peritoneal fluid from women with and without endometriosis. Concentrations were also measured in conditioned media of cultured endometrial stromal cells at basal conditions and after stimulation with interleukin-8 (0.001-10 ng/mL) and tumor necrosis factor-alpha (1-10 ng/mL). RESULT(S): Compared with fertile controls and women with early-stage of endometriosis, women with moderate to severe endometriosis had elevated serum (87.2 +/- 6.4, 88.2 +/- 6.9, and 162.3 +/- 7.8 pg/mL, respectively) and peritoneal fluid (81.0 +/- 6.0, 80.5 +/- 6.8, and 166.2 +/- 10.3 pg/mL, respectively) concentrations of soluble Fas ligand. Serum levels of soluble Fas ligand positively correlated with levels in peritoneal fluid. Comparison of patients in the same menstrual cycle in each group revealed that increased levels of soluble Fas ligand in patients with advanced endometriosis were not attributable to the difference in cycle phases. Soluble Fas ligand was not detected in conditioned media of endometrial stromal cells under baseline conditions or after stimulation. CONCLUSION(S): Serum and peritoneal fluid of women with moderate to severe endometriosis contain elevated concentrations of soluble Fas ligand compared to women with minimal or mild endometriosis and women without endometriosis. These findings suggest a role for apoptotic dysregulation in the pathophysiology of endometriosis.     

Reduction of the intraperitoneal inflammation associated with endometriosis by treatment with medroxyprogesterone acetate

An intraperitoneal inflammatory exudate has been repeatedly observed in infertile women without mechanical compromise of the pelvic viscera, particularly with endometriosis. This is manifested by increases in the peritoneal fluid volume, leukocyte number, and proteolytic enzyme concentrations. We tested the hypothesis that the stimulus responsible for eliciting this intraperitoneal inflammation is retrograde menstruation by measuring the peritoneal fluid volume and leukocyte count in 16 infertile women with endometriosis before and after ovulation suppression with medroxyprogesterone acetate, 30 mg/day for 4 months. Medroxyprogesterone acetate therapy significantly reduced the peritoneal fluid volume (22.5 +/- 4.1 versus 6.8 +/- 0.9 ml mean +/- SE, p less than 0.0001), the peritoneal fluid leukocyte count (30.7 +/- 6.5 versus 7.1 +/- 0.7 x 10(6) cells per patient, p less than 0.0001), and American Fertility Society score (23.2 +/- 5.1 versus 15.4 +/- 4.1, p less than 0.0002). We conclude that medroxyprogesterone acetate treatment reduces the intraperitoneal exudate associated with endometriosis. These results support the contention that the stimulus eliciting the intraperitoneal inflammation in infertile women with endometriosis is retrograde menstruation.     

Inducible nitric oxide synthase expression by peritoneal macrophages in endometriosis-associated infertility.

OBJECTIVE: Determine whether peritoneal macrophages from women with endometriosis-associated infertility express more inducible nitric oxide synthase (NOS2) and produce more NO than fertile controls. DESIGN: Unblinded clinical study. PATIENT(S): Nine infertile women with endometriosis and nine normal fertile women undergoing laparoscopy.Intervention(s): Peritoneal fluid and macrophages were collected. Cells were also cultured with the NOS2 inducers interferon-alpha (IFN-alpha) or IFN-gamma plus lipopolysaccharide (LPS). MAIN OUTCOME MEASURE(S): Peritoneal fluid NO levels, peritoneal macrophage NOS activity, and peritoneal macrophage NOS2 protein expression. RESULT(S): NOS enzyme activity was higher in peritoneal macrophages from endometriosis patients. Immunoblots demonstrated NOS2 protein only in peritoneal macrophages from women with endometriosis. Peritoneal fluid NO concentration was similar in the two groups, but total peritoneal fluid NO content was higher in endometriosis patients. After 3 days' culture, peritoneal macrophages from women with endometriosis produced more NO in response to IFN-alpha or IFN-gamma plus LPS than controls. CONCLUSION(S): Peritoneal macrophages from women with endometriosis-associated infertility express higher levels of NOS2, have higher NOS enzyme activity, and produce more NO in response to immune stimulation in vitro. As high levels of NO adversely affect sperm, embryos, implantation, and oviductal function, reducing peritoneal fluid NO production or blocking NO effects may improve fertility in women with endometriosis.     

Increased rate of endometriosis and spontaneous abortion in an in vitro fertilization program: No correlation with epidemiological factors

Background. There are conflicting data concerning endometriosis and spontaneous abortion (SAB). The aim of the present study was to evaluate if there was any association between endometriosis and SAB. Moreover, we investigated risk factors in women with endometriosis and SAB.

Methods. The medical files of 457 married women with endometriosis and 200 infertile women without endometriosis were studied retrospectively. All cases were diagnosed by laparoscopy. Data concerning demographic variables and menstrual characteristics were recorded from 226 women with endometriosis, which were divided into two groups. Group 1 included 126 cases with endometriosis and SAB, and Group 2 comprised 100 parous women with endometriosis and without SAB. Statistical comparisons between groups were made using the χ² test and odds ratios (OR) and 95% confidence intervals (CI).

Results. The proportion of SAB was significantly higher in women with endometriosis than in infertile women without endometriosis (126/457 (27.6%) vs. 36/200 (18.0% ); OR = 1.7, 95% CI 1.1 = 2.6; p = 0.01). The frequency of nulligravid women was significantly higher in women with endometriosis than in the control group (OR = 1.9, 95% CI 1.4 – 2.81; p = 0.001). Mean age, age at onset of endometriosis, race, height, weight, body mass index, medical history of allergies, and family histories of endometriosis and cancer were similar in women with endometriosis and SAB and in parous women with endometriosis but without SAB. Moreover, the two groups were similar in age at menarche, length of cycle, duration and amount of flow, and the severity of disease. The incidence of infertility was significantly higher in women with SAB (p < 0.001).

Conclusion. These data suggest but do not prove that the risk of SAB is increased in women with endometriosis. The epidemiological risk factors of endometriosis are not associated with an increase in the abortion rate.     

Peritoneal macrophages and infertility: the association between cell number and pelvic pathology

Increased numbers of peritoneal macrophages have been repeatedly associated with infertility. Because the factors contributing to this intraperitoneal exudate are unknown, this study was carried out to determine which anatomic or endocrinologic abnormalities in infertile women might be associated with an increase in leukocyte numbers. The peritoneal fluid from 103 women was analyzed. Nonparametric data analysis demonstrated significantly greater cell counts in infertile women with endometriosis, compared with other infertile women (P less than 0.01) or fertile control subjects (P less than 0.005). Multiple regression analysis was then used to determine the relationship of individual variables to cell number without the influence of confounding factors. These data demonstrate that the best correlation with elevated macrophage number is in women who have infertility and no mechanical fertility factors (of which mild endometriosis is a subgroup). Thus, an increase in peritoneal macrophage number is not restricted to women with endometriosis but, rather, is seen in a subset of infertile women generally without mechanical or endocrinologic infertility factors.     

Peritoneal fluid volume and sex steroids in the pre-ovulatory period in mild endometriosis

Twenty infertile women with laparoscopically confirmed mild endometriosis and ten women with tubal infertility underwent diagnostic laparoscopy 32 h after the onset of the endogenous luteinizing hormone (LH) surge during a spontaneous menstrual cycle. All visible peritoneal fluid was aspirated for assessment of volume and sex steroid content. There was no significant difference in peritoneal fluid volume or concentrations of oestradiol, progesterone and androstenedione between the two groups. Furthermore, in the endometriosis group there was no significant difference in peritoneal fluid volume and concentrations of sex steroids between those women who had been treated previously with danazol and those who were left untreated.     

Antizona and antisperm antibodies in women with endometriosis and/or infertility

OBJECTIVE: To measure the levels of antigamete antibodies in serum and peritoneal fluid of women with endometriosis and/or infertility. DESIGN: Antibody activity against human sperm and porcine oocytes was analyzed in selected subgroups of women. SETTING: Clinic of reproduction. PATIENT(S): Women with endometriosis and/or infertility. INTERVENTION(S): No treatment was implemented before peritoneal fluid and blood sample collection. MAIN OUTCOME MEASURE(S): Quantitative ELISA. RESULT(S): Four groups of women (n = 98) were analyzed for the presence of antizona and antisperm antibodies: infertile with endometriosis (n = 30), idiopathic infertility (n = 28), fertile with endometriosis (n = 20), and healthy fertile controls (n = 20). Antibodies were analyzed simultaneously in serum and peritoneal fluid. No statistically significant differences in antibody levels were detected in serum samples among the analyzed groups. The median values for antizona and antisperm antibodies in peritoneal fluid were significantly higher in women with idiopathic infertility than in the control group. In women with unexplained infertility, a high degree of correlation (Spearman) was found between the presence of antizona antibodies in peritoneal fluid and serum (r = 0.579). A positive predictive value of 80% was calculated for the presence of antizona antibodies (>5 ng/oocyte) in the peritoneal fluid of patients with infertility. CONCLUSION(S): Antizona antibodies locally produced in the peritoneal fluid have diagnostic value for infertility status; however, they cannot be treated as a marker or prognostic factor for minimal endometriosis and/or its treatment.     

Leptin is not involved in the pathophysiology of endometriosis-related infertility

OBJECTIVE: Changes in peritoneal fluid (PF) composition may affect fertilization as well as early embryonic development. Leptin, an adipocyte hormone, has been shown to act as a link between adipose tissue and the reproductive system. Therefore, we decided to assess peritoneal and serum leptin levels in infertile endometriotic patients. PATIENTS: Seventy-two women were studied, including 30 fertile and 18 infertile women with ovarian endometriotic cysts and, as a reference group, 24 patients with unexplained infertility. RESULTS: No significant difference in the peritoneal and leptin levels was found between the studied groups. Significantly higher PF leptin concentration was observed in patients with stages III and IV of endometriosis as compared to those with minimal stage of the disease. In fertile patients with endometriosis a positive correlation has been found between PF and serum leptin concentrations. CONCLUSIONS: No differences in peritoneal or serum leptin levels between infertile and fertile women with endometriosis suggest that this cytokine is not involved in pathophysiology of endometriosis-related infertility.