The prevalence of endometriosis in unexplained infertility: a systematic review.

In 15-30% of couples with infertility, no abnormalities are found after the initial diagnostic work-up. The aim of this study was to investigate the prevalence of endometriosis in patients with unexplained infertility undergoing diagnostic laparoscopy in the current era of improved imaging and assisted reproductive technology. A systematic search of PubMed, Embase and Cochrane Central was conducted to identify all studies reporting on pelvic pathologies found by laparoscopy in couples diagnosed with unexplained infertility. Normal ovulatory cycles, normal semen analysis and an infertility period of ≥12 months were the minimum requirements for a study population to be included. The prevalence of endometriosis was 44%, and most lesions were classified as minimal or mild (74%). The prevalence rates of tubal factors and adhesions were 20% and 16%, respectively. The detection rate for pelvic abnormalities was higher in women with prior fertility treatment (75%) compared with women without prior fertility treatment (53%). Despite the significant improvements in imaging for the diagnosis of endometriosis and tubal factors over the last decades, the prevalence rates of endometriosis and tubal abnormalities remain high in patients with unexplained infertility. The high prevalence of endometriosis in this population is important for decision-making in patients who also suffer from pain symptoms suggestive of endometriosis.

Correlation Between Surgical Phenotype and Pain Improvement After Endometriosis Surgery.

STUDY OBJECTIVE: To examine pain improvement after endometriosis surgery and whether it can be predicted by the observed surgical phenotype. DESIGN: Prospective longitudinal survey study. SETTING: A University hospital. PATIENTS: A total of 125 patients completed a preoperative questionnaire (response rate: n = 227 of 277, 81.9%), had surgically confirmed endometriosis (n = 202 of 227), and returned a second postoperative questionnaire (response rate: n = 125 of 202, 61.9%). INTERVENTIONS: All patients underwent complete laparoscopic removal of the endometriotic lesions. Surgical phenotype was classified according to the rASRM and #Enzian classification. MEASUREMENTS AND MAIN RESULTS: The intensity of 5 specific pain symptoms was questioned by postal paper-pencil questionnaires with a numerical rating scale (0-10) both preoperatively (3.01 ± 2.72 months before surgery) and one year after surgery (12.62 ± 1.59 months). A postoperative pain improvement score was computed (postoperative pain-preoperative pain) for each specific pain symptom (0-10) and for the overall/global pain sum score (0-50). The mean intensity of all pain scores was lower postoperatively as compared with preoperatively (p <.0001). A statistically significant weak correlation was observed between the surgical phenotype "rectovaginal endometriosis" and postoperative improvement of dyspareunia (r = .265; p = .003). The other 11 hypothesized correlations between surgical phenotype and postoperative improvement of pain intensity failed to reach statistical significance. CONCLUSION: Clinicians can inform patients that surgery is effective in reducing endometriosis-related pain symptoms and the overall/global pain scores at 12 months postoperatively. From our data, we can conclude that patients with rectovaginal endometriosis might benefit the most from the reduction of their sexual pain. On the basis of these results, we could suggest that deep dyspareunia (even if present as an isolated symptom) might be a valid indication for surgery. Further research could explore the association between a certain surgical phenotype and more detailed assessments of sexual functioning, as well as explore whether feedback from the surgeon on expected pain improvement affects patient-reported outcomes.

Non-Invasive Imaging Techniques for Diagnosis of Pelvic Deep Endometriosis and Endometriosis Classification Systems: An International Consensus Statement.

The International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) and International Deep Endometriosis Analysis (IDEA) group, the European Endometriosis League (EEL), the European Society for Gynaecological Endoscopy (ESGE), the European Society of Human Reproduction and Embryology (ESHRE), the International Society for Gynecologic Endoscopy (ISGE), the American Association of Gynecologic Laparoscopists (AAGL) and the European Society of Urogenital Radiology (ESUR) elected an international, multidisciplinary panel of gynecological surgeons, sonographers and radiologists, including a steering committee, which searched the literature for relevant articles in order to review the literature and provide evidence-based and clinically relevant statements on the use of imaging techniques for non-invasive diagnosis and classification of pelvic deep endometriosis. Preliminary statements were drafted based on review of the relevant literature. Following two rounds of revisions and voting orchestrated by chairs of the participating societies, consensus statements were finalized. A final version of the document was then resubmitted to the society chairs for approval. Twenty statements were drafted, of which 14 reached strong and three moderate agreement after the first voting round. The remaining three statements were discussed by all members of the steering committee and society chairs and rephrased, followed by an additional round of voting. At the conclusion of the process, 14 statements had strong and five statements moderate agreement, with one statement left in equipoise. This consensus work aims to guide clinicians involved in treating women with suspected endometriosis during patient assessment, counseling and planning of surgical treatment strategies.

Similar long-term recurrence rates with cystectomy and CO2 laser vaporization for endometrioma: a retrospective study.

RESEARCH QUESTION: Is there a difference in recurrence rate of endometrioma(s) after cystectomy versus CO2 laser vaporization of the cyst wall? DESIGN: This single-centre retrospective study included 270 patients undergoing laparoscopic surgery for endometriomas between January 2010 and December 2014, stratified according to the surgical technique used. All 270 included patients underwent complete laparoscopic surgery for endometrioma(s): 155 underwent cystectomy, 63 complete CO2 laser vaporization of the cyst wall and 52 a mixed technique. The primary outcome studied was the difference in recurrence rate between the cystectomy group and the CO2 laser vaporization group. RESULTS: The mean duration of follow-up was 58 (±34) months. Imaging-based recurrence (any cyst size) was reported in 9.9% of patients (n = 12/121) treated with cystectomy and in 13.3% of patients (n = 6/45) who underwent a vaporization (P = 0.577). The need for reintervention for endometrioma(s) was also similar in both groups, with a rate of 3.2% (n = 5/155) after cystectomy and 4.8% (n = 3/63) after vaporization (P = 0.476). Of 160 women who wanted to conceive immediately after surgery, 73.8% became pregnant (72.6% [77/106] in the cystectomy group and 75.9% [41/54] in the vaporization group [P = 0.310]). Conception occurred mostly by assisted reproductive technology (57.1% [44/77] in the cystectomy group and 70.7% [29/41] in the vaporization group [P = 0.074]). CONCLUSIONS: Similar rates of recurrence for endometrioma(s) were observed after cystectomy versus CO2 laser vaporization. As other studies have suggested that CO2 laser vaporization may be less harmful to the normal ovarian tissue, it can be considered as a safe alternative for cystectomy in women wishing to preserve their reproductive potential.

Endometriosis Classification Systems: An International Survey to Map Current Knowledge and Uptake.

OBJECTIVE: In the field of endometriosis, several classification, staging and reporting systems have been developed, but do clinicians routinely use these classification systems, which system do they use and what are the clinicians' motivations? DATA SOURCES: A cross-sectional study was performed to gather data on the current use of endometriosis classification systems, problems encountered and interest in a new simple surgical descriptive system for endometriosis. Of particular focus were three systems most commonly used: the Revised American Society for Reproductive Medicine (rASRM) classification, the Endometriosis Fertility Index (EFI), and the ENZIAN classification. Data were analysed by SPSS. A survey was designed using the online SurveyMonkey tool consisting of 11 questions concerning three domains-participants background, existing classification systems and intentions with regards to a new classification system for endometriosis. Replies were collected between 15 May and 1 July 2020. METHODS OF STUDY SELECTION: na TABULATION, INTEGRATION AND RESULTS: The final dataset included the replies of 1178 clinicians, including surgeons, gynecologists, reproductive endocrinologists, fertility specialists and sonographers, all managing women with endometriosis in their clinical practice. Overall, 75.5% of the professionals indicate that they currently use a classification system for endometriosis. The rASRM classification system was the best known and used system, the EFI system and ENZIAN system were known by a majority of the professionals but used by only a minority. The lack of clinical relevance was most often selected as a problem with using any system. The findings of the survey suggest that clinicians worldwide are open to using a new classification system for endometriosis that can achieve standardized reporting, and is clinically relevant and simple. The findings therefore support future initiatives for the development of a new descriptive system for endometriosis and provide information on user expectations and conditions for universal uptake of such a system. CONCLUSION: Even with a high uptake of the existing endometriosis classification systems (rASRM, ENZIAN and EFI), most clinicians managing endometriosis would like a new simple surgical descriptive system for endometriosis.

Endometriotic lung cyst causing catamenial hemoptysis; a case report and review of literature.

We report a rare case of an endometriotic lung cyst in a 47-year woman with recurrent catamenial hemoptysis. Chest computed tomography (CT) obtained outside the menstruation in October 2019 revealed a cystic lesion (2.5 cm) located in the right inferior lobe near the distal esophagus and the inferior pulmonary vein. Compared to CT abdomen in May 2019, this lesion had increased with a larger volume and a thicker wall. An endometrial lung cyst was suspected as episodes of hemoptysis no longer occurred after initiating hormonal treatment with nomegestrol acetate. Exploratory video-assisted thoracoscopic surgery with wedge resection of the cyst was performed. Histopathologic examination confirmed the diagnosis of an endometriotic cystic lesion. Postoperative course was uneventful with no further symptoms since then.

An International Terminology for Endometriosis, 2021.

OBJECTIVE: Different classification systems have been developed for endometriosis, using different definitions for the disease, the different subtypes, symptoms and treatments. In addition, an International Glossary on Infertility and Fertility Care has been published in 2017 by the International Committee for Monitoring Assisted Reproductive Technologies (ICMART) in collaboration with other organisations. An international working group convened over the development of a classification or descriptive system for endometriosis. As a basis for such system, a terminology for endometriosis was considered a condition sine qua non. The aim of the current study was to develop a set of terms and definitions be prepared on endometriosis that would be the basis for standardization in disease description, classification and research. DATA SOURCES: The working group listed a number of terms relevant to be included in the terminology, documented currently used and published definitions, and discussed and adapted them until consensus was reached within the working group. Following stakeholder review, further terms were added, and definitions further clarified. Although definitions were collected through published literature, the final set of terms and definitions is to be considered consensus-based. After finalization of the first draft, the members of the international societies and other stakeholders were consulted for feedback and comments, which lead to further adaptations. METHODS OF STUDY SELECTION: na TABULATION, INTEGRATION, AND RESULTS: A list of 49 terms and definitions in the field of endometriosis is presented, including a definition for endometriosis and its subtypes, different locations, interventions, symptoms and outcomes. Endometriosis is defined as a disease characterized by the presence of endometrium-like epithelium and/or stroma outside the endometrium and myometrium, usually with an associated inflammatory process. CONCLUSION: The current paper outlines a list of 49 terms and definitions in the field of endometriosis. The application of the defined terms aims to facilitate harmonization in endometriosis research and clinical practice. Future research may require further refinement of the presented definitions.

Endometriosis Classification, Staging and Reporting Systems: A Review on the Road to a Universally Accepted Endometriosis Classification.

OBJECTIVE: In the field of endometriosis, several classification, staging and reporting systems have been developed. Which endometriosis classification, staging and reporting systems have been published and validated for use in clinical practice? DATA SOURCES: A systematic PUBMED literature search was performed. Data were extracted and summarized. METHODS OF STUDY SELECTION: na TABULATION, INTEGRATION AND RESULTS: Twenty-two endometriosis classification, staging and reporting systems have been published between 1973 and 2021, each developed for specific, and different, purposes. There still is no international agreement on how to describe the disease. Studies evaluating the different systems are summarized showing a discrepancy between the intended and the evaluated purpose, and a general lack of validation data confirming a correlation with pain symptoms or quality of life for any of the current systems. A few studies confirm the value of the ENZIAN system for surgical description of deep endometriosis. With regards to infertility, the endometriosis fertility index has been confirmed valid for its intended purpose. CONCLUSION: Of the 22 endometriosis classification, staging and reporting systems identified in this historical overview, only a few have been evaluated for the purpose for which they were developed. The literature search was limited to PUBMED. Unpublished classification, staging or reporting systems, or those published in books were not considered. It can be concluded that there is no international agreement on how to describe endometriosis or how to classify it, and that most classification/staging systems show no or very little correlation with patient outcomes. This overview of existing systems is a first step in working towards a universally accepted endometriosis classification.

Development of organoids from mouse and human endometrium showing endometrial epithelium physiology and long-term expandability.

The endometrium, which is of crucial importance for reproduction, undergoes dynamic cyclic tissue remodeling. Knowledge of its molecular and cellular regulation is poor, primarily owing to a lack of study models. Here, we have established a novel and promising organoid model from both mouse and human endometrium. Dissociated endometrial tissue, embedded in Matrigel under WNT-activating conditions, swiftly formed organoid structures that showed long-term expansion capacity, and reproduced the molecular and histological phenotype of the tissue's epithelium. The supplemented WNT level determined the type of mouse endometrial organoids obtained: high WNT yielded cystic organoids displaying a more differentiated phenotype than the dense organoids obtained in low WNT. The organoids phenocopied physiological responses of endometrial epithelium to hormones, including increased cell proliferation under estrogen and maturation upon progesterone. Moreover, the human endometrial organoids replicated the menstrual cycle under hormonal treatment at both the morpho-histological and molecular levels. Together, we established an organoid culture system for endometrium, reproducing tissue epithelium physiology and allowing long-term expansion. This novel model provides a powerful tool for studying mechanisms underlying the biology as well as the pathology of this key reproductive organ.

Laparoscopic surgery for endometriosis.

BACKGROUND: Endometriosis is associated with pain and infertility. Surgical interventions aim to remove visible areas of endometriosis and restore the anatomy. OBJECTIVES: To assess the effectiveness and safety of laparoscopic surgery in the treatment of pain and infertility associated with endometriosis. SEARCH METHODS: This review has drawn on the search strategy developed by the Cochrane Gynaecology and Fertility Group including searching the Cochrane Gynaecology and Fertility Group's specialised register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, reference lists for relevant trials, and trial registries from inception to April 2020. SELECTION CRITERIA: We selected randomised controlled trials (RCTs) that compared the effectiveness and safety of laparoscopic surgery with any other laparoscopic or robotic intervention, holistic or medical treatment, or diagnostic laparoscopy only. DATA COLLECTION AND ANALYSIS: Two review authors independently performed selection of studies, assessment of trial quality and extraction of relevant data with disagreements resolved by a third review author. We collected data for the core outcome set for endometriosis. Primary outcomes included overall pain and live birth. We evaluated the quality of evidence using GRADE methods. MAIN RESULTS: We included 14 RCTs. The studies randomised 1563 women with endometriosis. Four RCTs compared laparoscopic ablation or excision with diagnostic laparoscopy only. Two RCTs compared laparoscopic excision with diagnostic laparoscopy only. One RCT compared laparoscopic ablation or excision with laparoscopic ablation or excision and uterine suspension. Two RCTs compared laparoscopic ablation and uterine nerve transection with diagnostic laparoscopy only. One RCT compared laparoscopic ablation with diagnostic laparoscopy and gonadotropin-releasing hormone (GnRH) analogues. Two RCTs compared laparoscopic ablation with laparoscopic excision. One RCT compared laparoscopic ablation or excision with helium thermal coagulator with laparoscopic ablation or excision with electrodiathermy. One RCT compared conservative laparoscopic surgery with laparoscopic colorectal resection of deep endometriosis infiltrating the rectum. Common limitations in the primary studies included lack of clearly described blinding, failure to fully describe methods of randomisation and allocation concealment, and poor reporting of outcome data. Laparoscopic treatment versus diagnostic laparoscopy We are uncertain of the effect of laparoscopic treatment on overall pain scores compared to diagnostic laparoscopy only at six months (mean difference (MD) 0.90, 95% confidence interval (CI) 0.31 to 1.49; 1 RCT, 16 participants; very low quality evidence) and at 12 months (MD 1.65, 95% CI 1.11 to 2.19; 1 RCT, 16 participants; very low quality evidence), where a positive value means pain relief (the higher the score, the more pain relief) and a negative value reflects pain increase (the lower the score, the worse the increase in pain). No studies looked at live birth. We are uncertain of the effect of laparoscopic treatment on quality of life compared to diagnostic laparoscopy only: EuroQol-5D index summary at six months (MD 0.03, 95% CI -0.12 to 0.18; 1 RCT, 39 participants; low quality evidence), 12-item Short Form (SF-12) mental health component (MD 2.30, 95% CI -4.50 to 9.10; 1 RCT, 39 participants; low quality evidence) and SF-12 physical health component (MD 2.70, 95% CI -2.90 to 8.30; 1 RCT, 39 participants; low quality evidence). Laparoscopic treatment probably improves viable intrauterine pregnancy rate compared to diagnostic laparoscopy only (odds ratio (OR) 1.89, 95% CI 1.25 to 2.86; 3 RCTs, 528 participants; I2 = 0%; moderate quality evidence). We are uncertain of the effect of laparoscopic treatment compared to diagnostic laparoscopy only on ectopic pregnancy (MD 1.18, 95% CI 0.10 to 13.48; 1 RCT, 100 participants; low quality evidence) and miscarriage (MD 0.94, 95% CI 0.35 to 2.54; 2 RCTs, 112 participants; low quality evidence). There was limited reporting of adverse events. No conversions to laparotomy were reported in both groups (1 RCT, 341 participants). Laparoscopic ablation and uterine nerve transection versus diagnostic laparoscopy We are uncertain of the effect of laparoscopic ablation and uterine nerve transection on adverse events (more specifically vascular injury) compared to diagnostic laparoscopy only (OR 0.33, 95% CI 0.01 to 8.32; 1 RCT, 141 participants; low quality evidence). No studies looked at overall pain scores (at six and 12 months), live birth, quality of life, viable intrauterine pregnancy confirmed by ultrasound, ectopic pregnancy and miscarriage. Laparoscopic ablation versus laparoscopic excision There was insufficient evidence to determine whether there was a difference in overall pain, measured at 12 months, for laparoscopic ablation compared with laparoscopic excision (MD 0.00, 95% CI -1.22 to 1.22; 1 RCT, 103 participants; very low quality evidence). No studies looked at overall pain scores at six months, live birth, quality of life, viable intrauterine pregnancy confirmed by ultrasound, ectopic pregnancy, miscarriage and adverse events. Helium thermal coagulator versus electrodiathermy We are uncertain whether helium thermal coagulator compared to electrodiathermy improves quality of life using the 30-item Endometriosis Health Profile (EHP-30) at nine months, when considering the components: pain (MD 6.68, 95% CI -3.07 to 16.43; 1 RCT, 119 participants; very low quality evidence), control and powerlessness (MD 4.79, 95% CI -6.92 to 16.50; 1 RCT, 119 participants; very low quality evidence), emotional well-being (MD 6.17, 95% CI -3.95 to 16.29; 1 RCT, 119 participants; very low quality evidence) and social support (MD 5.62, 95% CI -6.21 to 17.45; 1 RCT, 119 participants; very low quality evidence). Adverse events were not estimable. No studies looked at overall pain scores (at six and 12 months), live birth, viable intrauterine pregnancy confirmed by ultrasound, ectopic pregnancy and miscarriage. AUTHORS' CONCLUSIONS: Compared to diagnostic laparoscopy only, it is uncertain whether laparoscopic surgery reduces overall pain associated with minimal to severe endometriosis. No data were reported on live birth. There is moderate quality evidence that laparoscopic surgery increases viable intrauterine pregnancy rates confirmed by ultrasound compared to diagnostic laparoscopy only. No studies were found that looked at live birth for any of the comparisons. Further research is needed considering the management of different subtypes of endometriosis and comparing laparoscopic interventions with lifestyle and medical interventions. There was insufficient evidence on adverse events to allow any conclusions to be drawn regarding safety.

Mimicking Sampson's Retrograde Menstrual Theory in Rats: A New Rat Model for Ongoing Endometriosis-Associated Pain.

Endometriosis is a prevalent gynecologic disease, defined by dysfunctional endometrium-like lesions outside of the uterine cavity. These lesions are presumably established via retrograde menstruation, i.e., endometrial tissue that flows backwards during menses into the abdomen and deposits on the organs. As ongoing pain is one of the main pain symptoms of patients, an animal model that illuminates this problem is highly anticipated. In the present study, we developed and validated a rat model for ongoing endometriosis-associated pain. First, menstrual endometrial tissue was successfully generated in donor rats, as validated by gross examination, histology and qPCR. Next, endometriosis was induced in recipient animals by intraperitoneal injection of menstrual tissue. This resulted in neuro-angiogenesis as well as established endometriosis lesions, which were similar to their human counterparts, since epithelial and stromal cells were observed. Furthermore, significant differences were noted between control and endometriosis animals concerning bodyweight and posture changes, indicating the presence of ongoing pain in animals with endometriosis. In summary, a rat model for endometriosis was established that reliably mimics the human pathophysiology of endometriosis and in which signs of ongoing pain were detected, thus providing a new research tool for therapy development.

Cost-effectiveness of ovarian stimulation with gonadotrophin and clomiphene citrate in an intrauterine insemination programme for subfertile couples.

Ovarian stimulation with low-dose human menopausal gonadotrophin (HMG) is superior to clomiphene citrate in intrauterine insemination (IUI) cycles with respect to clinical pregnancy rate, but it is unclear whether HMG is also the more cost-effective option. The aim of this study was to compare the cost-effectiveness of ovarian stimulation with low-dose subcutaneously administred HMG (37.5-75 IU per day) to orally administred clomiphene citrate (50 mg/day from day 3-7) in an IUI programme for subfertile couples. A cost-effectiveness analysis was conducted using the results of a randomized trial, including 620 IUI cycles. The primary outcome was the incremental cost-effectiveness ratio (ICER) of using HMG versus clomiphene citrate. Results are presented from the healthcare payer perspective. The total cost per patient associated with one IUI treatment with HMG is €764, whereas it is €558 if clomiphene citrate is used, resulting in an incremental cost of €206 for HMG per treatment. The incremental clinical pregnancy rate of using HMG instead of clomiphene citrate, however, is also 5.7 percentage points higher, resulting in an ICER of HMG versus clomiphene citrate of €3615 per additional clinical pregnancy achieved. On average, HMG was found to be more cost-effective than clomiphene citrate.

A Real-Life Analysis of Reproductive Outcome after Fertility Preservation in Female Cancer Patients.

BACKGROUND: Fertility preservation before or during cancer treatment in young women has become an important health issue because of delayed motherhood and improved survival rates. This study evaluates the necessity and the efficacy of fertility preservation, with a focus on actual pregnancy wish and outcome after fertility preservation and cancer treatment. PATIENTS AND METHODS: All consecutive patients who received fertility preservation in 2 university referral centers before or during cancer treatment were included. After a minimal follow-up of 3 years, pregnancy wish, pregnancy attempts and fertility outcome were assessed during a dedicated consultation or during a telephone interview. RESULTS: A total of 159 patients received fertility preservation including hormonal protection with gonadotropin-releasing hormone agonist (n = 93, 58.5%), ovarian tissue cryopreservation (n = 44, 27.7%), and combined hormonal protection and ovarian tissue cryopreservation (n = 22, 13.8%). Among the 91 (57.2%) patients in remission after a mean follow-up of 61.5 months, 29 (31.9%) women actively attempted pregnancy. Patients who had received ovarian cryopreservation were more likely to attempt pregnancy (18/66) than those who only received hormonal protection (11/93, p = 0.02). Out of the 29 women who attempted pregnancy, 16 (55.2%) became pregnant, and most of them conceived spontaneously (87.5%, 14/16). Out of the 13 women who did not become pregnant, 1 patient adopted a child and 12 patients still wanted to become pregnant, including 1 patient who underwent a transplantation of her cryopreserved ovarian tissue without success. CONCLUSION: In one of the first studies reporting real-life experience in centers for fertility preservation, we found that, within 5 years following the end of cancer treatment, only one third of patients in remission attempted to become pregnant, with a pregnancy rate of 55%, mostly after spontaneous conception.

Evaluation of Total, Active, and Specific Myeloperoxidase Levels in Women with and without Endometriosis.

Myeloperoxidase (MPO) is a proinflammatory enzyme and a marker for neutrophil activation and oxidative stress. Since oxidative stress and inflammation are linked to the pathogenesis of endometriosis, we hypothesized that the total, active, and specific (active/total) MPO levels were significantly different in plasma of women with and without endometriosis. Samples were selected from our biobank from women with endometriosis (n = 212) and controls without endometriosis (n = 121) across the menstrual cycle. Total MPO plasma levels were measured by immunoassay and MPO activity by enzymatic assay. Total and active MPO levels did not differ significantly among endometriosis cases and controls, whereas the specific MPO activity was significantly lower in women with endometriosis than that in controls (p = 0.0159). After the subdivision of control patients into women with a normal pelvis and women with other benign gynecological disorders, a significant difference was observed only between women with endometriosis and women with other benign gynecological disorders (p = 0.0266). In conclusion, systemic MPO levels may not be suited as a single biomarker for endometriosis. Our data support the involvement of MPO in other gynecological disorders but do not provide any evidence for an association with endometriosis.

Functional Expression of TRP Ion Channels in Endometrial Stromal Cells of Endometriosis Patients.

Endometriosis is a common gynecological disease that is characterized by the presence of functional endometrial-like lesions in the abdominal cavity. Aside from epithelial cells, these lesions consist of stromal cells that have the capacity to migrate, adhere, proliferate, and induce neuro- and lymphangiogenesis, which allows them to survive at ectopic locations. However, the exact underlying mechanisms that regulate these changes are yet to be elucidated. The common ground of these processes, however, is the second messenger, calcium. In this regard, members of the superfamily of transient receptor potential (TRP) ion channels, which are known to be calcium-permeable and expressed in the endometrium, have emerged as key regulators. Here, we assessed the molecular and functional expression of TRP channels in stromal cells isolated from the eutopic endometrium of endometriosis patients and controls. Using RT-qPCR, high mRNA levels of TRPV2, TRPV4, TRPM4, TRPM7, TRPC1, TRPC3, TRPC4, and TRPC6 were observed in the whole endometrium throughout the menstrual cycle. Additionally, and in line with previous reports of control patients, TRPV2, TRPV4, TRPC1/4, and TRPC6 were present in human endometrial stromal cells (hESC) from endometriosis patients both at the molecular and functional level. Moreover, proliferation and migration assays illustrated that these parameters were not affected in stromal cells from endometriosis patients. Furthermore, comparison between eutopic and ectopic endometrial samples revealed that the RNA expression pattern of TRP channels did not differ significantly. Collectively, although a functional expression of specific ion channels in hESCs was found, their expression did not correlate with endometriosis.

Functional expression of transient receptor potential channels in human endometrial stromal cells during the luteal phase of the menstrual cycle.

STUDY QUESTION: Are members of the transient receptor potential (TRP) channel superfamily functionally expressed in the human endometrial stroma? SUMMARY ANSWER: The Ca(2+)-permeable ion channels TRPV2, TRPV4, TRPC6 and TRPM7 are functionally expressed in primary endometrial stromal cells. WHAT IS KNOWN ALREADY: Intercellular communication between epithelial and stromal endometrial cells is required to initiate decidualization, a prerequisite for successful implantation. TRP channels are possible candidates as signal transducers involved in cell-cell communication, but no fingerprint is available of the functional distribution of TRP channels in the human endometrium during the luteal phase of the menstrual cycle. STUDY DESIGN, SIZE, DURATION: Endometrial biopsy samples (previously frozen) from patients of reproductive age with regular menstrual cycles, who were undergoing diagnostic laparoscopic surgery for pain and/or infertility, were analysed. Samples were obtained from the menstrual (Days 1-5, n = 3), follicular (Days 6-14, n = 6), early luteal (Days 15-20, n = 5) and late luteal (Days 21-28, n = 5) phases. In addition, a total of 13 patient samples taken during the luteal phase were used to set up primary cell cultures for further experiments. PARTICIPANTS/MATERIALS, SETTING, METHODS: Quantitative real-time PCR (qRT-PCR), immunocytochemistry, Fura2-based Ca(2+)-microfluorimetry and whole-cell patch clamp experiments were performed to study the functional expression pattern of TRP channels. Specific pharmacological agents, such as Δ(9)-tetrahydrocannabinol, GSK1016790A and 1-oleoyl-2-acetyl-glycerol, were used to functionally assess the expression of TRPV2, TRPV4 and TRPC6, respectively. MAIN RESULTS AND THE ROLE OF CHANCE: Expression of TRPV2, TRPV4, TRPC1, TRPC4, TRPC6, TRPM4 and TRPM7 was detected at the mRNA level in endometrial biopsies (n = 19) and in primary endometrial stromal cell cultures obtained from patients during the luteal phase (n = 5) of the menstrual cycle. Messenger RNA levels of TRPV2, TRPC4 and TRPC6 were significantly increased (P < 0.01) in the late luteal phase compared with the early luteal phase. Immunocytochemistry experiments showed a positive staining for TRPV2, TRPV4, TRPC6 and TRPM7 in the plasma membrane and in the cytoplasm of primary endometrial stromal cells. Ca(2+)-microfluorimetry revealed significant increases (P < 0.001) in intracellular Ca(2+) levels when stromal cells were incubated with specific activators of TRPV2, TRPV4 and TRPC6. Further functional characterization was performed using whole-cell patch clamp experiments. Taken together, these data provide evidence for the functional activity of TRPV2, TRPV4, TRPC6 and TRPM7 channels in primary stromal cell cultures. LIMITATIONS, REASONS FOR CAUTION: Although mRNA levels are detected for TRPV6, TRPC1, TRPC4 and TRPM4, the limited supply of specific antibodies and lack of selective pharmacological agents restricted any additional analysis of these ion channels. WIDER IMPLICATIONS OF THE FINDINGS: Embryo implantation is a dynamic developmental process that integrates many signalling molecules into a precisely orchestrated programme. Our findings identified certain members of the TRP superfamily as candidate sensors in the epithelial-stromal crosstalk. These results are very helpful to unravel the signalling cascade required for successful embryo implantation. In addition, this knowledge could lead to new strategies to correct implantation failure and facilitate the development of novel non-hormonal contraceptives. STUDY FUNDING/ COMPETING INTERESTS: This work was supported by grants from the Research Foundation-Flanders (G.0856.13N to J.V.), the Research Council of the KU Leuven (OT/13/113 to J.V. and T.D. and PF-TRPLe to T.V.) and by the Planckaert-De Waele fund (to J.V.). K.D.C. and K.H. are funded by the FWO Belgium. None of the authors have a conflict of interest.

Frozen-thawed embryo transfer in a natural or mildly hormonally stimulated cycle in women with regular ovulatory cycles: a RCT.

STUDY QUESTION: Can ovarian stimulation with low dose hMG improve the implantation rate (IR) per frozen-thawed embryo transferred (FET) when compared with natural cycle in an FET programme in women with a regular ovulatory cycle? SUMMARY ANSWER: Both IR and live birth rate (LBR) per FET were similar in the group with mild ovarian stimulation and the natural cycle group. WHAT IS KNOWN ALREADY: Different cycle regimens for endometrial preparation are used prior to FET: spontaneous ovulatory cycles, cycles with artificial endometrial preparation using estrogen and progesterone hormones, and cycles stimulated with gonadotrophins or clomiphene citrate. At present, it is not clear which regimen results in the highest IR or LBR. More specifically, there are no RCTs in ovulatory women comparing reproductive outcome after FET during a natural cycle and during a hormonally stimulated cycle. STUDY DESIGN, SIZE, DURATION: A total of 410 women scheduled for FET during 579 cycles (December 2003-September 2013) were enrolled in an open-label RCT to natural cycle (NC FET group, n = 291) or to a cycle hormonally stimulated with s.c. gonadotrophins (hMG FET group, 37.5-75 IU per day, n = 288). A total of 672 embryos were transferred during 434 cycles (332 embryos and 213 cycles in the NC FET group; 340 embryos and 221 cycles in the hMG FET group). Assuming a = 0.05 and 80% power, it was calculated that 219 frozen-thawed embryos were required for transfer in each group to demonstrate a difference of 10% in IR. PARTICIPANTS/MATERIALS, SETTING, METHODS: Women were eligible according to the following inclusion criteria: regular ovulatory cycle, female age ≥21 years and ≤45 years, informed consent. FET cycles with preimplantation genetic screening were excluded. The primary outcome was IR per embryo transferred. Secondary outcomes included IR with fetal heart beat (FHB), LBR per embryo transferred and endometrial thickness on the day of hCG administration. Statistical analysis was by intention to treat and controlled for the presence of multiple measures, as eligible women could be randomized in more than one cycle. Chi-square and independent t-test were used to compare categorical and continuous variables. The relative risk (RR) was estimated using a Poisson model with log link. Hierarchical models with random intercepts for patient and cycle were considered to account for clustering of cycles within patients and of embryos within cycles. MAIN RESULTS AND THE ROLE OF CHANCE: The primary outcome, IR per embryo transferred, was not statistically different between the NC FET group (41/332 (12.35%)) and in the hMG FET group (55/340 (16.18%)) (RR 1.3 (95% confidence interval (CI) 0.9-2.0), P = 0.19). Similarly, the secondary outcome, IR with FHB per embryo transferred, was 34/332 (10.24%) in the NC FET group and 48/340 (14.12%) in the hMG FET group (RR 1.4 (95% CI 0.9-2.1), P = 0.15). The LBR per embryo transferred was 32/332 (9.64%) in the NC FET group and 45/340 (13.24%) in the hMG FET group (RR 1.4 (95% CI 0.9-2.2), P = 0.17). Endometrial thickness was also similar in both groups [8.9 (95% CI 8.7-9.1) in the NC FET group and 8.9 (95% CI 8.7-9.1) in the hMG FET group]. The duration of the follicular phase was significantly shorter (P < 0.001) in the hMG FET group [13.7 days (95% CI 13.2-14.2)] than in the NC FET group [15.4 days (95% CI 14.8-15.9)]. LIMITATIONS, REASONS FOR CAUTION: Randomization of cycles instead of patients; open-label design; relatively long period of recruitment. WIDER IMPLICATIONS OF THE FINDINGS: Our observation that the IR per embryo transferred is not significantly increased after FET during natural or gonadotrophin stimulated cycle, suggests that the effect of mild hormonal stimulation with gonadotrophins is smaller than what was considered clinically relevant with respect to reproductive outcome after FET. These data suggest that endometrial receptivity is not relevantly improved, but also not impaired after hormonal stimulation with gonadotrophins. Since FET during a natural cycle is cheaper and more patient-friendly, we recommend this regimen as the treatment of choice for women with regular cycles undergoing FET. TRIAL REGISTRATION NUMBER: clinicaltrials.gov NCT00492934. TRIAL REGISTRATION DATE: 26 June 2007. DATE OF FIRST PATIENT'S ENROLMENT: 1 December 2003.

Circulating microRNAs as Non-Invasive Biomarkers in Endometriosis Diagnosis-A Systematic Review.

The aim of this systematic review is to assess the power of circulating miRNAs as biomarkers as a diagnostic tool in endometriosis. In endometriosis-suspected women with uncertain imaging, the only way to confirm or exclude endometriosis with certainty is currently laparoscopy. This creates a need for non-invasive diagnostics. We searched the literature through the PubMed database using the Mesh terms 'endometriosis' and 'miRNAs'. Some, but limited, overlap was found between the 32 articles included, with a total of 20 miRNAs reported as dysregulated in endometriosis in two or more studies. MiR-17-5p was reported as dysregulated in six studies, followed by miR-451a and let-7b-5p in four studies and miR-20a-5p, miR-143-3p, miR-199a-5p and miR-3613-5p in three studies. Furthermore, a possible impact of the menstrual phase on miRNA expression was noted in five studies, while no influence of hormonal intake was observed in any included study. The modest reproducibility between studies may be attributable to biological variability as well as to the lack of universal protocols, resulting in pre- and analytical variability. Despite the identification of several suitable candidate biomarkers among the miRNAs, the need for high-quality studies with larger and well-defined population cohorts and the use of standardized protocols lingers.

FEMaLe: The use of machine learning for early diagnosis of endometriosis based on patient self-reported data-Study protocol of a multicenter trial.

INTRODUCTION: Endometriosis is a chronic disease that affects up to 190 million women and those assigned female at birth and remains unresolved mainly in terms of etiology and optimal therapy. It is defined by the presence of endometrium-like tissue outside the uterine cavity and is commonly associated with chronic pelvic pain, infertility, and decreased quality of life. Despite the availability of various screening methods (e.g., biomarkers, genomic analysis, imaging techniques) intended to replace the need for invasive surgery, the time to diagnosis remains in the range of 4 to 11 years. AIMS: This study aims to create a large prospective data bank using the Lucy mobile health application (Lucy app) and analyze patient profiles and structured clinical data. In addition, we will investigate the association of removed or restricted dietary components with quality of life, pain, and central pain sensitization. METHODS: A baseline and a longitudinal questionnaire in the Lucy app collects real-world, self-reported information on symptoms of endometriosis, socio-demographics, mental and physical health, economic factors, nutritional, and other lifestyle factors. 5,000 women with confirmed endometriosis and 5,000 women without diagnosed endometriosis in a control group will be enrolled and followed up for one year. With this information, any connections between recorded symptoms and endometriosis will be analyzed using machine learning. CONCLUSIONS: We aim to develop a phenotypic description of women with endometriosis by linking the collected data with existing registry-based information on endometriosis diagnosis, healthcare utilization, and big data approach. This may help to achieve earlier detection of endometriosis with pelvic pain and significantly reduce the current diagnostic delay. Additionally, we may identify dietary components that worsen the quality of life and pain in women with endometriosis, upon which we can create real-world data-based nutritional recommendations.

The use of a new gel foam for the evaluation of tubal patency.

AIMS: To evaluate the feasibility and the reliability of hysterosalpingo-foam sonography (HyFoSy) using gel foam in the assessment of tubal patency. METHODS: Nonrandomized, observational, academic and single-center study of 20 women being investigated because of subfertility and scheduled for a laparoscopy with chromopertubation. A detailed description of HyFoSy with a newly developed gel foam is given in the way it proved to be most efficient in our hands. The results of HyFoSy are compared to the data regarding tubal patency testing during laparoscopy by chromopertubation. RESULTS: All 20 HyFoSy were technically successful. Four of the 40 tubes, 1 right tube and 3 left tubes, were not patent at HyFoSy (3 tubes with proximal block and 1 tube with distal block). There was a 100% agreement between tubal patency data according to HyFoSy testing and laparoscopic chromopertubation testing. CONCLUSION: HyFoSy is both feasible and accurate in the diagnosis of tubal patency.