Despite occurring in up to 50% of the human population, menstruation is a fundamentally understudied process with limited treatment options when menstrual pathologies arise. Reasons for this deficit include the inherent ethical and technical constraints associated with researching menstruation. The multifactorial nature of many menstrual-related pathologies means in vivo research is necessary; however, this type of research is difficult in humans, and non-human species that menstruate naturally are often not suitable as research models. Consequently, most menstrual research relies on an artificially induced menstrual-like process in the non-menstruating laboratory mouse. This review investigates mouse models of menstruation and how specific technical variables are used to produce or modulate a menstrual-like process. The review describes two key categories of models, those that are ovariectomy-based versus those that are pseudopregnancy-based. The menstrual-like process occurring in these models varied slightly;the underlying reason for the variation is likely to be the method of progesterone withdrawal. Models that withdrew progesterone specifically had a far less rapid endometrial breakdown in comparison to those that withdrew all ovarian input. These outcomes suggest that a loss of ovarian factors other than progesterone is likely impacting the breakdown process. The review highlights the gaps in our understanding of the mechanisms of endometrial breakdown and repair in these proxies for menstruation and the subsequent impacts on any conclusions drawn from these models.

STUDY QUESTION:Can a panel of plasma protein biomarkers be identified to accurately and specifically diagnose endometriosis? SUMMARY ANSWER:A novel panel of 10 plasma protein biomarkers was identified and validated, demonstrating strong predictive accuracy for the diagnosis of endometriosis. WHAT IS KNOWN ALREADY:Endometriosis poses intricate medical challenges for affected individuals and their physicians, yet diagnosis currently takes an average of 7 years and normally requires invasive laparoscopy. Consequently, the need for a simple, accurate non-invasive diagnostic tool is paramount. STUDY DESIGN, SIZE, DURATION:This study compared 805 participants across two independent clinical populations, with the status of all endometriosis and symptomatic control samples confirmed by laparoscopy. A proteomics workflow was used to identify and validate plasma protein biomarkers for the diagnosis of endometriosis. PARTICIPANTS/MATERIALS, SETTING, METHODS:A proteomics discovery experiment identified candidate biomarkers before a targeted mass spectrometry assay was developed and used to compare plasma samples from 464 endometriosis cases, 153 general population controls, and 132 symptomatic controls. Three multivariate models were developed: Model 1 (logistic regression) for endometriosis cases versus general population controls, Model 2 (logistic regression) for rASRM stage II to IV (mild to severe) endometriosis cases versus symptomatic controls, and Model 3 (random forest) for stage IV (severe) endometriosis cases versus symptomatic controls. MAIN RESULTS AND THE ROLE OF CHANCE:A panel of 10 protein biomarkers were identified across the three models which added significant value to clinical factors. Model 3 (severe endometriosis vs symptomatic controls) performed the best with an area under the receiver operating characteristic curve (AUC) of 0.997 (95% CI 0.994-1.000). This model could also accurately distinguish symptomatic controls from early-stage endometriosis when applied to the remaining dataset (AUCs ≥0.85 for stage I to III endometriosis). Model 1 also demonstrated strong predictive performance with an AUC of 0.993 (95% CI 0.988-0.998), while Model 2 achieved an AUC of 0.729 (95% CI 0.676-0.783). LIMITATIONS, REASONS FOR CAUTION:The study participants were mostly of European ethnicity and the results may be biased from undiagnosed endometriosis in controls. Further analysis is required to enable the generalizability of the findings to other populations and settings. WIDER IMPLICATIONS OF THE FINDINGS:In combination, these plasma protein biomarkers and resulting diagnostic models represent a potential new tool for the non-invasive diagnosis of endometriosis. STUDY FUNDING/COMPETING INTEREST(S):Subject recruitment at The Royal Women's Hospital, Melbourne, was supported in part by funding from the Australian National Health and Medical Research Council (NHMRC) project grants GNT1105321 and GNT1026033 and Australian Medical Research Future Fund grant no. MRF1199715 (P.A.W.R., S.H.-C., and M.H.). Proteomics International has filed patent WO 2021/184060 A1 that relates to endometriosis biomarkers described in this manuscript; S.B., R.L., and T.C. declare an interest in this patent. J.I., S.B., C.L., D.I., H.L., K.P., M.D., M.M., M.R., P.T., R.L., and T.C. are shareholders in Proteomics International. Otherwise, the authors have no conflicts of interest. TRIAL REGISTRATION NUMBER:N/A.

BACKGROUND:Despite surgical and pharmacological interventions, endometriosis can recur. Reliable information regarding risk of recurrence following a first diagnosis is scant. The aim of this study was to examine clinical and survey data in the setting of disease recurrence to identify predictors of risk of endometriosis recurrence. METHODS:This observational study reviewed data from 794 patients having surgery for pelvic pain or endometriosis. Patients were stratified into two analytic groups based on self-reported or surgically confirmed recurrent endometriosis. Statistical analyses included univariate, followed by multivariate logistic regression to identify risk factors of recurrence, with least absolute shrinkage and selection operator (Lasso) regularisation. Risk-calibrated Supersparse Linear Integer Models (RiskSLIM) and survival analyses (with Lasso) were undertaken to identify predictive features of recurrence. RESULTS:Several significant features were repeatedly identified in association with recurrence, including adhesions, high rASRM score, deep disease, bowel lesions, adenomyosis, emergency room attendance for pelvic pain, younger age at menarche, higher gravidity, high blood pressure and older age. In the surgically confirmed group, with a score of 5, the RiskSLIM method was able to predict the risk of recurrence (compared to a single diagnosis) at 95.3% and included adenomyosis and adhesions in the model. Survival analysis further highlighted bowel lesions, adhesions and adenomyosis. CONCLUSIONS:Following an initial diagnosis of endometriosis, clinical decision-making regarding disease management should take into consideration the presence of bowel lesions, adhesions and adenomyosis, which increase the risk of endometriosis recurrence.

INTRODUCTION:Dysmenorrhea is the most common cause of gynecological pain among women that has considerable impact on quality of life and psychosocial wellbeing. Non-steroidal anti-inflammatory drugs (NSAIDs) and hormonal therapies are most commonly used to treat dysmenorrhea. However, given these drugs are often associated with bothersome side effects and are less effective when there is an underlying cause contributing to dysmenorrhea (e.g. endometriosis), a patient-centered approach to managing dysmenorrhea is important. Various new drugs are currently being investigated for the treatment of primary and secondary dysmenorrhea.AREAS COVERED:This review provides an updated overview on new therapeutic targets and investigational drugs for the treatment of primary and secondary dysmenorrhea. The authors describe the clinical development and implications of these drugs.EXPERT OPINION:Among the investigative drugs discussed in this review, anti-inflammatories show the most promising results for the treatment of dysmenorrhea. However, given some trials have considerable methodological limitations, many drugs cannot be currently recommended. Research focused on understanding the mechanisms involved in menstruation and its associated symptoms will be important to identify new therapeutic targets for dysmenorrhea. Further robust clinical trials are required to better understand the efficacy and safety of investigational drugs for treating primary and secondary dysmenorrhea.

Research question Is the expression of steroid hormone receptors (oestrogen receptor-α and progesterone receptor A/B) and proliferative markers (Bcl-2 and Ki67) uniform among superficial peritoneal endometriotic lesions? Design A retrospective cohort study of 24 patients with surgically and histologically confirmed endometriosis. Immunofluorescence was used to determine the proportion of oestrogen receptor-α (ERα), progesterone receptor A/B, Bcl-2 and Ki67 positive cells in 271 endometriotic lesions (defined as endometriotic gland profile/s within an individual region of CD10 stromal immunostaining from a single biopsy) from 67 endometriotic biopsies from 24 patients. Data were analysed to examine associations related to menstrual cycle stage, lesion location and gland morphology. Results Oestrogen receptor-α and progesterone receptor A/B expression in superficial peritoneal endometriotic lesions was extremely heterogeneous. Bcl-2 immunostaining in endometriotic lesions was also variable, whereas Ki67 immunostaining was minimal. Menstrual cycle stage associations were limited in steroid hormone receptor and Bcl-2 expression in lesions. Patterns in progesterone receptor A/B and Bcl-2 immunostaining were associated with lesion location. Bcl-2 was differentially expressed, based on lesion gland morphology. Conclusions These data demonstrate considerable diversity in the expression of steroid hormone receptors and Bcl-2 between lesions, even within an individual patient.

Pacific young people living in Aotearoa New Zealand experience disparities in their sexual and reproductive health outcomes, thought to stem from cultural differences and educational inequities. Although these barriers have been characterised in literature, their influence on Pacific youth's understandings of sexual and reproductive health have been relatively unexplored. This study investigated the sexual and reproductive health knowledge of Pacific students enrolled at a university in Aotearoa New Zealand in 2020 and where they gained this knowledge. The study used the theoretical framework of the (revitalised) Fonofale health model and was guided by the Kakala research methodology. Data were collected by means of an online survey comprised of open-ended questions and Likert scales, completed by eighty-one eligible students. Open-ended questions were analysed for general themes and responses to Likert scale items are reported using descriptive statistical analysis. The study found that Pacific youth have strong foundations of health knowledge that is heavily influenced by Polynesian cultural beliefs. Both formal and non-formal learning environments were important in developing participants' health knowledge of these topics and for encouraging independent help-seeking behaviours. This is the first reported study to investigate the sexual and reproductive health knowledges of a pan-Pacific tertiary cohort of young people.

INTRODUCTION:Endometriosis is an under-researched disease, with Aotearoa-specific data severely lacking. Current estimates of parameters such as rates of endometriosis diagnosis, indication for surgery and sites of disease are based on international data. There is currently no published data on endometriosis surgeries in Aotearoa New Zealand. AIMS:We aimed to describe the laparoscopic surgeries conducted for suspected endometriosis at Te Whatu Ora - Capital and Coast, including the prevalence of endometriosis in this cohort, indication for surgery, symptoms experienced, endometriosis stage and sites involved, number of repeat laparoscopies, and prevalence of endometriosis at repeat surgery. MATERIALS AND METHODS:To conduct this retrospective cross-sectional study, data were extracted from Te Whatu Ora - Capital and Coast systems to identify all records indicating surgery for suspected endometriosis during 2018 and 2019. Variables investigated included age, ethnicity, endometriosis diagnosis (International Classification of Diseases-10 Clinical Modification coding), stage of endometriosis, histological report and endometriosis symptoms (pain and/or fertility). RESULTS:There were 436 surgeries for suspected endometriosis performed during 2018 and 2019, and endometriosis was diagnosed in 68.3% of these surgeries. Pacific and Asian people were under-represented in the study cohort compared to the demographics of the hospital catchment area (Pacific: 3.0% vs 8.4%, Asian: 9.9% vs 12.9%). The most common indication for surgery was pain. There were 76 surgeries performed for suspected recurrence of endometriosis, and endometriosis was identified in 55.6% of these. CONCLUSIONS:Endometriosis surgeries in this hospital in Aotearoa show similar presentations and surgical findings to international data. Our findings highlight areas requiring more research in an Aotearoa-specific context.

The pathophysiology of endometriosis is underpinned by a complex interplay of inflammatory processes that are responsible for the local and systemic effects of the condition. Recent studies delve further into this inflammatory interplay; using animal models, they identify potential therapeutic tools and remind us to look beyond the endometriotic lesions.

OBJECTIVE:The aim of this study is to identify and explore the unmet needs of adolescents and young adults living with endometriosis. DESIGN:An open-ended online survey was conducted, with questions derived from prior research looking at areas of unmet need in healthcare, career and work, financial, information, psychological, social and cultural domains. SETTING AND POPULATION:Self-selecting 18-25 year olds with surgically diagnosed endometriosis (self-reported) currently living in Australia were included as participants. METHODS:Invitation to participate in an open-ended online survey was shared through the social media of Australian endometriosis organisations and the Royal Women's Hospital, Melbourne. Surveys were analysed qualitatively through template analysis. MAIN OUTCOME MEASURES:Recording of the unmet supportive care needs of this population was carried out. RESULTS:One hundred and thirty-one respondents fit the eligibility criteria of being aged 18-25 years (median age 23 years). Most were born in Australia (94%), university-educated (54%) and lived in a metropolitan setting (69%). There was a range of unmet needs that were presented across education, work, healthcare and relationships. Group-specific challenges were identified: doctors either over- or underemphasising future fertility; disrupted sexual and romantic life due to painful sex; managing pain in the classroom and workplace where periods are taboo; and being gender-queer in gynaecological medical spaces. CONCLUSIONS:The increasingly young age at which patients are receiving an endometriosis diagnosis precipitates a shift in patient care. The treatment decisions that are being made must be reflective of the unique needs of the adolescents who carry the burden of the disease. Clinicians are advised to be aware of and discuss needs with their patients. PATIENT OR PUBLIC CONTRIBUTION:The nine open-ended questions in this survey were developed from data from a preliminary series of interviews with endometriosis patients in a tertiary women's healthcare centre. In asking these data-informed questions to the online endometriosis community, patients across broader sociocultural demographics and disease states (including less symptomatic endometriosis) have provided a broader understanding of their supportive care needs.

aim: This study aimed to understand the role that menstrual apps ('' period tracking apps '' or '' fertility apps '') could perform in healthcare. methods: Expert stakeholders including healthcare providers, app users, and patients offered perspectives on potential benefits, concerns, and role of apps in healthcare. Responses from an online qualitative survey (N=144) and three online focus groups (N=10) were analysed using reflexive thematic analysis. results: The role of menstrual apps in healthcare could include keeping a record of cycle dates and symptoms and assisting in the management of menstrual disorders, diseases and conditions linked to the menstrual cycle such as endometriosis, PCOS, infertility, and perimenopause. Respondents are using app calendars and symptom tracking to improve communication between healthcare providers and patients, while also expressing concerns about inaccuracies and other uses of data. Respondents wished for assistance in managing their health, while noting that apps currently are limited and suggesting that apps need to be better suited to Aotearoa New Zealand specific menstrual disorders, diseases and life stages. conclusions: Menstrual apps may have a role in healthcare, but further research needs to develop and evaluate app functions and accuracy as well as providing education and guidelines for whether and when apps are appropriate for healthcare.

Natural variability in menstrual cycle length, coupled with rapid changes in endometrial gene expression, makes it difficult to accurately define and compare different stages of the endometrial cycle. Here we develop and validate a method for precisely determining endometrial cycle stage based on global gene expression. Our ‘molecular staging model’ reveals significant and remarkably synchronised daily changes in expression for over 3400 endometrial genes throughout the cycle, with the most dramatic changes occurring during the secretory phase. Our study significantly extends existing data on the endometrial transcriptome, and for the first time enables identification of differentially expressed endometrial genes with increasing age and different ethnicities. It also allows reinterpretation of all endometrial RNA-seq and array data that has been published to date. Our molecular staging model will significantly advance understanding of endometrial-related disorders that affect nearly all women at some stage of their lives, such as heavy menstrual bleeding, endometriosis, adenomyosis, and recurrent implantation failure.

Currently, our understanding of hormonal regulation within the female reproductive system is largely based on our knowledge of estrogen and progesterone signalling. However, while the important functions of androgens in male physiology are well known, it is also recognized that androgens play critical roles in the female reproductive system. Further, androgen signalling is altered in a variety of gynaecological conditions, including endometriosis and polycystic ovary syndrome, indicative of regulatory roles in endometrial and ovarian function. Co-regulatory mechanisms exist between different androgens, estrogens, and progesterone, resulting in a complex network of steroid hormone interactions. Evidence from animal knockout studies, in vitro experiments, and human data indicate that androgen receptor expression is cell-specific and menstrual cycle stage-dependent, with important regulatory roles in the menstrual cycle, endometrial biology, and follicular development in the ovaries. This review will discuss the expression and co-regulatory interactions of androgen receptors, highlighting the complexity of the androgen signalling pathway in the endometrium and ovaries, and the synthesis of androgens from additional alternative pathways previously disregarded as male-specific. Moreover, it will illustrate the challenges faced when studying androgens in female biology, and the need for a more in-depth, integrative view of androgen metabolism and signalling in the female reproductive system.

This review leads the 2023 Call for Papers in MHR: 'Cyclical function of the female reproductive tract' and will outline the complex and fascinating changes that take place in the reproductive tract during the menstrual cycle. We will also explore associated reproductive tract abnormalities that impact or are impacted by the menstrual cycle. Between menarche and menopause, women and people who menstruate living in high-income countries can expect to experience ∼450 menstrual cycles. The primary function of the menstrual cycle is to prepare the reproductive system for pregnancy in the event of fertilization. In the absence of pregnancy, ovarian hormone levels fall, triggering the end of the menstrual cycle and onset of menstruation. We have chosen to exclude the ovaries and focus on the other structures that make up the reproductive tract: uterine tubes, endometrium, myometrium, and cervix, which also functionally change in response to fluctuations in ovarian hormone production across the menstrual cycle. This inaugural paper for the 2023 MHR special collection will discuss our current understanding of the normal physiological processes involved in uterine cyclicity (limited specifically to the uterine tubes, endometrium, myometrium, and cervix) in humans, and other mammals where relevant. We will emphasize where knowledge gaps exist and highlight the impact that reproductive tract and uterine cycle perturbations have on health and fertility.

Background and Aims: Although opposing risk factors have been proposed for mate kirikōpū/endometriosis (oestrogen-dependence) and huahua hua kūao/polycystic ovary syndrome (PCOS; androgen dependence), there is a cohort of individuals with both endometriosis and PCOS. We propose that disease comorbidity will alter symptom profiles in comparison to those with only one disease, and that analysis of these differential profiles may hint at underlying mechanisms of disease pathology. Methods: An anonymous online survey was distributed via social media (NZ residents, >18 years) and included questions related to diagnosis, symptoms, treatment and management of endometriosis and/or PCOS. Results: In total, 1323 responses (median [range] = 31 years [18–72]) were received within a two-week period (endometriosis only: n=615, 48%; PCOS only: n=459, 35%; both diseases: n=247, 19%). When asked about symptoms ‘ever experienced’, comorbid individuals report both symptoms commonly ascribed to endometriosis (e.g, dysmenorrhea) as well as those ascribed to PCOS (e.g., irregular periods) thereby exacerbating impacts on quality of life. An exception, the proportion of individuals reporting absent menstrual periods was increased in cormobid individuals (45%) relative to those with endometriosis only (21%), but decreased relative to those with PCOS only (67%), suggesting a more complex interaction between the two diseases. Conclusions: These data highlight the heterogenity of disease phenotype in individuals with endometriosis and/or PCOS. We suggest that an understanding of the intersection of these two common diseases, and a recognition of the associated phenotypic diversity, will provide avenues of research to better understand the pathophysiology of both endometriosis and PCOS.

Endometriosis is a common condition associated with debilitating pelvic pain and infertility. A genome-wide association study meta-analysis, including 60,674 cases and 701,926 controls of European and East Asian descent, identified 42 genome-wide significant loci comprising 49 distinct association signals. Effect sizes were largest for stage 3/4 disease, driven by ovarian endometriosis. Identified signals explained up to 5.01% of disease variance and regulated expression or methylation of genes in endometrium and blood, many of which were associated with pain perception/maintenance (SRP14/BMF, GDAP1, MLLT10, BSN and NGF). We observed significant genetic correlations between endometriosis and 11 pain conditions, including migraine, back and multisite chronic pain (MCP), as well as inflammatory conditions, including asthma and osteoarthritis. Multitrait genetic analyses identified substantial sharing of variants associated with endometriosis and MCP/migraine. Targeted investigations of genetically regulated mechanisms shared between endometriosis and other pain conditions are needed to aid the development of new treatments and facilitate early symptomatic intervention. Meta-analyses of genome-wide association studies for endometriosis identify 49 distinct association signals. Fine-mapping of causal variants explores functional effects across various tissues. Genetic correlations between endometriosis and other pain conditions are also highlighted.

Research question: Do different subtypes of superficial peritoneal endometriotic lesions exist, based on the presence and morphology of smooth muscle, collagen fibres and immune cell populations? Design: A retrospective cohort study of 24 patients, from across the menstrual cycle, with surgically and histologically confirmed endometriosis. Immunofluorescence was used to delineate the CD10 stromal area of lesions (n = 271 lesions from 67 endometriotic biopsies), and then smooth muscle actin (SMA) positive tissue and immune cell populations (CD45+ and CD68+) were quantified within and adjacent to these lesions. Second harmonic generation microscopy was used to evaluate the presence and morphology of type -1 collagen fibres within and surrounding lesions. Results: Overall, immune cell numbers and the area of SMA and collagen within endometriotic lesions tended to be low, but a spectrum of presentations significantly varied, particularly in the adjacent tissue microenvironment, based on lesion locations, the morphology of endometriotic gland profiles, or both. Lesions in which collagen fibres formed well aligned capsules around the CD10+ stromal border were identified compared with lesions in which collagen fibre distribution was random. Considerable inter- and intra-patient variability in the morphology of SMA and collagen was observed within and surrounding lesions. Conclusion: These data demonstrate considerable diversity in the presence of immune cells and morphology of SMA and collagen within, but even more so, surrounding endometriotic lesions, even within individual patients. This heterogeneity, especially within individual patients, presents a challenge to incorporating these cell and tissue types into any new endometriosis classification systems or prognostic approaches.

Chronic pelvic pain (CPP) causes important negative effects on quality of life. Endometriosis is the most common cause of CPP in females, and diagnostic delay is over six years internationally. Data remain scarce for CPP impact or diagnostic delay in Aotearoa New Zealand. This study used an online survey to explore the impact of CPP on various life domains for those aged over 18. Additionally, for those with an endometriosis diagnosis, diagnostic delay and factors affecting this over time were explored. There were 800 respondent (620 with self-reported endometriosis). CPP symptoms, irrespective of final diagnosis, started prior to age 20 and negatively impacted multiple life domains including employment, education, and relationships. Mean diagnostic delay for those with endometriosis was 8.7 years, including 2.9 years between symptom onset and first presentation and 5.8 years between first presentation and diagnosis. Five doctors on average were seen prior to diagnosis. However, there was a reduction in the interval between first presentation and diagnosis over time, from 8.4 years for those presenting before 2005, to two years for those presenting after 2012. While diagnostic delay is decreasing, CPP, irrespective of aetiology, continues to have a significant negative impact on the lives of those affected.

Graphical abstract Abstract Endometriosis is a common yet under-recognised chronic disease with one in nine (more than 830,000) women and those assigned female at birth diagnosed with endometriosis by the age of 44 years in Australia. In 2018, Australia was the first country to develop a roadmap and blueprint to tackle endometriosis in a nationwide, coordinated manner. This blueprint is outlined in the National Action Plan for Endometriosis (NAPE), created from a partnership between government, endometriosis experts and advocacy groups. The NAPE aims to improve patient outcomes in the areas of awareness and education, clinical management and care and research. As researchers and clinicians are working to improve the lives of those with endometriosis, we discuss our experiences since the launch of the plan to highlight areas of consideration by other countries when developing research priorities and clinical plans. Historically, major barriers for those with endometriosis have been twofold; first, obtaining a diagnosis and secondly, effective symptom management post-diagnosis. In recent years, there have been calls to move away from the historically accepted ‘gold-standard’ surgical diagnosis and single-provider specialist care. As there are currently no reliable biomarkers for endometriosis diagnosis, specialist endometriosis scans and MRI incorporating artificial intelligence offer a novel method of visualisation and promising affordable non-invasive diagnostic tool incorporating well-established technologies. The recognised challenges of ongoing pain and symptom management, a holistic interdisciplinary care approach and access to a chronic disease management plan, could lead to improved patient outcomes while reducing healthcare costs. Lay summary Endometriosis is a chronic disease where tissue like the lining of the uterus is found in other locations around the body. For the 830,000 people living with endometriosis in Australia, this often results in an immense burden on all aspects of daily life. In 2018, Australia was the first country to introduce a roadmap and blueprint to tackle endometriosis in a nationwide coordinated manner with the National Action Plan for Endometriosis. This plan was created as a partnership between government, endometriosis experts and advocacy groups. There are several other countries who are now considering similar plans to address the burden of endometriosis. As researchers and clinicians are working to improve the lives of those with endometriosis, we share our experiences and discuss areas that should be considered when developing these national plans, including diagnostic pathways without the need for surgery, and building new centres of expertise in Endometriosis and Pelvic Pain.

Chronic pelvic pain (CPP) causes important negative effects on quality of life. Endometriosis is the most common cause of CPP in females, and diagnostic delay is over six years internationally. Data remain scarce for CPP impact or diagnostic delay in Aotearoa New Zealand. This study used an online survey to explore the impact of CPP on various life domains for those aged over 18. Additionally, for those with an endometriosis diagnosis, diagnostic delay and factors affecting this over time were explored. There were 800 respondent (620 with self-reported endometriosis). CPP symptoms, irrespective of final diagnosis, started prior to age 20 and negatively impacted multiple life domains including employment, education, and relationships. Mean diagnostic delay for those with endometriosis was 8.7 years, including 2.9 years between symptom onset and first presentation and 5.8 years between first presentation and diagnosis. Five doctors on average were seen prior to diagnosis. However, there was a reduction in the interval between first presentation and diagnosis over time, from 8.4 years for those presenting before 2005, to two years for those presenting after 2012. While diagnostic delay is decreasing, CPP, irrespective of aetiology, continues to have a significant negative impact on the lives of those affected.