General Gynecology · Pelvic Pain
Abstract
Endometriosis is an enigmatic, painful, complex disease that affects approximately 1 million people in Canada. The disease can involve multiple organ systems, often resulting in debilitating chronic pain and infertility. Social, medical, geographic, and other factors are implicated in years-long diagnostic delays and may limit access to care. An integrated approach from bench to bedside to community is urgently required. A pan-Canadian collaboration among patients, clinicians and researchers will improve endometriosis awareness, provide best practices, and link research across Canada.
Topics
By this author
Mid-Cycle Pain in Endometriosis: Clinical Correlations and Potential Etiological Factors
Rojas HE et al., 2026 · Journal of women's health (2002)
To characterize differences between individuals with and without mid-cycle pain in a registry cohort with endometriosis. Prospective analysis of data from the Endometriosis Pelvic Pain Interdisciplinary Cohort Data Registry (Clinicaltrials.gov #NCT02911090) at a tertiary referral center in Western Canada. Three hundred forty-five individuals aged 18-49 years who: (1) had at least one episode of menstrual bleeding in the last 3 months, (2) attended a baseline initial visit, and (3) subsequently had surgery with histological confirmation of endometriosis between January 2018 and December 2023. Exclusion criteria included (1) previous hysterectomy; (2) hormonal suppressive therapy use in the last 3 months; and (3) missing data on mid-cycle pain, history of hormonal therapy use, or menstrual cycle regularity. N/A. Mid-cycle pain in the last month versus No mid-cycle pain in the last month. Of the 345 participants, 67% (n = 232) reported mid-cycle pain in the last month. Mid-cycle pain in the last month was significantly associated with higher mean Central Sensitization Inventory score (48 ± 17 versus 36 ± 16, p < 0.001) and more months of prior hormonal suppressive therapy use (58 [14-120] versus 26 [0-109], p = 0.012). Abnormal anatomy at the time of surgery (e.g., endometrioma, ovarian adhesions) was not associated with mid-cycle pain in the last month. In this endometriosis cohort at a tertiary referral center, most participants reported mid-cycle pain in the last month, which was associated with central sensitization but was not clearly related to endometriosis anatomical distortion.
Effectiveness · Comparative Effectiveness
Validating ovulation prediction and confirmation with the Mira monitor: blinded ultrasound and serum hormone comparison
Bouchard TP et al., 2026 · Reproductive biomedicine online · Free to read
Do quantitative urinary hormone measurements on the Mira monitor predict and confirm ovulation accurately compared with ultrasound in women with regular menstrual cycles? Do Mira urine hormones correlate with serum hormones? This was a prospective, single-centre, blinded diagnostic accuracy study with 52 women aged 19-44 years with regular cycles (24-38 days) who tracked 153 cycles over 18 months. Daily first-morning urine was tested with the Mira monitor for follicle stimulating hormone (FSH), oestrone-3-glucuronide (E13G), luteinizing hormone (LH) and pregnanediol glucuronide (PDG). Serial transvaginal ultrasounds (890 scans) confirmed the day of ovulation. Serum hormones were measured twice per cycle. The 121 ovulatory cycles from 49 participants with sufficient index test and reference standard data were included in the final analysis. The Mira LH peak day strongly predicted ultrasound-confirmed ovulation (R² = 0.96, P < 0.001; intraclass correlation coefficient = 0.971), with 96% of ovulations occurring within ±1 day. The Mira PDG increase was also strongly associated with ultrasound-confirmed day of ovulation (R² = 0.87, P < 0.001). First-morning urine hormones were significantly associated with serum hormones when collected within 90 min (LH: R² = 0.92; E13G: R² = 0.73; R² = 0.61; R² = 0.75). Anovulatory cycles were identified in 11% of regularly cycling participants. Quantitative urinary hormone monitoring with the Mira monitor provides accurate prediction and confirmation of ovulation, with strong urine-serum associations supporting reduced reliance on serial serum draws in select patients. These findings support clinical adoption of quantitative urinary fertility monitoring.
Early Pregnancy · Miscarriage
Impact of the coronavirus disease-2019 (COVID-19) pandemic on reproductive outcomes in patients with recurrent pregnancy loss
Balachandran S et al., 2026 · Journal of obstetrics and gynaecology Canada : JOGC = Journal d'obstetrique et gynecologie du Canada : JOGC
To assess the impact of the COVID-19 pandemic on reproductive outcomes in patients with recurrent pregnancy loss (RPL) and the influence of material and social deprivation on these outcomes. This retrospective cohort study included RPL patients seen at a specialized clinic between March 1, 2018, and February 28, 2022. Patients were categorized into two groups based on care period: pre-pandemic (March 1, 2018-February 29, 2020) and pandemic (March 1, 2020-February 28, 2022). Cumulative probabilities of birth were estimated using the cumulative incidence function within a competing risk framework, treating pregnancy loss as a competing event. Fine and Gray regression models calculated sub-distribution hazard ratio (sHR) of birth. 544 patients were included in the study, with 255 in the pre-pandemic group and 289 in the pandemic group. Individuals in the pandemic group were less likely to achieve pregnancy than those in the pre-pandemic group (relative risk = 0.50, 95% confidence interval [CI] 0.39 - 0.66). Among those who conceived, the cumulative probability of live birth was 0.77 in both groups. Relative to individuals residing in high-social deprivation neighborhoods, those living in moderately deprived areas had higher sub-distribution hazards of live birth (adjusted sHR = 1.97, 95% CI 1.25 - 3.10; P = 0.003). Within specialized RPL care and a universal maternity care system, pregnancy rates were lower during the first two years of the COVID-19 pandemic. However, among those who conceived, the probability of achieving a live birth remained similar between the pre-pandemic and pandemic periods.
Ultrasound · Follicular Monitoring
Using corpus luteum formation with dominant follicle collapse to improve the criteria for identifying ovulation
Bouchard TP et al., 2026 · Reproductive biomedicine online · Free to read
Does formation of the corpus luteum help to identify the day of ovulation on ultrasound when follicular collapse is missed, and how reliable are sonographers versus a review panel in identifying the day of ovulation on ultrasound? Sonographers in a clinic in Canada performed serial endovaginal ultrasound scans (six to eight per cycle) to identify the day of ovulation in regularly cycling women (n = 40) who were followed for one to five cycles (n = 85). The day of ovulation was identified by: (i) identification of the dominant follicle; (ii) disappearance of the dominant follicle; and (iii) identification and dating of the corpus luteum. The main outcome measures were inter-rater reliability between two sonographers, and Bland-Altman agreement between the supervising sonographer and a panel that reviewed each scan to identify the day of ovulation. Of the 85 menstrual cycles reviewed, two cycles did not have sufficient data to date ovulation, one cycle showed an incidental dermoid cyst, and 11 cycles showed anovulatory patterns. This left a total of 71 cycles (84%) for which intra-rater reliability between two sonographers for identifying the day of ovulation was high (intraclass correlation coefficient = 0.99, P < 0.0001), and Bland-Altman agreement showed no significant difference in the estimated day of ovulation between the supervising sonographer and the panel (t = -0.28, P = 0.78). Corpus luteum criteria were necessary to help identify the day of ovulation in 14 of 71 cycles (20%). The estimated day of ovulation can be determined reliably on ultrasound by trained sonographers using collapse of the dominant follicle and formation of the corpus luteum based on six to eight scans per cycle.
Related research
Pelvic Pain · Chronic Pelvic Pain
Clinical diagnosis of endometriosis: a call to action
Agarwal SK et al., 2019 · American Journal of Obstetrics and Gynecology · Free to read
Endometriosis can have a profound impact on women's lives, including associated pain, infertility, decreased quality of life, and interference with daily life, relationships, and livelihood. The first step in alleviating these adverse sequelae is to diagnose the underlying condition. For many women, the journey to endometriosis diagnosis is long and fraught with barriers and misdiagnoses. Inherent challenges include a gold standard based on an invasive surgical procedure (laparoscopy) and diverse symptomatology, contributing to the well-established delay of 4-11 years from first symptom onset to surgical diagnosis. We believe that remedying the diagnostic delay requires increased patient education and timely referral to a women's healthcare provider and a shift in physician approach to the disorder. Endometriosis should be approached as a chronic, systemic, inflammatory, and heterogeneous disease that presents with symptoms of pelvic pain and/or infertility, rather than focusing primarily on surgical findings and pelvic lesions. Using this approach, symptoms, signs, and clinical findings of endometriosis are anticipated to become the main drivers of clinical diagnosis and earlier intervention. Combining these factors into a practical algorithm is expected to simplify endometriosis diagnosis and make the process accessible to more clinicians and patients, culminating in earlier effective management. The time has come to bridge disparities and to minimize delays in endometriosis diagnosis and treatment for the benefit of women worldwide.
Guidelines by Clinical Area · Gynecologic Guidelines
Guideline No. 449: Diagnosis and Impact of Endometriosis - A Canadian Guideline
Singh SS et al., 2024 · Journal of obstetrics and gynaecology Canada : JOGC = Journal d'obstetrique et gynecologie du Canada : JOGC
To provide a contemporary approach to the understanding of the impact and methods for the diagnosis of endometriosis in Canada. Individuals, families, communities, health care providers, and health care administrators who are affected by, care for patients with, or manage delivery of services for endometriosis. The diagnosis of endometriosis is facilitated by a detailed history, examination, and imaging tests with providers who are experienced in endometriosis care. Surgical evaluation with pathology confirms a diagnosis of endometriosis; however, it is not required for those whose diagnosis was confirmed with imaging. There is a need to address earlier recognition of endometriosis to facilitate timely access to care and support. Education directed at the public, affected individuals and families, health care providers, and health care administrators are essential to reduce delays in diagnosis and treatment. BENEFITS, HARMS, Increased awareness and education about the impact and approach to diagnosis may support timely access to care for patients and families affected by endometriosis. Earlier and appropriate care may support a reduced health care system burden; however, improved clinical evaluation may require initial investments. Each section was reviewed with a unique search strategy representative of the evidence available in the literature related to the area of focus. The literature searches for each section of this guideline are listed in Appendix A and include information from published systematic reviews described in the text. The recommendations were developed following two rounds of review by a national expert panel through an iterative 2-year consensus process. Further details on the process are shared in Appendix B. The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See Appendix C (Table C1 for definitions and Table C2 for interpretations of strong and conditional recommendations). This guideline is intended to support health care providers and policymakers involved in the care of those impacted by endometriosis and the systems required to support them. Endometriosis impact and diagnosis updated guidelines for Canadian health care providers and policymakers. RECOMMENDATIONS.
Diagnosis · Staging and Classification
Comprehensive Review of Endometriosis Care
Carey ET et al., 2025 · Obstetrics & Gynecology
Endometriosis is an estrogen-dependent, chronic inflammatory disorder characterized by the presence of endometrium-like tissue outside the uterus, affecting approximately 10% of individuals of reproductive age. It contributes to chronic pelvic pain, dysmenorrhea, and subfertility, resulting in substantial societal economic burdens. Genetic and environmental risk factors have been identified, and recent research suggests that endometriosis functions as a systemic disease affecting nonreproductive systems and increasing susceptibility to other health conditions. Various phenotypes-superficial peritoneal endometriosis, ovarian endometriomas, and deep endometriosis-may develop under different mechanisms, yet the relationship between these presentations remains unclear. Diagnosis relies on clinical evaluation, imaging, and surgical staging, and the advent of advanced ultrasonography and magnetic resonance imaging has helped to enhance accuracy. Although medical management focuses on hormonal modulation to alleviate symptoms, surgical intervention remains a critical tool for refractory symptoms. Postoperative care and patient education are essential to manage recurrence and to improve quality of life. Current research emphasizes the need for comprehensive, interdisciplinary approaches to endometriosis management, incorporating novel diagnostic tools, diverse therapeutic avenues, and patient-centered care models. Addressing disparities in treatment access is essential to improving outcomes. To achieve this, recruiting and analyzing data from racially, socioeconomically, and geographically diverse cohorts will reveal how disease presentation and treatment efficacy vary across populations. Continued efforts in research and health care policy are necessary to develop effective and personalized strategies in managing endometriosis.
Cost of Care · Treatment Costs
Hospital-Associated Cost of Endometriosis in Canada: A Population-Based Study
Chen I et al., 2020 · Journal of minimally invasive gynecology
To describe the hospital-associated cost of endometriosis in Canada from April 2008 to March 2013. Population-based descriptive study. Canada, with the exception of the province of Quebec. All women aged 15 to 59 years discharged with endometriosis between April 2008 and March 2013. None. Over 5 years, 47 021 women were admitted for endometriosis, resulting in a total hospital cost of Canadian dollars (CaD) $152.21 million (US dollars [US $] 147.79 million) and per-case cost of CaD $3237 (US $3143). Uterine endometriosis accounted for 28.29% of cases, ovarian endometriosis 27.44%, and other endometriosis 44.27%. Cost for uterine endometriosis was the highest at CaD $4137 (US $4017) per case, followed by ovarian endometriosis (CaD $3506; US $3404) and other endometriosis (CaD $2495; US $2422). The highest number of cases were in the groups aged 35 to 39 years (20.77%) and 40 to 44 years (20.44%). Hysterectomy accounted for 29.57% of surgical procedures. Encounters with hysterectomy were the costliest at CaD $5062 (US $4915) per case, followed by the ones with other surgical procedures at CaD $2477 (US $2405) per case, and admissions with no surgical procedure at CaD $2164 (US $2101) per case. The hospital cost associated with endometriosis was approximately CaD $30 million (US $29.56 million) per year, whereas uterine endometriosis, hysterectomy, and older age were found to have a higher average cost per case. Although this study focuses specifically on hospital admission and does not account for outpatient costs or indirect costs, it nonetheless highlights the economic burden of this debilitating disease on Canadian society during the study period.
General Gynecology › Pelvic Pain › Chronic Pelvic Pain · Endometriosis › Diagnosis › Diagnostic Delay
Kate J Wahl, Paul J Yong, Philippa Bridge-Cook, Catherine Allaire
Catherine Wahl, Katherine Wahl, Kathryn Wahl, K Wahl, P Yong, P Bridge-Cook, Cathy Allaire, Kate Allaire, C Allaire
PMID 32753352 32753352 DOI 10.1016/j.jogc.2020.05.009 10.1016/j.jogc.2020.05.009 Wahl et al. 2021, Wahl 2021