Endometriosis · Diagnosis
Abstract
Objective
To investigate ethnic differences for moderate-to-severe endometriosis.
Design
Analysis of a prospective registry (Canadian Task Force classification II-2).
Setting
Tertiary referral center.
Patients
A total of 1594 women with pelvic pain and/or endometriosis.
Interventions
None
Measurements and Main Results
On logistic regression, adjusting for potential confounders, East/South East Asians were 8.3 times more likely than whites to have a previous diagnosis of stage III/IV endometriosis before referral (adjusted odds ratio [aOR], 8.33; 95% confidence interval [CI], 3.74-18.57), 2.7 times more likely to have a palpable nodule (aOR, 2.66; 95% CI, 1.57-4.52), 4.1 times more likely to have an endometrioma on ultrasound (aOR, 4.10; 95% CI, 2.68-6.26), and 10.9 times more likely to have stage III/IV endometriosis at the time of surgery at our center (aOR, 10.87; 95% CI, 4.34-27.21).
Conclusion
Moderate-to-severe endometriosis was more common in women with East or South East Asian ethnicity in our tertiary referral center. This could be explained by East/South East Asians with minimal to mild disease being less likely to seek care or genetic/environmental differences that increase the risk of more severe disease among East/South East Asians. (ClinicalTrials.gov, NCT02911090.).
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.
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.
Medical Management · Pain Management
Guideline No. 468: Clinical Management of Endometriosis
Yong PJ et al., 2026 · Journal of obstetrics and gynaecology Canada : JOGC = Journal d'obstetrique et gynecologie du Canada : JOGC
To provide health care professionals with an evidence-based approach to the management of endometriosis and its associated symptoms. Women and gender-diverse individuals affected by endometriosis. BENEFITS, HARMS, Timely and effective management of endometriosis has the potential to reduce pain, improve fertility and quality of life, and enhance long-term health outcomes. Early intervention may also help mitigate the financial and health system burdens associated with delayed diagnosis and treatment. Published literature was retrieved through searches of PubMed, Ovid, Medline, Embase, Scopus, and the Cochrane Library from August 2010 through December 2025, using relevant MeSH heading and keywords. Results were restricted to systematic reviews, meta-analyses, randomized controlled trials/controlled clinical trials, observational studies, and clinical practice guidelines. Results were limited to English or French language materials. Evidence was supplemented with references from the 2010 Society of Obstetricians and Gynaecologists of Canada guideline No. 244. The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and conditional recommendations). Health care providers involved in the care of individuals with endometriosis. Early identification and management of endometriosis can significantly improve patient outcomes, reduce long-term health care costs and improve their quality of life. RECOMMENDATIONS.
Related research
Diagnosis · Staging and Classification
Epidemiology of endometriosis in female evacuated from the Eastern Ukrainian military conflict regions: results a multicenter study (2022-2024)
Salmanov AG et al., 2025 · Wiadomosci lekarskie (Warsaw, Poland : 1960)
To estimate the prevalence and risk factors associated with endometriosis in female evacuated from the Eastern Ukrainian military conflict regions. Materials and A prospective multicenter cohort study was based on surveillance data for endometriosis. 982 women undergoing pelvic surgery were compared to 264 patients unexposed to surgery. The study cohort included women, who underwent a diagnostic and/or therapeutic laparoscopy or laparotomy in 2022-2024. Endometriosis among women was diagnosed visually at laparoscopy/laparotomy or by pelvic magnetic resonance imaging. The prospective multicenter study included 1,246 women. The overall prevalence of endometriosis was 31.5%. Prevalence of the three types of endometrioses included peritoneal/superficial endometriosis, ovarian endometriotic cyst/endometrioma and deep infiltrating endometriosis was 13.8%, 9.8%, and 4.8%, respectively. Three hundred sixty-one women 36,8% in the surgical group and thirty-one women 13.3% in the community treatment group (unexposed to surgery, population cohort) were diagnosed with incident endometriosis. The pelvic pain, infertility and early age at menarche to be a consistent risk factor for endometriosis in both the operative and population cohorts. Data analysis showed that odds were decreased for gravidity, parity, and BMI. Factors that increased the odds of endometriosis diagnosis included dysmenorrhea, older age at first sex, pelvic pain as a surgical indication for laparoscopy, and higher education. Our study findings demonstrate the high prevalence of endometriosis among women in Ukraine. The pelvic pain, infertility and early age at menarche to be a consistent risk factor for endometriosis in both the operative and population cohorts.
Diagnosis · Imaging
Risk factors associated with endometriosis: importance of study population for characterizing disease in the ENDO Study
Peterson CM et al., 2013 · Am J Obstet Gynecol · Free full text on PubMed Central
We sought to identify risk factors for endometriosis and their consistency across study populations in the Endometriosis: Natural History, Diagnosis, and Outcomes (ENDO) Study. In this prospective matched, exposure cohort design, 495 women aged 18-44 years undergoing pelvic surgery (exposed to surgery, operative cohort) were compared to an ageand residence-matched population cohort of 131 women (unexposed to surgery, population cohort). Endometriosis was diagnosed visually at laparoscopy/laparotomy or by pelvic magnetic resonance imaging in the operative and population cohorts, respectively. Logistic regression estimated the adjusted odds ratios (AORs) and 95% confidence intervals (CIs) for each cohort. The incidence of visualized endometriosis was 40% in the operative cohort (11.8% stage 3-4 by revised criteria from the American Society for Reproductive Medicine), and 11% stage 3-4 in the population cohort by magnetic resonance imaging. An infertility history increased the odds of an endometriosis diagnosis in both the operative (AOR, 2.43; 95% CI, 1.57-3.76) and population (AOR, 7.91; 95% CI, 1.69-37.2) cohorts. In the operative cohort only, dysmenorrhea (AOR, 2.46; 95% CI, 1.28-4.72) and pelvic pain (AOR, 3.67; 95% CI, 2.44-5.50) increased the odds of diagnosis, while gravidity (AOR, 0.49; 95% CI, 0.32-0.75), parity (AOR, 0.42; 95% CI, 0.28-0.64), and body mass index (AOR, 0.95; 95% CI, 0.93-0.98) decreased the odds of diagnosis. In all sensitivity analyses for different diagnostic subgroups, infertility history remained a strong risk factor. An infertility history was a consistent risk factor for endometriosis in both the operative and population cohorts of the ENDO Study. Additionally, identified risk factors for endometriosis vary based upon cohort selection and diagnostic accuracy. Finally, endometriosis in the population may be more common than recognized.
Fertility and Outcomes · Ovarian Reserve
Is endometriosis typology a potentially better classification system for assessing risk of female infertility?
Schliep KC et al., 2025 · F S Rep · Free full text on PubMed Central
To determine whether endometriosis typology, namely ovarian endometriomas (OE), deep infiltrating endometriosis (DIE), or superficial endometriosis (SE), correlates with fertility history. Prospective cohort. One of fourteen surgical centers in Salt Lake City, Utah (n = 5) or San Francisco, California (n = 9). A total of 473 women (18-44 years) with no prior endometriosis diagnosis, undergoing laparoscopies/laparotomies, irrespective of indication, in Utah or California (2007-2009). Exposure: Incident endometriosis. Before surgery, we queried women about time to become pregnant for prior planned pregnancies. Generalized linear models were used to calculate adjusted prevalence ratios (aPR) for association between endometriosis typology and infertility, defined as having ever tried >12 months (>6 months for women ≥35 years) to get pregnant. We also generated fecundability odds ratios (aFOR) to capture time to pregnancy. Twenty-five percent (n = 116) of women were diagnosed with SE only, 5% (n = 23) with OE, 6% (n = 29) with DIE, and 5% (n = 22) with OE + DIE, and 60% (n = 283) with no endometriosis. Compared with women with no endometriosis, women with SE had a 1.58 higher aPR (95% confidence interval [CI], 1.16-2.14), although women with OE and/or DIE had a 2.41 higher aPR for subfertility after adjusting for women's age, body mass index, and site. Compared with women with no endometriosis, women with OE and/or DIE had a 53% lower historic fecundability (aFOR, 0.47; 95% CI, 0.24-0.95); however, no association was found among women with SE (aFOR, 0.81; 95% CI, 0.49-1.33). Specific endometriosis typologies may be associated with fecundability, with OE and/or DIE associated with nearly a 150% higher prevalence of subfertility and over a 50% lower historic fecundability.
Diagnosis · Diagnostic Delay
Incidence, prevalence, and trends in endometriosis diagnosis: a United States population-based study from 2006 to 2015
Christ JP et al., 2021 · American journal of obstetrics and gynecology
Accurate estimates of incidence and prevalence of endometriosis among nonselected cohorts are lacking in the United States, and earlier reports have produced varying results. This study aimed to define endometriosis incidence and prevalence in a US population and evaluate factors influencing these estimates over time. A 10-year retrospective cohort study using Kaiser Permanente Washington electronic health records database was completed. The primary analysis included women enrollees aged 16 to 60 years, from January 2006 to December 2015, who had a uterus, were continuously enrolled for at least 2 years before cohort entry and had at least 1 healthcare utilization. Secondary analysis included all women enrollees aged 16 to 60 years during this time. Incident endometriosis was identified using the International Classification of Diseases, Ninth Revision and Tenth Revision, diagnosis codes. Annual incidence rates were age-adjusted by direct standardization to the 2015 study population. Secular trends in incidence overall and by 5-year age group, race and ethnicity, diagnosis modality, and practitioner type were assessed using Poisson regression analyses. Prevalent cases were defined as women enrolled in 2015 and had an endometriosis diagnosis before the end of 2015. The prevalence rates of chronic pelvic pain and dysmenorrhea defined by the International Classification of Diseases, Ninth Revision and Tenth Revision, diagnosis codes in 2006-2015 were estimated. Among 332,056 eligible women who contributed 1,176,329 person-years during the 10-year study period, 2863 incident endometriosis cases were identified for an average incidence of 24.3 cases per 10,000 person-years. In our primary analysis, incidence rates declined over the study interval from a high of 30.2 per 10,000 person-years in 2006 to 17.4 per 10,000 person-years in 2015 and were highest among women aged 36 to 45 years in most years. Incidence rates were similar across race and ethnicity groups. The distribution of the 2863 incident cases by the diagnosis modality was as follows: 45.5% surgical, 5.7% imaging, and 48.8% clinical. Endometriosis incidence rates per 10,000 person-years were similar in women who were surgically and clinically diagnosed and decreased significantly from 2006 to 2015 (surgically diagnosed endometriosis dropped from 13.4 to 7.4 and clinically diagnosed endometriosis dropped from 16.1 to 8.9; P value of <.001 for linear trend over time for each). Incident case distribution by diagnosing provider was as follows: 73.6% obstetrician and gynecologist, 15.7% primary care provider, and 10.7% "other." Incidence of endometriosis diagnosed by an obstetrician and gynecologist and primary care provider decreased over the study interval (P<.001 for linear trend over time for each). Method of diagnosis and provider type did not differ by race and ethnicity. Among 135,162 women who contributed person-time in 2015, 2521 women were diagnosed with endometriosis, a prevalence rate of 1.9%. In our secondary analysis, the frequency of chronic pelvic pain diagnosis increased over the study interval from 3.0% in 2006 to 5.6% in 2015. The incidence rates of endometriosis declined over the 10-year study interval and did so uniformly across age groups, races and ethnicities, and the main diagnosing modalities and providers. Declining rates may reflect a shift in practice patterns in the United States away from the diagnosis of endometriosis both clinically and surgically, rather than favoring more general diagnoses of chronic pelvic pain. The prevalence of endometriosis in 2015 in the United States is in keeping with data from recent studies outside the United States using health record data.
Endometriosis › Diagnosis › Staging and Classification · General Gynecology › Pelvic Pain › Chronic Pelvic Pain
Alicia J Long, Catherine Allaire, Mohamed A Bedaiwy
A Long, Cathy Allaire, Kate Allaire, C Allaire, M Bedaiwy
PMID 29935381 29935381 DOI 10.1016/j.jmig.2018.06.009 10.1016/j.jmig.2018.06.009 Williams et al. 2019, Williams 2019