General Gynecology · Pelvic Pain
Abstract
Background
Chronic pelvic pain affects ∼15% of women, and is associated with significant societal cost and impact on women's health. Identifying factors involved in chronic pelvic pain is challenging due to its multifactorial nature and confounding between potential factors. For example, while some women with endometriosis have chronic pelvic pain, there may be comorbid conditions that are implicated in the chronic pelvic pain rather than the endometriosis itself.
Objective
We sought to explore multifactorial variables independently associated with the severity of chronic pelvic pain in women.
Study Design
We used baseline cross-sectional data from an ongoing prospective cohort, collected from patient online questionnaires, physical examination, and physician review of medical records. Participants were recruited from a tertiary referral center for endometriosis and chronic pelvic pain in Vancouver, British Columbia, Canada, from December 2013 through April 2015. Exclusion criteria included menopausal status or age >50 years. Primary outcome was self-reported severity of chronic pelvic pain in the last 3 months (0-10 numeric rating scale). Potential associated factors ranged from known pain conditions assessed by standard diagnostic criteria, validated psychological questionnaires, musculoskeletal physical exam findings, as well as pain-related, reproductive, medical/surgical, familial, demographic, and behavioral characteristics. Mann-Whitney, Kruskal-Wallis, or Spearman test were used to identify variables with an association with the primary outcome (P < .05), followed by multivariable linear regression to control for confounding and to identify independent associations with the primary outcome (P < .05).
Results
Overall, 656 women were included (87% consent rate), of whom 55% were diagnosed with endometriosis. The following factors were independently associated with higher severity of chronic pelvic pain: abdominal wall pain (P = .005), pelvic floor tenderness (P = .004), painful bladder syndrome (P = .019), higher score on Pain Catastrophizing Scale (P < .001), adult sexual assault (P = .043), higher body mass index (P = .023), current smoking (P = .049), and family history of chronic pain (P = .038). Severity of chronic pelvic pain was similar between women with and without endometriosis.
Conclusion
Multifactorial variables independently associated with severity of chronic pelvic pain were identified, ranging from myofascial/musculoskeletal, urological, family history, and psycho-social factors. Continued research is required to validate these factors and to determine whether any are potentially modifiable for the management of chronic pelvic pain.
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.
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.
Pelvic Pain · Chronic Pelvic Pain
Endometriosis Pain Index: development of a model to predict poor pain-related quality of life after endometriosis surgery through machine learning analysis of registry data
Tucker DR et al., 2026 · Pain · Free to read
Predictive tools are lacking for pain-related outcomes after endometriosis surgery. The objective of this study was to develop and validate a machine learning-based clinical model to predict poor pain-related quality of life after endometriosis surgery. Registry data from a prospective longitudinal cohort at a tertiary referral center (2013-2020) was used for model development and validation. Participants underwent an index endometriosis surgery, and completed the pain subscale of the Endometriosis Health Profile-30 (EHP-30) at baseline and 1-2-year follow-up. The outcome was poor pain-related quality of life defined as EHP-30 pain subscale above the 75th percentile for North America, at 1 to 2 years postsurgery. Thirty-two preoperative factors were evaluated, with final models retaining the top 10 most important predictors. Elastic net logistic regression, random forest (RF) and multilayer perceptron neural network models were developed. Internal validation was performed using 500 bootstrap samples, and a held-out test cohort. The study included 650 488 in the training cohort and 162 in a held-out test cohort. The RF model exhibited the most consistent discrimination, measured by the area under the receiver operating characteristic curve, between the training cohort (0.768; 95% CI: 0.690-0.837) and test cohort (0.766; 95% CI: 0.676-0.863, Δ = -0.002). The RF model also demonstrated the best integrated calibration index (0.029) and highest net benefit. Final preoperative predictors for the RF model included baseline EHP-30 score, surgery type (conservative fertility-sparing vs hysterectomy), anxiety scores, depression scores, pain catastrophizing scale scores, abdominal wall pain, pelvic floor myalgia, smoking status, back pain, and race/ethnicity. We present the RF model as the Endometriosis Pain Index to aid preoperative counselling for endometriosis surgery.
Related research
Pelvic Pain · Chronic Pelvic Pain
Chronic pelvic pain in an interdisciplinary setting: 1-year prospective cohort
Allaire C et al., 2018 · American journal of obstetrics and gynecology
Chronic pelvic pain affects ∼15% of women, and presents a challenging problem for gynecologists due to its complex etiology involving multiple comorbidities. Thus, an interdisciplinary approach has been proposed for chronic pelvic pain, where these multifactorial comorbidities can be addressed by different interventions at a single integrated center. Moreover, while cross-sectional studies can provide some insight into the association between these comorbidities and chronic pelvic pain severity, prospective longitudinal cohorts can identify comorbidities associated with changes in chronic pelvic pain severity over time. We sought to describe trends and factors associated with chronic pelvic pain severity over a 1-year prospective cohort at an interdisciplinary center, with a focus on the role of comorbidities and controlling for baseline pain, demographic factors, and treatment effects. This was a prospective 1-year cohort study at an interdisciplinary tertiary referral center for pelvic pain and endometriosis, which provides minimally invasive surgery, medical management, pain education, physiotherapy, and psychological therapies. Exclusion criteria included menopause or age >50 years. Sample size was 296 (57% response rate at 1 year; 296/525). Primary outcome was chronic pelvic pain severity at 1 year on an 11-point numeric rating scale (0-10), which was categorized for ordinal regression (none-mild 0-3, moderate 4-6, severe 7-10). Secondary outcomes included functional quality of life and health utilization. Baseline comorbidities were endometriosis, irritable bowel syndrome, painful bladder syndrome, abdominal wall pain, pelvic floor myalgia, and validated questionnaires for depression, anxiety, and catastrophizing. Multivariable ordinal regression was used to identify baseline comorbidities associated with the primary outcome at 1 year. Chronic pelvic pain severity decreased by a median 2 points from baseline to 1 year (6/10-4/10, P < .001). There was also an improvement in functional quality of life (42-29% on the pain subscale of the Endometriosis Health Profile-30, P < .001), and a reduction in subjects requiring a physician visit (73-36%, P < .001) or emergency visit (24-11%, P < .001) in the last 3 months. On multivariable ordinal regression for the primary outcome, chronic pelvic pain severity at 1 year was independently associated with a higher score on the Pain Catastrophizing Scale at baseline (odds ratio, 1.10; 95% confidence interval, 1.00-1.21, P = .04), controlling for baseline pain, treatment effects (surgery), age, and referral status. Improvements in chronic pelvic pain severity, quality of life, and health care utilization were observed in a 1-year cohort in an interdisciplinary setting. Higher pain catastrophizing at baseline was associated with greater chronic pelvic pain severity at 1 year. Consideration should be given to stratifying pelvic pain patients by catastrophizing level (rumination, magnification, helplessness) in research studies and in clinical practice.
Pelvic Pain · Chronic Pelvic Pain
Machine Learning Revealed New Correlates of Chronic Pelvic Pain in Women
Elgendi M et al., 2020 · Frontiers in digital health · Free full text on PubMed Central
Chronic pelvic pain affects one in seven women worldwide, and there is an urgent need to reduce its associated significant costs and to improve women's health. There are many correlated factors associated with chronic pelvic pain (CPP), and analyzing them simultaneously can be complex and involves many challenges. A newly developed interaction ensemble, referred to as INTENSE, was implemented to investigate this research gap. When applied, INTENSE aggregates three machine learning (ML) methods, which are unsupervised, as follows: interaction principal component analysis (IPCA), hierarchical cluster analysis (HCA), and centroid-based clustering (CBC). For our proposed research, we used INTENSE to uncover novel knowledge, which revealed new interactions in a sample of 656 patients among 25 factors: age, parity, ethnicity, body mass index, endometriosis, irritable bowel syndrome, painful bladder syndrome, pelvic floor tenderness, abdominal wall pain, depression score, anxiety score, Pain Catastrophizing Scale, family history of chronic pain, new or re-referral, age when first experienced pain, pain duration, surgery helpful for pain, infertility, smoking, alcohol use, trauma, dysmenorrhea, deep dyspareunia, CPP, and the Endometriosis Health Profile for functional quality of life. INTENSE indicates that CPP and the Endometriosis Health Profile are correlated with depression score, anxiety score, and the Pain Catastrophizing Scale. Other insights derived from these ML methods include the finding that higher body mass index was clustered with smoking and a history of life trauma. As well, sexual pain (deep dyspareunia) was found to be associated with musculoskeletal pain contributors (abdominal wall pain and pelvic floor tenderness). Therefore, INTENSE provided expert-like reasoning without training any model or prior knowledge of CPP. ML has the potential to identify novel relationships in the etiology of CPP, and thus can drive innovative future research.
Pelvic Pain · Chronic Pelvic Pain
Demographic and historic variables in women with idiopathic chronic pelvic pain
Reiter RC et al., 1990 · Obstet Gynecol
A comprehensive historic, demographic, and medical questionnaire was administered to 106 women referred to a multidisciplinary clinic for evaluation of idiopathic chronic pelvic pain and to 92 age-matched, pain-free control patients presenting for routine annual examination. Although racial distribution, mean gravidity and parity, and rates of elective abortion were similar in both groups of respondents, spontaneous abortion was reported significantly more frequently among women with pelvic pain. Patients in the study group were also more likely to be on active military duty, to have undergone previous nongynecologic surgery, and to have sought treatment for unrelated somatic complaints. Finally, although the mean ages at first intercourse were similar, women with idiopathic pelvic pain reported a higher total number of sexual partners and were significantly more likely to have experienced previous significant psychosexual trauma. These findings confirm that predisposing psychosocial variables are important in the pathogenesis of idiopathic pelvic pain and emphasize the significance of multidisciplinary evaluation and management.
Pelvic Pain · Chronic Pelvic Pain
Correlation between endometriosis and pelvic pain
Porpora MG et al., 1999 · J Am Assoc Gynecol Laparosc
To evaluate the relationship between prevalence and severity of chronic pelvic pain (CPP) and stage, site, and type of endometriosis. Prospective, observational study (Canadian Task Force classification II-2). University Hospital. Of 90 consecutive women with biopsy-proved endometriosis, laparoscopy was performed in 69 for pelvic pain and in 21 for infertility or clinical and ultrasonographic suspicion of ovarian endometriosis. Preoperatively, using a 10-point visual analog scale, the severity of dysmenorrhea, CPP, and deep dyspareunia was assessed. During laparoscopy all visible endometriotic lesions were recorded and treated. MAIN Ten women (11.1%) had no pain; 72 had dysmenorrhea (mild in 13, moderate in 37, severe in 22); 55 had CPP (mild in 11, moderate in 25, severe in 19); and 39 deep dyspareunia (mild in 5, moderate in 31, severe in 3). The severity of dysmenorrhea significantly correlated with the presence and extent of pelvic adhesions (p = 0.004); the severity of CPP correlated with deep endometriosis on the uterosacral ligaments (p = 0.0001) and extent of pelvic adhesions (p = 0.02); and deep dyspareunia correlated with deep endometriosis on the uterosacral ligaments (p = 0.04). Total pain score significantly correlated with deep endometriosis on the uterosacral ligaments (p = 0.0001), peritoneal adhesions (p = 0.01), and extent of adnexal adhesions (p = 0.01). No significant correlation was found among revised American Fertility Society stage of endometriosis; presence and size of ovarian endometriomas; extent, type, and site of peritoneal lesions; and pain scores. By logistic regression analysis, the presence and intensity of total pain could be predicted simultaneously by the presence of deep endometriosis (p = 0.0001) and presence and extent of adnexal adhesions without cystic endometriosis (p = 0.01), and by the presence of ovarian endometrioma with periovarian adhesions (p = 0.03). Chronic pelvic pain was predicted by both deep endometriosis (p = 0.0001) and ovarian endometriomas with adnexal adhesions (p = 0.03). Deep dyspareunia was predicted simultaneously by deep endometriosis (p = 0.01) and an ovarian endometrioma with periovarian adhesions (p = 0. 008). Conclusion. Deep endometriosis, pelvic adhesions, and ovarian cystic endometriosis were independent predictors of pelvic pain. These data strongly suggest that it is not the size of ovarian cystic endometriosis but the association with adhesions that causes pelvic pain.
General Gynecology › Pelvic Pain › Chronic Pelvic Pain
Ali Yosef, Catherine Allaire, Abdel Ghaffar Ahmed, Tarek Al-Hussaini, Mohamad S Abdellah, Fontayne Wong
A Yosef, Cathy Allaire, Kate Allaire, C Allaire, A Ahmed, T Al-Hussaini, M Abdellah, F Wong
PMID 27443813 27443813 DOI 10.1016/j.ajog.2016.07.023 10.1016/j.ajog.2016.07.023 Yosef et al. 2016, Yosef 2016