Reproductive history and endometriosis among premenopausal women

Relationship between endometriosis and uterine cervical elasticity assessed using ultrasound strain elastography

PURPOSE

Internal cervical os (ICO) stiffness is related to menstrual pain, a key symptom of endometriosis. The study evaluated whether women with endometriosis have a stiffer ICO than unaffected women.

METHODS

A retrospective cross-sectional analysis was conducted using prospectively collected data from women with and without endometriosis, spanning from June 2020 to September 2022. Endometriosis was diagnosed through clinical and ultrasound evaluations, with histological confirmation in a subset of participants. Strain elastography (SE) was employed to measure tissue elasticity in four cervical regions of interest: the ICO and the anterior, posterior, and middle cervical compartments (ACC, PCC, and MCC, respectively). Tissue elasticity was quantified using a color-based scoring system ranging from 0.1 (blue, indicating less elasticity) to 3.0 (red, indicating greater elasticity).

RESULTS

Overall, 287 women were included, with 157 diagnosed with endometriosis and 130 controls. On SE, women with endometriosis exhibited a lower color score (mean±standard deviation), indicating lower elasticity, for the ICO (0.56±0.28 vs. 0.70±0.26, P=0.001) and PCC (0.69±0.30 vs. 0.80±0.27, P=0.002). Additionally, they had a lower ICO/MCC ratio (0.45±0.28 vs. 0.60±0.32, P=0.001) and ICO/ACC ratio (0.68±0.42 vs. 0.85±0.39, P=0.001). Multiple logistic regression analysis revealed that endometriosis was associated with the ICO color score (odds ratio, 0.053; 95% confidence interval, 0.014 to 0.202; R2=0.358; P=0.001), even after adjusting for confounding factors like the presence of myomas (P=0.040) and the use of hormonal therapy (P=0.001). The results were corroborated in women with histologically confirmed endometriosis (n=71).

CONCLUSION

The findings suggest a potential relationship between a stiffer ICO and endometriosis.

Causal effects of endometriosis stages and locations on menstruation, ovulation, reproductive function, and delivery modes: a two-sample Mendelian randomization study

Background

Endometriosis is a chronic inflammatory disease of women during their reproductive years. The relationship between the severity and location of endometriosis and menstruation, ovulation, reproductive function, and mode of delivery remains unclear.

Methods

We explored the association between the various phenotypes of endometriosis and menstruation, ovulation, reproductive function, and mode of delivery, using two-sample Mendelian randomization (MR) and summary data on endometriosis stages and locations from the FinnGen consortium and women's menstruation, ovulation, reproductive function, and mode of delivery from OpenGWAS and ReproGen. Inverse-variance weighting was used for the primary MR analysis. In addition, a series of sensitivity analyses, confounding analyses, co-localization analyses, and multivariate MR analyses were performed.

Results

MR analysis showed a negative effect of moderate to severe endometriosis on age at last live birth (OR = 0.973, 95% CI: 0.960-0.986) and normal delivery (OR = 0.999, 95% CI: 0.998-1.000; values for endpoint were excluded), ovarian endometriosis on age at last live birth (OR = 0.976, 95% CI: 0.965-0.988) and normal delivery (OR = 0.999, 95% CI: 0.998-1.000; values for endpoint were excluded), and fallopian tubal endometriosis on excessive irregular menstruation (OR = 0.966, 95% CI: 0.942-0.990). Bidirectional MR analysis showed that age at menarche had a negative causal effect on intestinal endometriosis (OR = 0.417, 95% CI: 0.216-0.804). All MR analyses were confirmed by sensitivity analyses, and only the genetic effects of moderate to severe endometriosis on normal delivery and age at last live birth were supported by co-localization evidence.

Conclusion

Our findings deepen the understanding of the relationship between various types of endometriosis and menstruation, ovulation, reproductive function, and mode of delivery and clarify the important role of moderate to severe endometriosis.

Effect of Oral Contraceptive Use in Relation to Fertile Years on the Risk of Endometriosis in Women with Primary Infertility: A Ten-Year Single-Centre Retrospective Analysis

Background and Objectives: Oral contraceptives (OCs) are usually used to treat endometriosis; however, the evidence is inconsistent about whether OC use in the past, when given to asymptomatic women, is protective against the development of future disease. We aimed to assess the relationship between the use of OCs and the likelihood of discovering endometriosis, considering the length of time under OCs during their fertile age. Materials and Methods: This was a monocentric retrospective cohort study in a tertiary-care University Hospital (Department of Human Reproduction, Division of Gynaecology and Obstetrics, University Medical Centre Ljubljana, Slovenia) carried out from January 2012 to December 2022. Reproductive-aged women scheduled for laparoscopic surgery for primary infertility and subsequent histopathological diagnosis of endometriosis were compared to women without an endometriosis diagnosis. They were classified based on the ratio of years of OC use to fertile years in four subgroups: never, <25%, between 25 and 50%, and >50. Results: In total, 1923 women (390 with and 1533 without endometriosis) were included. Previous OC use was higher in those with endometriosis than controls (72.31% vs. 58.64%; p = 0.001). Overall, previous OC usage was not related to histopathological diagnosis of endometriosis (aOR 1.06 [95% CI 0.87-1.29]). Women who used OCs for less than 25% of their fertile age had reduced risk of rASRM stage III endometriosis (aOR 0.50 [95% CI 0.26-0.95]; p = 0.036) or superficial implants (aOR 0.88 [95% CI 0.58-0.95]; p = 0.040). No significant results were retrieved for other rASRM stages. Using OCs for <25%, between 25 and 50%, or >50% of fertile age did not increase the risk of developing superficial endometriosis, endometriomas, or DIE. Conclusions: When OCs are used at least once, histological diagnoses of endometriosis are not increased. A protective effect of OCs when used for less than 25% of fertile age on superficial implants may be present. Prospective research is needed to corroborate the findings due to constraints related to the study's limitations.

Is endometriosis due to evolutionary maladaptation?

Similar to diabetes and unlike many pathogen-induced diseases, endometriosis is likely a result of maladaptation to the evolutionary heritage of humans. The objective of this article is to review the literature and improve understanding of the evolutionary factors behind endometriosis, leading to more effective prevention and treatment approaches. In primates, spontaneous decidualization of the endometrium evolved to ensure optimal implantation of a limited number of early embryos, unlike many non-primates which depend on early embryos to induce decidualization and subsequent pregnancy. Spontaneous decidualization results in menstrual bleeding when embryo implantation does not occur, and endometriosis is commonly believed to be caused by retrograde menstruation. Although direct evidence is lacking, it is likely that hunter-gatherer women experienced fewer menstrual periods due to pregnancy shortly after menarche, followed by repeated pregnancies and lactation. However, the mismatch between the evolved uterine physiology and rapid societal changes has led to modern women delaying pregnancy and experiencing numerous menstrual periods, potentially increasing the incidence of endometriosis. The symptoms of endometriosis are often managed by suppressing menstruation through systemic hormonal treatments, but these may have side effects. For patients with a family history of endometriosis or in the early stages of the disease, intrauterine devices releasing progesterone locally could prevent uterine bleeding and the development of endometriosis while preserving fertility and minimizing side effects.

Proposal for targeted, neo-evolutionary-oriented, secondary prevention of early-onset endometriosis and adenomyosis. Part I: pathogenic aspects

The potential for repeated ovulation and menstruation is thought to have provided a Darwinian advantage during the Palaeolithic. Reproductive conditions remained relatively stable until the pre-industrial era, characterized by late menarche, very young age at first birth, multiple pregnancies, and prolonged periods of lactational amenorrhoea. For hundreds of thousands of years, menstruators experienced few ovulatory cycles, even though they were genetically adapted to ovulate and menstruate every month. In the post-industrial era, the age at menarche gradually declined, the age at first birth progressively increased, and breastfeeding became optional and often of short duration. This created a mismatch between genetic adaptation and socio-environmental evolution, so that what was initially a probable reproductive advantage subsequently contributed to increased susceptibility to diseases associated with lifetime oestrogen exposure, such as ovarian, endometrial and breast cancer and, hypothetically, also those associated with the number of ovulatory menstruations, such as endometriosis and adenomyosis. The incidence of endometriosis shows a steep and progressive increase around the age of 25 years, but given the consistently reported delay in diagnosis, the actual incidence curve should be shifted to the left, supporting the possibility that the disease has its roots in adolescence. This raises the question of whether, from an evolutionary point of view, anovulation and amenorrhoea should not still be considered the physiological state, especially in the postmenarchal period. However, an increase in the frequency of endometriosis in recent decades has not been demonstrated, although this deserves further epidemiological investigation. In addition, as endometriosis occurs in a minority of individuals exposed to retrograde menstruation, other important pathogenic factors should be scrutinised. Research should be resumed to explore in more detail the transtubal reflux of not only blood, but also endometrial cells, and whether they are systematically present in the peritoneal fluid after menstruation. If repetitive ovulatory menstruation during the early reproductive years is shown to increase the risk of endometriosis and adenomyosis development and progression in susceptible individuals, hormonal interventions could be used as secondary prevention in symptomatic adolescents.

Safety, Pharmacokinetics, and Pharmacodynamics of SHR7280, a Non-peptide GnRH Antagonist in Premenopausal Women with Endometriosis: A Randomized, Double-Blind, Placebo-Controlled Phase 1 Study

BACKGROUND

Oral gonadotropin-releasing hormone (GnRH) antagonists are promising agents in the treatment of endometriosis-related pain. Here we assessed the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of SHR7280, an oral non-peptide GnRH antagonist in premenopausal women with endometriosis.

METHODS

In the Phase 1 part of the randomized, double-blinded, placebo-controlled, dose-ascending, Phase 1/2 trial, premenopausal women with endometriosis were randomized (4:1) to receive SHR7280 or placebo treatment for 21 consecutive days. The treatment dose started from 200 mg QD, and then increased to 300 mg QD and 200 mg BID. Safety, PK, and PD parameters were assessed.

RESULTS

In total, 30 patients received assigned treatment, 24 with SHR7280 and 6 with placebo. SHR7280 was well tolerated. Adverse events (AEs) were reported in 19 (79.2%, 19/24) patients in the SHR7280 group and 5 (83.3%, 5/6) patients in the placebo group. Most AEs were mild and no severe AEs occurred. SHR7280 showed a rapid absorption, with a time to maximum plasma concentration (Tmax) of 1.0 h, 1.0 h, and 0.8 h for the 200 mg QD, 300 mg QD, and 200 mg BID regimens, respectively. Plasma concentration of SHR7280 was dose dependent. The mean half-life (t1/2) at steady state was 6.9 h, 7.4 h, and 2.8 h, respectively, and little or no accumulation was observed. Pharmacodynamic analysis showed that SHR7280 could effectively suppress estradiol and luteinizing hormone concentrations and prevent progesterone increase in a dose-dependent manner. SHR7280 at doses of 300 mg QD and 200 mg BID could suppress estradiol levels within the desired therapeutic window of 20-50 pg/mL throughout the treatment period.

CONCLUSIONS

SHR7280 showed favorable safety, PK, and PD profiles in the doses of 200 mg QD, 300 mg QD, and 200 mg BID. The results of this study provide evidence to support the further development of SHR7280 as a GnRH antagonist for the treatment of endometriosis-related pain in the subsequent Phase 2 trial.

TRIAL REGISTRY

Trial registration number: Clinicaltrials.gov, identifier: NCT04417972. Trial registration date: 5 June 2020.

Neutrophil gelatinase-associated lipocalin serum level: A potential noninvasive biomarker of endometriosis?

Neutrophil gelatinase-associated lipocalin (NGAL, also known as lipocalin-2) is an acute-phase protein expressed in many tissues and plays a role in cell proliferation, regulation, and epithelial-mesenchymal transformation. Therefore, this study aimed to investigate serum NGAL levels and endometrioma tissue expression in women with endometriosis. This cross-sectional study was conducted at a university hospital. The endometrioma group included 36 women who underwent ovarian cystectomy for endometrioma, which was compared with a control group (n = 36) of women who underwent ovarian cystectomy due to benign persistent cysts (follicle cyst, theca lutein cyst, and serous cystadenoma). NGAL levels were analyzed using both serum enzyme-linked immunosorbent assay analysis and immunohistochemical tissue staining. Serum C-reactive protein and CA-125 levels were also evaluated. NGAL serum levels were significantly higher in the endometrioma group than in the control group (P < .05). C-reactive protein and CA-125 levels were also significantly higher in the endometrioma group (P < .05) and were correlated with NGAL levels. Immunohistochemical staining for NGAL was also higher in the endometrioma group (P < .001). NGAL may be considered a potential noninvasive biomarker of endometriosis.

Insights from Mendelian randomization and genetic correlation analyses into the relationship between endometriosis and its comorbidities

BACKGROUND

Endometriosis remains a poorly understood disease, despite its high prevalence and debilitating symptoms. The overlap in symptoms and the increased risk of multiple other traits in women with endometriosis is becoming increasingly apparent through epidemiological data. Genetic studies offer a method of investigating these comorbid relationships through the assessment of causal relationships with Mendelian randomization (MR), as well as identification of shared genetic variants and genes involved across traits. This has the capacity to identify risk factors for endometriosis as well as provide insight into the aetiology of disease.

OBJECTIVE AND RATIONALE

We aim to review the current literature assessing the relationship between endometriosis and other traits using genomic data, primarily through the methods of MR and genetic correlation. We critically examine the limitations of these studies in accordance with the assumptions of the utilized methods.

SEARCH METHODS

The PubMed database was used to search for peer-reviewed original research articles using the terms 'Mendelian randomization endometriosis' and '"genetic correlation" endometriosis'. Additionally, a Google Scholar search using the terms '"endometriosis" "mendelian randomization" "genetic correlation"' was performed. All relevant publications (n = 21) published up until 7 October 2022 were included in this review. Upon compilation of all traits with published MR and/or genetic correlation with endometriosis, additional epidemiological and genetic information on their comorbidity with endometriosis was sourced by searching for the trait in conjunction with 'endometriosis' on Google Scholar.

OUTCOMES

The association between endometriosis and multiple pain, gynaecological, cancer, inflammatory, gastrointestinal, psychological, and anthropometric traits has been assessed using MR analysis and genetic correlation analysis. Genetic correlation analyses provide evidence that genetic factors contributing to endometriosis are shared with multiple traits: migraine, uterine fibroids, subtypes of ovarian cancer, melanoma, asthma, gastro-oesophageal reflux disease, gastritis/duodenitis, and depression, suggesting the involvement of multiple biological mechanisms in endometriosis. The assessment of causality with MR has revealed several potential causes (e.g. depression) and outcomes (e.g. ovarian cancer and uterine fibroids) of a genetic predisposition to endometriosis; however, interpretation of these results requires consideration of potential violations of the MR assumptions.

WIDER IMPLICATIONS

Genomic studies have demonstrated that there is a molecular basis for the co-occurrence of endometriosis with other traits. Dissection of this overlap has identified shared genes and pathways, which provide insight into the biology of endometriosis. Thoughtful MR studies are necessary to ascertain causality of the comorbidities of endometriosis. Given the significant diagnostic delay of endometriosis of 7-11 years, determining risk factors is necessary to aid diagnosis and reduce the disease burden. Identification of traits for which endometriosis is a risk factor is important for holistic treatment and counselling of the patient. The use of genomic data to disentangle the overlap of endometriosis with other traits has provided insights into the aetiology of endometriosis.

Genomic characterisation of the overlap of endometriosis with 76 comorbidities identifies pleiotropic and causal mechanisms underlying disease risk

Comorbid conditions can be driven by underlying pleiotropic and causal mechanisms that can provide insights into shared molecular and biological processes contributing to disease risk. Endometriosis is a chronic condition affecting one in nine women of reproductive age and poses many challenges including lengthy diagnostic delays and limited treatment efficacy owing to poor understanding of disease aetiology. To shed light on the underlying biological mechanisms and to identify potential risk factors, we examine the epidemiological and genomic relationship between endometriosis and its comorbidities. In the UK Biobank 292 ICD10 codes were epidemiologically correlated with endometriosis diagnosis, including gynaecological, immune, infection, pain, psychiatric, cancer, gastrointestinal, urinary, bone and cardiovascular traits. A subset of the identified comorbidities (n = 76) underwent follow-up genetic analysis. Whilst Mendelian randomisation suggested causality was not responsible for most comorbid relationships, 22 traits were genetically correlated with endometriosis, including pain, gynaecological and gastrointestinal traits, suggestive of a shared genetic background. Pleiotropic genetic variants and genes were identified using gene-based and colocalisation analysis. Shared genetic risk factors and potential target genes suggest a diverse collection of biological systems are involved in these comorbid relationships including coagulation factors, development of the female reproductive tract and cell proliferation. These findings highlight the diversity of traits with epidemiological and genomic overlap with endometriosis and implicate a key role for pleiotropy in the comorbid relationships.

Association of laparoscopically-confirmed endometriosis with long COVID-19: a prospective cohort study

BACKGROUND

Women are at greater risk than men of developing chronic inflammatory conditions and "long COVID." However, few gynecologic health risk factors for long COVID-19 have been identified. Endometriosis is a common gynecologic disorder associated with chronic inflammation, immune dysregulation, and comorbid presentation with autoimmune and clotting disorders, all of which are pathophysiological mechanisms proposed for long COVID-19. Therefore, we hypothesized that women with a history of endometriosis may be at greater risk of developing long COVID-19.

OBJECTIVE

This study aimed to investigate the association between history of endometriosis before SARS-CoV-2 infection and risk of long COVID-19.

STUDY DESIGN

We followed 46,579 women from 2 ongoing prospective cohort studies-the Nurses' Health Study II and the Nurses' Health Study 3-who participated in a series of COVID-19-related surveys administered from April 2020 to November 2022. Laparoscopic diagnosis of endometriosis was documented prospectively in main cohort questionnaires before the pandemic (1993-2020) with high validity. SARS-CoV-2 infection (confirmed by antigen, polymerase chain reaction, or antibody test) and long-term COVID-19 symptoms (≥4 weeks) defined by the Centers for Disease Control and Prevention were self-reported during follow-up. Among individuals with SARS-CoV-2 infection, we fit Poisson regression models to assess the associations between endometriosis and risk of long COVID-19 symptoms, with adjustment for potential confounding variables (demographics, body mass index, smoking status, history of infertility, and history of chronic diseases).

RESULTS

Among 3650 women in our sample with self-reported SARS-CoV-2 infections during follow-up, 386 (10.6%) had a history of endometriosis with laparoscopic confirmation, and 1598 (43.8%) reported experiencing long COVID-19 symptoms. Most women were non-Hispanic White (95.4%), with a median age of 59 years (interquartile range, 44-65). Women with a history of laparoscopically-confirmed endometriosis had a 22% greater risk of developing long COVID-19 (adjusted risk ratio, 1.22; 95% confidence interval, 1.05-1.42) compared with those who had never been diagnosed with endometriosis. The association was stronger when we defined long COVID-19 as having symptoms for ≥8 weeks (risk ratio, 1.28; 95% confidence interval, 1.09-1.50). We observed no statistically significant differences in the relationship between endometriosis and long COVID-19 by age, infertility history, or comorbidity with uterine fibroids, although there was a suggestive trend indicating that the association may be stronger in women aged <50 years (<50 years: risk ratio, 1.37; 95% confidence interval, 1.00-1.88; ≥50 years: risk ratio, 1.19; 95% confidence interval, 1.01-1.41). Among persons who developed long COVID-19, women with endometriosis reported on average 1 additional long-term symptom compared with women without endometriosis.

CONCLUSION

Our findings suggest that those with a history of endometriosis may be at modestly increased risk for long COVID-19. Healthcare providers should be aware of endometriosis history when treating patients for signs of persisting symptoms after SARS-CoV-2 infection. Future studies should investigate the potential biological pathways underlying these associations.

The genetic basis of endometriosis and comorbidity with other pain and inflammatory conditions

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.

The risk of endometriosis by early menarche is recently increased: a meta-analysis of literature published from 2000 to 2020

PURPOSE

The relationship between menarche age and endometriosis has been studied extensively; however, the results were inconsistent due to differences in study dates, populations, and methodology. The goal of this meta-analysis was to see how different research populations, dates, and types affected the estimated risk of endometriosis in early menarche.

METHODS

The terms "endometriosis", "early menarche", and other pertinent terms were searched in PubMed, Medline, and Embase. This meta-analysis comprised 16 papers published between 2000 and 2020, with a start year ranging from 1989 to 2017. Random effects were used to examine endometriosis risks in these articles. Study start years, countries, types (case-control and cohort studies), and quality (Newcastle-Ottawa scale, NOS) were all taken into account in further stratified analysis and meta-regression analyses.

RESULTS

Early menarche (< 12 years) was associated with a significant pooled risk of endometriosis with high heterogeneity (OR = 1.34, 95% CI 1.16-1.54, I² = 72.0%). Stratified analysis showed that this risk was increased in studies started after 2000 (OR = 1.62, 95% CI 0.96-1.35, I² = 74.4%), compared to those before 2000 (OR = 1.13, 95% CI 1.16-1.54, I² = 40.7%); additionally, this risk was higher in low-income countries (OR = 2.11, 95% CI 1.55-2.87, I² = 0%) than in other countries (OR = 1.25, 95% CI 1.09-1.43, I² = 70.6%). These results were further confirmed by meta-regression analysis (both P values < 0.1). No significant differences were found between different study types and NOS scores.

CONCLUSION

Our results suggested an increasing risk of endometriosis with early menarche, which was more noticeable in low-income countries. Large-scale studies are warranted.

Endometriosis and pregnancy: The illusion of recovery

The objective of this study was to investigate the feelings and experiences of infertile women with deep infiltrating endometriosis during and after a first pregnancy achieved by in-vitro fertilization (IVF). We conducted a qualitative monocentric study between May and November 2020. Semi-structured interviews were undertaken with infertile women with deep infiltrating endometriosis who achieved a first pregnancy by IVF and delivered at least two years prior to the interview. Data analysis was performed using an inductive approach to identify recurrent categories and themes. Fifteen interviews were conducted to reach data saturation. Pregnancy appeared to improve all components of the experience of endometriosis that were explored (psychological and physical well-being, social relationships, professional life, and sexuality). This improvement was only temporary and all symptoms and negative aspects of the women’s quality of life reappeared after a variable period.

The Double Engines and Single Checkpoint Theory of Endometriosis

Endometriosis is a chronic disease characterized by the ectopic localization of the endometrial tissue in the peritoneal cavity. Consequently, it causes local pathological changes and systemic symptoms, affecting at least one in every ten women. This disease is difficult to diagnose early, it is prone to dissemination, is difficult to eradicate, tends to recur, and is regarded as “a cancer of no kill”. Indeed, the development of endometriosis closely resembles that of cancer in the way of mutagenesis, pelvic spreading, and immunological adaptation. While retrograde menstruation has been regarded as the primary cause of endometriosis, the role of ovulation and menstrual stimuli in the development of endometriosis has long been overlooked. The development of ovarian and peritoneal endometrioses, similar to the development of high-grade serous carcinoma in the fallopian tube fimbriae with intraperitoneal metastasis, depends highly on the carcinogens released during ovulation. Moreover, endometriosis carries an extremely hypermutated genome, which is non-inferior to the ultra-mutated endometrial cancer. The hypermutation would lead to an overproduction of new proteins or neoantigens. Because of this, the developing endometriosis may have to turn on the PD-1/PDL-1 “self-tolerance” checkpoint to evade immune surveillance, leaving an Achilles tendon for an immune checkpoint blockade. In this review, we present the double engines and single checkpoint theory of the genesis of endometriosis, provide the current pieces of evidence supporting the hypothesis, and discuss the new directions of prevention and treatment.

Does it make sense to refreeze ovarian tissue after unexpected occurrence of endometriosis when transplanting the tissue?

Background

Ovarian insufficiency is a major concern for long-term cancer survivors. Ovarian tissue cryopreservation for fertility preservation is an emerging technique that has proven successful over the past decade through transplantation of frozen-thawed ovarian tissue. Compared to other established techniques, such as oocyte freezing, ovarian tissue cryopreservation preserves actual organ function and thus the production of sex hormones. Endometriosis in perimenopausal women is rare, however it can be surprising diagnosis in the planned transplantation of cryopreserved ovarian tissue and the already thawed tissue may not be transplanted, so that it has to be refrozen.

Results

Ovarian function returned in the patient two months after transplantation, as shown by estrogen production. Ten months after the ovarian tissue transplantation mild stimulation with FSH was initiated in accordance with a low-dose protocol. When ultrasonography revealed a follicle 17 mm in size in the ovarian graft, hCG was added and after follicular puncture one oocyte was obtained. The oocyte could be fertilized by IVF and transferred to the uterus. On day 14 after embryo-transfer, a positive hCG-Level was detected and after an uncomplicated pregnancy a healthy child was delivered.

Conclusions

We report the first pregnancy and live birth achieved using transplantation of thawed and refrozen ovarian tissue in a woman treated by chemotherapy and subsequent endometriosis surgery. Refreezing of cryopreserved ovarian tissue is not a hindrance to successful transplantation of ovarian tissue. Against the background of increasing numbers of candidates for transplantation of ovarian tissue is expected that the combination chemotherapy followed by endometriosis will increase.

Menstrual cycle length and adverse pregnancy outcomes among women in Project Viva

BACKGROUND

Retrospective studies suggest that menstrual cycle length may be a risk marker of adverse pregnancy outcomes, but this evidence is susceptible to recall bias.

OBJECTIVE

To evaluate the prospective association between menstrual cycle length and the risk of adverse pregnancy outcomes.

METHODS

Secondary analysis of 2046 women enrolled in Project Viva at ~10 weeks of gestation and followed through delivery. The exposure was menstrual cycle length. The outcomes included gestational glucose tolerance (gestational diabetes/impaired glucose tolerance [GDM/IGT] and isolated hyperglycaemia), hypertensive disorders of pregnancy (gestational hypertension/preeclampsia), gestational weight gain, birthweight-for-gestational age z-scores (BWZ) categorised in tertiles, preterm birth and birth outcome (live birth and pregnancy loss). We used modified Poisson and multinomial logistic regression adjusted for age, race/ethnicity, parity, age at menarche and pre-pregnancy body mass index.

RESULTS

Mean (SD) age at enrolment was 32.1 (4.9) years. Most women (74.3%) had a cycle length of 26-34 days (reference group), 16.2% reported short cycles (≤25 days), and 9.5% reported long/irregular cycles (≥35 days/too irregular to estimate). Compared with the reference group, women with short cycles had lower odds of GDM/IGT (odds ratio [OR] 0.50, 95% confidence interval [CI] 0.28, 0.89), whereas women with long/irregular cycles had higher odds (OR 1.72, 95% CI 1.04, 2.83). Additionally, women with short cycles had higher odds of having a newborn in the lowest tertile of BWZ (OR 1.45, 95% CI 1.06, 1.98). There was a U-shaped relation between cycle length and preterm birth with both short (relative risk [RR] 1.49, 95% CI 0.98, 2.27) and long/irregular (RR 2.04, 95% CI 1.30, 3.20) cycles, associated with a higher risk.

CONCLUSIONS

Variation in menstrual cycle length may be a risk marker of GDM/IGT, lower birth size and preterm birth and flag women who may benefit from targeted monitoring and care before and during pregnancy.

Efficacy of excision versus ablation for improving endometriosis related pain: A systematic review and meta-analysis

Background:

Surgical treatment of superficial peritoneal endometriosis includes excision or ablation. Controversy exists about which method is better for providing pain relief. We performed a meta-analysis of randomized control trials (RCTs) comparing the efficacy of excision versus ablation for improving the most frequently encountered endometriosis pain symptoms: dysmenorrhea, dyspareunia, non-cyclic pelvic pain, and dyschezia.

Methods:

A search from inception to May 2020 was conducted in PubMed, MEDLINE, Clinicaltrials.gov, Cochrane Central Register of Controlled Trials, and Web of Science. RCTs comparing excision versus ablation for peritoneal endometriosis were included if they assessed dysmenorrhea, dyspareunia, dyschezia, and pelvic pain/non-menstrual pain. Exclusion criteria included extra-peritoneal endometriosis or endometriomas, and non-English publications. Publications were assessed for risk of bias and quality of evidence using Cochrane risk of bias tool (RoB 2) and GradePro.

Results:

Of the 2025 records identified initially, four met inclusion criteria. The sample sizes of the included studies ranged from 24 to 133 participants. The excision and ablation groups included 204 participants each. There was no difference after excision or ablation for dysmenorrhea when comparing the mean change in pain scores from baseline to 12 months after surgery (−0.31, 95% CI −1.66, 1.04, p = 0.65), dyspareunia (−0.24, 95% CI −1.78, 1.30, p = 0.76), dyschezia (−0.72, 95% CI −1.94, 0.50, p = 0.25), or non-cyclic pain (−0.78, 95% CI −2.47, 0.91, p = 0.37).

Conclusions:

We found low to moderate quality evidence suggesting that neither excision nor ablation is superior in reduction of endometriosis-related pain up to 12 months after surgery.

A More Diverse Cervical Microbiome Associates with Better Clinical Outcomes in Patients with Endometriosis: A Pilot Study

Infection-induced chronic inflammation is common in patients with endometriosis. Although microbial communities in the reproductive tracts of patients have been reported, little was known about their dynamic profiles during disease progression and complication development. Microbial communities in cervical mucus were collected by cervical swabs from 10 healthy women and 23 patients, and analyzed by 16S rRNA amplicon sequencing. The abundance, ecological relationships and functional networks of microbiota were characterized according to their prevalence, clinical stages, and clinical features including deeply infiltrating endometriosis (DIE), CA125, pain score and infertility. Cervical microbiome can be altered during endometriosis development and progression with a tendency of increased Firmicutes and decreased Actinobacteria and Bacteroidetes. Distinct from vaginal microbiome, upregulation of Lactobacillus, in combination with increased Streptococcus and decreased Dialister, was frequently associated with advanced endometriosis stages, DIE, higher CA125 levels, severe pain, and infertility. Significantly, reduced richness and diversity of cervical microbiome were detected in patients with more severe clinical symptoms. Clinical treatments against infertility can partially reverse the ecological balance of microbes through remodeling nutrition metabolism and transport and cell-cell/cell-matrix interaction. This study provides a new understanding on endometriosis development and a more diverse cervical microbiome may be beneficial for patients to have better clinical outcomes.

Association Between Laparoscopically Confirmed Endometriosis and Risk of Early Natural Menopause

Importance

Early natural menopause (ENM) has been associated with reduced reproductive span, cardiovascular disease risk, and early mortality. The potential adverse implications of endometrioma surgery for ovarian reserve are known, yet the association of endometriosis with menopausal timing remains understudied.

Objective

To investigate the association between endometriosis and risk for ENM.

Design, Setting, and Participants

This large, population-based cohort study analyzed data from the Nurses' Health Study II cohort questionnaires from the 1989 to 2015 questionnaire cycles. The sample included premenopausal women aged 25 to 42 years at baseline or enrollment in 1989. Cumulative follow-up rate was greater than 90%, and participants continued follow-up until the onset of ENM, age 45 years, hysterectomy, oophorectomy, cancer diagnosis, death, loss to follow-up, or end of follow-up in May 2017, whichever occurred first. Data analyses were conducted from October 26, 2020, to April 27, 2021.

Exposures

Endometriosis diagnosis status was queried in the biennial questionnaires, with participants reporting physician diagnosis and whether the diagnosis was laparoscopically confirmed.

Main Outcomes and Measures

Natural menopause before age 45 years. Menopause status was assessed every 2 years.

Results

The study included 106 633 premenopausal women with a mean (SD) age of 34.8 (4.3) years at baseline, of whom 3921 reported a laparoscopically confirmed endometriosis diagnosis. During 1 508 462 person-years of follow-up, 6640 participants reported being diagnosed with endometriosis, 99 993 never reported endometriosis, and 2542 reported experiencing ENM. In the age- and calendar time-adjusted model, laparoscopically confirmed endometriosis was associated with a 50% greater risk for ENM (hazard ratio [HR], 1.51; 95% CI, 1.30-1.74). A similar risk was observed after adjusting for race and ethnicity and time-varying anthropometric and behavioral factors (HR, 1.46; 95% CI, 1.26-1.69). With additional adjustment for reproductive factors, the HR of ENM was attenuated but significant (HR, 1.28; 95% CI, 1.10-1.48). A greater risk of ENM was observed among women who were nulliparous after stratifying by parity (nulliparous vs parous: HR, 1.46 [95% CI, 1.15-1.86] vs 1.14 [95% CI, 0.94-1.39]; P for heterogeneity = .05) or who never used oral contraceptives when stratifying by oral contraceptive use (never vs ever: HR, 2.03 [95% CI, 1.34-3.06] vs 1.20 [95% CI, 1.02-1.42]; P for heterogeneity = .02). No significant differences were observed in the association between endometriosis and ENM when stratifying by body mass index (calculated as weight in kilograms divided by height in meters squared; <25 vs ≥25: HR, 1.20 [95% CI, 0.99-1.45] vs 1.43 [95% CI, 1.11-1.83; P for heterogeneity = .34), cigarette smoking status (never vs ever: HR, 1.36 [95% CI, 1.13-1.65] vs 1.11 [95% CI, 0.87-1.42]; P for heterogeneity = .57), or history of infertility attributed to ovulatory disorder (no vs yes: HR, 1.28 [95% CI, 1.08-1.51] vs 1.28 [95% CI, 0.90-1.82]; P for heterogeneity = .86).

Conclusions and Relevance

This cohort study found a risk for ENM in women with laparoscopically confirmed endometriosis. These women compared with those without endometriosis may be at a higher risk for shortened reproductive duration, particularly those who were nulliparous or never used oral contraceptives.

Brief Review of Endometriosis and the Role of Trace Elements

Endometriosis is a chronic, estrogen-dependent, inflammatory condition that is defined as the presence of endometrial glands and stroma outside the uterine cavity. Despite the progress in research into the mechanisms leading to the development of endometriosis, its cause has not yet been established. It seems to be possible that the formation of oxidative stress may be one of the main causes of the development of endometriosis. There is much research that studies the potential role of trace elements in the appearance of endometrial-like lesions. Most studies focus on assessing the content of selected trace elements in the blood, urine, or peritoneal fluid in women with endometriosis. Meanwhile, little is known about the content of these elements in endometrial-like implants, which may be helpful in developing the theory of endometriosis. Investigations that are more comprehensive are needed to confirm a hypothesis that some trace elements play a role in the pathomechanism of endometriosis.

Effects of Breastfeeding on Endometriosis-Related Pain: A Prospective Observational Study

Endometriosis is a gynecological estrogen-dependent disease whose commonest pain symptoms are dysmenorrhea, dyspareunia, and acyclic chronic pelvic pain (CPP). Hormonal changes occurring during breastfeeding seem to reduce pain and disease recurrence. The aim of this observational prospective study was to assess the effect of breastfeeding on pain and endometriotic lesions in patients with endometriosis and to evaluate a possible correlation between the duration of breastfeeding, postpartum amenorrhea, and pain. Out of 156 pregnant women with endometriosis enrolled, 123 who breastfed were included in the study and were monitored for 2 years after delivery; 96/123 exclusively breastfed for at least 1 month. Mode of delivery, type and duration of breastfeeding, intensity of pain symptoms, and lesion size before pregnancy and during the 24-month follow-up were analyzed. All patients experienced a significant reduction in dysmenorrhea proportional to the duration of breastfeeding. CPP was significantly reduced only in women who exclusively breastfed. No significant improvement in dyspareunia was observed. Ovarian endometriomas were significantly reduced. Therefore, breastfeeding, particularly if exclusive, may cause improvement in dysmenorrhea and CPP proportional to the duration of breastfeeding, as well as a reduction in the size of ovarian endometriomas.

Peripheral, Central, and Cross Sensitization in Endometriosis-Associated Pain and Comorbid Pain Syndromes

Endometriosis-associated pain and the mechanisms responsible for its initiation and persistence are complex and difficult to treat. Endometriosis-associated pain is experienced as dysmenorrhea, cyclical pain related to organ function including dysuria, dyschezia and dyspareunia, and persistent pelvic pain. Pain symptomatology correlates poorly with the extent of macroscopic disease. In addition to the local effects of disease, endometriosis-associated pain develops as a product of peripheral sensitization, central sensitization and cross sensitization. Endometriosis-associated pain is further contributed to by comorbid pain conditions, such as bladder pain syndrome, irritable bowel syndrome, abdomino-pelvic myalgia and vulvodynia. This article will review endometriosis-associated pain, its mechanisms, and its comorbid pain syndromes with a view to aiding the clinician in navigating the literature and terminology of pain and pain syndromes. Limitations of our current understanding of endometriosis-associated pain will be acknowledged. Where possible, commonalities in pain mechanisms between endometriosis-associated pain and comorbid pain syndromes will be highlighted.

Medical management of endometriosis

INTRODUCTION

Endometriosis is a benign gynecologic disorder that is defined as functional endometrial tissue outside of the uterine cavity. It is an estrogen-dependent, inflammatory disease that leads to symptoms of pelvic pain, dysmenorrhea, dyspareunia, and infertility, occurring in 6-10% of reproductive aged women. The severity of the disease ranges from asymptomatic to debilitating symptoms that have a major impact on women's lives. It is a chronic, recurrent disease, frequently requiring long term management until menopause and beyond. It is considered a chronic disorder that is managed with surgery, medical treatment, and oftentimes, both. Current medical therapy for endometriosis is considered suppressive of the disease, rather than curative. Fortunately, many patients do experience improvement and control of their symptoms with medical therapy. However, long-term efficacy of the medical treatments is often limited by side effects and the cost of therapy, and symptoms do tend to recur after discontinuation of these medications.

AREAS COVERED

This review summarizes our understanding of the pathogenesis of endometriosis and provides more in-depth discussion of specific medical management options used to treat endometriosis, including mechanism of action and side effects. It also provides recommendations on strategy with a forward look to novel endometriosis treatments in the future.

EXPERT OPINION

The authors emphasize that endometriosis is a chronic disorder requiring long term medical therapy. Early diagnosis of endometriosis is key in preventing severe, debilitating symptoms and progression of disease. By utilizing our current knowledge of the pathophysiology of endometriosis and by correctly implementing currently available medical and surgical therapies we can significantly reduce the physical, psychosocial and financial burden of this chronic, recurrent and indolent disease. Current available medications are suppressive therapies, but the authors are looking forward to future therapies that can effectively cure or at least control endometriosis with minimal side effects. Future research should continue to look for the genetic trigger for endometriosis which can lead us to its underlying pathogenesis and eventually a cure or prevention.

Current Knowledge on Endometriosis Etiology: A Systematic Review of Literature

Objective

To review the mechanisms of endometriosis development, including those related to epigenetic mutations, cellular dysregulation, inflammatory processes, and oxidative stress.

Methods

A systematic literature review regarding current aspects of endometriosis etiology, genesis and development was performed using the PubMed, Google Scholar, and eLibrary databases. Keywords included endometriosis, etiology, development, genesis, associations and mechanisms. A multilingual search was performed.

Results

Several mechanisms underline the pathophysiological pathways for endometriosis development. Epigenetic mutations, external and internal influences, and chronic conditions have a significant impact on endometriosis development, survival and regulation. Several historically valid theories on endometriosis development were discussed, as well as updated findings.

Conclusion

Despite recent advances, fundamental problems in understanding endometriosis remain unresolved. The identification of unknown circulating epithelial progenitors or stem cells that are responsible for epithelial growth in both the endometrium and endometriotic foci seems to be the next step in solving these questions.

Is primary dysmenorrhea a precursor of future endometriosis development?

Primary dysmenorrhea (PD) is the most common gynecologic disorder during adolescence and it is characterized by crampy lower abdominal pain that occurs during menstruation. Secondary dysmenorrhea, in contrast, has the same clinical features but occurs in women with a disease that could account for their symptoms (endometriosis, adenomyosis, uterine fibroids, pelvic inflammatory disease). Endometriosis is the most common cause of secondary dysmenorrhea and it should be considered in patients with persistent and clinically significant dysmenorrhea despite treatment. It is often diagnosed after a long delay, increasing the likelihood of pain chronicity and fertility problems at a later age. Women who suffer from dysmenorrhea in adolescence have higher risk of endometriosis in future. The open question is if endometriosis was already present at the onset of dysmenorrhea but undiagnosed or if PD favors subsequent development of endometriosis-associated pain. Since PD is associated with higher risk for developing chronic pain state and shares some of the same pain pathways of endometriosis (prostaglandins overproduction, inflammation, peripheral sensitization, central sensitization and abnormal stress responses), a correlation between PD and endometriosis is suggested. To know whether it is a risk factor for the development of endometriosis-associated pain may provide an opportunity for early intervention and prevention. The present review aims to investigate the clinical and pathogenetic features of PD and endometriosis in order to identify a possible association between the two conditions.

A prospective study of endometriosis and risk of type 2 diabetes

AIMS/HYPOTHESIS

The objective of this study was to investigate the association between laparoscopically confirmed endometriosis and risk of type 2 diabetes.

METHODS

We used data from the Nurses' Health Study II, a prospective cohort of female nurses followed for >25 years (N = 112,037). We used Cox proportional hazards models to estimate the HRs and 95% CIs of incident, confirmed type 2 diabetes (n = 8496 participants) adjusted a priori for confounding factors. We additionally investigated differences in the relationship between endometriosis and type 2 diabetes by age (<50 or ≥50 years), BMI (<30 or ≥30 kg/m²), infertility history, menopausal status and history of gestational diabetes mellitus (GDM; restricted to parous women).

RESULTS

We saw no association between laparoscopically confirmed endometriosis and risk of type 2 diabetes in multivariable confounder-adjusted models (HR 1.06 [95% CI 0.98, 1.13]) or models accounting for potential mediating factors (HR 0.94 [95% CI 0.87, 1.00]). However, we observed modest differences in the association between endometriosis and type 2 diabetes by BMI group, history of infertility and history of GDM. Among non-obese women (HR 1.17 [95% CI 1.02, 1.35]), women who never experienced infertility (HR 1.14 [95% CI 1.04, 1.25]) and women who never experienced GDM (HR 1.11 [95% CI 1.01, 1.22]), endometriosis was associated with greater risk of type 2 diabetes.

CONCLUSIONS/INTERPRETATION

Overall, women with endometriosis were not at increased risk of type 2 diabetes. However, among subgroups at low risk for type 2 diabetes (i.e. non-obese women and women with no prior history of infertility or GDM), endometriosis was associated with a modest increased risk of type 2 diabetes.

ADAMS-1 and ADAMS-9, novel markers in endometriosis

Objectives:

ADAMTS (A Disintegrin And Metalloproteinase with ThromboSpondin repeats) proteinases, which are released outside the cell (soluble) have very critical roles in damage and repair of extracellular matrix (ECM) processes. Our aim was to analyse the ADAMTS-1 and ADAMTS-9 which were the member of the ADAMTS gene family of metalloproteinases that might had been involved in the cytokines-mediated etiopathogenesis of endometriosis.

Methods:

A case-control study was performed in an university hospital. Thirty-four patient with endometriosis which was defined via laparoscopy and thirty-three healthy female volunteers were recruited in the present study. Serum ADAMTS-1 and ADAMTS-9 and IL-beta (IL-1 β) and vascular endothelial growth factor (VEGF) levels were determined by a human enzyme-linked immunoassay (ELISA) in all subjects.

Results:

The demographic characteristics of the patients were significantly higher than healthy control group. The IL-1 β and VEGF levels were significantly higher; ADAMTS-1 and ADAMTS-9 levels were significantly lower in the endometriosis patients compared to the controls. We also found a negative correlation between ADAMTS-1, ADAMTS-9, and IL-1 β, VEGF.

Conclusion:

The results of the study might suggest that ADAMS-1 and ADAMTS-9 have a role in the pathogenesis of the endometriosis.

A Systematic Two-Sample Mendelian Randomization Analysis Identifies Shared Genetic Origin of Endometriosis and Associated Phenotypes

Endometriosis, one of the most common gynecological disorders, is a complex disease characterized by the growth of endometrial-like tissue in extra-uterine locations and is a cause of pelvic pain and infertility. Evidence from observational studies indicate that endometriosis usually appears together with several other phenotypes. These include a list of autoimmune diseases, most of them more prevalent in women, anthropometric traits associated with leanness in the adulthood, as well as female reproductive traits, including altered hormone levels and those associated with a prolonged exposure to menstruation. However, the biological mechanisms underlying their co-morbidity remains unknown. To explore whether those phenotypes and endometriosis share a common genetic origin, we performed a systematic Two-Sample Mendelian Randomization (2SMR) analysis using public GWAS data. Our results suggest potential common genetic roots between endometriosis and female anthropometric and reproductive traits. Particularly, our data suggests that reduced weight and BMI might be mediating the genetic susceptibility to suffer endometriosis. Furthermore, data on female reproductive traits strongly suggest that genetic variants that predispose to a more frequent exposure to menstruation, through earlier age at menarche and shorter menstrual cycles, might also increase the risk to suffer from endometriosis.

Recreational and residential sun exposure and risk of endometriosis: a prospective cohort study

STUDY QUESTION

Is recreational and residential sun exposure associated with risk of endometriosis?

SUMMARY ANSWER

Tanning bed use in early adulthood, sunscreen use and history of sunburns were associated with a greater risk of endometriosis; however, higher residential UV exposure was associated with a lower endometriosis risk.

WHAT IS KNOWN ALREADY

Previous research has reported an association between endometriosis and skin cancer, with evidence of shared risk factors between the two diseases. We investigated the potential associations between ultraviolet radiation and endometriosis risk.

STUDY DESIGN, SIZE, DURATION

The Nurses' Health Study II is a prospective cohort of 116 429 female US nurses aged 25-42 years at enrolment in 1989. Participants completed self-administered biennial questionnaires through June 2015.

PARTICIPANTS/MATERIALS, SETTINGS, METHODS

We investigated self-reported measures of recreational sun-exposure and geocoded residential UV exposure in childhood and adulthood in relation to risk of laparoscopically confirmed endometriosis among premenopausal white women. We used Cox proportional hazards models to calculate hazard ratios (HRs) and 95% CIs.

MAIN RESULTS AND THE ROLE OF CHANCE

During follow-up, 4791 incident cases of laparoscopically confirmed endometriosis were reported among 1 252  248 person-years. Tanning bed use during high school/college (≥6 times per year vs. never use: HR = 1.19, 95% CI = 1.01-1.40; Ptrend = 0.04) and at ages 25-35 (HR = 1.24, 95% CI = 1.12-1.39; Ptrend ≤ 0.0001), number of sunburns during adolescence (Ptrend = 0.03) and percentage of time using sunscreen in adulthood (Ptrend = 0.002) were positively associated with risk of endometriosis. In contrast, residential UV level at birth (highest vs. lowest quintile: HR = 0.81, 95% CI = 0.72-0.92; Ptrend = 0.0001), at age 15 (HR = 0.79, 95% CI = 0.70-0.88; Ptrend ≤ 0.0001) and at age 30 (HR = 0.90, 95% CI = 0.82-0.99; Ptrend = 0.21) were associated with a decreased risk of endometriosis.

LIMITATIONS, REASONS FOR CAUTION

Self-reported endometriosis diagnosis may be prone to misclassification; however, we restricted our definition to laparoscopically confirmed endometriosis, which has been shown to have high validity compared to medical records.

WIDER IMPLICATIONS OF THE FINDINGS

Our results suggest that tanning bed use in early adulthood increases endometriosis risk, potentially through a harmful effect of ultraviolet A wavelengths, and that residential UV exposure reduces risk, possibly via optimal vitamin D synthesis. These findings should be investigated further to enhance our understanding of endometriosis aetiology.

STUDY FUNDING/COMPETING INTEREST(S)

This project was supported by NICHD grants HD48544 and HD52473, HD57210, NIH grant CA50385, CA176726. M.K. was supported by a Marie Curie International Outgoing Fellowship within the 7th European Community Framework Programme (#PIOF-GA-2011-302078) and is grateful to the Philippe Foundation and the Bettencourt-Schueller Foundation for their financial support. H.R.H. is supported by the National Cancer Institute, National Institutes of Health (K22 CA193860). The authors have nothing to disclose.

TRIAL REGISTRATION NUMBER

N/A.

Racial Differences in Population Attributable Risk for Epithelial Ovarian Cancer in the OCWAA Consortium

BACKGROUND

The causes of racial disparities in epithelial ovarian cancer (EOC) incidence remain unclear. Differences in the prevalence of ovarian cancer risk factors may explain disparities in EOC incidence among African American (AA) and White women.

METHODS

We used data from 4 case-control studies and 3 case-control studies nested within prospective cohorts in the Ovarian Cancer in Women of African Ancestry Consortium to estimate race-specific associations of 10 known or suspected EOC risk factors using logistic regression. Using the Bruzzi method, race-specific population attributable risks (PAR) were estimated for each risk factor individually and collectively, including groupings of exposures (reproductive factors and modifiable factors). All statistical tests were 2-sided.

RESULTS

Among 3244 White EOC cases and 9638 controls and 1052 AA EOC cases and 2410 controls, AA women had a statistically significantly higher PAR (false discovery rate [FDR] P < .001) for first-degree family history of breast cancer (PAR = 10.1%, 95% confidence interval [CI] = 6.5% to 13.7%) compared with White women (PAR = 2.6%, 95% CI = 0.8% to 4.4%). After multiple test correction, AA women had a higher PAR than White women when evaluating all risk factors collectively (PAR = 61.6%, 95% CI = 48.6% to 71.3% vs PAR = 43.0%, 95% CI = 32.8% to 51.4%, respectively; FDR P = .06) and for modifiable exposures, including body mass index, oral contraceptives, aspirin, and body powder (PAR = 36.0%, 95% CI = 21.0% to 48.8% vs PAR = 13.8%, 95% CI = 4.5% to 21.8%, respectively; FDR P = .04).

CONCLUSIONS

Collectively, the selected risk factors accounted for slightly more of the risk among AA than White women, and interventions to reduce EOC incidence that are focused on multiple modifiable risk factors may be slightly more beneficial to AA women than White women at risk for EOC.

Markers of Local and Systemic Estrogen Metabolism in Endometriosis

Estrogen metabolites (EMs) can work independently from their parent hormones. We hypothesize that in endometriosis, estrogen is metabolized preferentially along hormonally active pathways. We recruited 62 women with endometriosis (proven laparoscopically and histologically) and 52 control women (normal findings with laparoscopy) among patients undergoing surgery for pelvic pain and/or infertility during the proliferative phase of the menstrual cycle. Urinary samples were collected preoperatively. Biopsies from eutopic endometrium of control women and women with endometriosis were collected during surgery. EMs in urine and endometrial tissues were extracted and determined using Liquid Chromatography-Electrospray Ionization Tandem Mass Spectrometry (LC-ESI-MS/MS). These included: 2-hydroxyestrone (2OHE1), 16-α hydroxyestrone (16α-OHE1), 2OHE1/16α-OHE1 ratio, 4-hydroxyestrone (4OHE1), 2-hydroxyestradiol (2OHE2), and 4-hydroxyestradiol (4OHE2). Eutopic endometrium of endometriosis patients, as compared to control endometrium, contained significantly higher level of 4OHE1 (0.03 (IQR: 0.03-0.265) versus 0.03 (IQR: 0.03-0.03) μg/g, respectively, P = 0.005), 2-OHE2 (0.241 (IQR: 0.1-0.960) versus 0.1 (IQR: 0.1-0.1) μg/g, respectively, P < 0.001), and 4-OHE2 (0.225 (IQR: 0.22-1.29) versus 0.0.2 (IQR: 0.2-0.2) μg/g, respectively, P < 0.001). Only 2OHE1 showed higher concentration in urine of women with endometriosis than controls (9.9 (IQR: 3.64-14.88) versus 4.5 (IQR: 1.37-17.00) μg/mg creatinine, respectively, P = 0.042). Eutopic endometrium of women with endometriosis metabolizes estrogen preferentially to the biologically active 2OHE2, and potentially genotoxic 4OHE1 and 4OHE2 metabolites. This contributes to further understanding of endometriosis etiology, its link to ovarian cancer, and could help identifying an endometrial biomarker of the disease.

Developing Preoperative Nomograms to Predict Any-Stage and Stage III-IV Endometriosis in Infertile Women

Study objective: To generate and validate nomograms to predict any-stage and stage III-IV endometriosis before surgery in infertile women.

Design: A single center retrospective cohort study.

Setting: University affiliated hospital.

Patients: Infertile patients (n = 1,016) who underwent reproductive surgery between July 1, 2016 and June 30, 2019.

Interventions: None.

Main outcome measurements: We randomly selected 2/3 of the included patients (667 patients, training sample) to analyze and generate predictive models and validated the models on the remaining patients (339 patients, validation sample). A multivariate logistic regression model was used with the training sample to select variables using a back stepwise procedure. Nomograms to predict any-stage and stage III–IV endometriosis were constructed separately. The discriminations and calibrations of both nomograms were tested on the overall population and a subgroup without endometrioma diagnosed on transvaginal sonography (TVS) of training and validation samples. The impact of different variables in these models was evaluated.

Results: There were 377 (55.7%) women in the training sample and 196 (57.8%) in the validation sample who were diagnosed with endometriosis. The nomogram predicting any-stage endometriosis had an area under the curve (AUC) of 0.760 for the training sample and 0.744 for the validation sample, with favorable calibrations in the overall population. However, the performance was significantly decreased in patients without endometrioma on TVS, with an AUC of 0.726 in the training sample and 0.694 in the validation sample. Similarly, the nomogram predicting stage III–IV endometriosis had an AUC of 0.833 and 0.793 for the training and validation samples, respectively, as well as a favorable calibration. However, the performance of the nomogram on patients without endometrioma on TVS was poor. Endometrioma on TVS strongly predicted both any stage and stage III–IV endometriosis on both samples.

Conclusion: We developed nomograms to predict any-stage and stage III–IV endometriosis but their performance were significantly decreased in patients without endometrioma on TVS. Endometrioma on TVS strongly predicted any and III–IV stage endometriosis in both sample groups. Therefore, we recommend that this study be used as encouragement to advance the utilization of advanced imaging for endometriosis for better clinical prognosis.

The estimated prevalence and incidence of endometriosis with the Korean National Health Insurance Service-National Sample Cohort (NHIS-NCS): A National Population-based Study

Background

The incidence and prevalence of endometriosis remain unclear due to diagnostic difficulties. Especially, there has been little information regarding the population-based epidemiology of endometriosis. The purpose of this study is to estimate the prevalence and incidence of endometriosis in Korea based on the health insurance claims data.

Methods

This study is a retrospective cohort study using the Korean National Health Insurance Service-National Sample Cohort, which correspond to approximately 1 million Korean populations from 2002 to 2013. Patients aged 15–54 years were selected, and the prevalence and incidence of endometriosis were estimated by time and age groups.

Results

The age-adjusted prevalence rate of endometriosis also increased from 2.12 per 1,000 persons (95% confidence interval [CI], 2.01–2.24) in 2002 to 3.56 per 1,000 persons (95% CI, 3.40–3.71) in 2013. The average adjusted incidence showed no statistically significant increase. However, the age-specific incidence of the 15–19 and 20–24 years age groups increased significantly from 0.24 and 1.29 per 1,000 persons in 2003 to 2.73 and 2.71 per 1,000 persons in 2013 (R² = 0.93 and 0.77, P < 0.001), while the incidence rate of the age group 40–44 and 45–49 years decreased from 2.36 and 1.72 per 1,000 persons in 2003 to 0.81 and 0.27 per 1,000 persons in 2013 (R² = 0.83 and 0.89, P < 0.001).

Conclusion

The prevalence and incidence of endometriosis in Korean women were lower than that of previous reports in high-risk population studies. Furthermore, we found a significant increase in the diagnosis of endometriosis in younger age groups.

Endometriosis: current challenges in modeling a multifactorial disease of unknown etiology

Endometriosis is a chronic inflammatory hormone-dependent condition associated with pelvic pain and infertility, characterized by the growth of ectopic endometrium outside the uterus. Given its still unknown etiology, treatments usually aim at diminishing pain and/or achieving pregnancy. Despite some progress in defining mode-of-action for drug development, the lack of reliable animal models indicates that novel approaches are required. The difficulties inherent to modeling endometriosis are related to its multifactorial nature, a condition that hinders the recreation of its pathology and the identification of clinically relevant metrics to assess drug efficacy. In this review, we report and comment endometriosis models and how they have led to new therapies. We envision a roadmap for endometriosis research, integrating Artificial Intelligence, three-dimensional cultures and organ-on-chip models as ways to achieve better understanding of physiopathological features and better tailored effective treatments.

Peripheral Blood Leukocyte Telomere Length and Endometriosis

Endometriosis is a common gynecologic disease defined by the presence of endometrial-like tissue outside the uterine cavity. While its etiology is largely unknown, accumulating evidence suggests that inflammation plays a major role. Our objective was to investigate the association between peripheral blood leukocyte telomere length (LTL) and endometriosis using data from two large population-based studies, the New England Case-Control Study (NEC; n = 877) and the National Health and Nutrition Examination Survey (NHANES; n = 2268). NEC control participants were identified through a combination of random digit dialing, drivers' license lists, and town resident lists. In NHANES, selection algorithms were used to identify a nationally representative sample. Blood samples and demographic, reproductive, and health-related information were available from both data sources. Endometriosis was defined as self-reported of physician-diagnosed endometriosis. LTL was measured using quantitative polymerase chain reaction. Multivariable logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (CI) for the association between LTL and endometriosis. Shorter LTL was associated with greater odds of history of endometriosis. In NEC, women with the shortest LTL tertile compared with the longest had a 2.5-fold greater odds of endometriosis (OR_T3/T1 = 2.56, 95% CI = 1.16-5.63; p value, test for linear trend = 0.02). The association was stronger among women who usually experienced moderate or severe menstrual pain (OR _T3/T1 = 3.50, 95% CI = 1.12-10.97). In NHANES, the data suggested a similar but attenuated association (OR_T3/T1 = 1.29, 95% CI = 0.85-1.96). The observed associations in NEC suggest that shorter LTL may be associated with greater odds of endometriosis. A better understanding of how LTL influences endometriosis risk could elucidate novel disease pathophysiology.

Early-life factors, in-utero exposures and endometriosis risk: a meta-analysis

This meta-analysis aimed to offer a general picture of the available data on the effects of early-life factors on the risk of developing endometriosis in adult life. An advanced, systematic search of the online medical databases PubMed, EMBASE and CINAHL was limited to full-length manuscripts published in English in peer-reviewed journals up to February 2019. Log of relative risk (RR) was employed to calculate the pooled effect sizes using both fixed and random effects modelling and I-squared tests to assess heterogeneity. Funnel plots were used to investigation publication bias. The meta-analysis was registered in PROSPERO (ID CRD42019138668). Six studies that included a total of 2360 women affected by endometriosis were analysed. The pooled results showed that the risk of developing endometriosis in adult life was significantly increased by being born prematurely (logRR 0.21, 95% CI -0.03 to 0.40), having a low birthweight (logRR 0.35, 95% CI -0.15 to 0.54), being formula-fed (logRR 0.65, 95% CI -0.35 to 0.95) and having been exposed to diethylstilbestrol (DES) in utero (logRR 0.65, 95% CI 0.26 to 1.04. Among intrauterine and early neonatal exposures, prematurity, birthweight, formula feeding and DES were risk factors for the development of endometriosis in adult life.

Adolescent Endometriosis: An Update

Endometriosis is the leading pathologic cause of dysmenorrhea and chronic pelvic pain among adolescents. The appearance of endometriosis in adolescents may be different from that in female adults, resulting in delayed recognition and intervention. This article addresses the epidemiology, pathophysiology, clinical presentation, diagnosis, and management of endometriosis in the adolescent.

Adiposity and Endometriosis Severity and Typology

STUDY OBJECTIVE

Prior research has collectively shown that endometriosis is inversely related to women's adiposity. The aim of this study was to assess whether this inverse relationship holds true by disease severity and typology.

DESIGN

Cross-sectional study among women with no prior diagnosis of endometriosis.

SETTING

Fourteen clinical centers in Salt Lake City, UT, and San Francisco, CA.

PATIENTS

A total of 495 women (of which 473 were analyzed), aged 18-44 years, were enrolled in the operative cohort of the Endometriosis, Natural History, Diagnosis, and Outcomes (ENDO) Study.

INTERVENTIONS

Gynecologic laparoscopy/laparotomy regardless of clinical indication.

MEASUREMENTS AND MAIN RESULTS

Participants underwent anthropometric assessments, body composition measurements, and evaluations of body fat distribution ratios before surgery. Surgeons completed a standardized operative report immediately after surgery to capture revised American Society for Reproductive Medicine staging (I-IV) and typology of disease (superficial endometriosis [SE], ovarian endometrioma [OE], and deep infiltrating endometriosis [DIE]). Linear mixed models, taking into account within-clinical-center correlation, were used to generate least square means (95% confidence intervals) to assess differences in adiposity measures by endometriosis stage (no endometriosis, I-IV) and typology (no endometriosis, SE, DIE, OE, OE + DIE) adjusting for age, race/ethnicity, and parity. Although most confidence intervals were wide and overlapping, 3 general impressions emerged: (1) women with incident endometriosis had the lowest anthropometric/body composition indicators compared with those without incident endometriosis, (2) women with stage I or IV endometriosis had lower indicators compared with women with stage II or III, and (3) women with OE and/or DIE tended to have the lowest indicators, whereas women with SE had the highest indicators.

CONCLUSION

Our research highlights that the relationship between women's adiposity and endometriosis severity and typology may be more complicated than prior research indicates.

Evaluation of the ocular surface by impression cytology in patients with endometriosis

OBJECTIVE

The aim of this study was to investigate the effect of endometriosis on the ocular surface.

METHODS

A total of 50 patients were included in the study and divided into two groups. Group 1 consisted of 25 patients with endometriosis. Group 2 had 25 control patients. All patients underwent complete ophthalmic examination, and the right eyes were included in the study. To evaluate the ocular surface, both groups were tested with the following: the Schirmer I test, tear breakup time (TBUT), the conjunctival impression cytology (CIC), and the Ocular Surface Disease Index (OSDI). The results were subsequently compared.

RESULTS

The average Schirmer I test results were 8.40 ± 2.74 mm in group 1 and were significantly lower in patients with endometriosis (P < 0.001). The average TBUT test results were 9.04 ± 3.61 s in group 1 and were significantly lower in patients with endometriosis (P < 0.001). The average OSDI results were 24.04 ± 9.29 in group 1 and were significantly higher in patients with endometriosis (P < 0.001). The average CIC results were 1.76 ± 0.88 in group 1 and were significantly higher in patients with endometriosis (P < 0.001).

CONCLUSIONS

Ocular surface changes, including squamous metaplasia, may be observed in the conjunctiva of patients with endometriosis.

The Origin and Pathogenesis of Endometriosis

Recent molecular genetic findings on endometriosis and normal endometrium suggest a modified model in which circulating epithelial progenitor or stem cells intended to regenerate uterine endometrium after menstruation may become overreactive and trapped outside the uterus. These trapped epithelium-committed progenitor cells form nascent glands through clonal expansion and recruit polyclonal stromal cells, leading to the establishment of deep infiltrating endometriosis. Once formed, the ectopic tissue becomes subject to immune surveillance, resulting in chronic inflammation. The inflammatory response orchestrated by nuclear factor-κB signaling is exacerbated by aberrations in the estrogen receptor-β and progesterone receptor pathways, which are also affected by local inflammation, forming a dysregulated inflammation-hormonal loop. Glandular epithelium within endometriotic tissue harbors cancer-associated mutations that are frequently detected in endometriosis-related ovarian cancers. In this review, we summarize recent advances that have illuminated the origin and pathogenesis of endometriosis and have provided new avenues for research that promise to improve the early diagnosis and management of endometriosis.

Endometriosis and Risk of Adverse Pregnancy Outcomes

OBJECTIVE

To investigate the relationship between endometriosis and adverse pregnancy outcomes.

METHODS

Women between ages 25 and 42 years in 1989 (n=116,429) reported detailed information on pregnancies and reproductive health at baseline and every 2 years thereafter in the Nurses' Health Study II, a cohort study. In 2009, they completed a detailed, pregnancy-focused questionnaire. A total of 196,722 pregnancies were reported. Adverse pregnancy outcomes included spontaneous abortion, ectopic pregnancy, stillbirth, gestational diabetes mellitus (GDM), hypertensive disorders of pregnancy (preeclampsia or gestational hypertension), preterm birth, and low birth weight. We estimated the relative risks (RRs) and 95% CIs of adverse pregnancy outcomes comparing pregnancies in women with and without a history of laparoscopically confirmed endometriosis using multivariable log-binomial regression, with generalized estimating equations to account for multiple pregnancies per woman.

RESULTS

Endometriosis was associated with a greater risk of pregnancy loss (spontaneous abortion: RR 1.40, 95% CI 1.31-1.49; ectopic pregnancy: RR 1.46, 95% CI 1.19-1.80). Endometriosis was also associated with a greater risk of GDM (RR 1.35, 95% CI 1.11-1.63) and hypertensive disorders of pregnancy (RR 1.30, 95% CI 1.16-1.45).

CONCLUSIONS

We observed an association between laparoscopically confirmed endometriosis and several adverse pregnancy outcomes. Future research should focus on the potential biological pathways underlying these relationships to inform screening or preventive interventions.

Endometriosis

Pelvic endometriosis is a complex syndrome characterized by an estrogen-dependent chronic inflammatory process that affects primarily pelvic tissues, including the ovaries. It is caused when shed endometrial tissue travels retrograde into the lower abdominal cavity. Endometriosis is the most common cause of chronic pelvic pain in women and is associated with infertility. The underlying pathologic mechanisms in the intracavitary endometrium and extrauterine endometriotic tissue involve defectively programmed endometrial mesenchymal progenitor/stem cells. Although endometriotic stromal cells, which compose the bulk of endometriotic lesions, do not carry somatic mutations, they demonstrate specific epigenetic abnormalities that alter expression of key transcription factors. For example, GATA-binding factor-6 overexpression transforms an endometrial stromal cell to an endometriotic phenotype, and steroidogenic factor-1 overexpression causes excessive production of estrogen, which drives inflammation via pathologically high levels of estrogen receptor-β. Progesterone receptor deficiency causes progesterone resistance. Populations of endometrial and endometriotic epithelial cells also harbor multiple cancer driver mutations, such as KRAS, which may be associated with the establishment of pelvic endometriosis or ovarian cancer. It is not known how interactions between epigenomically defective stromal cells and the mutated genes in epithelial cells contribute to the pathogenesis of endometriosis. Endometriosis-associated pelvic pain is managed by suppression of ovulatory menses and estrogen production, cyclooxygenase inhibitors, and surgical removal of pelvic lesions, and in vitro fertilization is frequently used to overcome infertility. Although novel targeted treatments are becoming available, as endometriosis pathophysiology is better understood, preventive approaches such as long-term ovulation suppression may play a critical role in the future.

Age at menarche does not correlate with the endometriosis phenotype

Objective

To evaluate the association between the endometriosis phenotype and the age at menarche.

Design

An observational, cross-sectional study using prospectively collected data (Canadian Task Force classification II-2).

Setting

Single university tertiary referral center.

Patients

To be eligible, women had to have undergone their 1^st complete surgical exeresis of endometriotic lesions. For each patient, a standardized questionnaire was completed the month before the surgery. Endometriotic lesions were classified into 3 phenotypes: superficial peritoneal endometriosis (SUP), endometrioma (OMA), or deep infiltrating endometriosis (DIE). Patients were divided into 3 groups: early menarche (< 12 years), typical menarche (≥ 12 and ≤ 13 years) and late menarche (> 13 years). The groups were compared in terms of general characteristics, medical history, disease phenotype, and disease severity.

Interventions

Surgical management for a benign gynecologic condition.

Main Outcome Measure(s)

Correlation between the endometriosis phenotype and the age at menarche.

Measurements and main results

From January 2004 to December 2016, 789 women with histologically confirmed endometriosis were enrolled in the study. The mean age at menarche was 12.9 ± 1.6 years of age, (range 9 to 18). The mean age at menarche and the mean time interval between menarche and the 1^st surgery for endometriosis were not significantly different between the three phenotypes (SUP, OMA, DIE). When women with early menarche, typical menarche, or late menarche were compared, no differences were observed in terms of the endometriosis phenotype and the anatomical distribution of the endometriotic lesions.

Conclusion

For women operated for the first time for endometriosis, age at menarche is not associated with the disease phenotype.

Effects of clarithromycin on inflammatory markers and clinical manifestations in postsurgical follow-up of patients with endometriosis: a double-blinded randomized placebo-controlled clinical trial

PURPOSE

Studies showed anti-inflammatory and immunomodulatory effects of macrolide antibiotics such as clarithromycin in endometriosis. Therefore, the present study aims to investigate the therapeutic efficacy of clarithromycin in patients with endometriosis.

METHODS

This was a double-blinded randomized placebo-controlled trial conducted on endometriotic women during March 2016-2017 in Dena Hospital, Shiraz, Iran. Immediately after surgery, the patients were randomly divided into clarithromycin (real) (n = 120) and placebo group (n = 169). The real group received 500 mg of clarithromycin everyday for 6 months and the placebo group received the placebo. The serum levels of tumor necrosis factor-alpha (TNF-α), interleukin-10 (IL-10), Erythrocyte sedimentation rate (ESR) and C-reactive protein as well as clinical symptoms at baseline and 3 and 6 months of post-surgery were compared within and between groups.

RESULTS

The scores of dysmenorrhea, dyschezia, dyspareunia, and non-menstrual pain significantly decreased in both real and placebo groups compared with the baseline values. However, the real group showed greater reductions compared with the placebo group (p < 0.001). Similarly, the serum levels of CRP, TNF-α, and IL-10 decreased in both groups compared with the baseline values, but the real group showed greater reductions. Interestingly, the reductions in the clinical symptoms and serum levels did not significantly differ between the real and placebo groups. Moreover, the reductions in the studied variables showed no dependence on the time.

CONCLUSION

Clarithromycin may be an appropriate treatment in endometriotic patients. However, the non-significant differences between the real and placebo groups necessitate further studies on the therapeutic efficacy of clarithromycin.

Keeping an Eye on Perimenopausal and Postmenopausal Endometriosis

Introduction: We aimed to describe and review the epidemiological aspect of the disease pattern of a series of perimenopausal and postmenopausal women with a histology confirmation of endometriosis. Material and Methods: We retrospectively examined the clinical records of 184 perimenopausal and 46 postmenopausal women with endometriosis. Data were collected and analyzed from 1100 patients' charts with confirmed endometriosis and involved cases from two different geographical areas, New Haven (US) and Greece. The statistical methods included ײ and the Mann-Whitney U test. In the perimenopausal group (age 45⁻54 years), there were 184 patients (16.7%) and the postmenopausal group (55⁻80 years) had 46 (4.2%). The average age of diagnosis was (49 ± 2.3) and (61.2 ± 5.1), respectively (p < 0.01). Results: Advanced endometriosis was more aggressive in the perimenopausal group (p < 0.05); in the same group, we observed a higher left-sided predisposition of endometriosis in comparison with the right side (p < 0.01). Endometrioma was the most common gynecological condition among patients with perimenopausal endometriosis in relation to the postmenopausal group (p < 0.001). Additionally, we found uterine leiomyomata more prominent in the perimenopausal group (p < 0.05). In contrast, adenomyosis was found higher in postmenopausal patients (p < 0.05); further, 24 cases with dry eye we observed. Conclusions: Postmenopausal endometriosis is an important underestimated condition. Although the reported situation is not common, various clinicopathological characteristics were observed in both groups. Clinicians should be aware that there is a correlation between endometriosis and endometriosis-associated ovarian cancer in perimenopausal and postmenopausal age.

The complex relationship between body mass index and endometriosis

There is an inverse relationship between endometriosis and a women’s body mass index. To date, the precise mechanisms and aetiological basis linking body mass index with endometriosis remain unknown. Although an increased incidence of endometriosis is observed in women with low body mass indices; endometriosis is associated with conditions common to obesity (hypercholesterolemia, hypertension and coronary heart disease). In the context of endometriosis, further research is necessary in women with surgically confirmed disease to improve clinical advice and patient outcomes.

Early life abuse and risk of endometriosis

STUDY QUESTION

Is there an association between physical and sexual abuse occurring in childhood or adolescence and risk of laparoscopically-confirmed endometriosis?

SUMMARY ANSWER

Early life sexual and physical abuse was associated with an increased risk of endometriosis.

WHAT IS KNOWN ALREADY

Previous studies have reported that physical and sexual abuse are associated with chronic pelvic pain (CPP). However, only one study has examined the association between childhood physical abuse and laparoscopically-confirmed endometriosis, and did not observe an association with endometriosis risk.

STUDY DESIGN, SIZE, DURATION

Prospective cohort study using data collected from 60 595 premenopausal women from 1989 to 2013 as part of the Nurses' Health Study II cohort.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants completed an exposure to violence victimization questionnaire in 2001. Cases were restricted to laparoscopically-confirmed endometriosis. Cox proportional hazards models were used to calculate rate ratios (RR) and 95% confidence intervals (CI).

MAIN RESULTS AND THE ROLE OF CHANCE

Three thousand three hundred and ninety-four cases of laparoscopically-confirmed endometriosis were diagnosed during 24 years of follow-up. Compared to those reporting no physical or sexual abuse, the risk of endometriosis was greater among those who experienced severe physical abuse (RR = 1.20; 95% CI = 1.06, 1.37) or severe sexual abuse (RR = 1.49; 95% CI = 1.24, 1.79). There was a 79% increased risk of laparoscopically-confirmed endometriosis for women reporting severe-chronic abuse of multiple types (95% CI = 1.44, 2.22). The associations between abuse and endometriosis were stronger among women presenting without infertility, a group that was more likely to have been symptomatic with respect to pain.

LIMITATIONS, REASONS FOR CAUTION

The violence exposure was recalled by the study participants and thus is subject to misclassification as well as recall bias for the cases who were diagnosed prior to 2001. However, our results were similar in a sensitivity analysis including only endometriosis cases incident after their violence history report. In addition, residual or unmeasured confounding is a possibility; however, we were able to adjust for a variety of potential early life confounders. Finally, selection bias is also a possibility if those who chose to return the violence questionnaire did so based jointly on abuse history and endometriosis risk.

WIDER IMPLICATIONS OF THE FINDINGS

Early life sexual and physical abuse was associated with an increased risk of endometriosis. Severity, chronicity and accumulation of types of abuse were associated with greater risk. Understanding the mechanisms underlying these relations may better define the biologic impacts of abuse and the related pathophysiology of endometriosis.

STUDY FUNDING/COMPETING INTEREST(s)

This work was supported by National Institute of Child Health and Human Development [Grant numbers HD48544, HD52473, HD57210 and CA50385] and the Atlanta Clinical and Translational Science Institute [Grant number ULRR025008]. The Nurses' Health Study II is supported by the National Institutes of Health grant UM1 CA176726 from the National Cancer Institute. H.R.H. is supported by the National Cancer Institute, National Institutes of Health [Grant number K22 CA193860]. Authors report no conflict of interest.

Development and Validation of the Endometriosis Daily Pain Impact Diary Items to Assess Dysmenorrhea and Nonmenstrual Pelvic Pain

Daily diary-based dysmenorrhea and nonmenstrual pelvic pain impact items were developed and validated to measure efficacy in endometriosis clinical trial settings. Items were developed across 3 stages of qualitative research, and their psychometric properties were explored in a phase II randomized controlled trial. Eight focus groups, 20 semistructured telephone interviews, and 15 face-to-face concept elicitation and cognitive debriefing interviews constituted the qualitative phase of the research. Psychometric properties of reliability, convergent validity, and responsiveness of the dysmenorrhea and nonmenstrual pelvic pain daily items were examined quantitatively in a phase II clinical trial of an investigational endometriosis treatment. Both qualitative concept elicitation and cognitive debriefing research yielded wording for item response options that resonated with adult women with endometriosis. Daily assessment of dysmenorrhea and nonmenstrual pelvic pain impact was the preferred measurement approach among adult women with endometriosis. Quantitatively, correlations between the dysmenorrhea and nonmenstrual pelvic pain items and other measures of pain impact provided endorsement for the items' convergent validity. Longitudinal measurement properties, involving test-retest reliability and sensitivity to change/responsiveness, offered evidence for the adequacy of the measurement properties of the daily diary-based dysmenorrhea and nonmenstrual pelvic pain impact items. Data from a phase II trial provided evidence that the daily dysmenorrhea and nonmenstrual pelvic pain impact items, developed and tested through qualitative research involving both focus groups and individual interviews, are well-defined, reliable, valid, and responsive for measuring the impact of pain in endometriosis to assess therapeutic response.

Endometriosis

Endometriosis is a common inflammatory disease characterized by the presence of tissue outside the uterus that resembles endometrium, mainly on pelvic organs and tissues. It affects ~5-10% of women in their reproductive years - translating to 176 million women worldwide - and is associated with pelvic pain and infertility. Diagnosis is reliably established only through surgical visualization with histological verification, although ovarian endometrioma and deep nodular forms of disease can be detected through ultrasonography and MRI. Retrograde menstruation is regarded as an important origin of the endometrial deposits, but other factors are involved, including a favourable endocrine and metabolic environment, epithelial-mesenchymal transition and altered immunity and inflammatory responses in genetically susceptible women. Current treatments are dictated by the primary indication (infertility or pelvic pain) and are limited to surgery and hormonal treatments and analgesics with many adverse effects that rarely provide long-term relief. Endometriosis substantially affects the quality of life of women and their families and imposes costs on society similar to those of other chronic conditions such as type 2 diabetes mellitus, Crohn's disease and rheumatoid arthritis. Future research must focus on understanding the pathogenesis, identifying disease subtypes, developing non-invasive diagnostic methods and targeting non-hormonal treatments that are acceptable to women who wish to conceive.