Endometriosis is a gynecologic condition diagnosed in 6–10% of women of reproductive age, with a prevalence of 20–50% in infertile women and 71–87% of those with chronic pelvic pain (1–3). Hispanic/Latinx persons with endometriosis are underrepresented in research databases and thus unlikely to benefit from research on pathophysiology, biomarkers, and novel treatments (4). The World Endometriosis Research Foundation (WERF) Endometriosis Phenome and Biobanking Harmonization Project (EPHect) provides standardized protocols based on evidence to allow accrual of detailed surgical, clinical, and epidemiologic data from endometriosis patients to support future research. EPHect developed a clinical questionnaire to obtain self-reported demographic and clinical information to allow cross-sectional studies to better understand differences in the endometriosis phenome across populations (5–9).

A PubMed search using the keywords “endometriosis,” “ethnicity,” “Hispanic,” and “Latina” resulted in only three reports on the prevalence of endometriosis symptoms by race/ethnicity. The Nurse's Health Study II's multivariate hazard models concluded that Black [relative risk (RR) 0.6, 95% confidence interval (CI): 0.4–0.9] and Hispanic women (RR 0.6, 95% CI: 0.4–1.0) had a 40% lower rate of endometriosis diagnosis compared with White women (10). A nationwide study by Eggert et al. found rates (cases per 100,000) of endometriosis ranging from 126.2 (Asian countries) to 42.3 (Eritrea/Ethiopia/Somalia), with Latin American countries at 90.9 compared to 101.9 among Sweden-born patients (11). Both studies conclude that non-Hispanic white women have a higher likelihood of a diagnosis of endometriosis compared to other ethnic groups. However, Bougie et al. stated that there is not enough evidence to definitely conclude that the prevalence of endometriosis in Hispanic/Latinx populations is lower. In their recent systematic review and meta-analysis on the ethnic presentation of endometriosis, they identified only five studies that included patients of Hispanic/Latinx background, compared to 16 studies of White vs. Black women, and 10 studies of White vs. Asian women (12, 13). In total, these studies included only 14,951 Hispanic/Latinx patients compared to 65,332 White patients. This meta-analysis showed that endometriosis was more prevalent in Asian women (OR 1.63, 95% CI: 1.03–2.58), less prevalent in Black women (OR 0.49, 95% CI: 0.29–0.83), and less common in Hispanic women (OR 0.46, 95% CI: 0.14–1.50—not statistically significant), compared to White non-Hispanic women.

Lack of data on Hispanic/Latinx patients with endometriosis highlights the need to conduct more epidemiological investigations with diverse populations of patients to evaluate whether there are racial/ethnic differences in disease prevalence, clinical presentation, and response to treatments. More studies are needed to establish if differences in the prevalence of endometriosis and its clinical presentation among ethnic groups are due to socioeconomic factors that impact access to care, to biological/genetic correlates, or to cultural influences on healthcare seeking. To fill this knowledge gap, we aimed to obtain for the first time the clinical profile of endometriosis patients from Latin America and the Caribbean using a Spanish translation of the EPHect's Minimal Clinical Questionnaire (EPQ-M) (9). Here, we report data collected from Spanish-speaking endometriosis patients from 23 countries on demographics, lifestyle, Ob-Gyn, clinical history, pelvic pain symptoms, pain catastrophizing, impact of pain on quality of life, and utilization of pain medications and hormonal treatments.

This study was approved by the Institutional Review Board of the Ponce Research Institute of the Ponce Health Sciences University (PHSU) (IRB Approval #1811001620).

This study was conducted to determine, for the first time, the demographic and clinical profile of endometriosis patients from Ibero-America using the Spanish translation of the EPhect's Minimal Clinical Questionnaire (EPQ-M) (19). Also, we demonstrate that the EPHect questionnaire is an efficient tool for standardized self-reported data collection to allow comparisons of the endometriosis phenome across ethnicities and geographic regions (5). The scarcity of investigations on the prevalence, disease presentation, level of impact, access to health care, and treatments in endometriosis patients who identify as Hispanic/Latinx adds to the current belief that this disease is less prevalent than in non-Hispanic White or Asian women (20). Collecting comprehensive data from patient populations not well-represented in databases is also critical to understand if there are differences in the clinical presentation of endometriosis based on race, genetics, and environmental or cultural factors and ultimately could help solve disparities in their representation in endometriosis research (4).

The translated EPQ-M survey was well-understood and accepted by Spanish-speaking women. Most evaluators considered it to be too long but a useful tool to conduct research on endometriosis across populations. Cross-sectional data was then collected from 1,378 Hispanic/Latinx endometriosis patients, recruited through collaborations with patient associations from South America, Central America, the Caribbean, and Spain, which represents the largest patient cohort from this ethnic background. Though the study link was disseminated through well-organized patient associations, the sample size could be considered small. Since prevalence data of endometriosis in Latin American and Caribbean populations are lacking (21, 22), it is difficult to estimate the generalizability of our study findings. Based on self-reported race, our cohort was 49.6% White, 4.5% Black, and 42.1% mixed race, vs. the estimated racial distribution of Latin American and Caribbean populations of 11% indigenous, 20% Afro descendants, and 40% White, in average, and these proportions vary from country to country (23). On closer look, the distribution of races per country in our study in general is representative of the respective racial proportions, except for Colombia, Mexico, and Venezuela. For example, Spain, Uruguay, and Argentina had the highest proportions of White participants, while countries with high Amerindian heritage such as Ecuador, Perú, and Mexico had the highest proportions of mixed race (Supplemental Table 1). Also, as expected, Black women had the highest participation in Dominican Republic, Panamá, and Puerto Rico, three countries with rich African heritage. Notably, the study had appropriate representation of non-White women (46.6% overall, and either equal to or higher than expected in most countries), who are not often well-represented in research cohorts. Efforts to recruit more diverse patients are ongoing, and future studies to assess the impact of race and ethnicity on endometriosis symptomatology are warranted.

Our study population had a relatively high economic status, the majority being employed and many having a higher degree of education. The level of education of our cohort is within that reported in other studies, ranging from 45 to 85% of patients reporting a higher than high school education (10, 24–26). It has previously been noted that there is an increased prevalence of endometriosis among well-educated women of higher socio-economic status, which may be due to better access to care or health awareness or possibly other lifestyle factors or habits linked to endometriosis risk (27).

Health risk behaviors were uncommon in this patient cohort; <15% reported high levels of alcohol consumption and <10% were smokers. Correlations between current alcohol intake and smoking and endometriosis risk (in infertile women) have been reported (10). A recent meta-analysis, however, did not find any association between smoking and endometriosis risk (28). Overall, our population did not exercise regularly: only around 30% reported exercising weekly. Moderate-to-high intensity physical activity has been associated with reduced endometriosis risk (29), though randomized studies to establish if an exercise intervention is effective against endometriosis are lacking. Thus, while this cohort did not report high rates of risk behaviors, they also had low rates of protective behaviors against endometriosis development.

The mean age of the participants falls within the age groups with the highest incidence of endometriosis (24–36 years of age) (10). Our cohort reported a lower age at menarche compared to others (11.8 vs. 12.8–12.9 years of age) (28, 30, 31). Menorrhagia prevalence (11.2%) falls within what has been previously reported (2.3–13.2%) (32, 33). We identified known risk factors for endometriosis in this population, including early age at menarche, long and heavy menstrual cycles, and nulliparity (62.3%). The average number of children was 1.5, which is similar to another study (1.7 ± 1.1) (34). The prevalence of spontaneous abortions (20.5%) was within that reported by other endometriosis patient cohorts (14.3–20.8) (24, 34) and that of women without endometriosis (34). The rate of C-sections in our cohort (58.7%) was higher than the US national average (31.9% in 2018) (35) and other patient cohorts of (37.3%) (36, 37). Stillbirth rate (0.9%) was lower than that reported in other endometriosis cohorts (1.9%), while ectopic pregnancy rate was higher (4.4%) compared to another study (1.8%) (34).

Endometriosis has been associated with adverse maternal, fetal, and neonatal outcomes (34, 36, 38). Yet, in our cohort, we observed preeclampsia rates (4.5%) that are within the global rate of 2–8% (39) and lower than the rate reported by other cohorts of endometriosis patients (7.9 and 9.5%) (34, 36). The rate of gestational diabetes (3.4%) was also lower when compared to the average rate in the USA (6%) (39) and to other studies of endometriosis patients (4.3%) (34). Notably, a substantial proportion of our cohort had sought infertility treatment (67.2% of those ever trying to get pregnant), which is higher than that reported in other cohorts (33.7 and 52.8%) (28, 34). We calculated 3.7 years with infertility in average. Endometriosis was reported as the primary cause of infertility by 87.5%, much higher than that in other cohorts (52.8%) (31, 34). The utilization rate of in vitro fertilization (IVF) was 8.4%, similar to other cohorts (7.7%) (36, 37).

In average, the diagnosis of endometriosis was delayed 7 years, in accord with previous estimates (40). The primary reason for diagnostic surgery was for pelvic pain (>90%), higher than other cohorts (63 and 21%) (28, 33). Infertility as the reason for surgery (26%) was within what has been reported in other studies (4–55%) (28, 33). Overall, this study did not identify any major differences in the patient profile compared to other patient cohorts. The most common symptoms reported were back and leg pain, bloating, and fatigue, which were higher than more characteristic symptoms of endometriosis such as pelvic pain (30, 41). GI and urinary symptoms were also very commonly reported as in other cohorts (42).

The most common comorbidities self-reported in our cohort were migraines, PCOS, and IBS. Although endometriosis patients are more likely to suffer migraine headaches (43), the prevalence of migraines in our cohort (24.1%) is close to the upper range for the lifetime prevalence of migraine in women (20.0%; 95% CI: 16.6–23.8%) (44) and lower than in other patient cohorts (35.2 and 38.3%) (45, 46). The PCOS rate (22.2%) was higher than the worldwide incidence (3–10%) (47) and higher than in other cohorts (5%) (48). The IBS prevalence was higher in our study (21%) than what is reported in the US population (14.1%), but similar to other patient cohorts (22.4 and 24.0%) (49, 50). The prevalence of uterine leiomyomas was 12%, which is within what has been reported in other patient cohorts (5–21%) (24, 28, 33, 48) and lower than in the US population (35%) (51). The self-reported prevalence of cancer was relatively high (2.3%) for a young population (mean 33.7 years old); this rate is higher than what has been reported in another cohort (ovarian−0.2%, breast−0.4%, and melanoma−0.7%) (52). Rates of anxiety (19.5%) and depression (17.4%) were significantly lower than those reported in another cohort (45% anxiety and 30% depression) (53).

The majority of patients in this cohort reported feeling generalized pelvic pain early in their lives (in their 20's); endometriosis was the most common cause of this pain, followed by IBS and PID. Dysmenorrhea was reported by almost all participants (97%), and 79% considered the pain severe. This prevalence is higher than that in other studies (69%) (30, 31). Our patient cohort has been extremely affected by pelvic pain as 9 in 10 patients described their pain at its worst as being between intensity 8 and 10 on the NRS. The prevalence of dyspareunia (86.4%) was higher than that in other patient cohorts (38 and 45%) (30, 31), and 8 out of 10 reported severe symptomatology during their last sexual encounter. Many participants (49–65%) reported a substantial-to-extreme interference of daily activities by their pain, adding to the strong evidence that endometriosis impacts all aspects of the life course of those affected (54).

While it identified that there is access to surgical expertise across the region (55), our study was not designed to detect whether this access was determined by socioeconomic status or other variables. In fact, the EPQ-M survey does not capture information on income, urban/rural residence, or other known proxies of economic status when in fact these factors have been shown to influence access to standard of care in endometriosis. A study conducted in Puerto Rico showed that patients of endometriosis who had public health insurance were less likely to receive gynecologic consultation and more likely to seek emergency room services (56). Follow-up studies on factors that affect access to care in each country are needed to better understand and be able to solve any disparities.

This cohort used hormonal treatments (mainly OCP) predominantly for pain management, yet their use was reported by a relatively low number of participants (only half ever used them and 16% during the last 3 months). This indicates that there are opportunities to improve access to hormonal medications that have been shown to provide substantial endometriosis-related pain relief. It will be important to investigate whether cost limits access to hormonal medications or if cultural factors, such as taboos, religion, and stigma, can play a role in the low use of hormones that are also prescribed for contraception. Another important consideration is the high rate of treatment failure to hormonal drugs observed in this study and others that may impact treatment adherence (30).

The average age at diagnosis of our cohort was 22 years old. Patients' age has a profound impact in the management of endometriosis since modern trends avoid surgery and the use of advanced hormonal treatments during early reproductive years. Experts are leaning more toward a presumptive diagnosis of endometriosis trying to avoid multiple laparoscopies and toward combined oral contraceptives that are better tolerated and can be prescribed for a longer, indefinite time. In contrast, most advanced hormonal therapies such as GnRH analogs can only be used for 6–24 months. Furthermore, this young age for self-awareness of endometriosis may reflect a success story regarding patients' self-education and potential providers' detection in timely fashion leading to improved control of the condition.

One of the key symptoms that patients with endometriosis present is pelvic pain, which can become chronic and is often refractory to treatments. This debilitating symptom is cause for substantial detriments to the physical functioning, emotional wellbeing, and quality of life (57–59). We showed here high rates of all pain manifestations surveyed (dysmenorrhea, dyspareunia, and non-menstrual pain) compared to published data. Notably, negative coping responses to painful experience such as pain catastrophizing were common in this patient population. We also observed a positive correlation between reported pain levels and catastrophizing scores, as shown before (18, 60). This maladaptive mechanism has been associated with pain persistence and correlated with poorer quality of life and depression, and it may impact the clinical management of pelvic pain (15, 17, 18). Based on the Pain Catastrophizing Scale score, 46% of our cohort has a high risk of developing persistence of their pain and disability (PSC > 30) (18). This supports the importance of applying a psychosomatic approach for clinical management of chronic pain in endometriosis patients (61). Follow-up studies to assess the impact of race, ethnicity, and socioeconomic factors on the pain catastrophizing scores in this patient population are warranted.

This study may not be representative of all women with endometriosis in this population for various reasons. There may be a bias of recruitment through patient organizations as it is possible that members are more symptomatic. Collection of self-reported data has been previously shown to have relatively high concordance with surgical diagnosis (14). Our study population was highly educated, which may be explained by the fact that the study was conducted using an electronic link requiring of internet access. This finding is in accord to studies showing increased prevalence of endometriosis among well-educated women of higher socio-economic status (27). While, overall, the race distribution in each of the countries included was in accord with each country race proportions, there was a lower-than-expected participation of Black patients. Thus, it could be argued that these results are not representative of all endometriosis patients in this world region. Follow-up studies must be conducted to include a wider racial, ethnic, and socioeconomic representation of persons with endometriosis in these countries, to assess the impact of these factors on pain perception and impact. Our study highlights the need to establish a centralized repository of data collected longitudinally using the EPHect tools that are publicly available for future research, possibly with funding from local institutes of health, patient associations, gynecologic practices, and the WERF.

In conclusion, this study uncovered for the first time the phenome of endometriosis patients of Hispanic/Latinx background, showing substantial severity of symptoms, high pain catastrophizing scores, and overall negative impact on quality of life. As EPHect tools become more widely used, future studies must take into account confounding variables such as socioeconomic status, culture, race, and health systems, as these are known to impact access to care and thus could directly affect the clinical diagnosis of endometriosis. Such studies should also address cultural and religious factors regarding menstruation, contraception, and women's health issues, including normalization of symptoms and paternalistic nature of patient–doctor interactions (62). Importantly, forthcoming studies must recognize that the Hispanic/Latinx population is heterogeneous genetically and culturally and that there are differences in health insurance systems, availability/access to medications or surgical procedures, referral trends for sub-specialists, exposures, diet, and other environmental factors/stressors. Together, all these factors influence clinical care, disease presentation, and outcomes; thus, more research is needed to disentangle their contributions and to provide the best medical care possible to all patients, irrespective of race/ethnicity.

The raw data supporting the conclusions of this article will be made available by the authors by request.

The studies involving human participants were reviewed and approved by Ponce Research Institute Institutional Review Board (IRB). Written informed consent for participation was not required for this study in accordance with the national legislation and the institutional requirements.

IF-C made substantial contributions in the conception and design of the study, data acquisition, analysis and interpretation of data, drafting the article, critically revising the manuscript for important intellectual content, and giving the final approval. PR-E made substantial contributions in the analysis and interpretation of data, drafting and revising the article, and giving the final approval. JO-T, NS-P, ER-M, BH-C, LR-H, and LM made substantial contributions in the analysis and interpretation of data, revising the article, and giving the final approval. DS-S made substantial contributions in the analysis and interpretation of data, revising the article, and giving the final approval of the version to be published. MR-R made substantial contributions to the conception and design of the survey validation study, revising the manuscript critically for important intellectual content, and giving final approval. NB and ER made substantial contributions in the analysis and interpretation of data, revising the manuscript critically for important intellectual content, and giving the final approval. The Ibero-American Endometriosis Association^* made substantial contributions to the acquisition of data, revision of the article critically for important content, and the final approval. All authors contributed to the article and approved the submitted version.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.