{"paper_id":"de771475-77f8-497d-9d9f-610776f0f44d","body_text":"Sharma S et al. Reprod Med Int 2025, 7:026\nVolume 7 | Issue 1\nReproductive \nMedicine International\nOpen Access\nCitation: Sharma S, Deb S, Ferdous T, et al. (2025) Prevalence of Endometriosis in Sub-Fertile Women \nConfirmed at Laparoscopy: A Retrospective Analysis. Reprod Med Int 7:026. doi.org/10.23937/2643-\n4555/1710026\nAccepted: May 12, 2025: Published: May 14, 2025\nCopyright: © 2025 Sharma S et al. This is an open-access article distributed under the terms of the \nCreative Commons Attribution License, which permits unrestricted use, distribution, and reproduction \nin any medium, provided the original author and source are credited.\nSharma S et al. Reprod Med Int 2025, 7:026 • Page 1 of 5 •\nDOI: 10.23937/2643-4555/1710026\nISSN: 2643-4555\nPrevalence of Endometriosis in Sub-Fertile Women Confirmed \nat Laparoscopy: A Retrospective Analysis\nSwati Sharma1*, Shilpa Deb2, Taqwa Ferdous3, Fatema Abusin4, Ishan Wijewardana1\n1Specialty Trainee, Obstetrics and Gynecology Department, Nottingham University Hospital NHS Trust, \nNottingham, UK\n2Consultant Gynecologist , Obstetrics and Gynecology Department, Nottingham University Hospital NHS \nTrust, Nottingham, UK\n3Specialty trainee, Diana Princess of Wales Hospital, Grimsby, Northern Lincolnshire and Goole NHS \nFoundation trust, UK\n4Registrar, Obstetrics and Gynecology Department, Nottingham University Hospital NHS Trust, Nottingham, UK\n*Corresponding author: Dr. Swati Sharma, MBBS, MRCOG, Obstetrics and Gynaecology trainee, clinical research fellow \nreproductive medicine, Obstetrics and Gynecology Department, Nottingham University Hospital NHS Trust, Nottingham, UK\nAbstract\nIntroduction: Endometriosis is a chronic, estrogen-dependent gynecological condition affecting approximately 3-10% of \nwomen of reproductive age  [1]. The prevalence in infertile population could be up to 50%  [2]. Laparoscopy is considered \nas the gold standard for diagnosing endometriosis. However, its invasive nature limits its routine use and currently limited \nto women symptomatic of endometriosis. Advance imaging techniques such as MRI, enhances the detection rate of deep \ninfiltrating endometriosis but not as much for superficial/peritoneal endometriosis. This study aims to explore the prevalence of \nendometriosis in a sub-fertile population undergoing diagnostic laparoscopy.\nMethods: This retrospective study was conducted at Nottingham University Hospital between 01/07/2022 and 01/08/2023. \nWomen who were referred from fertility and benign gynaecology clinics for laparoscopy and dye testing were included. The \ndiagnosis of endometriosis was confirmed based on visual findings during laparoscopy. Patient characteristics, including age, \nBMI, type and reasons for subfertility, and laparoscopy finding were analysed.\nResults: A total of 100 women were included in the study, with the average age of 33.09 years in the endometriosis group. The \nprevalence of endometriosis within this cohort was found to be 55.34%, with 57 out of 100 women diagnosed. The subgroup \n(Endometriosis (Group 1) and other causes of sub-fertility (Group 2) analysis revealed a higher prevalence of endometriosis in \nwomen with primary infertility (36 vs. 21; p < 0.05). No significant differences were found between the demographic characteristics \nof the two groups including BMI or age (p = 0.709, p = 0.323). Out of 40 women who were initially thought to have unexplained \ninfertility, 28 were found to have mild/moderate endometriosis in diagnostic laparoscopy. \nConclusion: This study highlights a high prevalence of endometriosis (55.34%) among women undergoing diagnostic \nlaparoscopy and dye testing. High prevalence of endometriosis in unexplained infertility emphasizes the importance of early \ndiagnosis and intervention in improving reproductive outcomes. Further research is needed to examine the role of laparoscopy \nin different populations and to explore the broader implications of endometriosis in fertility management.\nKeywords\nEndometriosis, Laparoscopy and dye test, Fertility evaluation, Prevalence, Unexplained infertility.\nORIGINAL RESEARCH\nCheck for\nupdates\n\nISSN: 2643-4555DOI: 10.23937/2643-4555/1710026\nSharma S et al. Reprod Med Int 2025, 7:026\n• Page 2 of 5 •\nIntroduction\nEndometriosis is a chronic, estrogen dependent \ninflammatory condition characterized by the growth \nof endometrium-like tissue, outside the uterine \ncavity. These ectopic tissues respond to the hormonal \nchanges, causes proliferation, inflammation and \nscarring. This leads to pain, adhesions, and potential \nfertility impairments. It can involve various pelvic \nand extra-pelvic organs, including ovaries, fallopian \ntubes, ureter and bowels. It may result in a variety of \nsystemic symptoms depending on the extent of disease, \nwhich includes chronic pelvic pain, dysmenorrhea, \ndyspareunia, dyschezia and infertility. Epidemiological \nstudies estimate that endometriosis can affect 3 - 10% \nof women of reproductive age group  [1]. Despite its \nprevalence, the pathophysiology of this disease is not \nfully understood, especially when it comes to how it \nimpacts fertility. Up to 50% of women with infertility \nmay have endometriosis, though the exact mechanisms \nof the association between these two conditions are \ncomplex and involve several factors [2].\nInfertility is defined as the inability to conceive \nafter one year of unprotected intercourse. It affects \na significant proportion of couples worldwide. There \nare various causes of infertility, and about 15 - 30% \nof couples are labelled as unexplained infertility after \ninitial diagnostic tests. These tests typically include \nassessments of ovulatory function, ovarian reserve, \ntubal patency, and semen analysis. While, some cases \nof unexplained infertility can be attributed to peritoneal \nfactors such as subtle endometriosis or adhesions, \ndiagnosing these conditions remains challenging. \nLaparoscopy with dye testing has long been considered \nthe gold standard for diagnosing peritoneal factors, \nespecially in cases of unexplained infertility that are \naccompanied by other symptoms like pelvic pain, \ndysmenorrhea, and heavy periods [3,4].\nOver the past two decades, advancements in imaging \ntechniques, such as 2D/3D trans-vaginal ultrasound and \nMRI, have decreased the use of diagnostic laparoscopy \ndue to their non-invasive nature. However, these \nmethods continue to face challenges in detecting early \nstages of endometriosis and subtle pelvic pathology [2]. \nDespite these improvements and wide availability of \nimaging methods, the possibility of missed or delayed \ndiagnoses of peritoneal endometriosis remains. It is \nhypothesized that undiagnosed endometriosis may be \na contributing factor to continued sub-fertility in these \npatients [5]. \nEndometriosis is found in up to 50% of women \nstruggling with subfertility, with its association involving \ncomplex and multifactorial mechanisms 2. These \nfactors include distortion of the normal anatomy of \nthe pelvis including pelvic organs, altered peritoneal \nenvironment, impaired egg quality, and immunological \nfactors. Although, endometriosis is commonly present \nin women with unexplained infertility, but it can also \nbe a contributing factor in those with tubal disease \nand male infertility. Studies have shown that women \nwith endometriosis, especially those with moderate \nto severe forms, experience a significant reduction \nin fecundity compared to those without this disease \n[5]. Moreover, many women with the condition may \nnot show any symptoms, with infertility often being \nthe first sign of the disease [6, 7]. The identification of \nendometriosis in women with infertility not only aids \nin explaining the cause of infertility but also provides \nopportunities for targeted treatment strategies that \nmay improve reproductive outcomes. Early diagnosis \nand timely intervention will not only enhance the \nfertility outcomes but also improve the quality of life of \nthe affected women.\nThe aim of this retrospective study is to investigate \nthe prevalence of endometriosis in women population \nundergoing laparoscopy with dye test between \n01/07/2022 and 01/08/2023. Our findings provide \nvaluable insight into the link between endometriosis and \ninfertility, emphasizing the crucial role of laparoscopy in \ndiagnosing this condition in patients facing a range of \nfertility issues.\nMaterials and Method\nThis retrospective study was conducted at Queens \nMedical Centre, Nottingham university hospitals over \nthe period from 01/07/2022 to 01/08/2023. The study \nincluded women who underwent diagnostic laparoscopy \nwith dye test as a part of their fertility evaluation or \nalong-with other planned laparoscopic procedure for \nvarious gynaecological conditions. These patients were \nlisted for surgery from two main sources: the fertility \nclinic and the general benign gynaecology clinic. \nWomen referred from the fertility clinic had either \nexperienced failed or negative hysterosalpingography \n(HSG) results or had symptoms of gynaecological \nconditions such as chronic pelvic pain, heavy painful \nperiods in addition to sub-fertility. Additionally, \nsome women were referred from the general benign \ngynaecology clinic for laparoscopy for conditions like \nchronic pelvic pain, fibroids, or suspected endometriosis \nwhilst desiring fertility in near future. Their tubal patency \nwas assessed at the same time as a part of a fertility \nevaluation, either due to a history of infertility or because \nthey were planning to conceive in the near future.\nPatients referred from the fertility clinic were initially \nreviewed by a consultant, who conducted a thorough \nmedical and reproductive history assessment. In the \nabsence of other gynaecological symptoms, they had \nHSG as their initial test for tubal patency. Patients who \nhad negative or inconclusive results or were unable \nto tolerate the procedure were counselled thoroughly \nif they needed the laparoscopy with dye testing for \nfurther evaluation. A written informed consent was \n\nISSN: 2643-4555DOI: 10.23937/2643-4555/1710026\nSharma S et al. Reprod Med Int 2025, 7:026\n• Page 3 of 5 •\nobtained prior to the operation. The consent process \nincluded details of the procedure, potential risks, and \nthe benefits of the procedure. After the procedure, \npatients were reviewed at the fertility clinic to discuss \nfurther management options based on the laparoscopy \nfindings.\nThe laparoscopic procedure was carried out under \ngeneral anesthesia. During the procedure, a 360-degree \ndiagnostic laparoscopy was carried out and the pelvic \norgans were examined for any signs of pathology. \nMethylene blue dye was introduced into the uterus \nto evaluate tubal patency, and its passage through \nthe Fallopian tubes was carefully observed. If the dye \npassed freely into the peritoneal cavity, the tubes were \nconsidered patent. Blocked tubes or other abnormalities \nwere documented accordingly. We specifically included \npatients who underwent laparoscopy with dye testing \nto select the infertile population among women \nundergoing benign gynaecology surgery, ensuring that \nwe did not miss patients who had the procedure outside \nthe fertility theatre list.\nThe diagnosis of endometriosis was based on \nvisual findings during laparoscopy, with the extent \nand location of lesions documented. The severity of \nendometriosis was classified using the American Society \nfor Reproductive Medicine (ASRM) system, which \ncategorizes the condition from minimal to severe based \non the size and location of lesions, as well as the extent \nof pelvic involvement.\nData collected from patient records included age, \nBMI, ethnicity, medical history, duration of infertility, \nprimary or secondary infertility, and indications for \nlaparoscopy, laparoscopy findings, and the stage of \nendometriosis. The prevalence of endometriosis was \nassessed based on the number of women diagnosed \nduring laparoscopy, and its severity was analyzed across \ndifferent patient subgroups. Descriptive statistics were \nused to explore patient characteristics and the overall \nprevalence of endometriosis. Comparisons between \nsubgroups were made using appropriate statistical tests.\nResults \nA total of 100 patients were included in this study, \nwho underwent diagnostic laparoscopy with a dye test \nas a part of their fertility evaluation. Endometriosis \nwas present in 57 out of 100 patients, giving an overall \nprevalence of 55.34%.\nDemographic criteria\nAge: The mean age of patients in Group 1 \n(Endometriosis Group) was 33.09 years, ranging from \n21 to 42 years, while Group 2 (No Endometriosis) had \na mean age of 33.51 years, with age ranging from 23 to \n44 years. The analysis showed no significant difference \nin the average ages between the two groups (p = 0.709) \n(Table 1).\nBMI: The mean BMI of patients in Group 1 \n(Endometriosis Group) was 27.36 +/- 6.04kg/m 2, while \nGroup 2 (No Endometriosis) had a mean BMI of 26.72 \n+/- 6.19 kg/m 2. The statistical analysis showed no \nsignificant difference in the average ages between the \ntwo groups (p = 0.323), suggesting that their BMI levels \nwere similar (Table 2).\nEthnicity: The data suggests that the ethnic \ndistribution was similar between the two groups, with \nno significant differences found (Table 3).\nPrimary or secondary sub-fertility: For primary and \nsecondary sub-fertility, the available data indicated that \nthe Endometriosis group (Group 1) had 36 patients with \nprimary sub-fertility and 14 with secondary sub-fertility, \nwhile the group with other causes of sub-fertility \n(Group 2) had 21 patients with primary sub-fertility \nand 14 with secondary sub-fertility. The statistical \ncomparison yielded a p-value of 0.25, indicating that \nthere was no significant difference in the distribution \nof primary and secondary sub-fertility between the two \ngroups. However, on sub-group analysis, women with \nprimary subfertility showed a significant prevalence of \nendometriosis (36 vs. 21 - p value 0.25) (Table 4).\nDuration of sub-fertility: Duration is quite variable \nfrom both groups ranging from 2 years to 18 years and \nhence non-comparable. \nCauses of sub-fertility in Group 2: For Group 2 \nthe sub-fertility factors were as follows: 28 patients \nhad tubal factor-related sub-fertility diagnosed on \nHSG or ultrasound. 40 patients were thought to have \nunexplained infertility to begin with, out of which 28 were \nfound to have endometriosis during the laparoscopy, \nleaving 12 patients as unexplained infertility. 2 patients \nhad uterine polyp-related sub-fertility. These factors \nwere considered when evaluating the possible causes \nof sub-fertility in this group (Table 5).\nGroup Mean age \n(years) SD p-value \n(t-test)\nEndometriosis (Group 1)33.4 5.8 0.709\nOther causes of sub-\nfertility (Group 2) 32.4 5.7\nTable 1: Comparison of Age amongst the two groups.\nGroup Mean BMI \n(kg/m2) SD p-value \n(t-test)\nEndometriosis (Group 1)27.36 6.04 0.323\nOther causes of sub-\nfertility (Group 2) 26.72 6.19\nTable 2: Comparison of BMI amongst the two groups.\nGroup 1 Group 2\nWhite British 24 23\nBrown Asian 6 6\nOther white 3 4\nBlack African 1 2\nTable 3: Ethnicity distribution amongst the two groups.\n\nISSN: 2643-4555DOI: 10.23937/2643-4555/1710026\nSharma S et al. Reprod Med Int 2025, 7:026\n• Page 4 of 5 •\nDiscussion\nOur study’s prevalence of endometriosis (55.34%) \naligns with findings from Devabhaktuni, et al. who \nreported a prevalence of 52.17% in women undergoing \nlaparoscopy for infertility, reinforcing the high prevalence \nof endometriosis in this population. Similarly, Calhaz-\nJorge, et al. reported a prevalence of 45% in a large \ncohort of infertile women, a figure comparable to our \nstudy [8]. In contrast, Mahmood and Templeton found \na prevalence of 21% in women undergoing laparoscopy \nfor infertility, 15% in those with chronic abdominal pain, \nand 6% in women undergoing laparoscopic sterilization \n[9]. The relatively higher prevalence in our study may be \nattributed to the selective nature of the cohort, which \npredominantly includes women with suspected infertility \nor pain syndromes. Moreover, as prevalence estimates \nare influenced by symptom presence and diagnostic \nmethods, the true prevalence of endometriosis may \nbe underestimated when asymptomatic cases remain \nundetected, as highlighted in a systematic review by \nParazzini, et al. which estimated a prevalence of 33.5% \nin women undergoing surgery for benign gynaecological \nconditions and 23.8% in infertile women [10].\nThe mean age of our patients with endometriosis \n(33.09 years) is consistent with the reproductive age \nrange typically associated with the condition. Bosteels, \net al. emphasized the importance of laparoscopy \nin diagnosing endometriosis in women within the \nreproductive age group, particularly those with fertility \nconcerns, while Kristjansdottir, et al. reported that the \nactual age at diagnosis ranged from 16 to 69 years, with \na mean of 35.9 years[ 11,12]. For histologically verified \ncases, the mean age was 38.9 years. The study also \nrevealed that most diagnoses occurred in women aged \n30 - 34 years.\nOur study highlights the strong association between \nprimary infertility and endometriosis. Consistent with \nfindings by Calhaz-Jorge, et al. women with primary, \nwomen with primary subfertility have a higher risk of \nendometriosis compared to those with a history of \nprevious pregnancies [8]. The study revealed that the \nrisk of endometriosis was significantly lower in women \nwith a prior pregnancy, with the risk decreasing in a \n‘dose-dependent’ manner as the number of previous \npregnancies increased. Specifically, 36% of women \nwith primary subfertility had grade I/II endometriosis, \ncompared to 31% in women with a history of pregnancy \nbut no delivery, and 19% in women with a history of \ndelivery. In our study, we found that significantly higher \nproportion of women with endometriosis presented \nwith primary infertility (36%) compared to 14% with \nsecondary infertility, reinforcing the negative impact of \nendometriosis on fertility.\nLaparoscopy plays a crucial role in diagnosing \nendometriosis, especially in women struggling with \ninfertility. Although other diagnostic methods, such as \nultrasound and MRI, have shown promise, laparoscopy \nremains unmatched in its ability to directly visualize and \nconfirm the presence of endometriotic lesions, especially \nin cases of mild to moderate endometriosis. According \nto Bosteels, et al. diagnostic laparoscopy and surgical \ntreatment of minimal or mild endometriosis increases \nthe spontaneous pregnancy rate in infertile women [11]. \nTheir study emphasized that laparoscopy not only aids \nin diagnosis but also allows for the immediate treatment \nof endometriosis through excision or ablation. Study \nby Devabhaktuni, et al. reinforced the similar findings \nthat adequate surgical treatment by laparoscopy \nin women with endometriosis would improve the \nconception rates. Diagnosis of endometriosis as well as \nmanagement should be planned at the first laparoscopy \nto provide the maximum benefit to the patient [13]. \nCalhaz-Jorge, et al. developed a predictive model based \non medical history for risk assessment for endometriosis \nin a sub-fertile women, allowing for early diagnosis and \ntimely intervention of endometriosis by laparoscopy \npotentially improving reproductive outcomes [8].\nDespite advancements in imaging methods, such \nas transvaginal ultrasound, which has been shown to \ndetect ovarian endometriomas, laparoscopy remains \nindispensable, particularly in diagnosing more subtle \nforms of endometriosis like deep infiltrating disease \n[14]. Therefore, the value of laparoscopy in diagnosing \nendometriosis in the sub-fertile population cannot be \noverstated, as it provides both a definitive diagnosis and \nthe potential for immediate surgical treatment, which \nis crucial in improving fertility outcomes. Prospective \nstudies evaluating the efficacy of laparoscopic \nmanagement in improving fertility outcomes, both for \nmild and severe diseases, are essential to guide clinical \ndecision-making and optimize patient care.\nConclusion\nIn conclusion, this study highlights the high \nprevalence of endometriosis (55.34%) in women \nundergoing diagnostic laparoscopy and dye test as a \npart of their fertility evaluation. This aligns with existing \nliterature showing the high prevalence of endometriosis \nin infertile populations.\nGroup Primary Secondary p-value ( t-test)\nEndometriosis (Group 1)36 14 0.25\nOther causes of sub-\nfertility (Group 2) 21 14  \nTable 4: Comparison of type of sub-fertility amongst the two \ngroups.\nCause of sub-fertility Number of patients\nTubal factor 28\nUnexplained 12\nOvarian cyst/dermoid 2\nEndometrial polyp 1\nTable 5: Comparison of causes of sub-fertility amongst the two \ngroups.\n\nISSN: 2643-4555DOI: 10.23937/2643-4555/1710026\nSharma S et al. Reprod Med Int 2025, 7:026\n• Page 5 of 5 •\nDespite the limitations of our study, such as the \npotential selection bias of our cohort and small \nsample size, our results offer valuable insights into the \nprevalence and clinical presentation of endometriosis \nin women with fertility concerns. Overall, our findings \nreinforce the importance of early and accurate \ndiagnosis of endometriosis in women struggling with \ninfertility. Further research, including larger, more \ndiverse populations, is required to fully understand the \nimpact of endometriosis on fertility and to optimize \ndiagnostic and treatment strategies for affected women. \nAcknowledgments\nNone\nSources of support \nNo funding was received for this work.\nReferences\n1. All-Party Parliamentary Group on Endometriosis (2019) \nEndometriosis: The invisible injustice – The APPG inquiry \ninto endometriosis [Report]. Endometriosis UK. \n2. Nisenblat V, Bossuyt PM, Farquhar C, Johnson N, Hull ML \n(2016) Imaging modalities for the non-invasive diagnosis \nof endometriosis. Cochrane Database Syst Rev 2: \nCD009591. \n3. Carson SA, Kallen AN (2021) Diagnosis and Management \nof Infertility: A Review. JAMA 326: 65 - 76.\n4. 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(2020) The frequency of endometriosis in the \ngeneral and selected populations: A systematic review. J \nEndometriosis Pelvic Pain Disord 12: 176 -189.\n11. Bosteels J, Van Herendael B, Weyers S, D'Hooghe T \n(2007) The position of diagnostic laparoscopy in current \nfertility practice. Hum Reprod Update 13: 477 - 485. \n12. Kristjansdottir A, Rafnsson V, Geirsson RT (2023) \nComprehensive evaluation of the incidence and prevalence \nof surgically diagnosed pelvic endometriosis in a complete \npopulation. Acta Obstet Gynecol Scand 102: 1329 - 1337. \n13. Devabhaktuni P, Gogineni S, Yalamanchi S, Katragadda \nA (2019) Management of infertility in endometriosis by \noperative laparoscopy and medical therapy - practiced at \n3 different centres, from September 2005 to October 2007. \nOpen J Obstet Gynecol 9: 775 - 788. \n14. Alson S, Jokubkiene L, Henic E, Sladkevicius P (2022) \nPrevalence of endometrioma and deep infiltrating \nendometriosis at transvaginal ultrasound examination \nof subfertile women undergoing assisted reproductive \ntreatment. Fertil Steril 118: 915 - 923.","source_license":"CC0","license_restricted":false}