Clinical practice guidelines for endometriosis in Japan (The 3rd edition)

article OA: gold CC0 ⤵ 8 in-corpus citations
AI-generated summary by gemini-2.5-flash-lite, 2026-06-08

This paper presents the third edition of Japanese clinical practice guidelines for endometriosis, updating diagnostic and treatment strategies over the past decade with detailed flowcharts and clinical questions.

One-sentence paraphrase of the abstract; not a substitute for reading it. No clinical advice. How this works

AI-generated deep summary by claude@2026-06, 2026-06-14 · read from full text

This Japanese clinical practice guideline (3rd edition) reviews diagnosis and treatment strategies for endometriosis, building on its prior edition while incorporating changes from the past decade such as broader use of low-dose estrogen–progestin therapy and dienogest, shifts toward laparoscopic surgery, and improved imaging (ultrasound, MRI). It outlines clinical questions and provides decision-making flow charts, while noting limitations such as that symptom–lesion relationships remain largely unknown and that laparoscopic findings are not a perfect substitute for histology; it also highlights that biomarkers like CA125/CA19-9 have limited accuracy and are mainly helpful when combined with other evidence. The guideline specifically emphasizes practical diagnostic workup using history, pelvic/vaginal/rectal examination when feasible, imaging, and combined biomarker interpretation, including CA125/CA19-9 patterns and use of HE4 with CA125 to help distinguish epithelial ovarian cancer from ovarian endometriotic cysts. Relevance to endometriosis: This paper is centrally about endometriosis—it is a Japan guideline detailing contemporary diagnostic and treatment recommendations, with dedicated clinical questions addressing endometriosis-related pain and infertility, and it also includes guidance items explicitly involving adenomyosis as a related condition.

Read from the paper's body, not the abstract. Not a substitute for reading the paper. No clinical advice. How this works

Abstract

More than 10 years following the publication of "The General Rules for Clinical Management of Endometriosis: The second edition" in January 2010, the long-awaited third edition has arrived. The second edition represents the bible for endometriosis treatment and has become the go-to reference in clinical practice in Japan; it was published after the introduction of low-dose estrogen–progestin (LEP) therapy and the novel progestin dienogest on the market. Looking back, this was the turning point from the era when laparoscopic surgery + GnRH agonist therapy was the predominant treatment and introduced an era of novel treatments. With the development of lightweight, high-resolution endoscopes that allow for more delicate and precise surgical operations, endometriosis surgery has transitioned from laparotomy to laparoscopy. Conversely, despite their potency in alleviating the symptoms of endometriosis, GnRH agonists could only be used for up to 6 months due to adverse effects associated with estrogen deficiency. Thus, the predominant treatment was centered on laparoscopic surgery, with GnRH agonists used as an adjunct. Following the publication of the second edition, the use of LEP and dienogest became widespread. With both agents have been shown to be effective and safe, long-term medical therapy has become possible. Owing to technical advancements in laparoscopic surgery, surgery is now also performed for deep endometriosis or less common and rare site endometriosis. However, for ovarian endometriotic cysts, ova, and normal ovarian tissues should be resected along with the endometrial tissue, thus, diminishing the ovarian reserve. Therefore, surgery must be performed carefully for young women and women wishing to have children in the future. We are now in an era in which we take advantage of long-term medical therapy and laparoscopic surgery, as we consider treatment tailored to the life stages of individual women while attempting to preserve ovarian functions. In this revised edition, we refer to the second edition for fundamental knowledge in clearly elaborating current perspectives on the review of the diagnosis and treatment, in addition to the advance over the last 10 years. Therapeutic strategies are explained with detailed flow charts. The clinical questions (CQs) in the latter half of this edition are intended as a useful guide for decision-making in clinical practice. The authors are all physicians working tirelessly at the frontiers of endometriosis research in Japan, and this edition has undergone multiple generous revisions amid their busy schedules. Integration of the overall structure, revision of inconsistencies and duplication among CQs, and other onerous editing tasks were undertaken with tremendous dedication by the secretaries on the Japan Society of Endometriosis, Drs. Fuminori Taniguchi, Michio Kitajima, Kaori Koga, Taisuke Mori, and Ken Yamaguchi. Once again, I would like to offer them my deepest gratitude. I hope that this revised edition would be helpful in the treatment of women with endometriosis not only in Japan but worldwide. Tasuku Harada Table of Contents Introduction Chapter 3 Treatment guidelines (Clinical questions) CQ 1 How should adolescents with suspected endometriosis be treated? CQ 2 How should ovarian endometriotic cysts be managed in view of their potential for malignant transformation? CQ 3 Do endometriosis and adenomyosis increase the risk of obstetric complications? CQ 4 How should adenomyosis-associated pain be managed? CQ 5 How should adenomyosis-associated infertility be managed? CQ 6 Is endometriosis a risk factor for cardiovascular events? CQ 7 Does endometriosis affect quality of life? CQ 8 What to be aware of when performing conservative surgery for ovarian endometriotic cyst? CQ 9 Is surgery for ovarian endometriotic cysts effective in improving fertility? CQ 10 Is surgery for deep rectovaginal endometriosis effective in improving fertility? CQ 11 Is surgery effective in improving fertility in women with peritoneal lesions? CQ 12 Is assisted reproductive technology (ART) effective for endometriosis-associated infertility? CQ 13 Are hormone therapies effective for endometriosis-associated infertility? CQ 14 Is surgery effective for endometriosis-associated pain (excluding deep lesions)? CQ 15 Is surgery effective for deep rectovaginal endometriosis-associated pain? CQ 16 Are oral contraceptive/low dose estrogen-progestin (OCs/LEPs) effective for endometriosis-associated pain? CQ 17 Are GnRH agonists effective for endometriosis-associated pain? CQ 18 Are oral progestins effective for endometriosis-associated pain? CQ 19 Is the levonorgestrel intrauterine system (LNG-IUS) effective for endometriosis-associated pain? CQ 20 Is there evidence of a superior efficacy between oral contraceptive/low dose estrogen-progestin (OCs/LEPs), GnRH agonists, and progestins for endometriosis-associated pain? CQ 21 Is medical therapy effective for deep endometriosis-associated pain? CQ 22 Are complementary and alternative therapies effective for endometriosis-associated pain? CQ 23 Are pre-operative or post-operative medical therapies effective at surgery for endometriosis- associated pain? CQ 24 Is medical therapy following conservative surgery effective in preventing the recurrence of ovarian endometriotic cysts? Diagnosis Overview of Diagnosis Clinical significance of endometriosis diagnosis A pathologically benign disease, endometriosis is unlike other malignancies that are diagnosed by the detection of lesions. In the absence of symptoms, the diagnosis of microlesions has almost no clinical value, as they often disappear naturally and do not necessarily enlarge. In contrast, when symptoms are present, the lesions can be identified to establish a diagnosis that then becomes the basis for treatment. However, even in asymptomatic cases, lesions of a certain size can cause various symptoms and require therapeutic intervention. Diagnostic therapy is considered in endometriosis. When symptoms such as dysmenorrhea strongly indicate endometriosis, the patient's response to hormone therapy is considered. However, endometriosis can be difficult to distinguish from functional disorders, such as functional dysmenorrhea; this line of thinking is acceptable in certain circumstances. The relationship between lesions and symptoms in endometriosis patients remains largely unknown, while some aspects of the etiology of the lesions are vague. Consequently, the clinical significance of the diagnosis may change in the future. Methods for diagnosing endometriosis Endometriosis is characterized by the presence and growth of endometrial tissue in locations other than the uterine cavity. While a definitive diagnosis should be made histologically, alternative diagnostic methods, such as laparoscopy are performed. The American Society of Reproductive Medicine (ASRM) staging system has become the most common and international system, and diagnosis based on laparoscopic findings has been recognized as the standard. However, laparoscopic findings have various limitations and flaws and therefore cannot necessarily serve as a perfect alternative to histological diagnoses. Ultrasonography and magnetic resonance imaging (MRI) have later been incorporated into the diagnosis of endometriosis. As diagnostic imaging has improved in quality, invasive laparoscopic diagnosis has somewhat diminished in relative value, and the exclusive use of laparoscopy for diagnosis has become much less common. Subjective and objective findings and biochemical tests are all useful only when combined with the results of diagnostic imaging and laparoscopy; none are used separately for diagnosis. Procedure for diagnosing endometriosis The first steps in diagnosing endometriosis are an interview and a pelvic examination, as with a typical gynecological examination. Patients are asked in detail about the information related to endometriosis, such as family history, history of illness, menstrual history, and pregnancy/delivery history. If the history of the present illness includes pain, the chronological changes, properties, and sites of the pain are important. In vaginoscopy, observation of the posterior vaginal fornix is particularly important. If endometrial lesions are present, other methods can be used in addition to vaginoscopy to determine whether the lesions extend only to the vaginal wall or if they are continuous with deep endometriosis in the rectovaginal pouch. Subsequently, in the pelvic examination, important findings consist not only of the size, properties, and motility of the uterus and ovaries but also pain during examination and induration surrounding the rectouterine pouch. In a typical vaginal ultrasound during pelvic examination, asking the patient during observation whether the ultrasound probe cause any pain can be useful in the identification of lesions. If rectal endometriosis is suspected, a rectal examination may also be proactively performed to confirm the status of the bowel wall. However, when pelvic and rectal examinations are difficult, such as in the cases of young women and women who have not had sexual intercourse, a diagnosis should be established according to the results of other tests such as MRI, which yields even more detailed information regarding lesions. The finding of a serum CA 125 test can be used in combination with other tests as necessary, for differentiation with malignancy and to assess lesion activity. Details of diagnosis Subjective findings Commonly cited symptoms of endometriosis include menstrual pain (abdominal pain and low back pain) and infertility. In a survey of patients definitively diagnosed with endometriosis by the Japan Endometriosis Association, 88% of the patients experienced menstrual pain, and nonmenstrual abdominal pain, low back pain, dyspareunia, and dyschezia. Approximately half of the patients who responded reported infertility. Although uncommon, when lesions spread beyond the pelvic organs, symptoms may manifest elsewhere, such as in the gastrointestinal tract, urinary tract, or respiratory system (Table 1). Findings of the pelvic examination and rectal examination Adhesions secondary to endometrial lesions often develop in the rectovaginal pouch and around the adnexa and are a characteristic finding of endometriosis in pelvic examinations. The findings indicative of endometriosis include limited uterine motility, uterine retroflexion, tenderness, and induration of the rectouterine pouch. Rectal examination is crucial in the diagnosis of rectouterine endometriosis. Rectovaginal pouch lesions that have formed small masses may become fibrotic and be palpable as indurations with tenderness. However, these lesions are evidently palpable on rectal examination. Biochemical tests Although there are no definitive biomarkers to diagnose endometriosis, CA125 and CA19-9 levels are often mildly elevated in patients with endometriosis.1 Although these biomarkers do not have high diagnostic accuracy individually, they are useful for diagnosis when combined with other findings. Sometimes, the levels of these biomarkers increase abruptly in the rupture and acute phase of hemorrhage of ovarian endometriotic cysts. CA125 and CA19-9 levels seldom indicate positivity for early endometriosis and are useful only in advanced cases.2, 3 Serum HE4, in combination with serum CA125, is useful for differentiating between epithelial ovarian cancer and ovarian endometriotic cysts.4 Diagnostic imaging Ultrasound findings in endometriosis Ultrasonography is emphasized as a means of diagnosing endometriosis and determining its course. Vaginal ultrasonography is generally superior to abdominal ultrasonography for visualizing pelvic lesions and is therefore preferred. However, for women who have not had sexual intercourse, either abdominal ultrasonography is performed or ultrasonography is performed rectally with a vaginal probe. If endometriosis is suspected, ultrasonography is performed in which the entire pelvis is observed first according to a set procedure and then the details. For example, briefly scan the uterus and ovaries to check for endometriosis and ovarian endometriotic cysts. Next, determine any adhesion associated with endometriosis but not with the endometrial lesions themselves. Check for site-specific pain, ovarian mobility, and sliding between the uterus and surrounding organs. Lastly, evaluate the deep endometriosis in the region of the uterus, as necessary. Sites of cysts Ultrasound findings for ovarian endometriotic cysts present as nearly circular or elliptical unilocular or multilocular cysts that adhere to the uterus and are often located in the posterior aspect of the uterus or the rectovaginal pouch (Figure 1). Ultrasound findings of cysts Cyst wall The wall is seldom uniformly thin and often appears to be thickened. However, the images show blood clots and fibrin clots, not neoplastic thickening; papillary projections are also not observed in epithelial tumors. Internal echoes The inside of an ovarian endometriotic cyst is formed by accumulated blood and therefore presents with low, medium, or high intensity based on the density of free-floating blood. Uniform−diffuse echoes or low-intensity punctate−spotty echoes are often observed throughout the mass or in the inferior portion of the mass. When fibrin deposits are present, various hyperechoic regions and solid echoes are also observed. Fibrin clots demonstrate fluidity due to postural changes and present with a rippling motion when the cysts are vibrated from the abdominal wall manually or with a vaginal probe. Color Doppler can confirm the absence of blood flow in fibrin clots. The insides of the cysts occasionally present with relatively low-intensity solid echoes. As cysts can be localized near the wall, it is important to differentiate ovarian mature teratomas with ovarian cancer (Figure 2). Hair shafts and sebum in ovarian mature teratomas and papillary projections in cancer are often hyperechoic. Although cysts are often unilocular, they sporadically have a few loculi, in which case septa are depicted. The surfaces of these septa are relatively smooth, and the septa do not present with dendritic or papillary projections. In the case of thick, irregular septa, ovarian cancer must be considered. In rare cases, mixed tumors comprising serous cysts or ovarian mature teratomas may develop in the ipsilateral ovary. When several various echo patterns are present, mixed tumors must be considered. Ultrasound findings in deep endometriosis.5, 6 Although deep endometriosis has conventionally been defined as endometriosis involving deep infiltration (5 mm) from the peritoneal surface, this view is now considered as outdated. Recently, lesions that arise with fibrous or myogenic tissue from adenomyosis-like tissue (adenomyosis externa) have often been clinically addressed as deep endometriosis. Deep endometriosis most likely occurs in the vesicouterine pouch, the rectovaginal pouch, or the uterosacral ligaments. On ultrasonography, deep endometriosis is typically visualized as a hypoechoic area. To observe the vesicouterine pouch, a probe is inserted into the anterior vaginal fornix. To observe the bladder wall, storing urine in the bladder creates contrast, to visualize endometriosis; multiple small cystic echoes are often detected on the surface of the bladder. To observe the rectovaginal pouch or the uterosacral ligaments, a probe is inserted into the posterior vaginal fornix. Deep endometriosis generally involves rectovaginal pouch obliteration. The status of rectovaginal pouch obliteration can be determined based on the height of intraperitoneal effusion. In deep endometriosis of the bowel wall, the rectal serous membrane and mucosal surface are visualized as hyperechoic areas surrounding the hypoechoic deep endometriosis area, thus, confirming the diagnosis. While normal uterosacral ligaments are difficult to distinguish from the surrounding tissue in an ultrasound, deep endometriosis results in hypoechoic thickening, facilitating confirmation of the ligaments. The role of MRI diagnosis MRI can play a major role in diagnosing endometriosis because MRI "can specifically diagnose the blood flow based on signals." Hematomas present with characteristic signals from bleeding that change over time, facilitating the deduction of timing and composition (Table 2, Figure 3).7 The values of sensitivity and specificity of MRI for differentiating between ovarian endometriotic cysts and adnexal masses are extremely high, 95% and 91%, respectively, making MRI a reliable cornerstone for deciding on a therapeutic strategy.8 In contrast, small implants in the peritoneal surface and membranous adhesion are difficult to diagnose. Thus, although MRI is inferior to laparoscopy in terms of the exclusion and staging of endometriosis, it is worthwhile as a non-invasive method that can potentially reliably diagnose ovarian endometriotic cysts. Thus, the two types of tests are considered to complement each other. Due to the absence of other reliable methods for diagnosing deep/bladder/rectal endometriosis, MRI diagnosis contributes greatly to clinical practice. Imaging methods T1-weighted images and T2-weighted images must be taken in the same plane. Fat suppression is useful for differentiating between fat and blood. In addition, contrast media are sometimes necessary to differentiate between clots in ovarian endometriotic cysts and solid tissue indicative of ovarian cancer. The images are taken in the transverse plane in principle, although sagittal T2-weighted images are also often taken to observe adhesion between the uterus and ovaries as well as adhesion between the rectum and uterus. In addition, infusing water-soluble gel into the vagina and rectum to create contrast improves the diagnosis of deep endometriosis adjacent to the rectovaginal pouch.9 Diffusion-weighted imaging and apparent diffusion coefficient are useful for differentiating endometriosis from malignancy.10 Susceptibility-weighted imaging is reported to be useful for detecting microbleeding in endometriosis.11 Imaging findings Malignant ovarian tumors must not be misdiagnosed as ovarian endometriotic cysts. Ovarian endometriotic cysts can be confirmed in one of two ways: presentation of high signal intensity similar to that of subcutaneous fat on T1-weighted images and the presence of two or more cysts with signals not suppressed in fat-suppressed imaging, or similar cysts presenting with heterogenous low signal intensity on T2-weighted images (shading). The former demonstrates that the cysts are multiple cysts with blood, while the latter demonstrates that the cyst fluid is old blood that has become viscous, thereby, enabling differentiation with other hemorrhagic masses. In the images, only the pronounced adhesive changes, not the slight ones, can be identified, but not the slight adhesive changes. Adhesion must be suspected when the bilateral ovaries are in contact with each other, when the ovary is in contact with the uterus or pelvic wall over a wide area, or when the intestine appears to be pulled in a beak shape toward the uterine serosal surface or the ovary. Abdominal wall/deep/bladder/rectal endometriosis is depicted as fibrosis in MRI. Endometriosis is identified in the umbilical region, the groin, or scarring from gynecological operations, such as cesarean section or hysterectomy in T2-weighted images as hypoechoic nodules and as hypertrophy limited to the bladder wall and bowel wall. However, in several cases, these findings are slight and easy to miss. The diagnosis is definitive if a 2–3-mm section of tissue presenting with high signal intensity on T1- and T2-weighted images is observed in the center of the endometriosis. Differential diagnosis Blood and fat can present with markedly high signal intensity on T1-weighted images. Therefore, although differentiating ovarian endometriotic cysts from ovarian mature teratomas is sometimes difficult, they are easily differentiated with fat saturation. Fat presents with low signal intensity due to signal suppression, whereas blood continues to present with high signal intensity (Figure 4). The presence of chemical shift artifacts and morphological characteristics also help with differentiation; however, fat suppression is the most reliable method. It is important not to make a diagnosis of ovarian endometriotic cysts based solely on a cyst presenting with high signal intensity in T1-weighted images (i.e., signals indicating hematomas). This finding alone is not enough to differentiate an ovarian endometriotic cyst from a corpus luteum hemorrhage or ovarian tumoral hemorrhage. The corpus luteum is often 1–2 cm in size and disappears when observed during a menstrual cycle. Images of deposition of high-signal intensity tissue only in the base of a cyst show the hematocrit effect and indicate functional intracystic hemorrhage, such as in the corpus luteum. With ovarian tumoral hemorrhage, due to the mixture of blood and other fluids in cysts, the fluid often does not present with a signal intensity as high as that of blood or fat. Carcinomas such as clear cell carcinoma and endometrioid carcinoma rarely develop from ovarian endometriotic cysts. Even when all findings suggest ovarian endometriotic cysts, ovarian carcinoma should be suspected when the mass has a solid portion inside it. Differentiation between small mural nodules and clots adhering to walls based on MRI can also diagnosis. have no blood flow and do not show contrast, whereas solid mural nodules show Although solid areas also in ovarian endometriotic cysts such as that observed during imaging is useful for also presents with a of signals and can be difficult to differentiate from ovarian endometriotic cysts. However, a examination of the often it to have a examinations examination is useful for endometriosis and is necessary for a definitive diagnosis. The of endometriosis is used as a clinical staging This is used as an objective to demonstrate the status of in laparoscopic examination and to determine according to a However, this system is not necessarily with symptoms, such as pain or with after The system is superior to in unlike other it the of the of peritoneal lesions. Although the of peritoneal lesions have been reported to be associated with and lesions have also been to potentially an Table 3 the from cases to each of peritoneal lesion are also (Figure Treatment Overview of treatment The first in the treatment of endometriosis is to a that the most important and in the patient based on an diagnosis of clinical endometriosis. In most cases, the treatment are often into pain, and ovarian endometriotic cysts, and patients sometimes have two or all of the In of these based on a with the the most of the following therapeutic strategies is medical surgical fertility treatment, or treatment. symptoms markedly the quality of life for endometriosis patients at all stages of life from the of symptoms in or later In dysmenorrhea is a risk factor for endometriosis later in are performed as necessary, and endometriosis should be to Once sexual is ovarian endometriotic cysts should be in terms of the of recurrence after treatment and the risk of malignant However, conservative therapy intended to preserve the ovarian to fertility with the of ovarian endometriotic cysts. Therefore, a therapeutic must be with of these as have endometriosis is a risk factor for obstetric such as and 3 must also be considered. have determined endometriosis to be a risk factor for 5 Endometriosis must no be considered as a limited to the pelvis but as a that must be managed and old of only on symptoms during a a therapeutic that also should be considered for endometriosis therapy therapy for endometriosis is into treatment and hormone treatment of and used to pain associated with endometriosis. the only treatment that on endometriotic is hormone therapy in Japan in when the progestin was introduced as treatment in the and therapy with oral was performed. In was on the as a therapeutic for endometriosis and hormone therapy to In the first GnRH was by a of other GnRH agonists, which are used as In long-awaited low-dose were introduced to endometriosis-associated pain due to their 9 years the introduction of novel the progestin dienogest was in January The of the the first LEP was in Although these are the same as in are used for and are not by while have been by for the treatment of dysmenorrhea they were have been on the market. and dienogest are the most used therapies for endometriosis. the intrauterine system which was not by medical as an intrauterine is now by it for the treatment of dysmenorrhea and and is now also used for patients with endometriosis. Recently, oral GnRH is by medical for pelvic pain associated with endometriosis (Table 4). Although a definitive diagnosis of endometriosis both laparoscopic surgery and performing both in all cases is In clinical clinical endometriosis is diagnosed according to clinical symptoms and various other methods, such as examination, diagnostic imaging and and biochemical 125 with medical therapy after a diagnosis is treatment The of of is of are the treatment for menstrual pain in women from when women first of pain, to their In treatment, dysmenorrhea is as or and is with such as and and and and The for include of menstrual pain in and women and the of adverse effects associated with other therapy GnRH agonists have become used as a in hormone therapy they first However, the of dienogest and GnRH agonists have their status and are only when are not which specifically into the uterine is sometimes also is to be however, due to the of adverse and its use has in the years. When medical therapy to pain, surgical therapy is considered. Ovarian endometriotic cysts after conservative surgery, and hormone therapy is considered a means of preventing ovarian from and dienogest are effective for preventing the recurrence of ovarian endometriotic cysts. months of GnRH agonist by continuous of or dienogest is effective in preventing which are to estrogen and The long-term use of and
Full text 193,533 characters · extracted from pmc-nxml · 6 sections · click to expand

Chapter

Treatment guidelines (Clinical questions) Reference selection and clinical question (CQ) assessment. The detailed procedure used for the literature search is described below. The committee members and authors selected the keywords and the main papers associated with the CQs. To assess the evidence at the present stage from an impartial perspective, we requested the Japan Medical Library Association to conduct a comprehensive literature search by creating different queries for each CQ. When a query failed to yield enough papers, we changed or added keywords. The committee members and authors examined the sampled papers and selected important papers. The PubMed, Cochrane Library, and Ichushi Web databases were searched for studies published from 2010 to 2019. The selection criteria were as follows: Practice guidelines, meta‐analyses, and systematic reviews were given the highest priority. Subsequently, RCT, prospective cohort studies, case–control studies, clinical trials, and other epidemiological studies were selected. We also selected new papers (those published from January 2020 onwards), which the editing committee determined should be cited. For external assessment, we presented some of the CQs at the consensus meeting at the 42nd Annual Conference of the Japan Society of Endometriosis. The levels of evidence and the strengths of the recommendations were determined in accordance with the following criteria. The committee members and the authors reached a consensus through discussion on the assessment of each CQ. Evidence level I Systematic Review/Meta‐analysis II 1 or more RCTs III Non‐RCT IV Clinical Trial/Cohort Study V Descriptive Study VI Not based on patient data, or opinion of expert panel or individual expert Strength of recommendation. A Strongly recommended B Recommended C Recommended, but no clear evidence D Not recommended

Funding

This work was supported by the Japan Society of Obstetrics and Gynecology.

Section

1. The long‐term administration of OC/LEP combinations is effective. Long‐term administration of OCs/LEPs is effective. Evidence level II Strength of recommendation B 2. The intrauterine system releasing levonorgestrel (LNG‐IUS) does not evidently reduce the recurrence of ovarian endometriotic cysts. Evidence level II Strength of recommendation B 3. Long‐term administration of dienogest may reduce the recurrence of ovarian endometriotic cysts. Evidence level IV Strength of recommendation C Numbers of studies referenced 1. Systematic Reviews 1, RCTs 1, Cohort Studies 3 2. Systematic Reviews 1, RCTs 2, Cohort Studies 1 3. Cohort studies 2 Commentary. Studies of medical therapy following conservative surgery for ovarian endometriotic cysts are as follows. A systematic review and meta‐analysis have shown that the long‐term administration of an OC/LEP (≥ 12 months) inhibits the recurrence of ovarian endometriotic cysts (long‐term OC/LEP group: n  = 423, and no treatment group: n  = 341; RR 0.12, 95% CI 0.05–0.29). 1 However, this meta‐analysis included only one RCT and three cohort studies. With the cyclic administration of OCs/LEPs for 24 months following surgery, recurrence rates did not differ significantly according to the type of progestin included in the OC/LEP regimen (desogestrel, gestodene, and dienogest) (one RCT). 2 In a systematic‐review and meta‐analysis that compared cyclic versus continuous administration of OCs/LEPs, although the recurrence of ovarian endometriotic cysts tended to be less frequent with continuous administration, a significant difference was not observed with the sample size to date (continuous: n  = 156, cyclic: n = 187; RR 0.54, 95% CI 0.28–1.05). 3 This meta‐analysis included two RCTs and one cohort study. The reported effects of the LNG‐IUS (Mirena®) following conservative surgery for ovarian endometriotic cysts are as follows. In a meta‐analysis of two RCTs (LNG‐IUS group: n  = 68, and expectant management group: n  = 66), the LNG‐IUS did not demonstrate evident efficacy in terms of reducing recurrence of ovarian endometriotic cysts (RR 0.60, 95% CI 0.31–1.14). 4 The durations of postoperative observation in these two RCTs were 12 and 30 months. Although LNG‐IUS has not demonstrated a significant effect in terms of reducing the recurrence of ovarian endometriotic cysts, it has shown significant efficacy in reducing the recurrence of endometriosis compared to no treatment, and significant efficacy in reducing menstrual pain. 4 In cohort studies, postoperative dienogest (2 mg/day) significantly reduced the rate of ovarian endometrioma compared to expectant management. 5 , 6 In comparisons between a dienogest group and an expectant management group, the rate of recurrence 12 and 24 months after surgery in the expectant management group was 16.5% and 24.0%, respectively, whereas the dienogest group had no recurrences. 5 Studies with higher levels of evidence, such as RCTs, are desirable to assess the efficacy of dienogest in reducing postoperative recurrence of ovarian endometriotic cysts.

Disclosure

The authors declare no conflicts of interests for this article.

Introduction

More than 10 years following the publication of “The General Rules for Clinical Management of Endometriosis: The second edition” in January 2010, the long‐awaited third edition has arrived. The second edition represents the bible for endometriosis treatment and has become the go‐to reference in clinical practice in Japan; it was published after the introduction of low‐dose estrogen–progestin (LEP) therapy and the novel progestin dienogest on the market. Looking back, this was the turning point from the era when laparoscopic surgery + GnRH agonist therapy was the predominant treatment and introduced an era of novel treatments. With the development of lightweight, high‐resolution endoscopes that allow for more delicate and precise surgical operations, endometriosis surgery has transitioned from laparotomy to laparoscopy. Conversely, despite their potency in alleviating the symptoms of endometriosis, GnRH agonists could only be used for up to 6 months due to adverse effects associated with estrogen deficiency. Thus, the predominant treatment was centered on laparoscopic surgery, with GnRH agonists used as an adjunct. Following the publication of the second edition, the use of LEP and dienogest became widespread. With both agents have been shown to be effective and safe, long‐term medical therapy has become possible. Owing to technical advancements in laparoscopic surgery, surgery is now also performed for deep endometriosis or less common and rare site endometriosis. However, for ovarian endometriotic cysts, ova, and normal ovarian tissues should be resected along with the endometrial tissue, thus, diminishing the ovarian reserve. Therefore, surgery must be performed carefully for young women and women wishing to have children in the future. We are now in an era in which we take advantage of long‐term medical therapy and laparoscopic surgery, as we consider treatment tailored to the life stages of individual women while attempting to preserve ovarian functions. In this revised edition, we refer to the second edition for fundamental knowledge in clearly elaborating current perspectives on the review of the diagnosis and treatment, in addition to the advance over the last 10 years. Therapeutic strategies are explained with detailed flow charts. The clinical questions (CQs) in the latter half of this edition are intended as a useful guide for decision‐making in clinical practice. The authors are all physicians working tirelessly at the frontiers of endometriosis research in Japan, and this edition has undergone multiple generous revisions amid their busy schedules. Integration of the overall structure, revision of inconsistencies and duplication among CQs, and other onerous editing tasks were undertaken with tremendous dedication by the secretaries on the Japan Society of Endometriosis, Drs. Fuminori Taniguchi, Michio Kitajima, Kaori Koga, Taisuke Mori, and Ken Yamaguchi. Once again, I would like to offer them my deepest gratitude. I hope that this revised edition would be helpful in the treatment of women with endometriosis not only in Japan but worldwide. Tasuku Harada

Opening Section

2. Infertility Management of endometriosis‐associated infertility Endometriosis negatively affects fertility in both mechanically and biochemically. Mechanical mechanisms include impairment of fallopian tube oocyte capture associated with adhesion, and impairment of oocyte and sperm transport associated with abnormal uterine contraction. Biochemical mechanisms include abnormalities in the immune and endocrine environments in the peritoneal cavity, fallopian tube, ovaries, and uterus, which affect oocytes/sperms and embryos. Therefore, the control of endometriosis with surgery or medical treatment may inhibit these negative effects and thus improve fertility. ART also helps to improve fertility by bypassing the deteriorated pelvic milieu. Expectant management In women without notable pain and with normal findings of the partner's semen, expectant management with timed sex for approximately 12 months is not unreasonable, especially for young patients with only a short period of infertility with suspected minimal/mild endometriosis. Surgical therapy Surgical therapy potentially improves fertility by eliminating the mechanical factors described above through adhesiolysis, or by eliminating biochemical factors through peritoneal lavage and removal of lesions. However, surgery may not completely remove or repair these environments and might even harm reproductive function (i.e., reducing ovarian reserve) or decrease fertility by causing further adhesions. Therefore, estimating the efficacy of surgery requires balancing the benefits and risks of surgery and comparing it with alternative treatments, such as ART. Mild endometriosis It is well known that spontaneous pregnancy rates increase after laparoscopic surgery in patients with mild endometriosis. For this reason, guidelines in multiple countries recommend surgical therapy for mild endometriosis. 1 , 2 , 3 However, the benefits of surgery do not necessarily outweigh those of ART as the presence of mild endometriosis cannot be determined until laparoscopy is performed, and there is the high risk and cost of surgery with respect to the pregnancy rate with ART. 4 Taking into account the patient's age, symptoms, and social background, surgery should be planned when its benefits are evaluated to be relatively high, such as when improving pain is also an objective, or when the patient does not wish to undergo ART. Moderate/severe endometriosis Data on whether surgery for moderate/severe endometriosis helps to improve postoperative fertility have not been assessed in an RCT or elsewhere. However, compared to mild endometriosis, laparoscopic surgery has been shown to be less effective in improving postoperative fertility in patients with moderate/severe endometriosis, such as those with severe adhesions of the fallopian tubes. Therefore, ART should be considered for patients with moderate/severe endometriosis if the only goal is to improve fertility. However, surgery is recommended if it is deemed to be required for endometriosis itself, such as for relief from symptoms and pathological diagnosis. Endometriosis fertility index (EFI). The endometriosis fertility index (EFI) (See Reference 5, Page 1611) is a score that includes parameters such as the age of the patient, duration of infertility, pregnancy history, severity of endometriosis according to the r‐ASRM score, and the tubal, fimbrial, and ovarian appearance. This index is excellent for predicting postoperative spontaneous pregnancy rates and is useful for postoperative fertility treatment planning. 5 This score has been shown to be reproducible and highly correlated with the pregnancy rate, making it useful when planning to switch to ART after surgery. Cumulative pregnancy rates at 1 year after operation with scores of 5, 6, and 7 or 8 are approximately 20%, 30%, and 40%, respectively (See Reference 5, Page 1611). General fertility treatment (non‐assisted reproductive technology, ovulation induction and/or intrauterine insemination) There is evidence showing the efficacy of general fertility treatment (non‐assisted reproductive technology, induction of ovulation, and/or artificial insemination) in patients with endometriosis, particularly in mild endometriosis. Therefore, this treatment is recommended in both ASRM 1 and ESHRE 2 guidelines (notably, the ESHRE guideline does not recommend treatment with artificial insemination alone). However, the following points should be kept in mind: the efficacy of these treatments in patients with endometriosis is lower than that in infertile patients without endometriosis; if pregnancy is not achieved during the treatment period, the patient will age for that period and endometriosis will progress further; and ovulation induction may further exacerbate endometriosis. Caution must be taken to avoid continuing general reproductive therapy without planning. Assisted reproductive technology (ART) ART yields the highest pregnancy rates per period and the shortest time to conception among any fertility treatment. Stepping up to ART should be considered according to age, duration of infertility, pain, treatment history, ovarian reserve, recurrence of endometriosis, and other infertility‐related factors. Therapeutic strategy for patients with endometriosis‐associated infertility The therapeutic strategy (flowchart) for patients with endometriosis‐associated infertility is shown in Figure  7 . In dealing with infertile couples suspected of endometriosis, the patient's age, ovarian reserve, tubal function, and partner's semen findings should be assessed first. If the patient is older (age ≥ 36 years) or if at least one factor (ovarian reserve, tubal function, partner's semen findings) is abnormal, ART should be considered unless there is an indication for surgery for endometriosis itself. Laparoscopic surgery should be considered in cases of deep endometriosis with severe pain or large ovarian endometriotic cysts with a risk of rupture or difficulties in oocyte retrieval, or when malignancy cannot be ruled out. However, when planning surgery, it is necessary to consider its adverse effects, such as reduced ovarian reserve and complications. If the patient is young (age ≤ 35 years) and has high ovarian reserve, and there is no severely impaired tubal function, with normal semen findings in the partner, pregnancy independent of ART can be expected. Therefore, expectant management or ovulation induction and intrauterine insemination can be considered. If pregnancy is not achieved within 12 months, laparoscopic surgery should be considered. However, even in these cases, surgery should be considered immediately if endometriosis with an absolute indication for surgery (such as a large ovarian endometriotic cyst) is present. After surgery, expectant management or ovulation induction and intrauterine insemination should be recommended for up to 12 months. If pregnancy is not achieved by then, ART is recommended. In cases such as where tubal function is determined to be severely impaired in laparoscopy, ART immediately after surgery should be considered according to factors, such as the EFI score.

Text is read by the "Ask this paper" AI Q&A widget below. Extraction quality varies by source — PMC NXML preserves structure cleanly, OA-HTML may include some navigation residue, and OA-PDF can have broken hyphenation. The publisher copy (via DOI) is the canonical version.

My notes (saved in your browser only)

Ask this paper AI returns verbatim quotes from the full text · source: pmc-nxml

Answers must be backed by verbatim quotes from this paper's full text. Hallucinated quotes are dropped automatically; if no verbatim passage answers the question, we say so. How this works

Condition tags

endometriosisadenomyosisbowel_endometriosisdysmenorrheadyspareuniainfertility

MeSH descriptors

Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis Endometriosis

Citation neighborhood

Papers in the corpus that this work cites (lower rings, blue) and that cite this one (upper rings, green). Dot size scales with the paper's in-corpus citation count — bigger dot = more influential within the endo/adeno field. Click a dot to open that paper. [ expand to 2 hops ] — adds papers reached through this work's immediate citers/citees. Heavier; up to 60 extra dots.

References (100)

Cited by (9)

Source provenance

europepmc
last seen: 2026-09-06T09:34:12.023084+00:00
openalex
last seen: 2026-06-10T17:14:06.276822+00:00
pubmed
last seen: 2026-09-06T06:16:16.030829+00:00
License: CC0 · commercial use OK