Hysteroscopic Management of Asherman's Syndrome

Advancing intrauterine adhesion severity prediction: Integrative machine learning approach with hysteroscopic cold knife system, clinical characteristics and hematological parameters

Intrauterine Adhesion (IUA) constitute a significant determinant impacting female fertility, potentially leading to infertility, miscarriage, menstrual irregularities, and placental complications. The precise assessment of the severity of IUA is pivotal for the customization of personalized treatment plans, aimed at enhancing the success rate of treatments and mitigating reproductive health risks. This study proposes bTLSMA-SVM-FS, a novel feature selection machine learning model that integrates an enhanced slime mould algorithm (SMA), termed TLSMA, with support vector machines (SVM), aiming to develop a predictive model for assessing the severity of IUA. Initially, a series of optimization comparative experiments were conducted on the TLSMA using the CEC 2017 benchmark functions. By comparing it with eleven meta-heuristic algorithms as well as eleven SOTA algorithms, the experimental outcomes corroborated the superior performance of the TLSMA. Subsequently, the developed bTLSMA-SVM-FS model was employed to conduct a thorough analysis of the clinical features of 107 IUA patients from Wenzhou People's Hospital, comprising 61 cases of moderate IUA and 46 cases of severe IUA. The evaluation results of the model demonstrated exceptional performance in predicting the severity of IUA, achieving an accuracy of 86.700 % and a specificity of 87.609 %. Moreover, the model successfully identified critical factors influencing the prediction of IUA severity, including the preoperative Chinese IUA score, production times, thrombin time, preoperative endometrial thickness, and menstruation. The identification of these key factors not only further validated the efficacy of the proposed model but also provided vital scientific evidence for a deeper understanding of the pathogenesis of IUA and the enhancement of targeted treatment strategies.

Effects and safety of hyaluronic acid gel on intrauterine adhesion and fertility after intrauterine surgery: a systematic review and meta-analysis with trial sequential analysis of randomized controlled trials

OBJECTIVE

This study aimed to determine the efficacy and safety of hyaluronic acid gel for the prevention of intrauterine adhesions and improved fertility after intrauterine surgery.

DATA SOURCES

PubMed, EMBASE, Cochrane Library, Web of science, and ClinicalTrials.gov were searched up to November 1, 2023.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials that reported intrauterine adhesion and fertility outcomes among women who used hyaluronic acid after intrauterine surgery.

METHODS

The risk of bias was assessed using criteria of the Cochrane Handbook, and the quality of the evidence was evaluated using the Grades of Recommendation, Assessment, Development, and Evaluation system. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. A trial sequential analysis was conducted to assess the outcomes, and Stata 14 was used for sensitivity analyses and publication bias analyses.

RESULTS

Data from 16 randomized controlled trials involving 2359 patients were extracted and analyzed. The analysis revealed that hyaluronic acid reduced the incidence of intrauterine adhesion (risk ratio, 0.53; 95% confidence interval, 0.42-0.67; I2=48%) and improve pregnancy rates (risk ratio, 1.24; 95% confidence interval, 1.02-1.50; I2=0%). A subgroup analysis was conducted to evaluate factors that influence the effect of hyaluronic acid on the incidence of intrauterine adhesion. It was found that a small volume of hyaluronic acid reduced the incidence of intrauterine adhesions. Hyaluronic acid exhibited a protective effect among patients who underwent various intrauterine surgeries and who had different gynecologic medical histories. The protective effect was statistically significant after a follow-up of 6 to 12 weeks. The results of the trial sequential analysis indicated that the effect of hyaluronic acid on the incidence of mild intrauterine adhesions, pregnancy rates, live birth rates, and miscarriage rates after intrauterine surgery may be inconclusive and thus further evaluation is required in the form of additional clinical trials. However, the remaining effects were found to be verifiable and did not require more clinical trials for confirmation.

CONCLUSION

Hyaluronic acid can safely and effectively reduce the incidence of intrauterine adhesions and may improve fertility outcomes.

Treatment of intrauterine adhesions and subsequent pregnancy outcomes in an in vitro fertilization population

BACKGROUND

Asherman syndrome refers to the presence of intrauterine adhesions, which have clinical implications, including infertility. There are few studies assessing the effect of serial hysteroscopies for adhesiolysis on reproductive and pregnancy outcomes among women who subsequently undergo in vitro fertilization, and none have looked at maternal, neonatal, or placental pregnancy complications.

OBJECTIVE

This study aimed to explore the effect of hysteroscopic adhesiolysis among a cohort of patients who subsequently undergo in vitro fertilization.

STUDY DESIGN

This was a retrospective cohort study of all patients who underwent hysteroscopic adhesiolysis for intrauterine adhesions at our center between 2005-2020 and subsequently attempted conception by in vitro fertilization. A control group of patients who underwent in vitro fertilization for nonuterine factor infertility and had no history of intrauterine adhesions was chosen for comparison.

RESULTS

There were 691 patients included in this study, of whom 168 were intrauterine adhesion cases. The implantation rate (41.3% in both groups) and live birth rate (adjusted relative risk, 0.93 [95% confidence interval, 0.76-1.14]) were not statistically different between cases and controls. When grouped by number of previous adhesiolysis surgeries, patients who underwent ≥2 adhesiolysis surgeries had a lower live birth rate than controls (adjusted relative risk, 0.53 [95% confidence interval, 0.28-0.99]). Endometrial thickness before the transfer was significantly reduced in cases vs controls (8.23 vs 10.25 mm; adjusted relative risk, 0.84 [95% confidence interval, 0.78-0.90]). Adverse placental outcomes, including placenta accreta spectrum, placenta previa, or vasa previa, were significantly more likely to occur in cases than controls (adjusted relative risk, 2.08 [95% confidence interval, 1.25-3.46]). When grouped by the number of adhesiolysis surgeries, the risk appeared to increase as the number of prior surgeries increased. This is likely because of the increased severity of these adhesions.

CONCLUSION

Overall, patients with a history of treated intrauterine adhesions have the same live birth rate as patients undergoing in vitro fertilization for nonuterine factor indications. However, the subgroup of patients who require multiple surgeries for correction of intrauterine adhesions had a lower live birth rate after in vitro fertilization than controls. Patients with a history of treated intrauterine adhesions are at significantly greater risk of placenta accreta syndrome disorder than control patients who underwent in vitro fertilization for nonuterine factor indications.

Injectable "Homing-Like" Bioactive Short-Fibers for Endometrial Repair and Efficient Live Births

The prevalence of infertility caused by endometrial defects is steadily increasing, posing a significant challenge to women's reproductive health. In this study, injectable "homing-like" bioactive decellularized extracellular matrix short-fibers (DEFs) of porcine skin origin are innovatively designed for endometrial and fertility restoration. The DEFs can effectively bind to endometrial cells through noncovalent dipole interactions and release bioactive growth factors in situ. In vitro, the DEFs effectively attracted endometrial cells through the "homing-like" effect, enabling cell adhesion, spreading, and proliferation on their surface. Furthermore, the DEFs effectively facilitated the proliferation and angiogenesis of human primary endometrial stromal cells (HESCs) and human umbilical vein endothelial cells (HUVECs), and inhibited fibrosis of pretreated HESCs. In vivo, the DEFs significantly accelerated endometrial restoration, angiogenesis, and receptivity. Notably, the deposition of endometrial collagen decreased from 41.19 ± 2.16% to 14.15 ± 1.70% with DEFs treatment. Most importantly, in endometrium-injured rats, the use of DEFs increased the live birth rate from 30% to an impressive 90%, and the number and development of live births close to normal rats. The injectable "homing-like" bioactive DEFs system can achieve efficient live births and intrauterine injection of DEFs provides a new promising clinical strategy for endometrial factor infertility.

Fertility and anatomical outcomes following hysteroscopic adhesiolysis: An 11-year retrospective cohort study to validate a new classification system for intrauterine adhesions (Urman-Vitale Classification System)

OBJECTIVE

To propose a new classification system (Urman-Vitale Classification System) for intrauterine adhesions (IUAs) and to evaluate anatomical and fertility outcomes after hysteroscopic adhesiolysis accordingly.

METHODS

A retrospective analysis of consecutive patients treated over 11 years by a single operator in a tertiary care hospital. Women with sonographic suspicion of IUAs were scheduled for hysterosalpingography (HSG) and hysteroscopy for confirmation and treatment. IUAs were divided into five classes according to symptoms, ultrasound, HSG findings, and postsurgical hysteroscopic appearance. Hysteroscopic adhesiolysis was performed using a bipolar cutting electrode in an office setting. Evaluated outcomes were restoration of the uterine cavity, clinical pregnancy, pregnancy loss, and live birth rates.

RESULTS

A total of 227 patients (479 procedures) were included. Mean number of hysteroscopies increased in frequency with class of adhesions from Class 1 to Class 5 (1.0 ± 0.2 vs 2.3 ± 0.5; P = 0.001). Full restoration of the cavity was achieved in 100% of patients with Class 1 compared with 18.5% for Class 5 (43/43 vs 5/27; P = 0.001). Clinical pregnancy (Class 1 vs Class 4: P = 0.034; 1 vs 5: P = 0.006; 2 vs 5: P = 0.024) and live birth (Class 1 vs Class 4: P = 0.001; 1 vs 5: P = 0.006; 2 vs 4: P = 0.007; 2 vs 5: P = 0.0208) rates decreased with increasing severity of IUAs. Pregnancy loss rate was related to IUA severity (Class 1 vs Class 4: P = 0.012; 1 vs 5: P = 0.003: 2 vs 4: P = 0.014; 2 vs 5: P = 0.021).

CONCLUSION

A classification based on symptoms, imaging findings, and postsurgical macroscopic appearance of the uterine cavity could be useful in predicting prognosis and fertility in women with IUAs.

Reproductive outcomes following copper‑containing intrauterine device after hysteroscopic lysis for intrauterine adhesions

The present study aimed to investigate the reproductive outcomes of copper-containing intrauterine devices (IUDs) after hysteroscopic lysis in patients with mild to severe intrauterine adhesions (IUAs), according to the American Fertility Society (AFS) classification. Therefore, a prospective randomized controlled study was conducted at the Affiliated Jinhua Hospital of Wenzhou Medical University (Jinhua, China). A total of 173 women with IUAs were initially recruited between January 2020 and June 2021 and were then randomized to the copper-containing IUD group or the no barrier device group. Following hysteroscopic procedure, the fertility and obstetric outcomes were analyzed. Among the 173 patients enrolled, a total of 109 participants completed the study protocol. The results showed that AFS scores were not significantly different between the two groups prior to hysteroscopy. In addition, no statistically significant differences were recorded in pregnancy and live birth rates between the copper-containing IUD and no barrier device groups. Overall, the results of the current study indicated that the copper-containing IUDs had no positive effect on pregnancy and live birth rates in patients with mild to severe IUAs after hysteroscopic adhesiolysis. The present trial was retrospectively registered in the Chinese Clinical Trial Registry on 28th December 2023 (registration no. ChiCTR2300079233).

Extended balloon stent placement for reducing intrauterine adhesion recurrence: a retrospective cohort study

RESEARCH QUESTION

What are the efficacy, safety and reproductive outcomes of intrauterine balloon stent placement for 4 or 6 weeks after hysteroscopic adhesiolysis?

DESIGN

This retrospective cohort study was conducted at a university-affiliated hospital, and included 155 women with moderate to severe intrauterine adhesions who underwent hysteroscopic adhesiolysis between March 2016 and December 2019. Participants were divided according to whether the heart-shaped balloon stent was left in place for 4 (group 1) or 6 (group 2) weeks after surgery. Stents removed at the second-look hysteroscopy 4 or 6 weeks after surgery were sent for culturing of common bacteria. The incidence of adhesion reformation, adhesion score reduction, bacterial colonization of the intrauterine balloon stent, live birth rate and time to live birth were analysed.

RESULTS

Group 2 had a significantly lower adhesion reformation rate (45.7% versus 28.2%, P = 0.024) and a more significant reduction in adhesion score (5.2 ± 2.1 versus 6.3 ± 2.2, P = 0.003) compared with group 1. However, no statistical difference was observed in the percentage of bacterial colonization of the intrauterine balloon stent (55.9% versus 66.7%, P = 0.174), live birth rate (52.4% versus 42.3%, P = 0.331) or time to live birth (hazard ratio 1.09, 95% confidence interval 0.60-1.96, P = 0.778) between the two groups.

CONCLUSIONS

Extending intrauterine balloon stent use from 4 to 6 weeks further reduces the adhesion reformation rate after hysteroscopic adhesiolysis in patients with moderate to severe intrauterine adhesion. No increase in bacterial colonization of the balloon stent was observed. Extending the duration of intrauterine balloon stent placement did not significantly affect live birth rates.

Review of Asherman syndrome and its hysteroscopic treatment outcomes: experience in a low-resource setting

BACKGROUND

Asherman syndrome is one of the endometrial factors that influence a woman's reproductive capacity. However, in our context, it needs to be well-documented. This study aimed to evaluate the clinical characteristics and hysteroscopic treatment outcomes of Asherman syndrome.

METHOD

A retrospective follow-up study from January 1, 2019, to December 31, 2022, was conducted on cases of Asherman syndrome after hysteroscopic adhesiolysis at St.Paul's Hospital in Addis Ababa, Ethiopia. Clinical data were collected via telephone survey and checklist. Epidata-4.2 and SPSS-26 were employed for data entry and analysis, respectively.

RESULT

A total of 177 study participants were included in the final analysis. The mean patient age was 31 years (range: 21-39) at the initial presentation, and 32.3 years (range: 22-40) during the phone interview. The majority of the patients (97.7%) had infertility, followed by menstrual abnormalities (73.5%). Among them, nearly half (47.5%) had severe, 38.4% had moderate, and 14.1% had mild Asherman syndrome. The review identified no factor for 51.4% of the participants. Endometrial tuberculosis affected 42 patients (23.7%). It was also the most frequent factor in both moderate and severe cases of Asherman syndrome. Only 14.7% of patients reported menstrual correction. Overall, 11% of women conceived. Nine patients miscarried, three delivered viable babies, and six were still pregnant. The overall rate of adhesion reformation was 36.2%. Four individuals had complications (3 uterine perforations and one fluid overload) making a complication rate of 2.3%.

CONCLUSION

Our study revealed that severe forms of Asherman syndrome, which are marked by amenorrhea and infertility, were more common, leading to incredibly low rates of conception and the resumption of regular menstruation, as well as high recurrence rates. A high index of suspicion for Asherman syndrome, quick and sensitive diagnostic testing, and the development of a special algorithm to identify endometrial tuberculosis are therefore essential. Future multi-centered studies should focus on adhesion preventive techniques.

Photobiomodulation therapy at 632 nm wavelength ameliorates intrauterine adhesion via activation of cAMP/PKA/CREB pathway

Intrauterine adhesion (IUA), a major cause of uterine infertility, is pathologically characterized by endometrial fibrosis. Current treatments for IUA have poor efficacy with high recurrence rate, and restoring uterine functions is difficult. We aimed to determine the therapeutic efficacy of photobiomodulation (PBM) therapy on IUA and elucidate its underlying mechanisms. A rat IUA model was established via mechanical injury, and PBM was applied intrauterinely. The uterine structure and function were evaluated using ultrasonography, histology, and fertility tests. PBM therapy induced a thicker, more intact, and less fibrotic endometrium. PBM also partly recovered endometrial receptivity and fertility in IUA rats. A cellular fibrosis model was then established with human endometrial stromal cells (ESCs) cultured in the presence of TGF-β1. PBM alleviated TGF-β1-induced fibrosis and triggered cAMP/PKA/CREB signaling in ESCs. Pretreatment with the inhibitors targeting this pathway weakened PBM's protective efficacy in the IUA rats and ESCs. Therefore, we conclude that PBM improved endometrial fibrosis and fertility via activating cAMP/PKA/CREB signaling in IUA uterus. This study sheds more lights on the efficacy of PBM as a potential treatment for IUA.

Etiology, Risk Factors, and Management of Asherman Syndrome

Asherman syndrome is characterized by a triad of symptoms including pain, menstrual abnormalities, and infertility and is a result of intrauterine scar tissue after instrumentation of a gravid uterus. Saline sonohysterogram is typically the most sensitive diagnostic tool; however, hysteroscopy is the criterion standard for diagnosis. Treatment includes hysteroscopic-guided lysis of adhesion, with restoration of the anatomy of the uterine cavity. Several modalities are used in an attempt to reduce the reformation of scar tissue after surgery; however, there is no consensus on the ideal method. Stem cells and platelet-rich plasma are being explored as means of regenerative therapy for the endometrium, but data remain limited. At present, most individuals can have restoration of menstrual function; however, lower pregnancy rates and obstetric complications are not uncommon. These complications are worse for patients with a higher grade of disease. Efforts are needed in standardizing classification, reducing uterine instrumentation of the gravid uterus, and referring patients to health care professionals with clinical expertise in this area.

Treatment strategies for intrauterine adhesion: focus on the exosomes and hydrogels

Intrauterine adhesion (IUA), also referred to as Asherman Syndrome (AS), results from uterine trauma in both pregnant and nonpregnant women. The IUA damages the endometrial bottom layer, causing partial or complete occlusion of the uterine cavity. This leads to irregular menstruation, infertility, or repeated abortions. Transcervical adhesion electroreception (TCRA) is frequently used to treat IUA, which greatly lowers the prevalence of adhesions and increases pregnancy rates. Although surgery aims to disentangle the adhesive tissue, it can exacerbate the development of IUA when the degree of adhesion is severer. Therefore, it is critical to develop innovative therapeutic approaches for the prevention of IUA. Endometrial fibrosis is the essence of IUA, and studies have found that the use of different types of mesenchymal stem cells (MSCs) can reduce the risk of endometrial fibrosis and increase the possibility of pregnancy. Recent research has suggested that exosomes derived from MSCs can overcome the limitations of MSCs, such as immunogenicity and tumorigenicity risks, thereby providing new directions for IUA treatment. Moreover, the hydrogel drug delivery system can significantly ameliorate the recurrence rate of adhesions and the intrauterine pregnancy rate of patients, and its potential mechanism in the treatment of IUA has also been studied. It has been shown that the combination of two or more therapeutic schemes has broader application prospects; therefore, this article reviews the pathophysiology of IUA and current treatment strategies, focusing on exosomes combined with hydrogels in the treatment of IUA. Although the use of exosomes and hydrogels has certain challenges in treating IUA, they still provide new promising directions in this field.

Extracellular Vesicles Derived from Mesenchymal Stem Cells as Cell-Free Therapy for Intrauterine Adhesion

Intrauterine adhesion (IUA) can occur after trauma to the basal layer of the endometrium, contributing to severe complications in females, such as infertility and amenorrhea. To date, the proposed therapeutic strategies are targeted to relieve IUA, such as hysteroscopic adhesiolysis, Foley catheter balloon, and hyaluronic acid injection have been applied in the clinic. However, these approaches showed limited effects in alleviating endometrial fibrosis and thin endometrium. Mesenchymal stem cells (MSCs) can offer the potential for endometrium regeneration owing to reduce inflammation and release growth factors. On this basis, MSCs have been proposed as promising methods to treat intrauterine adhesion. However, due to the drawbacks of cell therapy, the possible therapeutic use of extracellular vesicles released by stem cells is raising increasing interest. The paracrine effect, mediated by MSCs derived extracellular vehicles (MSC-EVs), has recently been suggested as a mechanism for their therapeutic properties. Here, we summarizes the main pathological mechanisms involved in intrauterine adhesion, the biogenesis and characteristics of extracellular vesicles, explaining how these vesicles could provide new opportunities for MSCs.

Update on antiadhesion barriers and therapeutics in gynecological surgery

PURPOSE OF REVIEW

Postoperative adhesions remain a clinical challenge to both patients and providers, as they are associated with significant complications and a high economic burden. This article provides a clinical review of currently available antiadhesive agents and promising new therapies that have advanced past animal studies.

RECENT FINDINGS

Several agents have been investigated on their ability to reduce adhesion formation; however, there is no widely acceptable option. The few available interventions are barrier agents and while low-quality evidence suggests that they may be more effective than no treatment, there is no general agreement on their overall efficacy. There is an abundance of research on new solutions; however, their clinical efficacy is yet to be determined.

SUMMARY

Although a wide range of therapeutics have been investigated, majority are halted in animal models with only a select few being studied in humans and ultimately available in the market. Many agents have shown effectiveness in reducing adhesion formation, however, that has not been translated to improvement in clinically relevant outcomes; hence the need for high-quality large randomized trials.

The perinatal outcomes of women treated for Asherman syndrome: a propensity score-matched cohort study

STUDY QUESTION

Do the perinatal outcomes of patients following hysteroscopic treatment for Asherman syndrome (AS) differ from that of a control population?

SUMMARY ANSWER

Perinatal complications including placental issues, high blood loss, and prematurity in women after treatment for AS should be considered as moderate to high risk, especially in patients who have undergone more than one hysteroscopy (HS) or repeated postpartum instrumental revisions of the uterine cavity (Dilation and Curettage; D&C).

WHAT IS KNOWN ALREADY

The detrimental impact of AS on obstetrics outcomes is commonly recognized. However, prospective studies evaluating perinatal/neonatal outcomes in women with AS history are sparse, and the characteristics accounting for the respective morbidity of AS patients remain to be elucidated.

STUDY DESIGN, SIZE, DURATION

We conducted a prospective cohort study utilizing data from patients who underwent HS treatment for moderate to severe AS in a single tertiary University-affiliated hospital (enrolled between 01 January 2009 and March 2021), and who consequently conceived and progressed to at least 22nd gestational week of pregnancy. Perinatal outcomes were compared to a control population without an AS history, retrospectively enrolled concomitantly at the time of delivery for each patient with AS. Maternal and neonatal morbidity was assessed as well as the characteristics-related risk factors of AS patients.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Our analytic cohort included a total of 198 patients, 66 prospectively enrolled patients with moderate to severe AS and 132 controls. We used multivariable logistic regression to calculate a propensity score to match 1-1 women with and without AS history based on demographic and clinical factors. After matching, 60 pairs of patients were analysed. Chi-square test was used to compare perinatal outcomes between the pairs. Spearman's correlation analysis was utilized to investigate the correlation between perinatal/neonatal morbidity and the characteristics-related factors of AS patients. The odds ratio (OR) for the associations was calculated by logistic regression.

MAIN RESULTS AND THE ROLE OF CHANCE

Among the 60 propensity matched pairs, the AS group more frequently experienced overall perinatal morbidity, including abnormally invasive placenta (41.7% vs 0%; P < 0.001), retained placenta requiring manual or surgical removal (46.7% vs 6.7%; P < 0.001), and peripartum haemorrhage occurrence (31.7% vs 3.3%; P < 0.001). Premature delivery (<37 gestational weeks) was reported more frequently also for patients with AS (28.3% vs 5.0%; P < 0.001). However, no increased frequency of intra-uterine growth restriction or worsened neonatal outcomes were observed in AS group. Univariable analysis of risk factors for AS group morbidity outcomes revealed that the main factor related to abnormally invasive placenta was two or more HS procedures (OR 11.0; 95% CI: 1.33-91.23), followed by two or more D&Cs preceding AS treatment (OR 5.11; 95% CI: 1.69-15.45), and D&C performed postpartum as compared to post abortion (OR 3.0; 95% CI: 1.03-8.71). Similarly, two or more HS procedures were observed as the most important factor for retained placenta (OR 13.75; 95% CI: 1.66-114.14), followed by two or more preceding D&Cs (OR 5.16; 95% CI: 1.67-15.9). Premature birth was significantly associated with the number of preceding D&Cs (OR for two or more, 4.29; 95% CI: 1.12-14.91).

LIMITATIONS, REASONS FOR CAUTION

Although the cohort of patients with AS was enrolled prospectively, a baseline imbalance was intrinsically involved in the retrospective enrolment of the control group. However, to reduce the risk of bias, confounding factors were adjusted for using propensity score matching. The limitation to the generalization of our reported results is the single institution design in which all patients were treated for AS in one tertiary medical centre.

WIDER IMPLICATIONS OF THE FINDINGS

Within our search scope, our study represents one of the first and largest prospective studies of perinatal and neonatal outcomes in moderate to severe AS patients with a prospectively analysis of the risks factors of characteristics significantly influencing reported morbidities among patients with AS.

STUDY FUNDING/COMPETING INTEREST(S)

The study was supported by the Charles University in Prague [UNCE 204065] and by the institutional grant of The General Faculty Hospital in Prague [00064165]. No competing interests were declared.

TRIAL REGISTRATION NUMBER

N/A.

Construction and evaluation of intrauterine adhesion model in rats by different methods of mechanical injury

PURPOSE

The study aimed to establish a stable and effective animal model for the experimental study of intrauterine adhesion (IUA) by evaluating various mechanical injury methods.

METHODS

A total of 140 female rats were divided into four groups according to the extent and area of endometrial injury: group A (excision area: 2.0 × 0.5 cm²), group B (excision area: 2.0 × 0.25 cm²), group C (endometrial curettage) and group D (sham operation). On the 3rd, 7th, 15th and 30th day after the operation, the tissue samples of each group were collected, and the uterine cavity stenosis and histological changes were recorded by HE and Masson staining. Immunohistochemistry of CD31 was applied to visualize microvessel density (MVD). The pregnancy rate and the number of gestational sacs were used to evaluate the reproductive outcome.

RESULTS

The results showed that endometrium injured by small-area endometrial excision or simple curettage could be repaired. The ratio of fibrosis in groups A and B was higher than that in groups C and group D 30 days after modeling (P < 0.001). The number of endometrial glands and MVD in group A was significantly lower than those in groups B, C and D (P < 0.05). The pregnancy rate in group A was 20%, which was lower than that in groups B (33.3%), C (89%) and D (100%) (P < 0.05).

CONCLUSION

Full-thickness endometrial excision has a high rate of success in constructing stable and effective IUA models in rats.

Chitosan combined with intrauterine device prevents intrauterine adhesions after hysteroscopic adhesiolysis: A target trial emulation study

AIM

To compare the efficacy of chitosan and intrauterine device (IUD) combination with an IUD alone in patients with intrauterine adhesions (IUAs) who underwent hysteroscopic adhesiolysis.

METHODS

This retrospective study assessed 303 patients with moderate-to-severe IUA (American Fertility Society [AFS] score ≥5) who underwent hysteroscopic adhesiolysis between January 2018 and December 2020. Using observational data under a cohort design, we emulated a target trial with two treatment arms: chitosan plus IUD and IUD alone groups. Second-look hysteroscopy was performed in all patients 3 months after the initial hysteroscopy. The primary outcome was improved adhesion assessed using the AFS scoring system.

RESULTS

The baseline characteristics were balanced between the two groups. The second hysteroscopy revealed significantly better AFS scores in group A than in group B (values: 3 [1-4] vs. 4 [2-6], p < 0.001; change: 63% [50%-80%] vs. 44% [33%-67%], p < 0.001, respectively). Significantly better menstruation conditions (improved rate: 66% vs. 49%, p = 0.004) and endometrial thickness (mean: 7.0 mm vs. 6.0 mm, p < 0.001) were also observed in group A than in group B. Moreover, group A showed a significantly higher 1-year clinical pregnancy rate (40% vs. 28%, p = 0.037) and better quality of life (p < 0.001) than group B.

CONCLUSIONS

Chitosan and IUD combination showed better efficacy in reducing adhesions and improving clinical outcomes in patients with moderate-to-severe IUA after hysteroscopic adhesiolysis.

How platelet-rich plasma (PRP) intra-uterine injection improve endometrial receptivity of intrauterine adhesions in women: A time-series-based self-controlled study

Platelet-rich plasma (PRP) treatment proven to improve fertility outcomes in patients with a poor endometrial environment. However, the mechanism is not yet clear. In this study, we recruited 6 patients with infertility due to IUA and 6 normal control women. The subjects in the IUA group collected samples before and after PRP treatment. Endometrial receptivity was improved after PRP treatment. After PRP treatment, the endometrial NK cells, CD8 T cells and Th1 cells were significantly lower than those before treatment. Functional enrichment analysis suggested that the effects of changes in microbial composition played an important role in changes in the endometrial immune environment. Among them, the most significant difference was Bacillus. Our self-controlled cohort in this study can fully describe the detailed mechanism by which PRP treatment improves the endometrial environment.

Platelet-Rich Plasma Improves Pregnancy Outcomes in Moderate to Severe Intrauterine Adhesion: A Retrospective Cohort Study

The purpose of the present study was to investigate the therapeutic effects of platelet-rich plasma (PRP) in women with moderate to severe intrauterine adhesion (IUA). A retrospective cohort study was conducted at a reproductive medical center between July 2020 and June 2021 to compare the clinical pregnancy rate of two groups (PRP and non-PRP groups) after hysteroscopic adhesiolysis. A multivariate logistic regression analysis and propensity score matching (PSM) were performed to minimize potential bias. According to our inclusion and exclusion criteria, 133 patients were finally enrolled and divided into the PRP group (n = 48) and non-PRP group (n = 85). In the primary comparison, the clinical pregnancy rate in the PRP group was higher than that in the non-PRP group (41.7% vs. 28.2%, p = 0.114), albeit without statistical significance. Multivariate logistic regression analysis was performed, and the results of the adjusted model showed that PRP treatment significantly improved the clinical pregnancy rate (adjusted OR = 3.00, 95% CI = 1.22-7.38, p = 0.017). After PSM, the clinical pregnancy rate was higher in the PRP group than that in the non-PRP group (46.2% vs. 20.5%, p = 0.031). Based on the present study, we concluded that intrauterine perfusion of PRP had great potential in improving the clinical pregnancy rate in patients with moderate to severe IUA. Therefore, we recommend the application of PRP in the treatment of IUA.

Umbilical cord mesenchymal stem cell-derived exosomes reverse endometrial fibrosis by the miR-145-5p/ZEB2 axis in intrauterine adhesions

RESEARCH QUESTION

What is the specific mechanism of umbilical cord mesenchymal stem cell-derived exosomes (UCMSC-exos) in regulating endometrial repair and regeneration?

DESIGN

In this study, UCMSC-exos were harvested by differential ultracentrifugation from umbilical cord mesenchymal stem cell culture supernatant and identified with western blotting, transmission electron microscopy and nanoparticle tracking analysis. Transforming growth factor-β1 (TGFβ1) at different concentrations was used to construct the intrauterine adhesions cell model. The fibrotic markers were assessed by quantitative reverse transcription-polymerase chain reaction and western blotting. The effects of miR-145-5p over-expression on endometrial fibrosis were assessed. Dual luciferase assay was performed to verify the relationship between miR-145-5p and zinc finger E-box binding homeobox 2 (ZEB2).

RESULTS

The isolated UCMSC-exos had a typical cup-shaped morphology, expressed the specific exosomal markers Alix, CD63 and TSG101, and were approximately 50-150 nm in diameter. TGFβ1 at 10 ng/ml significantly promoted endometrial fibrosis, which was reversed by 20 µg/ml UCMSC-exos. Exosomal miR-145-5p ameliorated TGFβ1-induced endometrial fibrosis. ZEB2 was inversely regulated by exosomal miR-145-5p as a direct target.

CONCLUSIONS

UCMSC-exos might reverse endometrial stromal cell fibrosis by regulating the miR-145-5p/ZEB2 axis, representing a potential novel strategy to promote endometrial repair.

Endometrial Stem Cells and Their Applications in Intrauterine Adhesion

Intrauterine adhesion (IUA), resulting from pregnancy or nonpregnant uterine trauma, is one of the major causes of abnormal menstruation, infertility, or repeated pregnancy loss. Although a few methods, including hysteroscopy and hormone therapy, are routinely used for its diagnosis and treatment, they cannot restore tissue regeneration. Stem cells, which have self-renewal and tissue regeneration abilities, have been proposed as a promising therapy for patients with severe IUAs. In this review, we summarize the origin and features of endometrium-associated stem cells and their applications in the treatment of IUAs based on animal models and human clinical trials. We expect that this information will help to elucidate the underlying mechanism for tissue regeneration and to improve the design of stem cell-based therapies for IUAs.

Characteristics and transcriptomic analysis of scar tissues on the inner uterine cavity wall in patients with intrauterine adhesions

Introduction: It has been previously reported that intrauterine adhesions (IUAs) are the main cause of uterine infertility. However, the histological origin of scar tissue present on the inner wall of the uterine cavity with IUAs has not been previously studied, which is particularly necessary for follow-up research and prevention and treatment. Methods: In this study, myometrium with normal uterus were assigned to the control group and scar tissues with IUAs were assigned to the experimental group. And pathological characteristics and transcriptomic were analyzed between the two groups. Results: We founded no difference was noted in the histological morphology and the α-SMA expression between the experimental and control groups. A total of 698 differentially expressed genes were identified between the two groups. Gene Ontology (GO) analyses revealed that the DEGs were significantly enriched in cell proliferation, AP-1 complex formation, and angiogenesis. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses revealed that the target genes were significantly enriched in the AGE-RAGE, FOXO and TNF signaling pathway. Discussion: As far as we know, this is the first study to propose that the scar tissues are mainly derived from the myometrium and the first one to report differentially expressed genes in the scar tissues of IUAs.

Platelet-derived exosomes induce cell proliferation and wound healing in human endometrial cells

Aim: To investigate the regenerative effects of a platelet-derived purified exosome product (PEP) on human endometrial cells. Materials & methods: Endometrial adenocarcinoma cells (HEC-1A), endometrial stromal cells (T HESC) and menstrual blood-derived stem cells (MenSC) were assessed for exosome absorption and subsequent changes in cell proliferation and wound healing properties over 48 h. Results: Cell proliferation increased in PEP treated T HESC (p < 0.0001) and MenSC (p < 0.001) after 6 h and in HEC-1A (p < 0.01) after 12 h. PEP improved wound healing after 6 h in HEC-1A (p < 0.01) and MenSC (p < 0.0001) and in T HESC between 24 and 36 h (p < 0.05). Conclusion: PEP was absorbed by three different endometrial cell types. PEP treatment increased cell proliferation and wound healing capacity.

Uterine Cavity Parameters Evaluated by Hysteroscopy can Predict the Live Birth Rate For Intrauterine Adhesion Patients

We aim to establish an objective and accurate prediction model by evaluating the uterine cavity and correlate these key factors with the live birth rate after hysteroscopic adhesiolysis (HA). A total of 457 intrauterine adhesions (IUA) patients were retrospectively enrolled in this study. The participants underwent HA and second-look hysteroscopy at the Third Xiangya Hospital of Central South University. Pregnancy outcomes, including spontaneous live births and no live births (miscarriages and infertility), were followed. Clinical parameters, containing the number of visible uterine horns and tubal ostia, the length of the uterine cavity, among others, were measured and analyzed to determine the dominant variables in an attempt to establish the live birth rate, prediction models. Women in the no live birth group were older than that in the live birth group (P = 0.0002, OR = 0.895, 95% CI: 0.844–0.949) and were more likely to be 2 gravidity (P = 0.0136, OR = 2.558, 95% CI: 1.213–5.394). Uterine cavity length in pre-HA hysteroscopy was longer in the live birth group (P = 0.0018, OR = 1.735, 95% CI: 1.227–2.453), and adhesion scores in pre-HA hysteroscopy were more frequently above 6 (P = 0.0252, OR = 0.286, 95% CI: 0.096–0.856) in the no live birth group. During the second-look, hysteroscopy, visible bilateral fallopian tube ostia were more frequently observed in the live birth group (P = 0.0339, OR = 11.76, 95% CI: 1.207–114.611), and adhesion scores were 4–6 (P < 0.0001, OR = 0.032, 95% CI: 0.007–0.146) and above 6 (P < 0.0001, OR = 0.012, 95% CI: 0.002–0.073) in the no live birth group. The areas under the curves (AUCs) of the pre-HA and second-look hysteroscopy prediction models were 0.7552 and 0.8484, respectively. We established an objective and accurate method for evaluating the uterine cavity by hysteroscopy, and second-look hysteroscopy is more valuable than the fist hysteroscopy in predicting the live birth rate following HA. Visible bilateral fallopian tube ostia or adhesion scores were <4 in the second-look hysteroscopy might predict live birth after surgery.

An injectable gelatin/sericin hydrogel loaded with human umbilical cord mesenchymal stem cells for the treatment of uterine injury

Abnormal endometrial receptivity is a major cause of the failure of embryo transplantation, which may lead to infertility, adverse pregnancy, and neonatal outcomes. While hormonal treatment has dramatically improved the fertility outcomes in women with endometriosis, a substantial unmet need persists in the treatment. In this study, methacrylate gelatin (GelMA) and methacrylate sericin (SerMA) hydrogel with human umbilical cord mesenchymal stem cells (HUMSC) encapsulation was designed for facilitating endometrial regeneration and fertility restoration through in situ injection. The presented GelMA/10%SerMA hydrogel showed appropriate swelling ratio, good mechanical properties, and degradation stability. In vitro cell experiments showed that the prepared hydrogels had excellent biocompatibility and cell encapsulation ability of HUMSC. Further in vivo experiments demonstrated that GelMA/SerMA@HUMSC hydrogel could increase the thickness of endometrium and improve the endometrial interstitial fibrosis. Moreover, regenerated endometrial tissue was more receptive to transfer embryos. Summary, we believed that GelMA/SerMA@HUMSC hydrogel will hold tremendous promise to repair or regenerate damaged endometrium.

The Role of Endometrial Stem/Progenitor Cells in Recurrent Reproductive Failure

Recurrent implantation failure (RIF) and recurrent pregnancy loss (RPL), collectively referred to as recurrent reproductive failure (RRF), are both challenging conditions with many unanswered questions relating to causes and management options. Both conditions are proposed to be related to an aberrant endometrial microenvironment, with different proposed aetiologies related to a restrictive or permissive endometrium for an invading embryo. The impressive regenerative capacity of the human endometrium has been well-established and has led to the isolation and characterisation of several subtypes of endometrial stem/progenitor cells (eSPCs). eSPCs are known to be involved in the pathogenesis of endometrium-related disorders (such as endometriosis) and have been proposed to be implicated in the pathogenesis of RRF. This review appraises the current knowledge of eSPCs, and their involvement in RRF, highlighting the considerable unknown aspects in this field, and providing avenues for future research to facilitate much-needed advances in the diagnosis and management of millions of women suffering with RRF.

Human Platelet-Rich Plasma Facilitates Angiogenesis to Restore Impaired Uterine Environments with Asherman’s Syndrome for Embryo Implantation and Following Pregnancy in Mice

Asherman’s syndrome (AS) is caused by intrauterine adhesions and inactive endometrium from repeated curettage of the uterine endometrium. AS is a major cause of recurrent implantation failure and miscarriage and is very difficult to treat because of the poor recovery of endometrial basal cells. Platelet-rich plasma (PRP) has abundant growth factors that may induce angiogenesis and cell proliferation. Here, we demonstrate that human PRP (hPRP) significantly enhances angiogenesis to restore embryo implantation, leading to successful pregnancy in mice with AS. In mice with AS, hPRP treatment considerably reduced the expression of fibrosis markers and alleviated oligo/amenorrhea phenotypes. Mice with AS did not produce any pups, but the hPRP therapy restored their infertility. AS-induced abnormalities, such as aberrantly delayed embryo implantation and intrauterine growth retardation, were considerably eliminated by hPRP. Furthermore, hPRP significantly promoted not only the elevation of various angiogenic factors, but also the migration of endometrial stromal cells. It also increased the phosphorylation of STAT3, a critical mediator of wound healing, and the expression of tissue remodeling genes in a fibrotic uterus. PRP could be a promising therapeutic strategy to promote angiogenesis and reduce fibrosis in impaired uterine environments, leading to successful embryo implantation for better clinical outcomes in patients with AS.

Postsurgical barrier strategies to avoid the recurrence of intrauterine adhesion formation after hysteroscopic adhesiolysis: a network meta-analysis of randomized controlled trials

OBJECTIVE

To assess the efficacy of mechanical strategies to avoid the recurrence of intrauterine adhesions, to evaluate the impact on subsequent fertility after hysteroscopic adhesiolysis and to rank the available antiadhesive options.

DATA SOURCES

MEDLINE, Scopus, ClinicalTrials.gov, CINAHL, Scielo, EMBASE, PROSPERO, Cochrane Library, conference proceedings, and international controlled trials registries were searched without temporal, geographic, and language restrictions.

STUDY ELIGIBILITY CRITERIA

Randomized trials that analyzed the recurrence, reproductive outcomes, or both in women undergoing hysteroscopic adhesiolysis followed by mechanical prevention of intrauterine adhesions were included. The exclusion criteria included the following: quasi-randomized trials and trials without randomization and studies including patients undergoing hysteroscopic surgery that was different from adhesiolysis.

STUDY APPRAISAL AND SYNTHESIS METHODS

The Preferred Reporting Items for Systematic reviews and Meta-Analyses extension statement for network meta-analyses guidelines were followed. We performed a network meta-analysis based on the random effects model for mixed multiple treatment comparisons to rank the antiadhesive strategies by surface under the cumulative ranking curve area. Quality assessment was performed using the criteria outlined in the Cochrane Handbook for Systematic Reviews of Interventions. The primary outcome was the recurrent presence of intrauterine adhesions.

RESULTS

Eleven studies with data for 1596 women were identified as applicable. A copper intrauterine device together with an intrauterine balloon (surface under the cumulative ranking curve area=46.4%) or with cross-linked hyaluronic acid gel (surface under the cumulative ranking curve area=21.3%) seemed effective in preventing adhesions recurrence. Regarding the fecundity, hyaluronic acid gel demonstrated the highest pregnancy rates (surface under the cumulative ranking curve area=79.8%). The greatest degrees of change in the mean adhesions scores were found with the use of hyaluronic acid gel plus an intrauterine device (surface under the cumulative ranking curve area=38.9%). For postsurgical adhesion severity, hyaluronic acid gel plus intrauterine device (surface under the cumulative ranking curve area=49.9%) followed by intrauterine device alone (surface under the cumulative ranking curve area=30.8%) was ranked the highest. Dried amnion graft (surface under the cumulative ranking curve area=53.8%) and uterine balloon (surface under the cumulative ranking curve area=45%) showed the greatest menstrual pattern improvement.

CONCLUSION

Cross-linked hyaluronic acid gel, with or without insertion of a copper intrauterine device, seems to be the most effective approach. However, the lack of a clear best therapy suggests the need for further studies to draw firm conclusions.

Genetically engineered FGF1-sericin hydrogel material treats intrauterine adhesion and restores fertility in rat

Endometrial injury can cause intrauterine adhesions (IUA) and induce the formation of endometrial fibrosis, leading to infertility and miscarriage. At present, there is no effective treatment method for severe IUA and uterine basal injury with adhesion area larger than 1/3 of the uterus. In this study, we prepared FGF1 silk sericin hydrogel material (FGF1-SS hydrogel) to treat endometrial injury and prevent endometrial fibrosis. Compared with the silk sericin hydrogel material (WT-SS hydrogel), FGF1-SS hydrogel significantly promotes the cell migration and infiltration ability of endometrial stromal cells (ESCs). More importantly, FGF1-SS hydrogel can release FGF1 stably for a long time and inhibit The ESCs injury model forms fibrosis through the TGF-β/Smad pathway. In the IUA rat model, FGF1-SS hydrogel treatment effectively restored the number of uterine glands and uterine wall thickness in rats, with a fertility rate of 65.1 ± 6.4%. The results show that FGF1-SS hydrogel is expected to be a candidate to prevent IUA.

Approach to the Patient With New-Onset Secondary Amenorrhea: Is This Primary Ovarian Insufficiency?

Menstrual cyclicity is a marker of health for reproductively mature women. Absent menses, or amenorrhea, is often the initial sign of pregnancy-an indication that the system is functioning appropriately and capable of generating the intended evolutionary outcome. Perturbations of menstrual regularity in the absence of pregnancy provide a marker for physiological or pathological disruption of this well-orchestrated process. New-onset amenorrhea with duration of 3 to 6 months should be promptly evaluated. Secondary amenorrhea can reflect structural or functional disturbances occurring from higher centers in the hypothalamus to the pituitary, the ovary, and finally, the uterus. Amenorrhea can also be a manifestation of systemic disorders resulting in compensatory inhibition of reproduction. Identifying the point of the breakdown is essential to restoring reproductive homeostasis to maintain future fertility and reestablish reproductive hormonal integrity. Among the most challenging disorders contributing to secondary amenorrhea is primary ovarian insufficiency (POI). This diagnosis stems from a number of possible etiologies, including autoimmune, genetic, metabolic, toxic, iatrogenic, and idiopathic, each with associated conditions and attendant medical concerns. The dual assaults of unanticipated compromised fertility concurrently with depletion of the normal reproductive hormonal milieu yield multiple management challenges. Fertility restoration is an area of active research, while optimal management of estrogen deficiency symptoms and the anticipated preventive benefits of hormone replacement for bone, cardiovascular, and neurocognitive health remain understudied. The state of the evidence for an optimal, individualized, clinical management approach to women with POI is discussed along with priorities for additional research in this population.

Cell-based therapy in thin endometrium and Asherman syndrome

Numerous treatment strategies have so far been proposed for treating refractory thin endometrium either without or with the Asherman syndrome. Inconsistency in the improvement of endometrial thickness is a common limitation of such therapies including tamoxifen citrate as an ovulation induction agent, acupuncture, long-term pentoxifylline and tocopherol or tocopherol only, low-dose human chorionic gonadotropin during endometrial preparation, aspirin, luteal gonadotropin-releasing hormone agonist supplementation, and extended estrogen therapy. Recently, cell therapy has been proposed as an ideal alternative for endometrium regeneration, including the employment of stem cells, platelet-rich plasma, and growth factors as therapeutic agents. The mechanisms of action of cell therapy include the cytokine induction, growth factor production, natural killer cell activity reduction, Th17 and Th1 decrease, and Treg cell and Th2 increase. Since cell therapy is personalized, dynamic, interactive, and specific and could be an effective strategy. Despite its promising nature, further research is required for improving the procedure and the safety of this strategy. These methods and their results are discussed in this article.

Macrophage polarisation in caesarean scar diverticulum

AIMS

To determine immunohistochemical features and correlations between M1/M2 polarisation status with disease severity of post-caesarean scar diverticulum (CSD).

METHODS

Histological and immunohistological stainings were performed and inflammatory (CD16, CD163 and tumour necrosis factor-α (TNF-α)), fibrosis (α-smooth muscle actin (α-SMA)) and angiogenic (CD31) markers were examined in uterine tissues collected from patients with uterine scar diverticula (CSD) (n=37) and caesarean section (CS) (n=3).

RESULTS

CSD tissues have higher expression of α-SMA, TNF-α, CD16 and CD31 and lower expression of CD163 than CS tissue (p<0.05). Compared with adjacent tissues, thick-walled blood vessels, glands and fibrotic sites have higher expression of α-SMA, TNF-α and CD16. Statistical correlation was observed between the expression of CD16 and TNF-α (R=0.693, p<0.001), α-SMA (R=0.404, p<0.05) and CD31 (R=0.253, p<0.05) in CSD tissues, especially with the ratio of CD16/CD163 (R=0.590, p<0.01). A more significant difference was observed between the expression of CD16/CD163 and α-SMA (R=0.556, p<0.001), TNF-α (R=0.633, p<0.0001) and CD31 (R=0.336, p<0.05).

CONCLUSIONS

In this study, TNF-α, α-SMA, CD16 and CD31 proteins were overexpressed in all CSD cases, and CD16/CD163 was positively correlated with tissue inflammation, fibrosis and neovascularisation. Abnormal mononuclear macrophage infiltration may be involved in the origin and progression of CSD.

The potential of Zishen Yutai pills to facilitate endometrial recovery and restore fertility after induced abortion in rats

CONTEXT

Abortions damage the endometrium in women. Currently, therapeutic options for endometrial recovery are limited. Zishen Yutai Pill (ZYP) was found to promote endometrial blood supply as a traditional Chinese medicine. However, whether ZYP promotes endometrial recovery post-abortion has not yet been explored.

OBJECTIVE

This study evaluated the role of ZYP in rat endometrial recovery after induced abortion and explored its mechanism of action.

MATERIALS AND METHODS

Sprague-Dawley rats were divided into three groups: no-operation group, control group, and ZYP group. The rats in the control and ZYP group were induced abortion, and then treated with normal saline or ZYPs, respectively, for 1-3 oestrous cycles. Morphological changes in the endometrium were examined. Expression levels of the factors related to endometrial recovery were analyzed. The duration of this study was almost seven months.

RESULTS

The endometrial thickness (7.3 ± 0.17 mm) and number of glands (5.5 ± 0.20) increased significantly in the ZYP group compared with those in the control group (5.5 ± 0.15 mm and 3.5 ± 0.18; p < 0.05). Fibrosis of the endometrium was ameliorated by ZYP administration (45 ± 6% vs. 58 ± 7%; p < 0.05). ZYPs treatment increased the expression of VEGF, ER, MMP-9, LIF, and HB-EGF, but decreased TGF-β expression. Moreover, the average number of pups in the ZYP group (9.0 ± 1.5) was greater than that in the control (4 ± 1.3).

DISCUSSION AND CONCLUSION

ZYPs accelerate endometrial recovery and restored fertility in rats, suggesting its potential to promote human endometrial repair.

The Top 100 Most Cited Articles on Intrauterine Adhesion: a Bibliometric Analysis

Bibliometric analysis is a statistical method that attempts to assess articles by their citations, analyzing their frequency and citation pattern, which subsequently gleans direction and guidance for future research. Over the past few years, articles focused on intrauterine adhesions have been published with increasing frequency. Nevertheless, little is known about the properties and qualities of this research, and no current analysis exists that has examined the progress in intrauterine adhesion research. Web of Science Core Collection, BIOSIS Citation Index, and MEDLINE database were searched to identify articles on intrauterine adhesion published from 1950 to October 2020. The 100 most cited articles were chosen to analyze citation count, citation density, authorship, theme, geographic distribution, time-related flux, level of evidence, and network analysis. An overwhelming majority of these 100 articles were published in the 2010s (35%). Citations per article ranged from 30 to 253. Chinese authors published the most papers in the top 100, followed by the USA, France, Israel, and Italy. The most salient study themes included operative hysteroscopy and adjunctive treatments for improving reproductive outcomes. The most common level of evidence was level II, and there was no statistical difference in the number of citations between the levels. The network analysis indicated that hysteroscopy, hysteroscopic adhesiolysis, infertility, and the reproductive outcome had a great degree of centrality in the 2000s and 2010s. In comparison, placental implantation had a great degree of centrality in the 2000s, and stem cell and fibrosis had a great degree of centrality in the 2010s. The value of IUA investigation has been gradually appreciated recently. Hysteroscopic adhesiolysis was continuously explored to achieve better reproductive outcome. Over time, the main focus of research has gradually shifted from complications to postoperative adjuvant treatment. Moreover, breakthrough progress is needed in underlying mechanism and early prevention of IUA.

Severe intrauterine adhesions after life-threatening event caused by Epstein-Barr virus-associated atraumatic spleen laceration: Case report

This is the first known case report of severe intrauterine adhesion (IUA) following a life-threatening event caused by an Epstein-Barr virus-associated atraumatic spleen laceration. A 22-year-old nulligravid female suffered from infectious mononucleosis for approximately 1 month. Sudden severe hypovolemic shock with massive hemoperitoneum appeared and hemostasis was completely achieved by a splenectomy for an atraumatic spleen laceration, although that was followed by multiorgan failure and abdominal compartment syndrome. Complete recovery without any neurological sequelae was achieved by intensive treatment. A postoperative pathological evaluation revealed Epstein-Barr virus-associated splenomegaly. The patient was referred to our department because of secondary amenorrhea for approximately 5 months since the last menstruation, which occurred just prior to the event. Laboratory blood test results demonstrated normal thyroid and ovarian functions. Hysterofiberscopy revealed complete obstruction at the end of the cervical canal, indicating secondary uterine amenorrhea caused by severe IUA. Hysteroscopic adhesiolysis with a rigid hysteroscope reached the opening of the uterine cavity and menstruation was restored.

Uterine adhesion: Is luteal phase prior to follicular phase in uterine adhesiolysis?

To compare the patients' outcomes of Asherman syndrome who underwent uterine adhesiolysis in luteal phase or follicular phase.A retrospective cohort study.A tertiary hospital in China.Four hundred sixty-four women suffered intrauterine adhesion who underwent monopolar adhesiolysis from March 2014 to March 2017 were analyzed. One hundred seventy-eight patients underwent operations in follicular phase (OFP) and 286 underwent operations in luteal phase (OLP).Hormone therapy was accompanied with an intrauterine device and a second-look hysteroscopy was performed postoperatively.Endometrial thickness in women was analyzed by a transvaginal 3-dimensional ultrasound examination. Re-adhesion was confirmed by a second-look hysteroscopy 3 months after hysteroscopic adhesiolysis. Pregnancy rate was acquired by questionnaires 3 months after a second-look hysteroscopy.OLP has advantages with thicker luteal endometrium (P = .001), higher pregnancy rates (P < .001), and lower re-adhesion rates (P = 0015) compared to these values of OFP.For Asherman syndrome, our study showed that OLP is more feasible than OFP in intrauterine adhesiolysis.

Strategies for managing asherman's syndrome and endometrial atrophy: Since the classical experimental models to the new bioengineering approach

Endometrial function is essential for embryo implantation and pregnancy, but managing endometrial thickness that is too thin to support pregnancy or an endometrium of compromised functionality due to intrauterine adhesions is an ongoing challenge in reproductive medicine. Here, we review current and emerging therapeutic and experimental options for endometrial regeneration with a focus on animal models used to study solutions for Asherman's syndrome and endometrial atrophy, which both involve a damaged endometrium. A review of existing literature was performed that confirmed the lack of consensus on endometrial therapeutic options, though promising new alternatives have emerged in recent years (platelet-rich plasma, exosomes derived from stem cells, bioengineering-based techniques, endometrial organoids, among others). In the future, basic research using established experimental models of endometrial pathologies (combined with new high-tech solutions) and human clinical trials with large population sizes are needed to evaluate these emerging and new endometrial therapies.

Endometrial thickness measurements among Asherman syndrome patients prior to embryo transfer

STUDY QUESTION

Is there an association between endometrial thickness (EMT) measurement and clinical pregnancy rate among Asherman syndrome (AS) patients utilizing IVF and embryo transfer (ET)?

SUMMARY ANSWER

EMT measurements may not be associated with successful clinical pregnancy among AS patients undergoing IVF.

WHAT IS KNOWN ALREADY

Clinical pregnancy rate after IVF is significantly lower in patients with a thin endometrium, defined as a maximum EMT of <7 mm. However, AS patients often have a thin EMT measurement due to intrauterine scarring, with a paucity of data and no guidance on what EMT cutoff is appropriate when planning an ET among these patients.

STUDY DESIGN, SIZE, DURATION

This is a retrospective cohort study of 45 AS patients treated at a specialized advanced hysteroscopic clinic from 1 January 2015, to 1 March 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Review of EMT measurements prior to a total of 90 ETs, among 45 AS patients. The impact of the maximum EMT measurement prior to ET on clinical pregnancy rate was analyzed.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 25/45 (55.6%) AS patients ultimately went on to have ≥1 clinical pregnancy following a mean ± SD of 2.00 ± 1.26 ET attempts. There was a total of 90 ETs among the 45 AS patients, with 29/90 (32.2%) ETs resulting in a clinical pregnancy. Younger patient age (P = 0.05) and oocyte donation (P = 0.01) were the only variables identified to be significant predictors for a positive clinical pregnancy outcome on bivariate analysis. The mean EMT measurement prior to all ETs among AS patients was 7.5 ± 1.6 mm. EMT measurement prior to ET did not predict a positive clinical pregnancy on either bivariate (P = 0.84) or multivariable analysis (odds ratio 0.91, P = 0.60). 31.8% of EMT measurements measured <7.0 mm. In this small cohort, no difference in the clinical pregnancy rate was detected when comparing ETs with EMT measurements of <7.0 mm versus ≥7.0 mm (P = 0.83). The mean EMT measurement decreased with increasing AS disease severity; 8.0 ± 1.6 mm for mild disease, 7.0 ± 1.4 mm for moderate disease and 5.4 ± 0.1 mm for severe disease.

LIMITATIONS, REASONS FOR CAUTION

Our small sample size limits our ability to draw any definitive conclusions. In addition, patients utilized various infertility clinics. This limits our ability to evaluate the consistency of EMT measurements and the IVF care that was received.

WIDER IMPLICATIONS OF THE FINDINGS

EMT measurement cutoff values should be used with caution if canceling a scheduled ET in AS patients.

STUDY FUNDING/COMPETING INTEREST(S)

This study was not funded. K.I. reports personal fees from Karl Stroz and personal fees from Medtronics outside the submitted work. The other authors have no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Cell-based endometrial regeneration: current status and future perspectives

Endometrial-related disorders including Asherman's syndrome, thin endometrium, pelvic organ prolapse, and cesarean scar pregnancies can be accompanied by different symptoms such as amenorrhea, infertility, abnormal placental implantation and recurrent miscarriage. Different methods have been introduced to overcome these problems such as surgery and hormonal therapy but none of them has shown promising outcomes. On the other hand, the development of novel regenerative therapeutic strategies has opened new avenues for the treatment of endometrial-related deficiencies. In this regard, different types of scaffolds, acellular matrices and also cell therapy with adult or stem cells have been investigated for the treatment of endometrial-related deficiencies. In this paper, we review the current status of cell-based endometrium regeneration using scaffold dependent and scaffold-free methods and future perspectives in this field. Moreover, we discuss the endometrial diseases that can be candidates for cell-based treatments. Also, the cells with the potential for endometrial regeneration are explained.

The incidence of placenta related disease after the hysteroscopic adhesiolysis in patients with intrauterine adhesions

OBJECTIVE

To analyze the correlation between placenta related disease of pregnant women with antecedent hysteroscopic adhesiolysis due to intrauterine adhesions (IUA).

MATERIALS AND METHODS

This is a single center, non-randomized, open-label, retrospective cohort Study. 74 patients who had adhesiolysis and hormone therapy for IUA and progressed into the third trimester were group A and 296 without IUA were group B. The main outcome measure is the incidence of placenta related disease including placenta accreta spectrum, placenta previa, placental abruption, intrauterine growth restriction (IUGR), and pregnancy-induced hypertension (PIH). The second outcome is the perinatal, and intrapartum complications.

RESULTS

Patients in group A had a higher frequency of prior pregnancy times (2.51 ± 1.56 vs.1.84 ± 1.06, p = 0.001) and lower frequency of prior delivery times (0.20 ± 0.41 vs. 1.30 ± 0.51, p < 0.05) than group B at baseline. At delivery, there is no difference between the incidence of PIH and IUGR between two groups. However, a significantly higher frequency of placenta accreta (17.6% vs. 1.4%, OR = 15.56, 95% CI 4.91-49.34), placenta increta (5.4% vs. 0.7%, OR = 8.4, 95% CI 1.51-46.78), placenta previa (8.1% vs. 2.0%, OR = 4.265, 95%CI1.33-13.63) and postpartum hemorrhage (21.6% vs. 3.4%, OR = 7.890, 95% CI 3.41-18.26) were observed in group A than in group B.

CONCLUSIONS

Compared to general population, the rates of placenta accreta, placenta increta, placenta previa, postpartum hemorrhage are higher among the IUA patients after hysteroscopic adhesiolysis, and special attention is needed at the termination of the pregnancy.

Expression and significance of estrogen receptor and progesterone receptor in endometrial tissue of patients with intrauterine adhesions

Background

Our study aims to analyze the expression and significance of estrogen receptor (ER) and progesterone receptor (PR) in endometrial tissues of patients with intrauterine adhesion (IUA).

Methods

Fifty-four patients with IUAs examined in our hospital from January 2017 to January 2019 were selected as the research object (observation group), 54 healthy women who had physical examinations during the same period were selected as the control group, and the immunohistochemical EnVision was used. Two-step and real-time fluorescent quantitative PCR methods were used to detect the expression levels of ER and PR in the endometrial tissues of the two groups of subjects.

Results

The immunohistochemical test results showed that ER's expression level in the observation group was significantly higher than that in the control group, and the difference between the two groups was statistically significant (P<0.05). The difference in PR expression levels between the two groups was insignificant (P<0.05). Real-time fluorescent quantitative PCR results showed ER and PR's expression levels in the observation group were significantly higher than those in the control group, and the difference between the two groups was statistically significant (P<0.05).

Conclusions

After IUA can detect ER and PR expression, we can formulate a personalized hormone treatment plan to improve the clinical treatment effect.

Patient-reported menstrual and obstetric outcomes following hysteroscopic adhesiolysis for Asherman syndrome

Objective

Review the menstrual and obstetric outcomes among Asherman syndrome patients when stratified by disease severity.

Design

Retrospective cohort study.

Setting

A community teaching hospital affiliated with a large academic medical center.

Patients

A total of 355 Asherman syndrome patients stratified by March classification who underwent hysteroscopic adhesiolysis.

Interventions

Telephone survey, analyzed with multivariable analysis.

Main Outcome Measures

Return of menstruation. Pregnancy, miscarriage, and live birth rate.

Results

A total of 355 patients underwent hysteroscopic adhesiolysis. Of these, 150 (42.3%) patients completed the telephone survey with a mean follow-up of 2.21 years. Additionally, 40.7% had mild, 52.7% had moderate, and 6.6% had severe disease. Furthermore, 25.3% of patients reported amenorrhea at presentation, with mild disease patients having the highest rate of returning menstruation (93.8%) following treatment. The cumulative pregnancy rate was 81.9%, and the cumulative live birth rate was 51.2%, with no statistical differences identified by the classification group.

Conclusion

Asherman syndrome disease severity predicted returning menstruation but not pregnancy or live birth rate.

Sustained delivery of 17β-estradiol by human amniotic extracellular matrix (HAECM) scaffold integrated with PLGA microspheres for endometrium regeneration

The endometrial injury usually results in intrauterine adhesions (IUAs). However, there is no effective treatment to promote the regeneration of the endometrium currently. The decellularized amnion membrane (AM) is a promising material in human tissue repair and regeneration due to its biocompatibility, biodegradability, as well as the preservation of abundant bioactive components. Here, an innovative drug-delivering system based on human amniotic extracellular matrix (HAECM) scaffolds were developed to facilitate endometrium regeneration. The 17β-estradiol (E2) loaded PLGA microspheres (E2-MS) were well dispersed in the scaffolds without altering their high porosity. E2 released from E2-MS-HAECM scaffolds in vitro showed a decreased initial burst release followed with a sustained release for 21 days, which coincided with the female menstrual cycle. Results of cell proliferation suggested E2-MS-HAECM scaffolds had good biocompatibility and provided more biologic guidance of endometrial cell proliferation except for mechanical supports. Additionally, the mRNA expression of growth factors in endometrial cells indicated that HAECM scaffolds could upregulate the expression of EGF and IGF-1 to achieve endometrium regeneration. Therefore, these advantages provide the drug-loaded bioactive scaffolds with new choices for the treatments of IUAs.

Reproductive Outcomes of In Vitro Fertilization-Intracytoplasmic Sperm Injection after Transcervical Resection of Adhesions: A Retrospective Cohort Study

STUDY OBJECTIVE

To investigate pregnancy and obstetric outcomes of patients with intrauterine adhesions (IUAs) after treatment with in vitro fertilization-intracytoplasmic sperm injection (IVF-ICSI) and fresh embryo transplantation after transcervical resection of adhesions (TCRA).

DESIGN

Retrospective cohort study.

SETTING

University-based reproductive medical center.

PATIENTS

A total of 535 patients with IUAs and with a history of TCRA and 1605 matched patients without a history of IUAs underwent IVF-ICSI and received fresh embryo transfers.

INTERVENTIONS

Between January 2014 and December 2018, all patients underwent IVF-ICSI treatment and received fresh embryo transfers.

MEASUREMENTS AND MAIN RESULTS

The patients in the TCRA group were matched with the control group according to strict criteria. Pregnancy and obstetric outcomes were compared. There were no significant differences in clinical pregnancies, ectopic pregnancies, live births, preterm births, and obstetric outcomes between the 2 groups (p >.05). However, the TCRA group had a higher risk of miscarriage than the control group (p = .048).

CONCLUSION

TCRA improved the reproductive outcomes of patients with IUAs, but the risk of miscarriage was higher than that in the general population. To avoid miscarriage, careful monitoring is critical for pregnant patients with a history of TCRA who undergo embryo transfers during IVF treatment.

Surgical and Reproductive Outcomes after Hysteroscopic Removal of Retained Products of Conception: A Systematic Review and Meta-analysis

OBJECTIVE

To evaluate the impact of hysteroscopy for retained products of conception (RPOC) removal on surgical and reproductive outcomes.

DATA SOURCES

Electronic databases (MEDLINE, Scopus, ClinicalTrials.gov, SciELO, EMBASE, and the Cochrane Central Register of Controlled Trials at the Cochrane Library) were searched from inception to March 2020.

METHODS OF STUDY SELECTION

Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Meta-analysis of Observational Studies in Epidemiology guidelines were followed. Medical Subject Headings terms and text words such as "retained products of conception," "placental remnants," "placenta," and "hysteroscopy" were used for the identification of relevant studies. We included observational and randomized studies that analyzed surgical and/or reproductive outcomes of women who underwent hysteroscopic removal of RPOC. The primary outcome was the complete resection rate after 1 procedure.

TABULATION, INTEGRATION, AND RESULTS

Twenty out of 245 studies were applicable, with data provided for 2112 women. The pooled complete resection rate was 91% (95% confidence interval [CI], 0.83-0.96). The incomplete resection rate evaluated was 7% (95% CI, 0.03-0.14), with a complication rate of 2% (95% CI, 0.00-0.04). Out of 1478 procedures, only 12 cases (0.8%) of postsurgical intrauterine adhesions were reported. Regarding post-therapy fecundity, women attempting postoperative conception had a clinical pregnancy rate of 87% (95% CI, 0.75-0.95), with a live birth rate of 71% (95% CI, 0.60-0.81) and a pregnancy loss rate of 9% (95% CI, 0.06-0.12).

CONCLUSION

Hysteroscopy has a high rate of completely removing RPOC in a single surgical step, with low complication rates. Subsequent fecundity seems reassuring, with appropriate clinical pregnancy and live birth rates. However, standardization of approach and comparative trials of different hysteroscopic approaches are needed.

Recent Advances in Understandings Towards Pathogenesis and Treatment for Intrauterine Adhesion and Disruptive Insights from Single-Cell Analysis

Intrauterine adhesion is a major cause of menstrual irregularities, infertility, and recurrent pregnancy losses and the progress towards its amelioration and therapy is slow and unsatisfactory. We aim to summarize and evaluate the current treatment progress and research methods for intrauterine adhesion. We conducted literature review in January 2020 by searching articles at PubMed on prevention and treatment, pathogenesis, the repair of other tissues/organs, cell plasticity, and the stem cell–related therapies for intrauterine adhesion. A total of 110 articles were selected for review. Uterine cell heterogeneity, expression profile, and cell-cell interaction were investigated based on scRNA-seq of uterus provided by Human Cell Landscape (HCL) project. Previous knowledge on intrauterine adhesion (IUA) pathogenesis was mostly derived from correlation studies by differentially expressed genes between endometrial tissue of intrauterine adhesion patients/animal models and normal endometrial tissue. Although the TGF-β1/SMAD pathway was suggested as the key driver for IUA pathogenesis, uterine cell heterogeneity and distinct expression profile among different cell types highlighted the importance of single-cell investigations. Cell-cell interaction in the uterus revealed the central hub of endothelial cells interacting with other cells, with endothelial cells in endothelial to mesenchymal transition and fibroblasts as the strongest interaction partners. The potential of stem cell–related therapies appeared promising, yet suffers from largely animal studies and nonstandard study design. The need to dissect the roles of endometrial cells, endothelial cells, and fibroblasts and their interaction is evident in order to elucidate the molecular and cellular mechanisms in both intrauterine adhesion pathogenesis and treatment.

Intrauterine infusion of platelet-rich plasma is a treatment method for patients with intrauterine adhesions after hysteroscopy

Objective

To evaluate the efficacy of an intrauterine infusion of platelet‐rich plasma (PRP) in patients with intrauterine adhesions (IUAs).

Methods

A retrospective study was conducted from April 2018 to December 2019 to compare the efficacy of intrauterine infusion of PRP with balloon for patients with IUAs. All patients had moderate or severe IUAs, including 28 patients with intrauterine infusion of PRP (group A), 22 patients with intrauterine balloon (group B), and 20 patients with both intrauterine infusion of PRP and balloon in the first operative hysteroscopy. American Fertility Society (AFS) score and rates of chemical pregnancy were compared.

Results

The AFS score decreased with an average of 5.18 ± 3.93, 4.91 ± 4.39, and 5.15 ± 3.17 comparing the third hysteroscopy with the first operative hysteroscopy in group A, group B, and group C, respectively. No significant differences were found among these groups (P=0.734). The rates of chemical pregnancy were 40.0% in group A, 38.9% in group B, and 33.3% in group C without significant differences (P=0.944).

Conclusion

There were no significant differences between intrauterine infusion of PRP and balloon. PRP is a treatment method for IUAs.

There were no significant differences between intrauterine infusion of platelet‐rich plasma and a balloon, and platelet‐rich plasma is a treatment for intrauterine adhesions.

Concomitant Adenomyosis among Patients with Asherman Syndrome

STUDY OBJECTIVE

To characterize obstetric outcomes for concomitant Asherman syndrome and adenomyosis.

DESIGN

A retrospective cohort study.

SETTING

A community teaching hospital affiliated with a large academic medical center.

PATIENTS

A total of 227 patients with Asherman syndrome with available hysteroscopy and pelvic ultrasound reports.

INTERVENTIONS

Telephone survey to assess and compare the obstetric outcomes of patients with Asherman syndrome with concomitant adenomyosis (Group A) vs patients with Asherman syndrome without concomitant adenomyosis (Group B).

MEASUREMENTS AND MAIN RESULTS

A telephone survey and confirmatory chart review were conducted to obtain information on patients' demographics, gynecologic and obstetric history, past medical and surgical history, and Asherman syndrome management. Adenomyosis was a common sonographic finding, detected in 39 patients with Asherman syndrome (17.2%). In this cohort, 77 patients attempted pregnancy and produced 87 pregnancies. Age (odds ratio [OR] 0.67; 95% confidence intervals [CI], 0.52-0.86) was negatively associated with a pregnancy outcome. Age (OR 0.83; 95% CI, 0.73-0.95) and severe Asherman disease (OR 0.06; 95% CI, <0.01-0.99) were negatively associated with a live birth outcome. Adenomyosis was not an independent predictor of pregnancy rate, miscarriage rate, or live birth rate among patients with Asherman syndrome.

CONCLUSION

Adenomyosis is relatively common in patients with Asherman syndrome. Adenomyosis does not seem to add any distinct detriment to fertility among patients with Asherman syndrome.