Intrauterine adhesion prevention after hysteroscopy: a systematic review and meta-analysis

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.

Early GnRH-agonist therapy does not negatively impact the endometrial repair process or live birth rate

Study objective

To investigate whether different timings of GnRH-a downregulation affected assisted reproductive outcomes in infertile women with moderate-to-severe intrauterine adhesions (IUAs) accompanied by adenomyosis.

Design

A retrospective case series.

Setting

An assisted reproductive technology center.

Patients

The study reviewed 123 infertile women with moderate-to-severe IUAs accompanied by adenomyosis undergoing their first frozen-thawed embryo transfer (FET) cycles between January 2019 and December 2021.

Measurements and main results

The majority of patients had moderate IUA (n=116, 94.31%). The average Basal uterine volume was 73.58 ± 36.50 cm3. The mean interval from operation to the first downregulation was 21.07 ± 18.02 days (range, 1-79 days). The mean duration of hormone replacement therapy (HRT) was 16.93 ± 6.29 days. The average endometrial thickness on the day before transfer was 10.83 ± 1.75 mm. A total of 70 women achieved clinical pregnancy (56.91%). Perinatal outcomes included live birth (n=47, 67.14%), early miscarriage (n=18, 25.71%), and late miscarriage (n=5, 7.14%). The time interval between uterine operation and the first downregulation was not a significant variable affecting live birth. Maternal age was the only risk factor associated with live birth (OR:0.89; 95% CI: 0.79-0.99, P=0.041).

Conclusions

The earlier initiation of GnRH-a to suppress adenomyosis prior to endometrial preparation for frozen embryo transfer did not negatively impact repair of the endometrium after resection.

Mechanism of Smilax china L. in the treatment of intrauterine adhesions based on network pharmacology, molecular docking and experimental validation

BACKGROUND

Smilax china L. (SCL) is a traditional herbal medicine for the potential treatment of intrauterine adhesion (IUA). However, the mechanisms of action have not yet been determined. In this study, we explored the effects and mechanisms of SCL in IUA by network pharmacology, molecular docking and molecular biology experiments.

METHODS

Active ingredients and targets of SCL were acquired from TCMSP and SwissTargetPrediction. IUA-related targets were collected from the GeneCards, DisGeNET, OMIM and TTD databases. A protein‒protein interaction (PPI) network was constructed by Cytoscape 3.9.1 and analysed with CytoHubba and CytoNCA to identify the core targets. The DAVID tool was used for GO and KEGG enrichment analyses. Furthermore, molecular docking was employed to assess the interaction between the compounds and key targets. Finally, the mechanisms and targets of SCL in IUA were verified by cellular experiments and western blot.

RESULTS

A total of 196 targets of SCL were identified, among which 93 were related to IUA. Topological and KEGG analyses results identified 15 core targets that were involved in multiple pathways, such as inflammation, apoptosis, and PI3K/AKT signalling pathways. Molecular docking results showed that the active compounds had good binding to the core targets. In vitro experiments showed that astilbin (AST), a major component of SCL, significantly reduced TGF-β-induced overexpression of fibronectin (FN), activation of the PI3K/AKT signalling pathway and the expression of downstream factors (NF-κB and BCL2) in human endometrial stromal cells, suggesting that AST ameliorates IUA by mediating the PI3K/AKT/NF-κB and BCL2 proteins.

CONCLUSIONS

AST, a major component of SCL, may be a potential therapeutic agent for IUA. Moreover, its mechanism is strongly associated with regulation of the PI3K/AKT signalling pathway and the downstream NF-κB and BCL2 proteins. This study will provide new strategies that utilize AST for the treatment of IUA.

Integrating Network Pharmacology and In Vitro Experimental Verification Revealing Bushenhuoxue Recipe Against Intrauterine Adhesions via PI3K-AKT Signaling Pathway

We aimed to investigate therapeutic effect of Bushenhuoxue recipe in intrauterine adhesions (IUA) and explore the underlying molecular mechanism via integrating network pharmacology and in vitro experimental verification. The active compounds and gene targets of Bushenhuoxue recipe were screened in the TCMSP database and the IUA-related genes were identified using GeneCards database by the keyword "Intrauterine adhesions". Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were conducted to reveal the underlying molecular mechanism of Bushenhuoxue recipe treating IUA. T-HESC cells were inducted to fibrotic state using TGF-β1 of 10 ng/ml concentration treating for 24 h. RT-qPCR or western blot was used to demonstrate the expression levels of fibrosis markers (COL1A1 and α-SMA) and KEGG pathway markers. Cell counting kit-8 (CCK8) assay was performed to illustrate the cell viability of endometrial stromal cell. The treatment of Bushenhuoxue recipe could significantly inhibit the proliferation and fibrosis of endometrial stromal cells. We obtained a total of 169 no-repeat ingredients of Bushenhuoxue recipe and 3044 corresponding targets. After taking intersection with 4230 no-repeat IUA-related genes, a total of 83 target genes related to both Bushenhuoxue recipe and IUA were finally identified. KEGG analysis found that PI3K-AKT signaling pathway might be the key pathway. Further experiment revealed that PI3K-AKT signaling pathway was significantly activated in endometrial stromal cells of fibrotic state and the treatment of Bushenhuoxue recipe could inhibit the PI3K-AKT signaling pathway. Further rescue assay demonstrated that Bushenhuoxue recipe suppressed the proliferation and fibrosis of endometrial stromal cells via PI3K-AKT signaling pathway. Bushenhuoxue recipe suppresses the proliferation and fibrosis of endometrial stromal cells via PI3K-AKT signaling pathway, eventually inhibiting the progression of IUA.

Long noncoding RNAs regulate intrauterine adhesion and cervical cancer development and progression

Intrauterine adhesion, one of reproductive system diseases in females, is developed due to endometrial injury, such as infection, trauma, uterine congenital abnormalities and uterine curettage. Intrauterine adhesion affects female infertility and causes several complications, including amenorrhoea, hypomenorrhoea, and recurrent abortion. Cervical cancer is one of the common gynecological tumors and the fourth leading cancer-related death in women worldwide. Although the treatments of cervical cancer have been improved, the advanced cervical cancer patients have a low survival rate due to tumor recurrence and metastasis. The molecular mechanisms of intrauterine adhesion and cervical tumorigenesis have not been fully elucidated. In recent years, long noncoding RNAs (lncRNAs) have been known to participate in intrauterine adhesion and cervical carcinogenesis. Therefore, in this review, we will summarize the role of lncRNAs in regulation of intrauterine adhesion development and progression. Moreover, we will discuss the several lncRNAs in control of cervical oncogenesis and progression. Furthermore, we highlight that targeting lncRNAs could be used for treatment of intrauterine adhesion and cervical cancer.

Endometrium procurement and transplantation restores fertility in rats

RESEARCH QUESTION

Can rat endometrium be successfully procured and transplanted, and can a similar method be used to procure human endometrium?

DESIGN

Rat endometrium was procured using an endometrium stripping method and transplanted into female Sprague-Dawley rats. Macroscopic and histological changes, endometrial receptivity-related protein concentrations and fertility were assessed. Additionally, a preliminary experiment was conducted to procure human endometrium using a similar method.

RESULTS

Endometrium was successfully procured from both rats and humans, which contained intact endometrium and parts of the adjacent inner annulus myometrium. Endometrium auto-transplantation was conducted in rats and the procedure lasted a total of 41.3 ± 5.7 min with a mean blood loss of 0.09 ± 0.04 g. The transplanted endometrium survived well, but a fibrotic zone formed between the transplant and recipient tissue. Compared with sham rats, those with endometrium transplantation had similar endometrial thickness and endometrial gland numbers but reduced vascular density at 8 weeks after surgery. Endometrium transplantation also retained expression of the endometrial receptivity-related proteins leukaemia inhibitory factor and vascular endothelial growth factor. In contrast to non-pregnancy in the stripped horn, a mean of 5.0 ± 2.7 fetuses developed in the transplanted horn, and full-term live fetuses were conceived in the horns with transplanted endometrium.

CONCLUSIONS

Endometrium procurement by stripping method can obtain an intact and functional endometrium, and endometrium transplantation can reconstruct the uterine cavity and restore fertility in rats.

S100A8/A9 promotes endometrial fibrosis via regulating RAGE/JAK2/STAT3 signaling pathway

Intrauterine adhesion (IUA) is characterized by endometrial fibrosis. S100A8/A9 plays an important role in inflammation and fibroblast activation. However, the role of S100A8/A9 in IUA remains unclear. In this study, we collect normal and IUA endometrium to verify the expression of S100A8/A9. Human endometrial stromal cells (hEnSCs) are isolated to evaluate fibrosis progression after S100A8/A9 treatment. A porcine IUA model is established by electrocautery injury to confirm the therapeutic effect of menstrual blood-derived stromal cells (MenSCs) on IUA. Our study reveals increased S100A8/A9 expression in IUA endometrium. S100A8/A9 significantly enhances hEnSCs proliferation and upregulates fibrosis-related and inflammation-associated markers. Furthermore, S100A8/A9 induces hEnSCs fibrosis through the RAGE-JAK2-STAT3 pathway. Transplantation of MenSCs in a porcine IUA model notably enhances angiogenesis, mitigates endometrial fibrosis and downregulates S100A8/A9 expression. In summary, S100A8/A9 induces hEnSCs fibrosis via the RAGE-JAK2-STAT3 pathway, and MenSCs exhibit marked effects on endometrial restoration in the porcine IUA model.

The humanin analogue (HNG) alleviates intrauterine adhesions by inhibiting endometrial epithelial cells ferroptosis: a rat model-based study

STUDY QUESTION

Does a humanin analogue (HNG) have a therapeutic effect on intrauterine adhesions (IUAs) caused by uterine cavity surgery in a rat model?

SUMMARY ANSWER

HNG supplementation attenuated the development of endometrial fibrosis and IUAs, improved fertility, and contributed to the regulation of endometrial fibrosis by inhibiting endometrial ferroptosis in rats with IUAs.

WHAT IS KNOWN ALREADY

IUAs, which are characterized by endometrial fibrosis, are a common cause of female infertility. Humanin (rattin in rats) is a mitochondrial-derived peptide that is widely expressed in multiple tissues. S14G-humanin (HNG) is an HNG that has been reported to have a protective effect against myocardial fibrosis.

STUDY DESIGN, SIZE, DURATION

Endometrial tissues from three patients with IUAs and three controls were tested for humanin expression. Two animal models were used to evaluate the modelling effect of IUAs and the preventive effect of HNG against IUAs. In the first model, 40 rats were equally randomized to control and Day 7, 14, and 21 groups to establish the IUA model. In the second model, 66 rats were equally randomized to the control, IUA, and IUA + humanin analogue (HNG) groups. Erastin was used to induce ferroptosis in the Ishikawa cell line.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The endometrium was scraped with a surgical spatula, combined with lipopolysaccharide treatment, to establish the rat model of IUAs. Rats were intraperitoneally injected with 5 mg/kg/day HNG for 21 consecutive days beginning from the day of operation to evaluate the therapeutic effect on IUAs. Haematoxylin-eosin and Masson's trichrome staining were used to assess endometrial morphology and evaluate fibrosis. Ferroptosis-related markers, namely nuclear factor E2-related factor 2 (Nrf2), acyl-CoA synthetase long-chain family member 4 (ACSL4), haeme oxygenase-1 (HO-1), solute carrier family 7 member 11 (SLC7A11), glutathione peroxidase 4 (GPX4), and ferritin, were measured by immunohistochemistry and western blotting to determine whether ferroptosis was involved in the development of IUAs and to assess the attenuative effect of HNG on ferroptosis. Additionally, the female rats were mated with male rats with normal fertility to assess fertility.

MAIN RESULTS AND THE ROLE OF CHANCE

Humanin was widely expressed in endometrial cells, including epithelial and stromal cells, in both humans and rats. Humanin expression levels were downregulated in the endometria of patients and rats with IUAs relative to the endometria of controls. Endometrial thickness and the number of glands were significantly decreased on Day 7, 14, and 21 after endometrial scraping when compared with the controls (all P < 0.05), whereas the fibrotic area was significantly increased (P < 0.05). Among the tested ferroptosis markers, the expression levels of Nrf2, SLC7A11, and GPX4 were significantly downregulated and those of ACSL4, HO-1, and ferritin were significantly upregulated after endometrial scraping relative to their expression levels in controls (all P < 0.05). The mating rates in the control, IUA, and IUA + HNG groups were 100% (10/10), 40% (4/10), and 80% (8/10), respectively. The number of embryos in rats with IUAs (mean ± SD: 1.6 ± 2.1) was significantly less than the number in the controls (11.8 ± 1.5). HNG supplementation significantly attenuated this decrease in the number of implanted embryos (6.3 ± 4.5) (P < 0.01). Further results showed that HNG significantly attenuated the altered expression levels of proteins involved in ferroptosis in the endometria of rats with IUAs. Moreover, in vitro experiments showed that HNG significantly attenuated the erastin-induced decrease in the viability of the Ishikawa cell line and also attenuated the increase in reactive oxygen species production and the downregulation of GPX4.

LARGE SCALE DATA

None.

LIMITATIONS, REASONS FOR CAUTION

The findings of this study showed that HNG inhibited ferroptosis and reduced fibrosis in a rat model of IUAs. However, we could not establish a causal relationship between ferroptosis and the development of IUAs.

WIDER IMPLICATIONS OF THE FINDINGS

HNG may be effective at alleviating fibrosis during the development of IUAs, and the inhibition of ferroptosis is a promising new strategy for IUA therapy.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the National Natural Science Foundation of China (No. 82171647); the '1000 Talent Plan' of Yunnan Province (No. RLQN20200001); and the Basic Research Project of the Yunnan Province-Outstanding Youth Foundation (No. 202101AW070018). The authors declare no competing financial interests.

Determinants and Assessment of Menstrual Blood Flow

Purpose of review

a)The modifiable and non-modifiable determinants and the currently available methods of assessment of menstrual blood flow will be discussed, with the goal of helping healthcare providers, researchers, and those interested in public health.

Recent findings

b)Several factors can impact menstruation. The determinants include modifiable factors such as smoking, nutrition, exercise, stress, weight fluctuation, and benign gynecologic diseases, and non-modifiable factors such as age, race, and the individual's genes. The intertwined dynamic among these determinants needs more critical attention. Currently, the methods for the assessment of menstruation all have advantages and disadvantages, often with a tradeoff between practicality and accuracy.

Summary

c)Considered by many as the fifth vital, menstruation provides a window to an individual's general health. The discussion of its determinants and assessment can be more appropriate for individual contexts, especially from a public health perspective as it can improve the reproductive health of the population.

Cyclical endometrial repair and regeneration: Molecular mechanisms, diseases, and therapeutic interventions

The endometrium is a unique human tissue with an extraordinary ability to undergo a hormone-regulated cycle encompassing shedding, bleeding, scarless repair, and regeneration throughout the female reproductive cycle. The cyclical repair and regeneration of the endometrium manifest as changes in endometrial epithelialization, glandular regeneration, and vascularization. The mechanisms encompass inflammation, coagulation, and fibrinolytic system balance. However, specific conditions such as endometriosis or TCRA treatment can disrupt the process of cyclical endometrial repair and regeneration. There is uncertainty about traditional clinical treatments' efficacy and side effects, and finding new therapeutic interventions is essential. Researchers have made substantial progress in the perspective of regenerative medicine toward maintaining cyclical endometrial repair and regeneration in recent years. Such progress encompasses the integration of biomaterials, tissue-engineered scaffolds, stem cell therapies, and 3D printing. This review analyzes the mechanisms, diseases, and interventions associated with cyclical endometrial repair and regeneration. The review discusses the advantages and disadvantages of the regenerative interventions currently employed in clinical practice. Additionally, it highlights the significant advantages of regenerative medicine in this domain. Finally, we review stem cells and biologics among the available interventions in regenerative medicine, providing insights into future therapeutic strategies.

Electroacupuncture alleviates intrauterine adhesion through regulating autophagy in rats

Autophagy is a well-conserved metabolic system that maintains homeostasis by relying on lysosomal breakdown. The endometrium of patients with intrauterine adhesion (IUA) and an animal model exhibits impaired autophagy. Autophagy is negatively correlated with inflammation. Activation of autophagy can inhibit the inflammatory response, while defects in autophagy will activate the inflammatory response. Here, we studied whether electroacupuncture (EA) inhibits inflammation and promotes endometrial injury repair by activating endometrial autophagy. The IUA animal model was established by mechanical injury plus lipopolysaccharide infection. EA stimulation was applied to the acupoints Guanyuan (CV4), bilateral Sanyinjiao (SP6), and Zusanli (ST36). The results indicated that EA could improve endometrial morphology, attenuate endometrial fibers, and enhance endometrial receptivity in the rat. EA could increase the autophagosomes of endometrial epithelial cells, increase the levels of LC3 and Beclin1, and decrease the level of p62. Additionally, EA may also suppress the nuclear factor kappa-B (NF-κB) signaling pathway and reduce the release of inflammatory factors. Additionally, the effect of EA was comparable to that of the autophagy agonist rapamycin, and the autophagy inhibitor 3-methyladenine reversed the therapeutic effect of EA. Therefore, we assume that EA may facilitate endometrial healing by activating autophagy and reducing NF-κB signal pathway-mediated inflammation.

MenSCs Transplantation Improve the Viability of Injured Endometrial Cells Through Activating PI3K/Akt Pathway

Endometrial injury is one of the leading causes of female infertility and is caused by intrauterine surgery, endometrial infection, repeated abortion, or genital tuberculosis. Currently, there is little effective treatment to restore the fertility of patients with severe intrauterine adhesions and thin endometrium. Recent studies have confirmed the promising therapeutic effects of mesenchymal stem cell transplantation on various diseases with definite tissue injury. The aim of this study is to investigate the improvements of menstrual blood-derived endometrial stem cells (MenSCs) transplantation on functional restoration in the endometrium of mouse model. Therefore, ethanol-induced endometrial injury mouse models were randomly divided into two groups: the PBS-treated group, and the MenSCs-treated group. As expected, the endometrial thickness and gland number in the endometrium of MenSCs-treated mice were significantly improved compared to those of PBS-treated mice (P < 0.05), and fibrosis levels were significantly reduced (P < 0.05). Subsequent results revealed that MenSCs treatment significantly promoted angiogenesis in the injured endometrium. Simultaneously, MenSCs enhance the proliferation and antiapoptotic capacity of endometrial cells, which is likely contributed by activating the PI3K/Akt signaling pathway. Further tests also confirmed the chemotaxis of GFP-labeled MenSCs towards the injured uterus. Consequently, MenSCs treatment significantly improved the pregnant mice and the number of embryos in pregnant mice. This study confirmed the superior improvements of MenSCs transplantation on the injured endometrium and uncovered the potential therapeutic mechanism, which provides a promising alternative for patients with serious endometrial injury.

Incidence of Intrauterine Adhesions After Hysteroscopic Myomectomy in Patients Seeking Fertility

STUDY OBJECTIVE

To study the incidence of intrauterine adhesions (IUAs) after hysteroscopic myomectomy. Previous studies report a range of incidence for IUAs after hysteroscopic myomectomy.

DESIGN

A retrospective review study.

SETTING

An academic community hospital in the Boston metropolitan area.

PATIENTS

Patients undergoing hysteroscopic myomectomy at our institution from January 2019 to February 2022. Patients were excluded if they did not have plans for future fertility or had a new diagnosis of cancer.

INTERVENTIONS

All patients underwent hysteroscopic myomectomy using bipolar resectoscope without postoperative medical or barrier treatment. All procedures were performed by 1 of 4 fellowship-trained high-volume gynecologic surgeons with resident and fellow assistance. Incidence of postoperative IUAs was assessed and treated using second-look office hysteroscopy.

MEASUREMENTS AND MAIN RESULTS

A total of 44 patients without preoperative IUAs underwent hysteroscopic myomectomy during our study period, and 4 patients (9.1%) developed new IUAs. Among 9 patients who were found to have preoperative IUAs and underwent concurrent hysteroscopic myomectomy and lysis of adhesions, we found a recurrence of IUAs in 5 patients (55.6%). We found the number, size, and deepest type of myoma removed were not correlated to an increased risk of new IUA formation. In addition, removing myomas on opposing walls during the same operation did not increase the incidence of new IUAs.

CONCLUSION

Formation of IUAs after hysteroscopic myomectomy is a well-documented consequence. Our reported incidence of 9.1% of new IUAs that are not affected by the number, size, deepest type of myoma resected, and resection of myomas on opposing uterine walls contributes to the current literature. In addition, our finding of 55.6% of recurrent IUAs in patients undergoing both hysteroscopic myomectomy and lysis of adhesions highlights a high-risk population requiring additional study.

Comparison of the efficacy of autologous platelet gel and medical chitosan in the prevention of recurrence of intrauterine adhesions after transcervical resection of adhesion: a prospective, randomized, controlled trial

PURPOSE

Intrauterine adhesion (IUAs) in women is a debatable topic and there is no clear consensus in its management and treatment strategies. Previous treatment measures have limitations which necessitates to consider effective measures for prevention of recurrence of IUAs. Hence, the aim of this study to explore the efficacy and safety of intrauterine infusion of autologous platelet gel (APG) and medical chitosan in preventing recurrence of IUAs in females after transcervical resection of adhesion (TCRA).

METHODS

A prospective, randomized controlled trial was conducted among 80 patients presented with moderate to severe IUAs. Patients were randomized into two groups, APG group (n = 40) and medical chitosan group (n = 40). All patients were injected with either APG or medical chitosan after TCRA.

RESULTS

The postoperative recurrence rate of adhesions in APG group was significantly lower than those in medical chitosan group (21% vs 49%). The median AFS score during the second-look hysteroscopy was significantly lower in APG group than in medical chitosan group (P = 0.008). The median AFS score reduction after TCRA surgery was significantly higher in APG group than in medical chitosan group (median, 95% CI 7.000, 6.0 to 8.3 vs. 6.000, 5.0 to 7.0, P = 0.004). Subgroup analysis of platelet concentration (1000 as cut-off value) into high- and low-dose subgroups reported no significant correlation existed between APG and baseline characteristics, recurrence rate and postoperative AFS reduction score except for previous intrauterine operation (P < 0.05).

CONCLUSION

Thus, after TCRA, intrauterine injections of APG provides better efficacy and safety compared with intrauterine injections of medical chitosan in preventing recurrence of intrauterine adhesions.

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.

Embryo-derive TNF promotes decidualization via fibroblast activation

Decidualization is a process in which endometrial stromal fibroblasts differentiate into specialized secretory decidual cells and essential for the successful establishment of pregnancy. The underlying mechanism during decidualization still remains poorly defined. Because decidualization and fibroblast activation share similar characteristics, this study was to examine whether fibroblast activation is involved in decidualization. In our study, fibroblast activation-related markers are obviously detected in pregnant decidua and under in vitro decidualization. ACTIVIN A secreted under fibroblast activation promotes in vitro decidualization. We showed that arachidonic acid released from uterine luminal epithelium can induce fibroblast activation and decidualization through PGI₂ and its nuclear receptor PPARδ. Based on the significant difference of fibroblast activation-related markers between pregnant and pseudopregnant mice, we found that embryo-derived TNF promotes CPLA_2α phosphorylation and arachidonic acid release from luminal epithelium. Fibroblast activation is also detected under human in vitro decidualization. Similar arachidonic acid-PGI₂-PPARδ-ACTIVIN A pathway is conserved in human endometrium. Collectively, our data indicate that embryo-derived TNF promotes CPLA_2α phosphorylation and arachidonic acid release from luminal epithelium to induce fibroblast activation and decidualization.

Changes of Vaginal Microecology of Women with Intrauterine Adhesions

Background

Reproductive tract infection is one of the important causes of intrauterine adhesions (IUA). The evaluation of vaginal microecology could provide significant guidance for the treatment of reproductive tract infection. This study aimed to investigate the correlation between IUA and vaginal microecology.

Methods

Patients who came to the gynecology department of our hospital from March 2020 to February 2022 and were diagnosed with IUA were selected as the research subjects (n=150). Patients with normal uterine cavity were selected as the control group (n=150). All research subjects underwent hysteroscopy and vaginal microecological examination. The vaginal pH, hydrogen peroxide (H₂O₂), leukocyte esterase (LE), sialidase (SNA), 3-glucuronidase (GUS), and acetylglucosidase (NAG) of the participants were recorded and analyzed, respectively. Vulvovaginal candidiasis (VVC), trichomonas vaginitis (TV), and bacterial vaginosis (BV) were evaluated and diagnosed separately.

Results

The incidence of abnormal vaginal microecological morphological and functional indicators in the IUA group was remarkably higher than that in the control group, mainly manifested as relatively high pH value, reduction of Lactobacillus, increased ratio of flora density I, IV and flora diversity I, IV, higher detection rate of TV and BV. In addition, the increase in the positive rate of H₂O₂, LE, SNA, and NAG were observed in IUA patients.

Conclusion

Vaginal microecological imbalance is closely related to the occurrence of IUA, which should cause clinical concern.

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.

Transdermal estrogen gel vs oral estrogen after hysteroscopy for intrauterine adhesion separation: A prospective randomized study

BACKGROUND

This randomized controlled trial (RCT) aimed to compare two different routes of postoperative estrogen treatment on the improvements of menstruation, postoperative endometrial thickness, and fertility outcomes in patients with moderate to severe intrauterine adhesions (IUA).

METHODS

This study prospectively included 78 women (age: 25 to 45 years) with moderate to severe IUA who underwent hysteroscopic resection of adhesions between March 2019 and October 2020. The enrolled patients were randomized 1:1 into either the transdermal gel group (n = 39) or the estradiol valerate oral tablet group (n = 39) on the day of receiving hysteroscopy. Postoperative endometrial thickness, AFS (American Fertility Society) score, estrogen level, and the pattern and amount of menstruation were compared. Pregnancy information was actively collected during 1-year follow-up after the operation.

RESULTS

The postoperative endometrium thickness was improved in both groups, and both groups gained menstruation improvement rates of 67%. For patients who underwent second-look hysteroscopy (17 from the oral group and 19 from the transdermal group), the mean AFS score declined greater than 2 in both groups. For patients with postoperative pregnancy intention, the pregnancy rates at 1-year follow-up after the procedures were 40.5% and 28% in the transdermal group and oral group, respectively. Although no statistically significant difference was observed between the two groups, patients in the transdermal group had a tendency toward increased pregnancy rate.

CONCLUSIONS

Transdermal administration of estrogen is equally efficacious as oral estrogen in postoperative treatment of IUA patients with a relatively safe profile. It is very likely to broaden its indication to the field of IUA.

TRIAL REGISTRATION

http://www.chictr.org.cn/showproj.aspx?proj=37197, identifier ChiCTR1900022110.

Telocyte-Derived Exosomes Provide an Important Source of Wnts That Inhibits Fibrosis and Supports Regeneration and Repair of Endometrium

Intrauterine adhesions (IUAs) often occurred after common obstetrical and gynecological procedures or infections in women of reproductive age. It was characterized by the formation of endometrial fibrosis and prevention of endometrial regeneration, usually with devastating fertility consequences and poor treatment outcomes so far. Telocytes (TCs), as a novel interstitial cell type, present in female uterus with in vitro therapeutic potential in decidualization-defective gynecologic diseases. This study aims to further investigate the role of TC-derived Wnt ligands carried by exosomes (Exo) in reversal of fibrosis and enhancement of regeneration repair in endometrium. IUA cellular and animal models were established from endometrial stromal cells (ESCs) and mice, followed with treatment of TC-conditioned medium (TCM) or TC-derived Exo. In cellular model, fibrosis markers (collagen type 1 alpha 1 [COL1A1], fibronectin [FN], and α-smooth muscle actin [α-SMA]), angiogenesis (vascular endothelial growth factor [VEGF]), and pathway protein (β-catenin) were determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR), Western blotting (WB), and immunofluorescence. Results showed that, TCs (either TCM or TC-derived Exo) provide a source of Wnts that inhibit cellular fibrosis, as evidenced by significantly elevated VEGF and β-catenin with decreased fibrotic markers, whereas TCs lost salvage on fibrosis after being blocked with Wnt/β-catenin inhibitors (XAV939 or ETC-159). Further in mouse model, regeneration repair (endometrial thickness, number of glands, and fibrosis area ratio), fibrosis markers (fibronectin [FN]), mesenchymal-epithelial transition (MET) (E-cadherin, N-cadherin), and angiogenesis (VEGF, microvessel density [MVD]) were studied by hematoxylin-eosin (HE), Masson staining, and immunohistochemistry. Results demonstrated that TC-Exo treatment effectively promotes regeneration repair of endometrium by relieving fibrosis, enhancing MET, and angiogenesis. These results confirmed new evidence for therapeutic perspective of TC-derived Exo in IUAs.

The Correlation between Chronic Endometritis and Tubal-Factor Infertility

OBJECTIVE

To identify the prevalence and risk factors for chronic endometritis (CE) with tubal factors and the correlation between chronic endometritis and tubal factors among infertile populations.

METHOD

A total of 52 patients with chronic endometritis (CE group) who underwent laparoscopy and hysteroscopic surgery were recruited between July 2020 and December 2021. A total of 38 patients without chronic endometritis (non-CE group) were included as a control. Patients with endometriosis and intra-uterine abnormalities were excluded. Endometrial samples were collected during surgery for CD138 immunohistochemistry staining for the diagnosis of CE. Preoperative information (including age, reproductive health characteristics, previous medical and surgical history), intra-operative information (including the patency of the fallopian tube, the presence of hydrosalpinx, score and the grade of tubal lesion condition) and post-operative information (counts of CD138-positive HPF in the endometrial specimen) were collected.

RESULT

A multivariate analysis revealed that tubal factors with unilateral or bilateral occlusion were significantly higher in the CE group (OR 3.066, 95% CI 1.020-9.213, p = 0.046). The bilateral occlusion of fallopian tubes (OR 8.785, 95% CI 1.408-54.818, p = 0.020) rather than unilateral occlusion (OR 2.860, 95% CI 0.893-9.162, p = 0.077) was significantly associated with chronic endometritis. The presence of a hydrosalpinx on one side (OR 7.842, 95% CI 1.279-48.086, p = 0.026) or both sides (OR 9.450, 95% CI 1.037-86.148, p = 0.046) was significantly associated with chronic endometritis. The comparison of CD138-positive HPF counts among the tubal occlusion patients without hydrosalpinx, patients with unilateral hydrosalpinx and patients with bilateral hydrosalpinx were as follows: 1 HPF (50.00% vs. 12.50% vs. 11.11%, p = 0.051), 2 HPF (38.89% vs. 25.00% vs. 22.22%, p = 0.615), ≥3 HPF (11.11% vs. 62.50% vs. 66.67%, p = 0.005). The stage of tubal condition was positively correlated with CD138-positive HPF counts in women with chronic endometritis (r = 0.460, p = 0.001).

CONCLUSION

CE was closely related to the blockage of fallopian tubes and hydrosalpinx. The severity degree of the fallopian lesion condition was associated with inflammation of the endometrium.

CRC Therapy Identifies Indian Hedgehog Signaling in Mouse Endometrial Epithelial Cells and Inhibition of Ihh-KLF9 as a Novel Strategy for Treating IUA

Intrauterine adhesion (IUA) causes menstrual disturbance and infertility. There is no effective treatment available for moderate to severe IUA cases. Stem cell-based therapy has been investigated for treating IUA but is limited in clinical applications due to issues including the precise induction of differentiation, tumorigenesis, and unclear molecular mechanisms. In our recent study, we isolated and expanded the long-term cultures of conditional reprogrammed (CR) mouse endometrial epithelial cells. Treating IUA mice with these CR cells (CRCs) restored the morphology and structure of the endometrium and significantly improved the pregnancy rate. In this study, our data with high-throughput sequencing, CRISPR knockout Ihh^-/-CRCs, and transplantation identified for the first time that the Indian hedgehog (Ihh) gene plays a critical role in the regulation of endometrial epithelial cell proliferation. We also found that aberrant activated Ihh-krüppel-like factor 9 (KLF9) signaling contributes to the inhibition of normal progesterone receptor (PR) function in IUA mice. Thus, we hypothesized that inhibition of the Ihh-KLF9 pathway may be a novel strategy to treat IUA. Our data demonstrated that treatment with the hedgehog signaling inhibitor Vismodegib restored the morphology, structure, and microenvironment of the endometrium, and greatly improved the pregnancy rate in IUA mice. This study suggests a promising application of hedgehog inhibitors as a targeted drug in the IUA clinic.

Amniotic membrane extract-enriched hydrogel augments the therapeutic effect of menstrual blood-derived stromal cells in a rat model of intrauterine adhesion

We previously demonstrated that transplantation of menstrual blood-derived stromal cells (MenSCs) is a safe and effective therapy for treating intrauterine adhesions (IUA). However, improving the colonization and therapeutic efficiency of MenSCs is still needed before full clinical application. Here, we established an amniotic membrane extract (AME)-enriched RGD hydrogel, and evaluated the therapeutic effect of this adjuvant combined with MenSCs transplantation in an IUA rat model. Our results indicated that AME promoted the proliferation and secretion of MenSCs in vitro, up-regulated the expression of apoptosis-suppressing gene BCL2 and down-regulated the expression of apoptosis-related genes Caspase-3 and Caspase-8. The AME-enriched hydrogel was biocompatible, and improved the survival of MenSCs in vitro and in vivo. It also promoted the retention of MenSCs in IUA uterus and augmented the effects of MenSCs on improving uterus morphology, endometrial proliferation, endometrial receptivity and fibrosis suppression. In addition, co-transplantation of MenSCs with AME-enriched hydrogel markedly down-regulated the expressions of inflammation-related genes IL10 and TGFβ while up-regulated the IL4/IFN-γ ratio in the IUA endometrium, and improved the expressions of cell proliferation-related antigen, gland-regeneration-related marker leucine-rich repeat-containing G-protein coupled receptor 5 (LGR5), angiogenesis-related marker platelet and endothelial cell adhesion molecule 1 (PECAM1), endometrial receptivity related genes ITGα5 and ITGβ3. Our study suggested that AME and MenSCs had a synergistic effect. Co-transplantation of MenSCs with AME-enriched hydrogel provided a promising approach for stem cell-based IUA treatment.

Study on Risk Factors Related to Intrauterine Adhesion Based on Meta-Analysis

Objective. Intrauterine adhesion (IUA) is a severe complication that occurs following abortion. To evaluate the related risk factors of uterine cavity adhesion by meta-analysis. Methods. The research literature on the influencing factors of patients with intrauterine adhesions published from January 2010 to December 2020 in PubMed, EMBASE, Cochrane Library, web of science, CNKI, Wanfang Data, VIP, and CBM were retrieved by computer. Two evaluators independently screened the literature, extracted the data, and evaluated the treatment according to the inclusion and exclusion criteria and then analyzed it with revman5.3 software. Results. Finally, 12 literatures were included, with a total sample size of 2341 cases. The results of meta-analysis showed that pelvic inflammation ( $p=0.05$ ), negative pressure during uterine suction ( $p<0.0001$ ), and uterine suction time ( $p<0.00001$ ) were the risk factors for uterine cavity adhesion. The combined or and 95% CI of each factor were 2.05 (1.24, 3.38), 125.61 (67.35, 183.87), and 4.52 (4.21, 4.84), respectively. However, the number of pregnancies, the number of curettages, the average number of births, abortion, myomectomy, menstrual abnormalities, and infertility have little impact on the occurrence of intrauterine adhesions ( $p>0.05$ ). Conclusion. Pelvic inflammatory disease, negative pressure during uterine suction and uterine suction time are the risk factors leading to uterine cavity adhesion.

Animal models in intrauterine adhesion research

Intrauterine adhesion (IUA) is a gynaecological disease caused by uterine cavity surgeries and infections that leads to partial or total occlusion of the uterine cavity. However, the underlying mechanism(s) and progression of the disease have not yet been identified. IUA has a high recurrence rate and poor prognosis, and effective drugs to prevent adhesion are lacking. Therefore, establishing an effective animal model of IUA is of great significance for revealing the pathogenesis of IUA and the mechanism(s) governing drug effects. Rats, mice, rabbits, and other animals are currently used to establish intrauterine adhesion models. The IUA induction methods include chemical, thermal, or mechanical damage and mechanical damage combined with an infective method. We analysed the advantages and disadvantages of various models and their clinical simulations in order to provide a precise animal model for exploring the pathogenesis, treatment strategies, and prevention of IUA.

A novel technique for moderate to severe intrauterine adhesions: A historical cohort study

To evaluate the feasibility and efficiency of our novel technique, ultrasound guided hysteroscopic catheter dilation (US-HCD), for the treatment of moderate to severe intrauterine adhesion (IUA). A total of 126 patients diagnosed with IUA and met the enrollment criteria were admitted in this historical cohort study from June 1, 2016 to December 31, 2018. All patients were divided into 2 groups according to the surgical techniques used. Group A (n = 68) were treated with traditional hysteroscopic adhesiolysis with scissors (THA) and Group B (n = 58) were treated with US-HCD. Their data for the next 2 years following the initial surgery were analyzed. Safety and feasibility (operation time, surgical complications and the third-look hysteroscopic surgery rate), and post-operation efficacy (reduction of American Fertility Society [AFS] scores, pregnancy and live birth rates) were evaluated between groups. Between the groups, there was no statistically significant differences in basic preoperative information and AFS scores (P > .05). While there were significant differences in the operation time of the initial surgery (P < .05) and reduction of AFS scores (P < .05). No surgical complications were recorded and only 3 patients (5.2%) received a third-look hysteroscopy in Group B, while there were 6 cases of complications and 13 cases (19.1%) of third-look hysteroscopy in Group A, indicating significant differences between Groups (P < .05). Both groups exhibited comparable pregnancy rate, live birth rate and obstetric complications (P > .05). Our new technique is a safe, feasible and effective procedure for moderate to severe IUA patients, which can be mastered more quickly and easily by surgeons and applied in areas with less affluent economy and without hysteroscopic scissors, thus worthy of further study.

Prevalence of and risk factors for chronic endometritis in patients with intrauterine disorders after hysteroscopic surgery

OBJECTIVE

To identify the prevalence of and risk factors for chronic endometritis (CE) in patients with intrauterine disorders and the therapeutic efficacy of hysteroscopic surgery in the treatment of CE without antibiotic therapy.

DESIGN

Prospective cohort study.

SETTING

Hospital specializing in reproductive medicine.

PATIENT(S)

The study population consisted of 350 women with infertility, of whom 337 were recruited, who underwent hysteroscopic surgery between November 2018 and June 2021. Eighty-nine consecutive patients without intrauterine disorders were also recruited as controls.

INTERVENTION(S)

Endometrial samples were collected during the surgery for CD138 immunostaining for the diagnosis of CE. In women diagnosed with CE, endometrial biopsy was performed without antibiotic use in the subsequent menstrual cycle.

MAIN OUTCOME MEASURE(S)

Prevalence of and risk factors for CE in intrauterine disorders and therapeutic effects of hysteroscopic surgery on CE.

RESULT(S)

The prevalence of CE with ≥5 CD138-positive cells in women with no intrauterine disorder and with endometrial polyps, myomas, intrauterine adhesions (IUAs), and septate uterus was 15.7%, 85.7%, 69.0%, 78.9%, and 46.2%, respectively. A multivariate analysis revealed that CE was diagnosed significantly more often in the endometrial polyp (odds ratio, 27.69; 95% confidence interval, 15.01-51.08) and IUA groups (odds ratio, 8.85; 95% confidence interval, 3.26-24.05). The rate of recovery from CE with surgery in women with endometrial polyps, myomas, IUA, and septate uterus was 89.7%, 100%, 92.8%, and 83.3%, respectively.

CONCLUSION(S)

Endometrial polyp and IUA were risk factors for CE. Most CE cases with intrauterine disorders were cured with hysteroscopic surgery without antibiotic therapy, regardless of the type of intrauterine abnormalities.

Estradiol and intrauterine device treatment for moderate and severe intrauterine adhesions after transcervical resection

Objective

To explore the effect of 4 mg/day, 6 mg/day, and 8 mg/day estradiol alone or in combination with an intrauterine device (IUD) in patients with moderate and severe intrauterine adhesion (IUA) after transcervical resection of adhesion (TCRA).

Methods

Patients with moderate or severe IUA who reived 4 mg/day, 6 mg/day, and 8 mg/day estradiol alone or in combination with an intrauterine device (IUD) after TCRA in Women’s Hospital, Zhejiang University School of Medicine, from March 2014 to December 2014 were enrolled in this retrospective case–control study. In group A, 14 patients received estradiol 4 mg/day + IUD after the first operation; in group B, 29 patients (group B0) received estradiol 6 mg/day after the first operation, and 73 patients (group B1) received estradiol 6 mg/day + IUD; in group C, 14 patients received estradiol 8 mg/day + IUD after the first operation. Referring to ESGE's IUA diagnostic classification method, 72 patients had moderate adhesion, and 58 cases had severe adhesion. Outpatient follow-up was performed at 1 and 23 months and after 1 year. The postoperative menstrual improvement, uterine cavity recovery, drug side effects at two to three months, and pregnancy situation at one year were recorded.

Results

There were no significant differences in age, BMI, and previous intrauterine operation times between the 3 groups (all p > 0.05). Compared with Group A, more patients in group C had severe IUA (p = 0.008). In addition, there were no differences in menstrual recovery, uterine cavity recovery, and pregnancy in one year between the 3 groups (p > 0.05) and between groups B₀ and B₁ (p > 0.05). In group B1, 51 (69.86%) patients had IUD incarceration.

Conclusion

This data suggests that 4 mg/d doses of estrogen may have the same effect in improving the menstrual condition, uterine cavity morphology, and reproductive ability compared to a higher dosage (6 mg/day estrogen and 8 mg/day). In addition, the placement of IUD in the uterine cavity during TCRA may cause IUD incarceration, and the treatment results for the prevention of IUA are not better than without IUD.

The Mechanism of Wnt Pathway Regulated by Telocytes to Promote the Regeneration and Repair of Intrauterine Adhesions

Background

Telocytes (TCs), a novel interstitial cell type in the reproductive tract, participating in pathophysiology of intrauterine adhesions (IUA). This study further investigates the hypothesis that TCs, a source of Wnt, promote the regeneration and repair of IUA.

Methods

RNA sequencing datasets of IUA patient (GSE160633) and mouse intestine mesenchymal cells (GSE94072) in GEO database were analyzed for differentially expressed genes (DEGs), and quantitative real-time PCR (qRT-PCR) measured indicated gene expression in TC-educated endometrial stromal cells (ESCs) and noneducated ESCs and verified the results of data mining from GEO database.

Results

The expression levels of Wnt genes were downregulated in IUA compared to the control and were upregulated in TCs. In particular, the changes of Wnt5a expression level were the most significant (logFC = 4.0314 and adjusted P value = 0.0023), and the relative Wnt5a expression level was remarkably higher in TC-educated ESCs than noneducated ESCs verified by qRT-PCR (P = 0.0027).

Conclusions

TCs may enhance the regeneration and repair of IUA through the Wnt signaling pathway.

Clinical Evaluation of Autologous and Allogeneic Stem Cell Therapy for Intrauterine Adhesions: A Systematic Review and Meta-Analysis

Objective

Intrauterine adhesions (IUAs) are a major cause of female infertility. Stem cells can be used to restore endometrial function owing to their regenerative abilities. We compared the safety and efficacy of autologous and allogeneic stem cell treatments in patients with recurrent IUA after conventional therapy based on a systematic review of the related literature.

Methods

The PubMed, Embase, and Cochrane databases were systematically searched. All analysis were performed using Review Manager 5.4. We compared improvements in endometrial thickness, pregnancy rates, menstruation, and side effects after autologous and allogeneic stem cell therapy. The study was registered with PROSPERO, CRD 42022322870.

Results

Our search returned 154 reports, 10 of which met the inclusion criteria, representing 116 patients. Of these, 44 patients in two studies were treated with allogeneic stem cells and 72 patients in eight studies were treated with autologous stem cells. Improvements in endometrial thickness and pregnancy rates after intrauterine device treatment were compared between the autologous and allogeneic stem cell groups. Endometrial thickness increased more after autologous stem cell IUA treatment (mean difference, 1.68; 95% confidence interval [CI]: 1.30–2.07; P < 0.00001), and the pregnancy rate was also improved (relative risk, 1.55; 95% CI: 1.19–2.02, P < 0. 001). No obvious and serious adverse reactions were observed during stem cell therapy in either group.

Conclusions

This meta-analysis and systematic review of the results of randomized trials of autologous and allogeneic stem cell treatments for IUA suggests that autologous stem cells have a better effect in improving the endometrium thickness and pregnancy rate.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022322870.

Hysteroscopic resection of type 3 fibroids could improve the pregnancy outcomes in infertile women: a case-control study

Background

Type 3 fibroids are a special subtype of intramural fibroids that are likely to affect the pregnancy outcomes of assisted reproductive techniques. Hysteroscopic resection is a treatment for type 3 fibroids, but there has few study of its efficacy to date. In this study we evaluated the effect of hysteroscopic resection of type 3 fibroids on the pregnancy outcomes in infertile women.

Methods

This retrospective case–control study was conducted from January 1, 2014 to June 30, 2021. Patients who underwent IVF-ICSI in our unit were divided into a type 3 fibroid group and a hysteroscopic myomectomy group. The inclusion criteria for the type 3 fibroid group and the hysteroscopic myomectomy group were as follows: 1) age ≤ 40 years; 2) fibroid diameter or total fibroid diameter > 2.0 cm. The following exclusion criteria were used: 1) oocyte donor treatment cycles and 2) presence of chromosomal abnormalities; 3) history of other uterine surgery; 4) presence of intracavitary lesions, including submucosal fibroids; 5) single fibroid > 5.0 cm; 6) cervical fibroids; 7) unclear ultrasound description of fibroids; 8) preimplantation genetic testing was performed and 9) congenital or acquired uterine malformations. The control group in our study was selected from patients who were treated with IVF only because of fallopian tube factors. According to the age of the type 3 fibroid group and hysteroscopic myomectomy group, random sampling was carried out in the patients between 25 and 47 years of age to determine a control group. The outcomes measured included the average transfer times to live birth, cumulative clinical pregnancy rate, and cumulative live birth rate.

Results

A total of 302 cycles were enrolled in our study, including 125 cycles with type 3 fibroids, 122 cycles with hysteroscopic myomectomy, and 139 cycles of control patients. The average transfer times to live birth were significantly higher in the type 3 fibroid group than in the other two groups. The frequency of cumulative live births in the type 3 fibroid group was significantly lower than that in the control group. Compared with the control group, the hysteroscopic myomectomy patients had no statistically significant differences in the cumulative clinical pregnancy rate and cumulative live birth rate.

Conclusions

Type 3 fibroids significantly reduced the cumulative live birth rate of IVF patients. Ultrasound-guided hysteroscopic myomectomy can be used as a treatment for type 3 fibroids and could improve the pregnancy outcomes in infertile women.

Hysteroscopic and ultrasound evaluation of a novel degradable polymer film for the prevention of intrauterine adhesion formation after hysteroscopic surgery

OBJECTIVE

To collect information on the application and behavior of a novel degradable polymeric film (DPF) developed to prevent intra-uterine adhesions (IUAs) after hysteroscopic surgery.

STUDY DESIGN

A prospective observational study conducted in a university hospital in Naples, Italy. Women undergoing hysteroscopic myomectomy, metroplasty or adhesiolysis, were eligible for the study. Women had their uterine cavity assessed by transvaginal ultrasound scan before their hysteroscopic surgery, which was followed by the DPF insertion. Ultrasonographic and hysteroscopic assessments were undertaken immediately after insertion then at 2 h, 2-5 days, and 6 weeks postoperative. The main outcome of interest was to assess the behavior of the DPF, from insertion to degradation, by ultrasound and hysteroscopy. Other outcomes included ease of DPF insertion, any patient reported adverse events and the presence of IUAs at 6 weeks.

MEASUREMENTS AND MAIN RESULTS

A total of 15 patients were enrolled into the study. The DPF insertion was reported to be very easy in almost all the cases and was visualized immediately and 2 h after insertion in all patients. At the 2-5 day follow-up 5 and 2 of the 15 participants still had the entire or partially hydrolyzed film respectively. By 6 weeks there was no evidence of the DPF in all women. No adverse events were reported at the time of insertion or follow-up. None of the study participants had IUAs at the 6-week assessment.

CONCLUSIONS

According to this pilot study, the solid degradable polymer film, Womed Leaf, is a promising, easy to apply and well tolerated novel option for the prevention of intrauterine adhesion formation after hysteroscopic surgery.

Protective Effects of Engineered Lactobacillus crispatus on Intrauterine Adhesions in Mice via Delivering CXCL12

Endometrial injury is the main cause of intrauterine adhesions (IUA), and there is currently no effective prevention and treatment. Immune cells play an important role in damage repair by sensing the change in the microenvironment. Exogenous CXCL12 can promote tissue regeneration and repair by recruiting immune cells, but its effect and possible mechanism on endometrial regeneration and repair have not been reported. In the present study, we constructed an engineered a Lactobacillus crispatus strain by transforming a pMG36e plasmid carrying a CXCL12 gene into the bacterium, and developed two animal models, the intrauterine adhesion mice with or without diabetes to evaluate the positive effects of this strain on the prevention of IUA after accepting intrauterine surgery in normal and diabetic mice. The results showed that vaginal application of L. crispatus-pMG36e-mCXCL12 strains significantly diminished the levels of pro-inflammatory factors interleukin-1β (IL-1β) and tumour necrosis factor-α (TNF-α) in serum and uterine tissues of IUA mice, and resulted in the inhibition of the inflammatory (toll-like receptor 4/nuclear factor-κb, TLR4/NF-κB) and fibrotic (transforming growth factor-β1/smads, TGF-β1/Smads) signalling pathways in the uterine tissues. The high-throughput sequencing results further indicated that treatment with L. crispatus-pMG36e-mCXCL12 strains greatly increased the abundance of Lactobacillus spp. and reduced that of the pathogenic Klebsiella spp. in IUA mice. Furthermore, among intrauterine adhesion mice with diabetes, we obtained similar results to non-diabetic mice, that is, L.crispatus-pMG36e-mCXCL12 significantly improved fibrosis and inflammation in the uterine cavity of diabetic mice, and restored the vaginal microbiota balance in diabetic mice. Therefore, we speculated that vaginal administration of L. crispatus-pMG36e-mCXCL12 strains can effectively alleviate intrauterine adhesions by restoring the microbial balance and reducing inflammation and fibrosis caused by surgery.

Treating intrauterine adhesion using conditionally reprogrammed physiological endometrial epithelial cells

Background

There is unmet need for effective therapies of intrauterine adhesions (IUAs) that are common cause of menstrual disturbance and infertility, since current clinical procedures do not improve prognosis for patients with moderate to severe IUA, with a recurrence rate of 23–50%. Stem cell-based therapy has emerged as a therapeutic option with unsolved issues for IUA patients in the past few years. Primary endometrial epithelial cells for cell therapy are largely hampered with the extremely limited proliferation capacity of uterine epithelial cells. This study was to evaluate whether IUA is curable with conditionally reprogrammed (CR) endometrial epithelial cells.

Methods

Mouse endometrial epithelial cells (MEECs) were isolated from C57BL female mice, and long-term cultures of MEECs were established and maintained with conditional reprogramming (CR) method. DNA damage response analysis, soft agar assay, and matrigel 3D culture were carried out to determine the normal biological characteristics of CR-MEECs. The tissue-specific differentiation potential of MEECs was analyzed with air–liquid interface (ALI) 3D culture, hematoxylin and eosin (H&E) staining, Masson’s trichrome and DAB staining, immunofluorescence assay. IUA mice were constructed and transplanted with CR-MEECs. Repair and mechanisms of MEECs transplantation in IUA mice were measured with qRT-PCR, Masson’s trichrome, and DAB staining.

Results

We first successfully established long-term cultures of MEECs using CR approach. CR-MEECs maintained a rapid and stable proliferation in this co-culture system. Our data confirmed that CR-MEECs retained normal biological characteristics and endometrium tissue-specific differentiation potential. CR-MEECs also expressed estrogen and progesterone receptors and maintained the exquisite sensitivity to sex hormones in vitro. Most importantly, allogeneic transplantation of CR-MEECs successfully repaired the injured endometrium and significantly improved the pregnancy rate of IUA mice.

Conclusions

Conditionally reprogrammed physiological endometrial epithelial cells provide a novel strategy in IUA clinics in a personalized or generalized manner and also serve as a physiological model to explore biology of endometrial epithelial cells and mechanisms of IUA.

Arrowhead Composite Microneedle Patches with Anisotropic Surface Adhesion for Preventing Intrauterine Adhesions

Biomedical patches are considered as a promising strategy to help tissue repair and regeneration, prevent tissue adhesion, and reduce neighboring friction. Here, novel arrowhead composite microneedle patches (MNPs) are presented with anisotropic surface adhesion and growth factor encapsulation using a heterogeneous template replication approach for endometrium repair and intrauterine adhesions (IUAs) prevention. The arrowhead structures bring about interlocking between the microneedle (MN) tips and tissues, allowing these MNPs to steadily adhere to the tissues. Besides, benefitting from the cytoadhesive needle-tip material and the antiadhesive base material, these MNPs possess anisotropic surface adhesion and can facilitate cell adhesion on one surface to repair damaged tissues while restrain tissue contact on the other to prevent adverse adhesion. In the meanwhile, the encapsulated growth factor can be delivered through the MNs to the deep tissue, further accelerating tissue repair. Additionally, as the bases are soft and their patterns are highly tunable, the MNPs can change their shapes flexibly to adjust to the irregular morphology of uteri. It is demonstrated that these MNPs show good performances in treating injured endometrium and preventing IUAs of a rat model, indicating their great potential in versatile postoperative adhesion prevention and other clinical applications.

Reproductive outcomes and reproductive tract microbiota shift in women with moderate-to-severe intrauterine adhesions following 30-day post-hysteroscopic placement of balloon stents or intrauterine contraceptive devices: A randomized controlled trial

BACKGROUND

Intrauterine adhesions (IUA) develop in up to 20% of women with a history of abortion. After hysteroscopic adhesiolysis, balloon stents are usually placed for seven days to prevent recurrence. The efficacy of prolonged use (30 days) of balloon stents has not been determined.

METHODS

The trial was conducted from June 2019 to March 2021. Ninety-one patients who underwent hysteroscopic adhesiolysis for moderate or severe IUA were randomized to receive a 30-day placement of a balloon stent (n = 44) or an intrauterine device (IUD) (n = 47). The primary outcomes were the ongoing pregnancy and miscarriage rates assessed at 15-19 months. The secondary outcomes were the recurrence of IUA and the American Fertility Society (AFS) intrauterine adhesion scores at the first and second hysteroscopies, the diagnosis of new chronic endometritis at the second-look hysteroscopy, and the vaginal/uterine microbiome assessed using 16S rRNA sequencing. The trial was registered at Chinese Clinical Trial Registry (ChiCTR1900023306).

FINDINGS

The ongoing pregnancy rates (balloon 56·4% versus IUD 57·1%) and miscarriage rates (balloon 10·3% versus IUD 22·9%) were not significantly different between the groups. No differences in the recurrence of IUA, reduction of AFS scores, or new endometritis rates were detected. The bacterial load in the uterus and vagina increased in the IUD group but not in the balloon group.

INTERPRETATION

Balloon placement has a similar effect on ongoing pregnancy rates as intrauterine device (IUD) placement. Patients who underwent balloon placement had a lower miscarriage rate, although the difference was not significant. There were no differences in the recurrence rate of IUA, reduction of American Fertility Society scores, or rate of new chronic endometritis. The balloon stent has less effects on the uterine microbiota.

FUNDING

National Natural Science Foundation of China (81802593).

Metabolomics and pharmacodynamic analysis reveal the therapeutic role of Prunella vulgaris oil on intrauterine adhesion rats

Metabolomics is applied to explore the curative effect of complex systems, such as Chinese medicine. Intrauterine adhesion (IUA) harms the reproductive system and affects fertility, and hence is a significant public health concern. Prunella vulgaris oil (PVO) protects the reproductive system and exerts anti-inflammatory effects, but its effect on IUA and the underlying mechanism is unclear. In this study, we established a serum metabolomics method based on GC-TOF-MS to evaluate the mechanism of PVO in the IUA rat model established by mechanical injury and infection. Animal experiments showed that PVO improves the inflammatory response in the uterus of IUA model rats and reduces the content of inflammatory factors to improve the microenvironment of the reproductive system. It also regulates the expression of TGF-β1 and Smad-related mRNA and protein to inhibit fibrosis. Metabolomics indicated a significant abnormality in serum metabolism in IUA rats, and a total of 51 differential markers were screened and identified. After PVO treatment, these metabolic abnormalities improved significantly. The metabolic pathway analysis revealed that PVO affects glyoxylate and dicarboxylate metabolism, and β-alanine metabolism pathways. This study showed that PVO significantly improves inflammation and fibrosis in IUA rats combined with the pharmacological results. The primary mechanism is related to regulating the metabolism of amino acids and their derivatives to balance the associated disorders and control energy metabolism.

The Latest Developments in Immunomodulation of Mesenchymal Stem Cells in the Treatment of Intrauterine Adhesions, Both Allogeneic and Autologous

Intrauterine adhesion (IUA) is an endometrial fibrosis disease caused by repeated operations of the uterus and is a common cause of female infertility. In recent years, treatment using mesenchymal stem cells (MSCs) has been proposed by many researchers and is now widely used in clinics because of the low immunogenicity of MSCs. It is believed that allogeneic MSCs can be used to treat IUA because MSCs express only low levels of MHC class I molecules and no MHC class II or co-stimulatory molecules. However, many scholars still believe that the use of allogeneic MSCs to treat IUA may lead to immune rejection. Compared with allogeneic MSCs, autologous MSCs are safer, more ethical, and can better adapt to the body. Here, we review recently published articles on the immunomodulation of allogeneic and autologous MSCs in IUA therapy, with the aim of proving that the use of autologous MSCs can reduce the possibility of immune rejection in the treatment of IUAs.

Autocross-linked hyaluronic acid gel and adipose-derived mesenchymal stem cell composites for the treatment intrauterine adhesions

OBJECTIVE

To evaluate the effect of adding adipose-derived mesenchymal stem cells (ASCs) to autocross-linked hyaluronic acid (HA) gel for intrauterine adhesion (IUA) treatment.

METHODS

A rat IUA model was established by mechanical curettage and infection, and then different treatments were administered to the rats on day 7 after modeling. Ninety-six rats were randomly divided into the following groups: IUA model group, gel therapy group, and combination therapy group (HA gel combined with ASCs). Eight rats per group were sacrificed on days 7, 10, 14 and 21 for the subsequent experiments. Morphological changes were determined by hematoxylin-eosin staining and Masson staining. Smad3 and leukocyte inhibitory factor (LIF) were analyzed by quantitative real-time polymerase chain reaction and immunohistochemistry.

RESULTS

The endometrial lines in the gel therapy group and the combination therapy group were more complete than those in the model group. Masson staining showed that fibrosis area rates in the gel therapy group and the combination therapy group were significantly lower than those in the model group on day 7(P < 0.05). During the observation period, the fibrosis area rates in the combination therapy group remained lower than those in the model group (P < 0.05). The mRNA expression of Smad3 in the combination therapy group was lower than that in the model group and gel therapy group during the observation period (P < 0.05). The mRNA expression level of LIF in the combination therapy group was higher than that in the model group and the gel therapy group throughout the observation period (P < 0.05).

CONCLUSIONS

HA gel was effective in preventing the IUA adhesion formation at the early stage of the observation period, while ASC enhanced this effect throughout the observation period. Gel and ASC composites helped to improve endometrial receptivity.

Women-specific routes of administration for drugs: A critical overview

The woman's body presents a number of unique anatomical features that can constitute valuable routes for the administration of drugs, either for local or systemic action. These are associated with genitalia (vaginal, endocervical, intrauterine, intrafallopian and intraovarian routes), changes occurring during pregnancy (extra-amniotic, intra-amniotic and intraplacental routes) and the female breast (breast intraductal route). While the vaginal administration of drug products is common, other routes have limited clinical application and are fairly unknown even for scientists involved in drug delivery science. Understanding the possibilities and limitations of women-specific routes is of key importance for the development of new preventative, diagnostic and therapeutic strategies that will ultimately contribute to the advancement of women's health. This article provides an overview on women-specific routes for the administration of drugs, focusing on aspects such as biological features pertaining to drug delivery, relevance in current clinical practice, available drug dosage forms/delivery systems and administration techniques, as well as recent trends in the field.

Effectiveness of Hyaluronic Acid Gel and Intrauterine Devices in Prevention of Intrauterine Adhesions after Hysteroscopic Adhesiolysis in Infertile Women

STUDY OBJECTIVE

To compare the recurrence rate, post-treatment American Fertility Society (AFS) score, ongoing pregnancy rate, and endometrial thickness of 3 secondary prevention therapies in preventing recurrent intrauterine adhesions (IUAs) and increasing pregnancy rates in infertile women after hysteroscopic adhesiolysis.

DESIGN

A retrospective study.

SETTING

A private fertility hospital.

PATIENTS

A total of 200 consecutive infertile women, with the desire to have a baby and were diagnosed as having IUAs detected by hysterosalpingogram, who underwent hysteroscopic adhesiolysis for IUAs from January, 2018 to May, 2020.

INTERVENTIONS

Women who underwent hysteroscopic adhesiolysis received hormone therapy, and one of the 3 secondary preventions: hyaluronic acid (HA) gel alone, intrauterine devices (IUDs) alone, or HA gel + IUD.

MEASUREMENTS AND MAIN RESULTS

Of the 200 women included in the final analysis, 121 received HA alone, 59 were treated with IUD alone, and 20 received HA gel + IUD combination. The mean post-treatment AFS score for IUAs was significantly lower in the HA gel + IUD group than the HA alone or the IUD alone groups (adjusted p = .01 and p = .02, respectively). Multivariable analysis revealed a significantly lower recurrence rate in the women after treatment with HA gel + IUD than HA alone (adjusted odds ratio, 0.19; 95% credible interval [CreI], 0.03-0.88). Women treated with HA gel + IUD also had reduced post-treatment AFS scores compared with HA alone (β coefficients, -0.83; 95% CreI, -1.64 to -0.01). For ongoing pregnancy rates after in vitro fertilization, the adjusted odds ratio for HA gel + IUD vs HA alone was 2.03 (95% CreI, 0.44-11.00) and for IUD alone vs HA alone was 1.13 (95% CreI, 0.41-3.29), indicating nonsignificant differences. There were no differences observed in endometrial thickness on the day of embryo transfer among the 3 groups.

CONCLUSION

The investigation of the primary outcome in reducing the recurrence rate IUA after treatment demonstrated that a combination of HA gel + IUD provides greater prevention of recurrent IUAs and may decrease post-treatment AFS scores for infertile women undergoing hysteroscopic adhesiolysis. However, for the secondary outcome of increasing pregnancy rates, there was no improvement in the ongoing pregnancy rates after in vitro fertilization.

Endometrial polyps: diagnosis and treatment options - a review of literature

INTRODUCTION AND AIM

Endometrial polyps (EPs) are a common gynecologic condition, associated with abnormal uterine bleeding (AUB), infertility, and premalignant and malignant conditions. Technologies for diagnosis and treatment of EPs are constantly evolving. We aim to provide an updated review on diagnosis and management options for patients with EPs.

MATERIAL AND METHODS

We conducted an electronic search in databases including MEDLINE, PubMed, Cochrane Central Register and others. We included 68 publications regarding EPs, their clinical burden, diagnostic modalities, treatment options and new technologies.

RESULTS

Transvaginal ultrasound (TVS) is the common modality for EP detection and color doppler increases its diagnostic accuracy. Dilation and curettage (D&C) should be avoided for diagnosis and treatment of EPs. Hysteroscopy shows high diagnostic value in EPs and allows for both histological diagnosis and effective treatment. Office hysteroscopy and see and treat hysteroscopy without anesthesia is feasible and safe for EP diagnosis and treatment, gaining more trained surgeons globally. Effective and safe technological tools for EP resection include Laser, resectoscopes, morcellators, MyoSure, Truclear and scissors\graspers.

CONCLUSIONS

EPs are safely and effectively diagnosed and treated with the hysteroscopic tools reviewed in this article. More research is needed to define the best treatment modality.

Removal of uterine polyps: clinical management and surgical approach

Endometrial polyps have a reported prevalence from 7.8% up to 30% and are one of the most cost-consuming gynecological conditions for our specialty. There are strong practitioner beliefs that surgical removal of endometrial polyps is highly beneficial, particularly for those with abnormal uterine bleeding and infertility. Additionally, polypectomy is indicated to reduce the risk of malignancy. Transvaginal ultrasound is the first-line diagnostic option for detection of endometrial polyps, while sonohysterography has similar accuracy as hysteroscopy in the diagnostic confirmation. Blind dilatation and curettage is not recommended for polyp removal; rather, hysteroscopy in the operating room and office setting using small-diameter hysteroscopic equipment is the standard approach. This can be performed without anesthesia in most women. While hysteroscopy is an effective method for polypectomy with a low complication rate, it is unknown whether this is truly beneficial for reproductive-age women with infertility and prior assisted reproduction therapy. The risk of malignancy in women with postmenopausal bleeding justifies the necessity of polypectomy with histologic tissue examination. In asymptomatic women, the risk of malignancy is low, and there are no known benefits of polyp removal in the prevention of malignant transformation. Cost-effective studies remain to be done to provide us with the optimal approach to endometrial polyps including the management of asymptomatic and/or infertile women, ideal location including office-based or the operating room setting, complication prevention including intrauterine adhesions, and recurrence issues.

Noninvasive assessment of endometrial fibrosis in patients with intravoxel incoherent motion MR imaging

Recently, few noninvasive methods have been reported to evaluate endometrial fibrosis. Our study was to investigate the feasibility of intravoxel incoherent motion (IVIM) MR imaging in the detection of endometrial fibrosis in patients with intrauterine injury. 30 patients with hysteroscopy-confirmed endometrial fibrosis and 28 healthy women were enrolled to undergo MR examination including the IVIM sequence. Endometrial thickness (ET); apparent diffusion coefficient (ADC); and IVIM parameters, including pure diffusion coefficient (D), pseudodiffusion coefficient (D*) and vascular fraction (f) were evaluated. A multivariable model combing ADC, D, and f values using binary logistic regression analysis was built to diagnose endometrial fibrosis. Endometrial fibrosis patients demonstrated lower endometrial ADC, D, f values and ET (all p < 0.05). The multivariable model, ADC, D, f values and ET performed well in diagnosing endometrial fibrosis with AUC of 0.979, 0.965, 0.920, 0.901 and 0.833, respectively. The multivariable model revealed a better diagnostic accuracy than D, f and ET (all p < 0.05). Although ADC achieved a better diagnostic value than ET (z = 2.082, p < 0.05), no difference in AUC was shown among ADC, D, and f (all p > 0.05); between ET and D (p > 0.05); and between ET and f (p > 0.05). The reproducibility of ADC, D, f and D* values in patients with endometrial fibrosis and healthy women were good to excellent (ICC: 0.614-0.951). IVIM parameters exhibit promising potential to serve as imaging biomarkers in the noninvasive assessment of endometrial fibrosis.

Expression and potential role of CXCL5 in the pathogenesis of intrauterine adhesions

Objective

C-X-C motif chemokine ligand 5 (CXCL5), a member of the chemokine family, is associated with remodeling of connective tissues. However, its role in formation of intrauterine adhesions (IUA) remains unclear. We aimed to investigate the expression and mechanism underlying the role of CXCL5 in IUA.

Methods

Expression of CXCL5 in IUA was detected by immunohistochemistry in a rat model of IUA and by real-time PCR and western blotting in patients with IUA. The protein levels of matrix metalloproteinase 9 (MMP9) and transcription factor p65 in human endometrial cells were assessed by western blotting after CXCL5 overexpression.

Results

Protein expression of CXCL5 was significantly decreased in the endometria of IUA rats compared with that of control and sham-operated rats. Real-time PCR and western blotting in patients with IUA showed similar results to those from the rat model. After overexpression, CXCL5 significantly upregulated expression of MMP9 and slightly upregulated expression of p65 in human endometrial cells.

Conclusions

CXCL5 plays an important role in IUA formation after endometrial injury. We propose a molecular mechanism to explain formation of IUA, including downregulation of MMP9 by low CXCL5 expression. These findings provide valuable information for the prevention and targeted therapy of IUA.

Factors affecting the success of fallopian tube recanalization in treatment of tubal obstructive infertility

OBJECTIVE

To examine potential risk factors associated with the success rate following fallopian tube recanalization (FTR) in infertile women with obstruction of the proximal fallopian tube.

METHODS

We retrospectively studied patients who underwent FTR for tubal obstructive infertility between January 2016 and December 2018 at the Third Affiliated Hospital of Guangzhou Medical University. FTR was performed using a catheter and guidewire system to clear tubal obstruction. Predictive factors potentially associated with the success rate were assessed by logistic regression.

RESULTS

A total of 762 patients were included. Multivariable analysis showed that age (odds ratio [OR] = 2.38, 95% confidence interval [CI]: 1.24-4.58), infertility type (OR = 2.82, 95% CI: 1.36-6.21), history of ectopic pregnancy (OR = 7.87, 95% CI: 4.05-15.81), history of abdominal surgery (OR = 4.30, 95% CI: 2.22-8.60), history of artificial abortion curettage (OR = 4.08, 95% CI: 2.12-8.03), and duration of infertility (OR = 2.03, 95% CI: 1.06-3.85) were independently associated with postoperative tubal patency.

CONCLUSIONS

Our findings suggest that risk factors, such as age ≥35 years, secondary infertility, duration of infertility ≥5 years, and histories of ectopic pregnancy, abdominal surgery, and artificial abortion curettage, affect the success rate of FTR. These factors may also predict surgical success in treating tubal obstructive infertility.

Focus on the Primary Prevention of Intrauterine Adhesions: Current Concept and Vision

Intrauterine adhesion (IUA), and its severe form Asherman syndrome (Asherman’s syndrome), is a mysterious disease, often accompanied with severe clinical problems contributing to a significant impairment of reproductive function, such as menstrual disturbance (amenorrhea), infertility or recurrent pregnancy loss. Among these, its correlated infertility may be one of the most challenging problems. Although there are many etiologies for the development of IUA, uterine instrumentation is the main cause of IUA. Additionally, more complicated intrauterine surgeries can be performed by advanced technology, further increasing the risk of IUA. Strategies attempting to minimize the risk and reducing its severity are urgently needed. The current review will expand the level of our knowledge required to face the troublesome disease of IUA. It is separated into six sections, addressing the introduction of the normal cyclic endometrial repairing process and its abruption causing the formation of IUA; the etiology and prevalence of IUA; the diagnosis of IUA; the classification of IUA; the pathophysiology of IUA; and the primary prevention of IUA, including (1) delicate surgical techniques, such as the use of surgical instruments, energy systems, and pre-hysteroscopic management, (2) barrier methods, such as gels, intrauterine devices, intrauterine balloons, as well as membrane structures containing hyaluronate–carboxymethylcellulose or polyethylene oxide–sodium carboxymethylcellulose as anti-adhesive barrier.