An Update on the Progress of Endometrial Receptivity in Women with Polycystic Ovary Syndrome

The impact of long-acting Gonadotropin-releasing hormone agonist pretreatment on the clinical pregnancy outcomes of hormone replacement therapy-frozen embryo transfer in recurrent implantation failure patients with and without polycystic ovary syndrome: a retrospective clinical study

BACKGROUND

Several studies have demonstrated that pre-treatment with long-acting Gonadotropin-Releasing Hormone agonists (GnRHa) can significantly enhance the clinical pregnancy rate among recurrent implantation failure (RIF) patients. Investigations have also suggested that GnRHa pre-treatment could ameliorate the clinical pregnancy and live birth rates in polycystic ovary syndrome (PCOS) patients. But there is a dearth of research on whether long-acting GnRHa pre-treatment yields superior clinical outcomes for RIF patients with PCOS.

METHODS

The retrospective study enrolled 1602 patients under the age of 40 meeting the criteria for RIF at the Reproductive Medicine Center of Nanjing Drum Tower Hospital, who underwent frozen-thawed embryo transfer (FET) between January 2017 and December 2021. All cycles were categorized into hormone replacement therapy (HRT) Group (n = 1283) and GnRHa-HRT Group (n = 319), contingent on the usage of long-acting GnRHa pretreatment. Primary outcomes investigated in this study was clinical pregnancy rate, while live birth rate and early miscarriage rate were deemed as secondary outcomes. Univariate analysis and a multivariate logistic regression model were employed to assess the impact of GnRHa pretreatment on the clinical pregnancy rate in RIF patients. The influence of long-acting GnRHa pretreatment on clinical pregnancy outcomes was re-examined in PCOS and non-PCOS subgroups. Additionally, an interaction analysis was performed to evaluate the effect of PCOS on the relationship between long-acting GnRHa pretreatment and the clinical pregnancy rate.

RESULTS

Multiple regression analysis showed that long-acting GnRHa pretreatment had a positive impact on the clinical pregnancy rate (aOR = 1.51, 95%CI: 1.15-1.99, P = 0.003). We divided the RIF population into two subgroups, for PCOS patients, although the clinical pregnancy rate was higher in women who received GnRHa pretreatment compared to those who did not, it was not statistically significant (aOR = 1.51, 95%CI: 0.81-2.82, P = 0.195). Interaction analysis suggested that for PCOS patients, there was no significant difference in the clinical pregnancy rate between women who received GnRHa pretreatment and those who did not (P interaction = 0.818), indicating that the effect of GnRHa pretreatment on the clinical pregnancy rate was not influenced by PCOS.

CONCLUSIONS

Our study demonstrates that long-acting GnRHa pretreatment can enhance clinical pregnancy outcomes in patients with RIF. Among RIF patients without PCOS, the clinical pregnancy rate exhibited a significant increase following GnRHa pretreatment compared to the control group. However, in RIF patients with concurrent PCOS, there was no significant elevation in the clinical pregnancy rate post-GnRHa pretreatment. Therefore, GnRHa pretreatment is effective in improving pregnancy outcomes for RIF patients. However, whether GnRHa pretreatment is suitable for RIF patients with PCOS requires more cautious clinical discussion.

Dysregulation of Leukaemia Inhibitory Factor (LIF) Signalling Pathway by Supraphysiological Dose of Testosterone in Female Sprague Dawley Rats During Development of Endometrial Receptivity

OBJECTIVE

This study investigated the effects of a supraphysiological dose of testosterone on uterine morphology and the regulation of the leukaemia inhibitory factor (LIF) signalling pathway during endometrial receptivity.

METHODS

In this study, 30 adult female Sprague-Dawley rats were divided into treatment and control groups. The treatment groups received subcutaneous injections of 1 mg/kg/day of testosterone from gestational day 1 to day 3, either testosterone alone or in combination with inhibitors (anastrozole, finasteride, or both). A control group of six untreated rats was maintained for comparison. Rats were euthanised on the evening of gestational day 4 to examine uterine morphological changes, gene expression and the distribution of proteins associated with the LIF signalling pathway (LIF, LIFR, JAK1 and STAT3) and MUC1 by quantitative polymerase chain reaction (qPCR) and immunohistochemistry (IHC), respectively.

RESULTS

The results of this study showed that the thickness of the endometrium and myometrium, as well as the number of glands, markedly decreased in all testosterone-treated rats. In addition, the mRNA levels of LIF, LIFR, JAK1 and STAT3 were significantly downregulated in response to supraphysiological testosterone treatment, while the mRNA of MUC1 was significantly upregulated. The IHC results were consistent with the mRNA data and confirmed the changes in protein distribution in all treatment groups.

CONCLUSIONS

A supraphysiological dose of testosterone may impair endometrial receptivity through dysregulation of the LIF signalling pathway, potentially affecting fertility.

Metabolism-related proteins as biomarkers for predicting prognosis in polycystic ovary syndrome

OBJECTIVE

The study aimed to explore the role of metabolism-related proteins and their correlation with clinical data in predicting the prognosis of polycystic ovary syndrome (PCOS).

METHODS

This research involves a secondary analysis of proteomic data derived from endometrial samples collected from our study group, which includes 33 PCOS patients and 7 control subjects. A comprehensive identification and analysis of 4425 proteins were conducted to screened differentially expressed proteins (DEPs). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were subsequently performed on the DEPs. To identify independent prognostic metabolism-related proteins, univariate Cox regression and LASSO regression were applied. The expression levels of these proteins were then used to develop a prognostic model, with their predictive accuracy evaluated through receiver operating characteristic (ROC) curves, decision curve analysis (DCA), and calibration curves. Furthermore, we also investigate the correlation between clinical data and prognostic proteins.

RESULTS

The study identified 285 DEPs between the PCOS and control groups. GO enrichment analysis revealed significant involvement in metabolic processes, while KEGG pathway analysis highlighted pathways such as glycolysis/gluconeogenesis and glucagon signaling. Ten key metabolism-related proteins (ACSL5, ANPEP, CYB5R3, ENOPH1, GLS, GLUD1, LDHB, PLCD1, PYCR2, and PYCR3) were identified as significant predictors of PCOS prognosis. Patients were separated into high and low-risk groups according to the risk score. The ROC curves for predicting outcomes at 6, 28, and 37 weeks demonstrated excellent predictive performance, with AUC values of 0.98, 1.0, and 1.0, respectively. The nomogram constructed from these proteins provided a reliable tool for predicting pregnancy outcomes. DCA indicated a net benefit of the model across various risk thresholds, and the calibration curve confirmed the model's accuracy. Additionally, we also found BMI exhibited a significant negative correlation with the expression of GLS (r =-0.44, p = 0.01) and CHO showed a significant positive correlation with the expression of LDHB (r = 0.35, p = 0.04).

CONCLUSION

The identified metabolism-related proteins provide valuable insights into the prognosis of PCOS. The protein based prognostic model offers a robust and reliable tool for risk stratification and personalized management of PCOS patients.

Utilizing follicular fluid on endometrial stromal cells enhances decidualization by induced inflammation

BACKGROUND

Polycystic ovary syndrome (PCOS) is a disease associated with inflammation and the follicular fluid of this patient contains proinflammatory cytokines. Abdominal obesity (AO) is also linked to increased levels of proinflammatory cytokines. This study investigated the induction of inflammation and decidualization of in vitro cultured endometrial stromal cells (ESCs) obtained from women with a normal uterus using the follicular fluid of PCOS and non-PCOS patients with or without abdominal obesity.

METHODS AND RESULTS

Forty patients under 35 years old, referred to the Royan Institute, were divided into four groups: PCOS with AO, PCOS without AO, non-PCOS with AO, and non-PCOS without AO. Follicular fluid samples were added to the culture medium of ESCs for each group. The rate of decidualization was measured by examining decidual markers. The study also investigated morphological changes in uterine endometrial cells, cell migration rates, and gene expression across all groups. We found that the non-PCOS group without AO had the highest decidualization potential and the highest expression of decidualization markers (P ≤ 0.05). Groups with an inflammatory phenotype of PCOS or abdominal obesity showed the highest expression of decidual pathway markers. The expression levels of inflammatory and proliferative markers in the PCOS group with AO were significantly higher than in the other groups (P ≤ 0.05).

CONCLUSIONS

The inflammatory profile present in the follicular fluid may trigger the decidualization process. Consequently, in the future, follicular fluid could be utilized as a natural supplement with human cells to promote decidualization and enhance endometrial receptivity in assisted reproductive technology.

Yishen Huatan Huoxue decoction and quercetin ameliorate decidualization dysfunction in polycystic ovary syndrome: A comprehensive investigation combining clinical trial and experimental studies

Polycystic ovary syndrome (PCOS) is a common gynecological endocrine disorder characterized by a complex pathogenesis and limited treatment options. Yishen Huatan and Huoxue decoction (YHHD), as a traditional Chinese Medicine formula, has shown effectiveness in treating PCOS. However, the specific mechanisms by which YHHD exerts its therapeutic effects remain unclear. In this study, we performed to investigate the therapeutic effects of YHHD and quercetin on dehydroepiandrosterone-induced PCOS mice, and examine the effect of quercetin on the decidualization of T-HESCs under hyperinsulinemic conditions. The results showed that YHHD could reduce early miscarriage rates in PCOS patients and significantly improved glucose metabolism disorders, sex hormone levels, and the estrous cycles in PCOS mice. Quercetin could alleviate effect of high insulin levels and restore the low expression of insulin receptor substrate1/2 (IRS1/2) and glucose transporte 4 (GLUT4) in T-HESCs, demonstrating its potential to mitigate hyperinsulin-induced decidualization dysfunction via the GLUT4 signaling pathway mediated by IRS1/2. This study provides valuable molecular insights of YHHD and highlight the therapeutic potential of quercetin in treating decidualization dysfunction in PCOS.

Polycystic ovary syndrome and adverse pregnancy outcomes: potential role of decidual function

Polycystic ovary syndrome (PCOS) is a common endocrine disorder affecting fertility and mental health among women of reproductive age. In addition to anovulation and hyperandrogenism, patients also experience metabolic issues, such as insulin resistance, obesity, and dyslipidemia, as well as chronic low-grade inflammation throughout the body. Recent studies have shown that even with assisted reproductive technology to treat anovulatory issues, patients with PCOS still have higher rates of adverse pregnancy outcomes and abortion compared to normal pregnancies. These findings suggest that PCOS may impair the endometrium and disrupt the onset and maintenance of healthy pregnancies. Decidualization is a crucial step in the process of healthy pregnancy, during which endometrial stromal cells (ESCs) differentiate into secretory decidual stromal cells (DSCs) regulated by hormones and local metabolism. This article comprehensively reviews the pathological processes of PCOS and the mechanisms involved in its impaired decidualization. In addition, we explore how PCOS increases the incidence of adverse pregnancy outcomes (APO). By gaining a better understanding of the adverse effects of PCOS on pregnancy and its specific mechanisms, we hope to provide a theoretical basis for reducing APO and improving the live birth rate among women with PCOS.

Assisted Reproductive Technology in the Presence of Polycystic Ovary Syndrome: Current Evidence and Knowledge Gaps

OBJECTIVE

In this narrative review, we discuss the current evidence as well as the knowledge gaps concerning assisted reproductive technology (ART) indications, protocols, and results in the presence of polycystic ovary syndrome (PCOS).

METHODS

An electronic literature search was performed for English-language publications in the last decade in databases such as PubMed, Medline, the Web of Sciences, Embase, and Scopus.

RESULTS

We found evidence that ovarian steroidogenesis and folliculogenesis are deeply altered by PCOS; however, the oocyte quality and pregnancy rates after ART are not affected. Patients with PCOS are more sensitive to the action of exogenous gonadotropins and more likely to develop ovarian hyperstimulation syndrome. This risk can be mitigated by the adoption of the gonadotropin-releasing hormone antagonist protocols for pituitary blockade and ovarian stimulation, along with frozen embryo transfer, without compromising the odds of achieving a live birth. Pregnancy complications, such as miscarriage, gestational diabetes, preeclampsia, and very preterm birth, are more frequent in the presence of PCOS, requiring more intense prenatal care. It remains uncertain whether weight reduction or insulin sensitizers used before ART are beneficial for the treatment outcomes.

CONCLUSION

Although PCOS is not a drawback for ART treatments, the patients need special care to avoid complications. More in-depth studies are needed to uncover the mechanisms of follicular growth, gamete maturation, and endometrial differentiation during ART procedures in the presence of PCOS.

Progress of the application clinical prediction model in polycystic ovary syndrome

Clinical prediction models play an important role in the field of medicine. These can help predict the probability of an individual suffering from disease, complications, and treatment outcomes by applying specific methodologies. Polycystic ovary syndrome (PCOS) is a common disease with a high incidence rate, huge heterogeneity, short- and long-term complications, and complex treatments. In this systematic review study, we reviewed the progress of clinical prediction models in PCOS patients, including diagnosis and prediction models for PCOS complications and treatment outcomes. We aimed to provide ideas for medical researchers and clues for the management of PCOS. In the future, models with poor accuracy can be greatly improved by adding well-known parameters and validations, which will further expand our understanding of PCOS in terms of precision medicine. By developing a series of predictive models, we can make the definition of PCOS more accurate, which can improve the diagnosis of PCOS and reduce the likelihood of false positives and false negatives. It will also help discover complications earlier and treatment outcomes being known earlier, which can result in better outcomes for women with PCOS.

Mechanism of human chorionic gonadotropin in endometrial receptivity via the miR-126-3p/PI3K/Akt/eNOS axis

Human chorionic gonadotropin (hCG) might affect endometrial receptivity, exerting integral roles in embryo implantation. This study explored the action of hCG in endometrial receptivity via the miR-126-3p/PIK3R2/PI3K/Akt/eNOS axis. The embryo implantation dysfunction (EID) mouse models were established by administrating mifepristone and human endometrial epithelial cells (EECs) were used for in vivo experiments, both followed by hCG treatment. Expression level of CD105 and protein levels of cadherin CD144 and CD146 in mice were determined by immunohistochemistry and Western blot. The levels of miR-126-3p and PIK3R2 mRNA and PIK3R2, p-PI3K p85 α, PI3K p110 α, p-Akt, Akt, p-eNOS, and eNOS protein levels were measured. Cell proliferation was evaluated by CCK-8 and EdU assays. The binding sites of miR-126-3p and PIK3R2 were predicted and verified. hCG-treated EECs were further transfected with miR-126-inhibitor for functional rescue experiments. hCG ameliorated endometrial receptivity in EID mice. Moreover, hCG promoted miR-126-3p and suppressed PIK3R2 in EID mice and EECs. miR-126-3p targeted PIK3R2. EEC proliferation was enhanced after hCG treatment but inhibited by miR-126-3p downregulation. Both in vivo and in vitro experiments validated that hCG activated the PI3K/Akt/eNOS pathway through the miR-126-3p/PIK3R2 axis. Collectively, hCG improves endometrial receptivity by activating the PI3K/Akt/eNOS pathway via regulating miR-126-3p/PIK3R2.

A Preliminary Study on the Correlation Between Age and Endometrial Receptivity

Background

It is well established that female fertility declines with age, primarily because of loss of ovarian function. However, few studies have clarified the relationship between increasing age and endometrial receptivity. Here, we aimed to study the impact of age on endometrial receptivity, meanwhile, we examined the expression of endometrial mesenchymal stem cell (eMSC) surface markers (CD146 and PDGF-Rβ), essential for endometrial development and re-growth, in different age groups.

Methods

Participants were enrolled in this study between October 2020 and July 2021. All 31 patients were divided into three age groups; early (30-39 years old, n=10), intermediate (40-49 years old, n=12) and advanced (≥50 years old, n=9). We assessed localization and expression of CD146 and PDGF-Rβ by immunofluorescence and further analyzed selected endometrial receptivity markers (Homeobox A10 HOXA10, leukemia inhibitory factor LIF and osteopontin) and steroid hormone receptors by immunohistochemistry.

Results

There were no significant differences in expression of HOXA10 and OPN (p>0.05) among the three groups. However, we found a significant difference in LIF expression between the early and advanced age groups, with higher expression noted in the latter group (p=0.02). Similarly, estrogen receptor (ER) and progesterone receptor (PR) expression were significantly increased (p=0.01 and p=0.01, respectively) in the advanced age group compared with the early age group. There were no significant difference in CD146 and PDGF-Rβ expression among the three groups (p>0.05).

Conclusion

These results suggest that the age of the patient does not influence their endometrial receptivity. So, this study serves to increase our understanding of the impact of age and eMSCs on endometrial receptivity and expands the etiology of age-related infertility.

Commercially Available Molecular Approaches to Evaluate Endometrial Receptivity: A Systematic Review and Critical Analysis of the Literature

Despite the advances in the field of reproductive medicine, implantation failure represents a challenging condition affecting 10-30% of patients subjected to in vitro fertilization (IVF). Research has focused on the identification of molecules playing crucial roles in endometrial receptivity, with the aim of designing predictive tools for efficient detection of the implantation window. To that end, novel molecular genomic and transcriptomic approaches have been introduced as promising tools to enable personalized approaches with the aim of optimizing embryo transfer dating. However, the clinical value of these approaches remains unclear. The aim of this study is to provide a systematic review and critical analysis of the existing evidence regarding the employment of commercially available novel approaches to evaluate endometrial receptivity. An Embase and PubMed/Medline search was performed on 1 February 2022. From the 475 articles yielded, only 27 were included and analyzed. The considerable heterogeneity of the included articles indicates the uniqueness of the implantation window, showcasing that the optimal time for embryo transfer varies significantly between women. Moreover, this study provides information regarding the technical aspects of these advanced molecular tools, as well as an analysis of novel possible biomarkers for endometrial receptivity, providing a basis for future research in the field.

Association between Pre-Pregnancy Overweightness/Obesity and Pregnancy Outcomes in Women with Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis

Polycystic ovary syndrome (PCOS) is a common metabolic problem in women of reproductive age. Evidence suggests pregnant women with PCOS may have a higher risk of the development of adverse pregnancy outcomes; however, the relationship between pre-pregnancy overweight/obesity and pregnancy outcomes in women with PCOS remains uncertain. We try to clarify the relationship between pre-pregnancy overweight/obesity and subsequent pregnancy outcomes. Therefore, we conducted this systematic review and meta-analysis. We used the databases obtained from the PubMed, Embase, Web of Science, and Cochrane databases, plus hand-searching, to examine the association between pre-pregnancy overweightness/obesity and pregnancy outcomes in women with PCOS from inception to 4 February 2022. A total of 16 cohort studies, including 14 retrospective cohort studies (n = 10,496) and another two prospective cohort studies (n = 818), contributed to a total of 11,314 women for analysis. The meta-analysis showed significantly increased odds of miscarriage rate in PCOS women whose pre-pregnancy body mass index (BMI) is above overweight (OR 1.71 [95% CI 1.38–2.11]) or obese (OR 2.00 [95% CI 1.38–2.90]) under a random effect model. The tests for subgroup difference indicated the increased risk was consistent, regardless which body mass index cut-off for overweight (24 or 25 kg/m²) or obesity (28 and 30 kg/m²) was used. With the same strategies, we found that pregnant women in the control group significantly increased live birth rate compared with those pregnant women with PCOS as well as pre-pregnancy overweight/obesity (OR 0.79 [95% CI 0.71–0.89], OR 0.78 [95% CI 0.67–0.91]). By contrast, we did not find any association between PCOS women with pre-pregnancy overweight/obesity and preterm birth. Based on the aforementioned findings, the main critical factor contributing to a worse pregnancy outcome may be an early fetal loss in these PCOS women with pre-pregnancy overweight/obesity. Since PCOS women with pre-pregnancy overweightness/obesity were associated with worse pregnancy outcomes, we supposed that weight reduction before attempting pregnancy in the PCOS women with pre-pregnancy overweightness/obesity may improve the subsequent pregnancy outcomes.

The Dose-Related Efficacy of Acupuncture on Endometrial Receptivity in Infertile Women: A Systematic Review and Meta-Analysis

Background

Progress has been achieved by using acupuncture widely for poor endometrial receptivity (PER). However, different acupuncture dosages may lead to controversy over efficacy.

Objective

To evaluate the evidence-based conclusions of dose-related acupuncture on infertile women with PER.

Method

References were retrieved from nine databases from inception to 26 February 2022. This meta-analysis included randomized controlled trials (RCTs) that investigated the dose-related efficacy of acupuncture for PER with outcomes of endometrium receptivity (ER) parameters by transvaginal sonography (TVS) and the subsequent pregnancy outcomes in three acupuncture-dose groups: the high-dosage group (three menstrual cycles), the moderate-dosage group (one menstrual cycle), and the low-dosage group (two or four days). Since there remained sufficient heterogeneity among the three subsets, we prespecified seven subgroup variables (four clinical and three methodological) to investigate the heterogeneities.

Results

A total of 14 RCTs (1,564 women) of moderate or low overall quality were included. The results were different when the dosage of acupuncture was restricted. For the moderate or high-dosage group, CPR and part of ER parameters were improved in the acupuncture group (i.e., CPR: OR = 2.00, 95% CI [1.24, 3.22], p = 0.004, I ² = 0% in one menstrual cycle; OR = 2.49, 95%CI [1.67, 3.72], p < 0.05, I ² = 0% in three menstrual cycles). However, for the low-dosage group, no statistical difference was observed in CPR (OR = 0.07, 95% CI [-0.10, 0.23], p = 0.44, I ² = 82%) and a part of the ER parameters. In subgroup analysis, four subgroup variables (the routine treatment, risk of performance bias, duration of acupuncture treatment, and the age of participants) could explain some of the heterogeneities across all trials.

Conclusion

The finding indicated that the trend of relatively more acupuncture dosage showed better effects for poor endometrial receptivity among PER women. It remains a potential heterogeneity in our studies. Further high-quality trials with a homogeneity trial design need to be conducted.

Transcriptomic Analysis Reveals Endometrial Dynamics in Normoweight and Overweight/Obese Polycystic Ovary Syndrome Women

The aim of this work was to identify the transcriptomic characteristics of the endometrium in normoweight and overweight/obese polycystic ovary syndrome (PCOS) potentially underlying the pathogenesis. This study included 38 patients undergoing in vitro fertilization: 22 women with PCOS and 16 matched controls. Each of the groups was subdivided into normoweight (body mass index (BMI) < 25 kg/m²) and overweight/obese (BMI ≥25 kg/m²) subgroups. Endometrium samples were collected in the secretory phase from controls or in a modeled secretory phase using daily administration of progesterone from women with PCOS before in vitro fertilization treatment. Transcriptome profiles were assessed by high-throughput RNA sequencing to investigate distinct endometrial gene expression patterns in PCOS. Bioinformatics analyses revealed that the endometrium from PCOS expresses significantly different transcripts encoding endometrial receptivity, inflammatory response, angiogenesis, and energy metabolism. Additionally, our study demonstrated that the differentially expressed genes between normoweight and overweight/obese PCOS are involved in fatty acid metabolism, endometrial decidualization, and immune response. For the first time, we have described the transcriptome characteristics of normoweight and overweight/obese PCOS endometria. Our results indicate different endometrial gene expressions between different subtypes of PCOS and non-PCOS women, which might affect endometrial functions in PCOS patients.

Research Progress on the Mechanism Between Polycystic Ovary Syndrome and Abnormal Endometrium

As a highly dynamic tissue, the endometrium is periodically shed in response to the secretion of estrogen and progesterone. After menarche, the endometrium of healthy women proliferates and differentiates under the action of steroid hormones (e.g., 17β-estradiol and progesterone) that are secreted by the ovaries to provide appropriate conditions for embryo implantation. Polycystic ovary syndrome (PCOS), a prevalent endocrine and metabolic disorder in reproductive-aged women, is usually associated with multiple cysts within the ovaries and excess levels of androgen and is characterized by hirsutism, acne, menstrual irregularity, infertility, and increased risk of insulin resistance. Multiple factors, such as anovulation, endocrine-metabolic abnormalities, and inflammation, can disrupt the endometrium in PCOS patients and can lead to endometrial hyperplasia, pregnancy complications, or even cancer. Despite many recent studies, the relationship between PCOS and abnormal endometrial function is still not fully understood. In this review, we investigate the correlation of PCOS patient endometrium with anovulation, hyperandrogenemia, insulin resistance, progesterone resistance, and inflammatory cytokines, aiming to provide a theoretical basis for the treatment of disorders caused by endometrial dysfunction in PCOS patients.