Recurrent Implantation Failure Group Research Articles

Paternal thrombophilia and recurrent implantation failure: an exploratory case-control study.

Many pieces of literature have reported that inherited and acquired thrombophilia might be a risk factor for recurrent implantation failure (RIF), however, most studies have only focused on RIF patients and not their male partners. We studied the possible association of paternal thrombophilia with RIF risk. Forty-two male partners aged 20-45 suffered from RIF compared with 42 males from couples with at least one successful pregnancy. All participants were investigated for thrombophilia markers. The prevalence of coagulation Factor V activity was significantly higher in the case group (42.9%) than in the control group (16.7%) (p=0.008) (OR=3.75; 95% CI, 1.38, 10.12). The prevalence of protein C and protein S deficiencies in RIF patients were 4.8% and 2.4%, respectively, and 0% in the controls. The prevalence of antithrombin III (ATIII) deficiency was significantly higher in the case group (19%) than in the control group (2.4%) (p=0.01). None of MTHFR C677T and MTHFR A1298C were statistically significant between the two groups. Combined thrombophilia was 45.2% in the men of the RIF group when compared with the control, 14.2% (p=0.001) (OR = 4.95; 95% CI, 1.75-13.86). Paternal thrombophilia may be related to recurrent implantation failure, so evaluation of this factor in RIF patients could be used to identify relevant risk groups and may help in the proper management of these cases to enhance the chance of implantation.

APOE-E4 allele as a potential marker for implantation failure: A comparison between fertile women, ART success and RIF patients.

Apolipoprotein E (APOE) is the most important precursor for the production of steroid hormones and is also involved in regulating the function of steroid hormones, hence playing a significant role in reproductive processes. So, APOE gene expression may be correlated with the implantation process. This study tries to make a better clarification of the correlation between APOE gene polymorphisms and recurrent implantation failure (RIF), where we compared the frequency of APOE polymorphisms in RIF patients, assisted reproductive treatment (ART) success cases and fertile women. In all, 100 women with successful ART who got pregnant (fetal heart rate positive) in their first or second cycle of invitro fertilization or intracytoplasmic sperm injection, 100 infertile RIF cases, and 100 normal fertile control cases with at least one live birth were included in present study. Following DNA extraction, genotypes were determined through polymerase chain reaction-restriction fragment length polymorphism method using HhaI restriction enzyme. Finally, statistical analysis was performed by chi-squared (χ2) test in SPSS software (P < 0.05). The RIF group showed significantly higher frequency for E3/E4 genotype (29%) compared with the other two control groups (fertile = 15%, ART success [ART+] = 13%) (P = 0.007). There was also a significantly higher frequency of the E4 allele in the RIF group (14.5%) compared with both of the control groups (fertile = 7.5%, ART+ = 6.5%) (P = 0.018). APOE4 is correlated with recurrent failure in the process of embryo implantation and, accordingly, it may potentially be considered a possible risk factor to the implantation process. The presence of E4 can be proposed as a predictive indicator in determining the results of assisted reproductive techniques.

Macrophage polarization disorder in the endometrial immune microenvironment may contribute to recurrent implantation failure

Objective: To investigate the role and mechanisms by which macrophages (MΦ) contribute to the immune environment of the endometrium in cases of recurrent implantation failure (RIF). Methods: Endometrial transcriptome data from women with and without RIF (control group) were collected. The CIBERSORT software was used to determine the abundance of immune cells within the endometrial tissue based on expression profiles. Weighted gene co-expression network analysis was used to identify crucial regulatory genes and pathways. Results: Application of CIBERSORT confirmed significant infiltration of macrophages in the RIF group. SOX6, TTC21A, KLHL31, NFIA, TNNT1, TPM1, CPVL, FUS, PEX5, and SLC43A3 were all closely correlated with M2 and M0 macrophages. Metascape and DisNor analyses revealed that these genes contribute to the regulation of macrophage polarization via the Wnt signaling pathway. Conclusion: This study identified dysregulation of macrophage polarization within the immune microenvironment of the endometrium in patients with RIF. A comprehensive analysis was conducted to investigate the potential mechanisms underlying this disorder. Dysregulation of macrophage polarization in the endometrium of patients with RIF is strongly associated with the Wnt signaling pathway.

Evaluation of endometrial receptivity in recurrent pregnancy loss and recurrent implantation failure.

The cause of implantation defects in patients with recurrent implantation failure (RIF) and recurrent pregnancy loss (RPL) has not been clearly established. We aimed to evaluate the immunohistochemical changes in HOXA-11, β1 integrin, focal adhesion kinase (FAK), cluster of differentiation 44 (CD44), and extracellular matrix protein 1 (ECM1) molecules during the receptive endometrial period in patients with RIF and RPL. This study was retrospectively conducted at a university hospital. After the exclusion of cases with pathology that may cause a change in the level of receptors in the endometrium, biopsies performed during the receptive period were selected, and the patients were categorized into RPL (n=15), RIF (n=16), control (n=16) groups. All preparations were immunohistochemically stained for HOXA-11, β1 integrin, FAK, CD44, and ECM1. HOXA-11 and β1 Integrin expression changes were similar between the RIF and control groups. However, FAK expression was significantly increased in the RIF group (p<0.01). Additionally, ECM1 and CD44 expressions were significantly decreased in the RIF group compared with the control group (p<0.01). There was no significant difference in the endometrial staining of HOXA-11, FAK, and ECM1 in patients with a history of RPL. However, β1 Integrin and CD44 levels were significantly decreased in the RPL group compared with the control group (p<0.05). Implantation is a complex process, and altered adhesion mechanisms involved in endometrial receptivity may be related to defective implantation in patients with RIF and RPL. Among the adhesion molecules, the expression of CD44, β1 integrin, FAK, and ECM1 molecules varies in inappropriate implantation compared with the normal population.

Centromeric AA motif in KIR as an optimal surrogate marker for precision definition of alloimmune reproductive failure

Throughout pregnancy, the decidua is predominantly populated by NK lymphocytes expressing Killer immunoglobulin-like receptors (KIR) that recognize human leukocyte antigen-C (HLA-C) ligands from trophoblast cells. This study aims to investigate the association of KIR-HLA-C phenotypes in couples facing infertility, particularly recurrent pregnancy loss (RPL) and recurrent implantation failure (RIF), in comparison to a reference population and fertile controls. This observational, non-interventional retrospective case–control study included patients consecutively referred to our Reproductive Immunology Unit from 2015 to 2019. We analyzed the frequencies of KIR and HLA-C genes. As control groups, we analyzed a reference Spanish population for KIR analysis and 29 fertile controls and their male partners for KIR and HLA-C combinations. We studied 397 consecutively referred women with infertility and their male partners. Among women with unexplained RPL (133 women) and RIF (176 women), the centromeric (cen)AA KIR genotype was significantly more prevalent compared to the reference Spanish population (p = 0.001 and 0.02, respectively). Furthermore, cenAA was associated with a 1.51-fold risk of RPL and a 1.2-fold risk of RIF. Conversely, the presence of BB KIR showed a lower risk of reproductive failure compared to non-BB KIR (OR: 0.12, p < 0.001). Women and their partners with HLA-C1C1/C1C1 were significantly less common in the RPL-Group (p < 0.001) and RIF-Group (p = 0.002) compared to the control group. Moreover, the combination of cenAA/C1C1 in women with C1C1 partners was significantly higher in the control group than in the RPL (p = 0.009) and RIF (p = 0.04) groups, associated with a 5-fold increase in successful pregnancy outcomes. In our cohort, the cenAA KIR haplotype proved to be a more accurate biomarker than the classic AA KIR haplotype for assessing the risk of RPL and RIF, and might be particularly useful to identify women at increased risk among the heterogeneous KIR AB or Bx population. The classification of centromeric KIR haplotypes outperforms classical KIR haplotypes, making it a better indicator of potential maternal–fetal KIR-HLA-C mismatch in patients.

#271 : Association Between Monoaromatic Hydro Exposure and Vaginal Microbiota Disorder in Recurrent Implantation Failure

Background and aims: MACHs are present in common everyday products and are defined as endocrine disrupting chemicals (EDCs) that can negatively impact human health by interfering with the endocrine system. There is a lack of human studies on the association between MACHs and the microbiota in the female reproductive tract. In this study, we recruited a prospective randomized controlled cohort to investigate potential correlations between MACHs exposure and the vaginal microbiota, as well as their potential impacts on embryo implantation. Methods: This study recruited a randomized controlled cohort prospectively to investigate the correlation between MACHs exposure and the vaginal microbiota, as well as their potential impact on embryo implantation. The types and concentrations of MACHs exposure were detected using LC-MS, while the vaginal microbiota was characterized by metagenomics. Results: The findings reveal that exposure to MEHP, Methyl N-methylanthranilate, and Benzene was associated with a disruption of the microbial community structure in the recurrent implantation failure (RIF). The RIF group exhibited an instable vaginal microbial community structure, with reduced abundance of Lactobacillus spp. and increased abundance of potentially pathogenic bacteria, such as Streptococcus anginosus, Peptoniphilus asaccharolyticus. The atypical composition of the vaginal microbiota was associated with unfavorable pregnancy outcomes. Impairment of sphingolipid metabolism was a crucial factor for abnormal microbiota to trigger unfavorable pregnancy outcomes. Furthermore, exposure to Methyl N-methylanthranilate and MEHP was associated with reduced abundance of Lactobacillus spp. (including L.crispatus and L.jensenii) and reduction of the protective barrier function of the reproductive tract. Conclusions: Multiple MACHs, such as Benzene, Methyl N-methylanthranilate, and MEHP, were associated with changes in the RIF group’s vaginal microbiota. MACHs exposure might cause embryo implantation failure by affecting the vaginal microbial composition.

Establishment of Cut-off Values for Uterine and Peripheral Blood Natural Killer Cells During the Peri-implantation Period in Fertile Controls and Women with Unexplained Recurrent Implantation Failure.

The purpose of the study was to determine the cut-off values for peripheral and uterine natural killer (pNK, uNK) cells in fertile controls and in women with recurrent implantation failure (RIF). In this study, 50 women with RIF and 50 fertile controls were enrolled. Midluteal endometrial biopsy samples from both cases and controls were obtained for CD 56+ cell immunohistochemistry labeling to identify uNK cells. Peripheral venous blood was also taken during the biopsy to detect pNK cells in peripheral blood mononuclear cells using flow cytometry. Cut-off values were obtained from fertile controls. Using a non-parametric Mann-Whitney U-test, the medians of the data sets were compared. The median values for uNK and pNK cell levels in the control group were 7% and 11.6%, respectively. The median value for uNK cells in RIF patients was 9%, which was higher than the one in controls but not statistically significant (p-value of 0.689). The median pNK levels (11.6% vs. 12.4%) were comparable between the RIF group and the controls. Moreover, it was found that 68% of individuals had uNK cell counts below the reference value, while 32% had excessive levels exceeding 7%. Additionally, only 51.4% of the RIF group had increased pNK cells. The pNK cell cut-off values need to be used with caution because there was no difference between fertile controls and RIF women. If immunotherapy is recommended for RIF women, uNK cell testing should be used as the preferred approach.

Association of human leukocyte antigen-G and -F with recurrent miscarriage and implantation failure: A systematic review and meta-analysis.

The immune system plays an essential role in embryonic implantation and pregnancy, but the molecular details remain controversial. In the past four decades, human leukocyte antigen (HLA)-G and -F have garnered significant attention. MEDLINE, EMBASE, Web of Science, and the Cochrane Trials Registry were searched from their inception dates until December 2022. Studies were selected following PRISMA guidelines. Meta-analyses were used to assess the relationship of soluble HLA-G (sHLA-G) and HLA-G 3'-untranslated region polymorphisms with recurrent miscarriage (RM) and recurrent implantation failure (RIF). Narrative synthesis was conducted to determine the association of RM with other single nucleotide polymorphisms (SNPs) and HLA-G protein in tissues and of RIF with HLA-F. Risk-of-bias was assessed using ROBINS-I. Publication bias was assessed using Egger's and Begg's tests. Finally, 42 articles were eligible for inclusion in the systematic review (32 in the meta-analysis; 13 in narrative synthesis). We found a significant association between the 14-bp ins/del HLA-G polymorphism and RM risk, but no definitive association with RIF risk. Women with RM had lower blood concentrations of sHLA-G during pregnancy and non-pregnancy than did controls. For women in the RIF group, no significant difference was found. HLA-G protein and gene expression levels may be closely related to RM. The relevance of HLA-G to RIF is still being determined. A narrative synthesis of current studies has shown that HLA-F is likely associated with RIF.

Decreased CD56+CD16‐CD94+uNK cells in the mid‐luteal phase in women with recurrent implantation failure are associated with IL‐15 deficiency

AbstractProblemWhether the abnormal development of uterine natural killer (uNK) cells contributes to women with recurrent implantation failure (RIF) remains unclear.Method of studyWe characterized the development of uNK cells and peripheral blood NK cells (pbNK) in the mid‐luteal phase in women with RIF (n = 31) and controls (n = 14) by flow cytometry. Endometrial IL‐15 mRNA expression was studied by quantitative reverse transcription‐PCR. The GSE58144 dataset was used to validate the correlation results.ResultsWe found decreased proportions of stage 4 CD56+CD16‐CD94+ uNK cells (median: 9.56% vs. 17.78%, P .014) and increased proportions of stage 6 CD56+CD16+CD57+ uNK cells (median: 1.54% vs. 0.74%, P = .020) in the mid‐luteal endometrium of women with RIF compared to fertile women. We also found that there was no quantitative correlation between uNK cells and the corresponding pbNK cell subpopulations (P &gt; .05). In addition, IL‐15 mRNA levels in the mid‐luteal endometrium were positively correlated with the proportion of CD56+ uNK cells (r = .392, P = .008), especially with stage 4 uNK cell populations (r = .408, P = .005).ConclusionsWe showed that the proportion of stage 4 uNK cells decreased in the RIF group compared to controls, and the decrease in stage 4 uNK cells correlated positively with low IL‐15 mRNA expression. We suggest that the reduced stage 4 uNK cells in women with RIF are associated with IL‐15 deficiency.

Myeloid-derived suppressor cells as a potential biomarker for recurrent pregnancy loss and recurrent implantation failure: Increased levels of MDSCs in recurrent reproductive failure.

Recurrent pregnancy loss (RPL) and recurrent implantation failure (RIF) represent distinct clinical conditions with established definitions, both of which have been linked to an underlying pro-inflammatory state. This study aimed to explore the levels of monocytic-myeloid-derived suppressor cells (M-MDSCs) and regulatory T cells (TReg ) in a cohort of RPL and RIF women and their potential contribution to RPL and RIF. One hundred and eight non-pregnant women were evaluated: 40 RPL, 41 RIF, and 27 fertile healthy controls (HC). A multiparametric flow cytometry approach was utilized to measure and quantify the frequency of M-MDSCs and TReg cells. Cytokine levels in plasma samples were evaluated through a multiplex assay. M-MDSCs levels were significantly higher in RPL and RIF patients compared to HC. M-MDSCs levels were significantly higher in RPL (9.4% [7-11.6]) and RIF (8.1% [5.9-11.6]) patients compared to HC (6% [4.2-7.6]). An optimal cut-off of 6.1% for M-MDSCs disclosed a sensitivity of 75.6% and 89.7% and a specificity of 57.7% and 57.7% in RIF and RPL groups, respectively. A significant negative correlation was observed between M-MDSCs and TReg (p=.002, r=-.51). Our preliminary data allowed us to build a predictive model that may aid as a potential diagnostic tool in the clinic. These findings could provide a better understanding of these pathologies and a better definition of patients that could benefit from personalized treatments to promote pregnancy. Additional exploration and confirmation in distinct study groups are needed to fully assess the diagnostic capabilities of this biomarker.

Association of angiotensin II and receptors in peri-implantation endometrium with microvessel density and pregnancy outcomes of women with recurrent implantation failure after embryo transfer.

Investigate whether local angiotensin II (AngII) and its AngII type 1 and 2 receptors (AT1R, AT2R) in the endometrium are different and correlate with microvessel density in women with reproductive failure and pregnancy outcomes. Endometrium during the window of implantation from 40 women with recurrent miscarriage (RM) and 40 with recurrent implantation failure (RIF) were compared with 27 fertile women. Peri-implantation endometrium from 54 women prior to euploid embryo transfer were collected and compared in women with successful pregnancy and unsuccessful pregnancy. Compared with fertile women, expression of AT2R was significantly lower, while AT1R/AT2R expression ratio was significantly higher in the stroma of the RIF group. Endometrium arteriole MVD was significantly lower and negatively correlated with the AT1R/AT2R expression ratio in the stroma of the RIF group. No significant differences and correlations were found in the RM group. Compared with the pregnancy group, expression of AT1R and AT2R were significantly lower in all compartments, but only AT1R/AT2R ratio was significantly higher in the stroma of the non-pregnancy group. Similarly, endometrium arteriole MVD was also significantly lower and negatively correlated with the AT1R/AT2R ratio in the stroma of the non-pregnancy group. Local renin-angiotensin system is dysregulated in peri-implantation endometrium and associated with abnormal angiogenesis in RIF and poor implantation outcome after embryo transfer.

O-221 Regenerative endometrial PRGF (plasma rich in growth factors) treatment in patients with thin endometrium, recurrent implantation failure, and recurrent miscarriages: a retrospective, self-controlled, cohort study

Abstract Study question What reproductive outcomes are observed in patients submitted to endometrial PRGF therapy due to thin endometrium (ThE), recurrent implantation failure (RIF) and recurrent miscarriages (RM)? Summary answer Following endometrial PRGF treatment, success rates were significantly increased in ThE and RIF patients, whereas in the RM group pregnancy loss rates were not affected. What is known already Adequate development of a functional endometrium is a prerequisite for successful embryo implantation in ART cycles. In contrast, the management of patients with thin endometrial lining or recurrent implantation failure has been an ongoing challenge with none of the proposed surgical, hormonal, and pharmacological interventions achieving satisfactory results. In recent years, the use of plasma rich in growth factors (PRGF) - successfully applied in other medical fields - has become a novel treatment option in reproductive medicine. It was used experimentally both for ovarian follicle activation and to enhance endometrial receptivity although published studies are small with often contradictory results. Study design, size, duration All consecutive patients (n = 107) who underwent endometrial PRGF treatment (n = 150) in a single, private centre between 2016-2022 were included in this retrospective analysis. Patients were recruited into ThE (n = 64), RIF (n = 36) and RM (n = 7) groups, respectively. Live birth / ongoing pregnancy rates per embryo transfer were compared to success rates obtained in previous embryo transfers preceding the endometrial PRGF intervention. External Ethics Committee approval was obtained for a comparative pilot study including above patient groups. Participants/materials, setting, methods PRGF was obtained by processing the patients’ autologous blood sample in an in-house validated open system. Endometrial PRGF interventions were performed using a thawed PRGF sample with a series of intrauterine instillations (43%) or with a combined approach performing hysteroscopic subendometrial infiltration during early follicular phase (57%). Endometrial preparation was conducted using an artificial hormone replacement protocol with high-dose oral estrogens and vaginal progesterone. Most embryo transfers involved the replacement of a single, vitrified-thawed blastocyst. Main results and the role of chance A total of 107 patients underwent 150 endometrial PRGF treatments and 131 subsequent embryo transfers. Altogether 19 (13%) embryo transfers were cancelled, higher in ThE than in the RIF group (16 vs 7.1%). In the ThE group (64 patients, 98 PRGF cycles and 107 controls), positive pregnancy (41 vs 32%, NS), clinical pregnancy (35 vs 22%, p = 0.049) and ongoing pregnancy/live birth rates (24 vs 4.7%, p &amp;lt; 0.0001) per embryo transfer were significantly higher in the endometrial PRGF treatment group compared to previous embryo transfers. In the RIF group (36 patients, 42 PRGF cycles and 101 controls), positive pregnancy (59 vs 20%, p &amp;lt; 0.0001), clinical pregnancy (44 vs 11%, p &amp;lt; 0.0001) and ongoing pregnancy/live birth rates (33 vs 7.9%, p &amp;lt; 0.0001) per embryo transfer were significantly higher in the endometrial PRGF treatment group compared to previous embryo transfers. In the RM group (7 patients, 10 PRGF cycles and 15 controls), positive pregnancy (50 vs 60%), clinical pregnancy (20 vs 27%) and ongoing pregnancy/live birth rates (0 vs 0%) per embryo transfer were not significantly different and no ongoing pregnancies were achieved. So far, 20 singletons and 1 set of twins have been confirmed to be born from the above PRGF cycles (12 pregnancies still ongoing). Limitations, reasons for caution Heterogeneity of clinical severity between included ThE patients could affect observed reproductive outcomes. The self-controlled design of the study might have influenced the comparison between pre-, and post-intervention pregnancy rates, although this also highlights the poor-prognostic nature of included participants. RM patients were too few to evaluate pregnancy loss rates. Wider implications of the findings This preliminary, retrospective study has shown that regenerative therapy using autologous PRGF is a safe, affordable, and efficient treatment option for ThE and RIF patients. Further randomized studies are warranted, although they are hampered by patient selection issues and the lack of applicable efficient treatment options in the non-intervention group. Trial registration number not applicable

The EZH2–PRC2–H3K27me3 axis governs the endometrial cell cycle and differentiation for blastocyst invasion

Infertility occurs in 15% of couples worldwide. Recurrent implantation failure (RIF) is one of the major problems in in vitro fertilization and embryo transfer (IVF–ET) programs, and how to manage patients with RIF to achieve successful pregnancy outcomes remains unresolved. Here, a uterine polycomb repressive complex 2 (PRC2)-regulated gene network was found to control embryo implantation. Our RNA-seq analyses of the human peri-implantation endometrium obtained from patients with RIF and fertile controls revealed that PRC2 components, including its core enzyme enhancer of zeste homolog 2 (EZH2)-catalyzing H3K27 trimethylation (H3K27me3) and their target genes are dysregulated in the RIF group. Although fertility of uterine epithelium-specific knockout mice of Ezh2 (eKO mice) was normal, Ezh2-deleted mice in the uterine epithelium and stroma (uKO mice) exhibited severe subfertility, suggesting that stromal Ezh2 plays a key role in female fertility. The RNA-seq and ChIP-seq analyses revealed that H3K27me3-related dynamic gene silencing is canceled, and the gene expression of cell-cycle regulators is dysregulated in Ezh2-deleted uteri, causing severe epithelial and stromal differentiation defects and failed embryo invasion. Thus, our findings indicate that the EZH2–PRC2–H3K27me3 axis is critical to preparing the endometrium for the blastocyst invasion into the stroma in mice and humans.

Association between endometrial senescent cells and immune cells in women with repeated implantation failure.

The aim of this study was to compare women with recurrent implantation failure (RIF) and control group in terms of the associations between p16-positive senescent cells and certain types of immune cells in human endometrium during the mid-luteal phase METHODS: Immunohistochemical staining was performed in 116 endometrial biopsies taken from 57 women presenting RIF, and control group of 59 women who became pregnant after the first intracytoplasmic sperm injection. Endometrial tissue sections were stained immunohistochemically for p16 (Senescent cells), CD4 (T-helpers), CD8 (T-killers), CD14 (Monocytes), CD68 (Macrophages), CD56 (Natural killers), and CD79α (B-cells). The percentage of positively stained cells for each marker was calculated by HALO image analysis software. The quantity and the relationship between senescent cells and immune cells were assessed and compared between the two groups. The correlation coefficient was highest between senescent cells and CD4+ cells and was lowest between senescent cells and CD14+ cells in RIF women, similarly to the control group. However, most of the observed correlations among senescent and immune cells weaken notably or disappear in the RIF group. When comparing senescent cell-to-immune cell quantitative ratios, only p16+/CD4+ cell ratio was significantly higher in RIF women as compared with patients from the control group. Our study indicates that the quantity of senescent cells in human endometrium during the mid-luteal phase has the strongest association with the amount of T helpers. Moreover, the specificity of this association might have an important impact on the occurrence of RIF.

Opposing impacts of HLA-G haplotypes PROMO-G010104-UTR-3 and PROMO-G010101b/c-UTR-4 on risk of recurrent implantation failure

Research questionThe human leukocyte antigen (HLA) class Ib molecules HLA-F and HLA-G are implicated in pregnancy success, but how do HLA-G and HLA-F genetic polymorphisms impact recurrent implantation failure (RIF)? DesignProspective cohort study at a fertility clinic including a cohort of 84 women experiencing RIF and 35 IVF controls to assess the influence of HLA-G haplotypes and diplotypes and HLA-F single nucleotide polymorphisms (SNP) on RIF. ResultsOver-representation trends for HLA-F SNP genotypes rs1362126, rs2523405 and rs2523393, previously linked with a short time-to-pregnancy, were detected in female control groups compared with RIF patients with no identified pathology linked to infertility. The HLA-G promoter haplotype PROMO-G010101b/c linked with the HLA-G 3’-untranslated region (3’UTR) haplotype UTR-4, which previously has been associated with positive IVF outcome and pregnancy success, was less frequent in the RIF group. For RIF patients carrying the UTR-4 haplotype, the odds ratio (OR) was 0.27 (95% CI 0.12–0.66; P = 0.0044, Pc = 0.026). The HLA-G PROMO-G010104-UTR-3 haplotype was associated with an increased risk of RIF. For RIF patients carrying the UTR-3 haplotype, the OR was 5.86 (95% CI 1.52–26.23; P = 0.0115, Pc = 0.069). ConclusionsThese results show that specific HLA-G haplotypes based on the promoter region and the 3’UTR are either associated with an increased risk of reduced fertility, including the manifestation of RIF, and lower chance of achieving pregnancy, or with a reduced risk of experiencing RIF.

Association between monoaromatic hydrocarbons exposure and vaginal microbiota disorder in recurrent implantation failure

Recurrent implantation failure (RIF) is a significant challenge facing population development, with the impact of monoaromatic hydrocarbons (MACHs) exposure on embryo implantation and reproductive hazards remaining largely unclear. As such, we conducted a prospective randomized controlled cohort study to explore the potential correlations between exposure to MACHs and vaginal microbiota, and their potential adverse effects on embryo implantation. Our findings suggest that exposure to Mono(2-ethylhexyl) phthalate (MEHP), Methyl N-methylanthranilate, and Benzene is closely linked with the disruption of the microbial community in the RIF group. The RIF group thus exhibited a fragile vaginal microbial community structure, with lower lactic acid bacterial abundance, and higher potential pathogenic bacterial abundance, such as Streptococcus anginosus and Peptoniphilus asaccharolyticus. This abnormal vaginal microbiota composition was associated with adverse pregnancy outcomes, with sphingolipid metabolism dysfunction being a key factor in abnormal microbiota leading to such outcomes. Additionally, we found that exposure to Methyl N-methylanthranilate and MEHP was closely associated with decreased abundance of Lactobacillus (including L.crispatus and L.jensenii) and diminished reproductive tract protective barrier function. Our study underscores the significance of acknowledging the impact of MACHs, a ubiquitous everyday exposure, on female fertility.

Identification and validation of immune cells and hub genes alterations in recurrent implantation failure: A GEO data mining study.

Introduction: Recurrent implantation failure (RIF) is a distressing problem in assisted reproductive technology (ART). Immunity plays a vital role in recurrent implantation failure (RIF) occurrence and development, but its underlying mechanism still needs to be fully elucidated. Through bioinformatics analysis, this study aims to identify the RIF-associated immune cell types and immune-related genes. Methods: The differentially expressed genes (DEGs) were screened based on RIF-associated Gene Expression Omnibus (GEO) datasets. Then, the enrichment analysis and protein-protein interaction (PPI) analysis were conducted with the DEGs. The RIF-associated immune cell types were clarified by combining single sample gene set enrichment analysis (ssGSEA) and CIBERSORT. Differentially expressed immune cell types-related modules were identified by weighted gene co-expression network analysis (WGCNA) and local maximal quasi-clique merger (lmQCM) analysis. The overlapping genes between DEGs and genes contained by modules mentioned above were delineated as candidate hub genes and validated in another two external datasets. Finally, the microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) that interacted with hub genes were predicted, and the competing endogenous RNA (ceRNA) regulatory network was structured. Results: In the present study, we collected 324 DEGs between RIF and the control group, which functions were mainly enriched in immune-related signaling pathways. Regarding differential cell types, the RIF group had a higher proportion of activated memory CD4 T cells and a lower proportion of γδ T cells in the endometrial tissue. Finally, three immune-related hub genes (ALOX5AP, SLC7A7, and PTGS2) were identified and verified to effectively discriminate RIF from control individuals with a specificity rate of 90.8% and a sensitivity rate of 90.8%. In addition, we constructed a key ceRNA network that is expected to mediate molecular mechanisms in RIF. Conclusion: Our study identified the intricate correlation between immune cell types and RIF and provided new immune-related hub genes that offer promising diagnostic and therapeutic targets for RIF.

Expressions of miR-199a-5p and miR-125b-5p and their target genes in the endometrium of recurrent implantation failure patients following in uterus infusion of autologous peripheral blood mononuclear cells

Despite numerous advances in fertility techniques, some individuals experience implantation failure. One of the therapeutic approaches is the study of immunological aspects of the implantation process in recurrent implantation failure (RIF) patients. Peripheral blood mononuclear cell (PBMC) therapy and platelet-rich plasma are currently available cell therapies. The aim of this study was to determine the expressions of the FGFR-2 and LIF genes that are regulated by miR-199a-5p and miR-125b-5p. These genes play a fundamental role in implantation in RIF patients treated with PBMCs. 20 patients clinically diagnosed with RIF were randomly assigned to a RIF patient with PBMCs intrauterine infusion group (n = 10) and RIF group (n = 10). Normal, healthy females (n = 10) comprised the control group. In order to examine the efficacy of the PBMCs injection in the treatment group, expressions of miR-199a-5p and miR-125-5p and FGFR-2 and LIF as their target genes, were evaluated in all three groups and were compared the results. We discovered that the RIF group had higher expressions of miR-199a-5p and miR-125-5p along with decreased expressions of their target genes. However, both FGFR-2 and LIF gene had elevated expressions in the RIF patients with PBMCs intrauterine infusion group compared to the RIF group, with significant decrease in miR-199a-5p and miR-125b-5p reciprocally. The treatment with PBMCs can be effective in changing the expression of microRNAs and genes associated with endometrial receptivity and by changes in the expression of them and their role during embryo development improve this process.

Dysregulation in Multiple Transcriptomic Endometrial Pathways Is Associated with Recurrent Implantation Failure and Recurrent Early Pregnancy Loss.

Overlapping disease aetiologies associated with multiple altered biological processes have been identified that change the endometrial function leading to recurrent implantation failure (RIF) and recurrent early pregnancy loss (REPL). We aimed to provide a detailed insight into the nature of the biological malfunction and related pathways of differentially expressed genes in RIF and REPL. Endometrial biopsies were obtained from 9 women experiencing RIF, REPL and control groups. Affymetrix microarray analysis was performed to measure the gene expression level of the endometrial biopsies. Unsupervised clustering of endometrial samples shows scattered distribution of gene expression between the RIF, REPL and control groups. 2556 and 1174 genes (p value < 0.05, Fold change > 1.2) were significantly altered in the endometria of RIF and REPL patients’ group, respectively compared to the control group. Downregulation in Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of the differentially expressed genes (DEGs) in RIF and REPL including ribosome and oxidative phosphorylation pathways. Gene Ontology (GO) analysis revealed ribosomes and mitochondria inner membrane as the most significantly downregulated cellular component (CC) affected in RIF and REPL. Determination of the dysregulated genes and related biological pathways in RIF and REPL will be key in understanding their molecular pathology and of major importance in addressing diagnosis, prognosis, and treatment issues

Autophagy markers are dysregulated in the endometrial tissues of patients with unexplained repeated implantation failure.

Endometrium decidualization is a complex biological process, which includes the interplay of transcription factors, cytokines, cell cycle regulators, and other signaling pathways. However, the underlying molecular mechanisms of this process are not fully elucidated to date. In this study, we aimed to investigate the possible association between autophagy and recurrent implantation failure (RIF). A total of 81 genes were downregulated and 231 genes were upregulated in the RIF group compared with the control group, and the differences were statistically significant (p < 0.05). Further, Gene Ontologyand Kyoto Encyclopedia of Genes and Genomespathway were analyzed, and we found that some autophagy markers, for example, LC3-II, LAMP2, and HIF-1α were significantly increased, whereas P62 was drastically downregulated in the RIF group. Similar results were observed in proteins level; and the autophagy puncta were also markedly enhanced in the endometrial tissues of RIF patients. Autophagy is closely associated with the RIF occurs and may be involved in the pathogenesis of RIF.