Investigation and treatment of repeated implantation failure following IVF-ET

Innate and adaptive immune dysregulation in women with recurrent implantation failure

Recurrent implantation failure (RIF) is a condition where a woman fails to obtain pregnancy after multiple embryo transfer cycles, even with superior-quality blastocysts. There are various factors that can contribute to RIF, including immunologic disturbances. The immune system is extremely important during pregnancy. Immune cells such as T cells, B cells, natural killer (NK) cells, and macrophages (MQ) are present in the female reproductive tract and are accountable for regulating the immune response to invading pathogens and maintaining tissue homeostasis. Dysregulation of these immune cells can lead to inflammation, which can impair fertility. One of the most common immunological disturbances observed in RIF is an altered Th1/Th2 ratio, along with changes in NK cell and macrophage numbers. In addition, the presence of some antibodies, such as anti-ovarian antibodies, can also contribute to RIF. Interleukins have been implicated in the development of an inflammatory response that can interfere with successful embryo implantation. As a result, a comprehensive understanding of immunological compartments in RIF women could assist us in determining the immunological origins of this disease. We will discuss immunological factors that might contribute to RIF etiology, including cellular and molecular components.

Total gonadotropin dose did not affect euploid blastocyst rates: an analysis of more than 19,000 oocytes

BACKGROUND

To evaluate whether increasing total gonadotropin (Gn) dose is associated with changes in euploid blastocyst rate in preimplantation genetic testing (PGT) oocytes.

METHODS

This retrospective cohort study was conducted between 2017 and 2022, and 19,246 oocytes were grouped and analyzed based on tri-sectional quantiles of total Gn doses.

SETTING

Single reproductive medical center.

SUBJECTS

All the patients who underwent PGT cycles, including PGT for aneuploidy, monogenic disorders, and structural rearrangements, were included.

EXPOSURE

Next-generation sequencing platforms for chromosomal analysis.

MAIN OUTCOME MEASURES

Blastocyst formation and euploid blastocyst rates.

RESULTS

In total, 19,246 oocytes and 5375 PGT blastocysts were analyzed. There were significant differences in blastocyst formation and euploid blastocyst rates among the groups classified according to tri-sectional quantiles of total Gn doses. Significant differences in age, body mass index (BMI), proportion of primary infertility, anti-Müllerian hormone (AMH) levels, number of oocytes retrieved, controlled ovarian stimulation (COS) regimen, type of Gn, and PGT category were observed among the three groups. After stratifying the analysis by age, BMI, infertility diagnosis, AMH levels, number of oocytes retrieved, PGT category, type of Gn, and COS regimen, significant differences were only seen in a small number of specific subgroups. Furthermore, the results of the multiple logistic regression analysis showed that the blastocyst formation and euploid blastocyst rates did not significantly increase or decrease with the total Gn dose, whether treated as a continuous variable or divided into three Gn groups as categorical variables. Notably, advancing age was a risk factor for blastocyst formation and euploid blastocyst rates. PGT for structural rearrangements was a risk factor for blastocyst formation and euploid blastocyst rates as compared with PGT for aneuploidy.

CONCLUSION

In the total PGT cycles, advancing age, and preimplantation genetic testing for structural rearrangements negatively affected blastocyst formation and euploid blastocyst rates; however, the total Gn dose did not affect blastocyst formation and euploid blastocyst rates.

Performance of preimplantation genetic testing for aneuploidy for patients with unexplained recurrent pregnancy loss and repeated implantation failure

Objective

The primary objective was to investigate whether the utilization of next-generation sequencing (NGS) for preimplantation genetic testing for aneuploidy (PGT-A) could enhance the reproductive outcomes in patients with unexplained recurrent pregnancy loss (uRPL) or unexplained repeated implantation failure (uRIF) undergoing intracytoplasmic sperm injection (ICSI) cycles.

Materials and methods

We studied the reproductive outcomes of uRPL or uRIF sufferers in Chengdu women and children's central hospital from July 2020 to Jan 2024 retrospectively. These patients were categorized into two groups based on whether they underwent PGT-A or not. As the patients in the PGT-A group all had ICSI and frozen-thawed embryo transfer (FET), only patients who underwent ICSI and FET were included in the non-PGT-A group for comparison. Demographic characteristics and reproductive outcomes were compared in uRPL or uRIF sufferers.

Results

For uRPL group, a significant increased ongoing pregnancy rate (63.6 % vs 26.1 %, p = 0.002) and reduced pregnancy loss rate (18.4 % vs 73.3 %, p < 0.001) were found in the PGT-A group in comparison with those in the non-PGT-A group. For uRIF group, no significant difference was noted in the HCG-positive rate, ongoing pregnancy rate, or pregnancy loss rate between the two groups. It is noteworthy that the maternal age in the PGT-A group was significantly higher than that in the non-PGT-A group (p = 0.048).

Conclusions

NGS-based PGT-A effectively optimized the reproductive outcomes in uRPL sufferers. Although its benefits in uRIF appeared to be limited, there is a potential advantage for those with advanced maternal age. Considering the small sample size, further randomized controlled trials are warranted to validate these findings.

Atosiban interacts with growth hormones as adjuvants in frozen-thawed embryo transfer cycles

Objective

To investigate the interaction between atosiban and growth hormone (GH) as adjuvants in frozen-thawed embryo transfer (FET) cycles.

Method

A total of 11627 patients who underwent FET at Xiamen University Affiliated Chenggong Hospital between January 2018 to December 2022 were retrospectively analyzed. Among them, 482 patients received atosiban and 275 patients received GH. The interactions were estimated by comparing the odds ratio (OR) for pregnancy comparing patients with or without atosiban adjuvant in cohorts stratified according to the presence of GH use in either the overall cohort or a propensity score (PS) matched cohort. An interaction term (atosiban × GH) was introduced to a multivariate model to calculate the ratio of OR (ORR) adjusted for confounders.

Results

For all patients receiving atosiban administration, no obvious effect on pregnancy was observed in comparison with either matched or unmatched controls. However, when the patients were stratified according to GH administration, atosiban showed a significant association with clinical pregnancy in comparison with either matched or unmatched controls among patients with GH treatment with rate ratios (RR) of 1.32 (95%CI: 1.05,1.67) and 1.35 (95%CI: 1,1.82), respectively. On the other hand, however, the association was absent among patients without GH treatment. The adjusted ORRs in both matched and unmatched cohorts were 2.44 (95%CI: 1.07,5.84) and 1.95 (95%CI: 1.05, 3.49) respectively.

Conclusion

The combination use of atosiban and GH in FET cycles is potentially beneficial to the pregnancy. However, indications for the use of atosiban and GH may need further assessment.

Preimplantation genetic testing for aneuploidy optimizes reproductive outcomes in recurrent reproductive failure: a systematic review

Introduction

Recurrent reproductive failure (RRF) is a common pregnancy complication, imposing great physical, emotional and financial burden for the suffered couples. The leading cause of RRF is believed to be aneuploid embryo, which could be solved by preimplantation genetic testing for aneuploidy (PGT-A) in theory. With molecular genetic development, PGT-A based on comprehensive chromosomal screening (CCS) procedures and blastocyst biopsy is widely applied in clinical practice. However, its effects in RRF were not defined yet.

Methods

A systematic bibliographical search was conducted without temporal limits up to June, 2023. Studies about the effects of PGT-A based on CCS procedures and blastocyst biopsy in RRF were included.

Results

Twenty studies about the effects of PGT-A based on CCS procedures and blastocyst biopsy in RRF were included. It revealed that PGT-A could optimise the reproductive outcomes of RRF sufferers, especially in those with advanced age. However, in patients with multiple occurrences of pregnancy losses, the benefits of PGT-A were limited.

Discussion

More randomized controlled trials with large sample size are required to evaluate the benefits of PGT-A in RRF sufferers and identify which population would benefit the most.

Title: Repeated implantation failure is associated with increased Th17/Treg cell ratio, during the secretory phase of the human endometrium

Repeated implantation failure (RIF) is a significant limiting factor in assisted reproduction. Chronic endometrial inflammation has been noted in RIF women, therefore we sought to investigate the potential association of endometrial Th17/Treg ratio and endometrial inflammation in these cases. Endometrial pipelle biopsies were obtained from volunteers, 29 women with RIF (failure to achieve pregnancy following at least 3 transfers of high-grade embryos in IVF-cycles) and 27 fertile women (at least one child) in total, at the secretory phase of the menstrual cycle. Using tissues from 17 fertile and 18 RIF endometrial samples, stromal and immune cells were isolated and flow cytometry analysis was performed to determine Th17 and CD4+ CD25high FOXP3+ cell populations in endometrial stromal cell suspensions. Another group of tissues from 10 fertile and 11 RIF samples were used for mRNA expression levels of Treg and Th17-cell transcription factors, FOXP3 and RORγt respectively. Endometrial inflammatory mediators' mRNA expression was also analyzed. A statistically significant increase in protein flow cytometry analysis of Th17/Treg ratio (p ≤ 0.05) as well as a reduction in absolute Treg cells in the endometrium (p ≤ 0.05) was noted in women with RIF. Additionally, RNA analysis on the same set of women indicated RORγt/FOXP3 significantly increased in women with RIF compared to fertile ones (p ≤ 0.05). Finally, women with RIF exhibited significantly (p ≤ 0.05) elevated mRNA levels of pro-inflammatory mediators (ΤΝF-a, ΙL-6, IL-8 and CCl2). Women with RIF exhibit elevated Th17/Treg ratio, mostly due to endometrial Treg depletion, as well as a pro-inflammatory state in the endometrium.

Endometrial BMP2 Deficiency Impairs ITGB3-Mediated Trophoblast Invasion in Women With Repeated Implantation Failure

BACKGROUND

Repeated implantation failure (RIF) leads to a waste of high-quality embryos and remains a challenge in assisted reproductive technology. During early human placentation, the invasion of trophoblast cells into the decidua is an essential step for the establishment of maternal-fetal interactions and subsequent successful pregnancy. Bone morphogenetic protein 2 (BMP2) has been reported to regulate endometrial receptivity and promote trophoblast invasion. However, whether there is dysregulation of endometrial BMP2 expression in patients with RIF remains unknown. Additionally, the molecular mechanisms underlying the effects of BMP2 on human trophoblast invasion and early placentation remain to be further elucidated.

METHODS

Midluteal phase endometrial samples were biopsied from patients with RIF and from routine control in vitro fertilization followed by quantitative polymerase chain reaction and immunoblotting analyses. Human trophoblast organoids, primary human trophoblast cells, and an immortalized trophoblast cell line (HTR8/SVneo) were used as study models.

RESULTS

We found that BMP2 was aberrantly low in midluteal phase endometrial tissues from patients with RIF. Recombinant human BMP2 treatment upregulated integrin β3 (ITGB3) in a SMAD2/3-SMAD4 signaling-dependent manner in both HTR8/SVneo cells and primary trophoblast cells. siRNA-mediated integrin β3 downregulation reduced both basal and BMP2-upregulated trophoblast invasion and vascular mimicry in HTR8/SVneo cells. Importantly, shRNA-mediated ITGB3 knockdown significantly decreased the formation ability of human trophoblast organoids.

CONCLUSION

Our results demonstrate endometrial BMP2 deficiency in patients with RIF. ITGB3 mediates both basal and BMP2-promoted human trophoblast invasion and is essential for early placentation. These findings broaden our knowledge regarding the regulation of early placentation and provide candidate diagnostic and therapeutic targets for RIF clinical management.

Pretreatment with long-acting gonadotropin-releasing hormone agonists improved pregnancy outcomes after hysteroscopic multiple polypectomies: A retrospective study of 660 frozen-thawed embryo transfer cycles

OBJECTIVE

To compare the reproductive pregnancy outcomes of pretreatment with long-acting gonadotropin-releasing hormone agonist (GnRH-a) plus hormone replacement therapy (HRT) with HRT-only cycles, and investigate differences between single polypectomy and multiple polypectomies, and between one or two doses of GnRH-a.

MATERIALS AND METHODS

This was a retrospective cohort study on patients undergoing polypectomy who underwent frozen-thawed embryo transfer (FET) from March 2018 to May 2019. They were divided into GnRH-a pretreatment and HRT-only groups. Each group was divided into single polypectomy or multiple polypectomies (in a single hysteroscopic session) subgroups. Clinical pregnancy rate and live birth rate (LBR) were the main outcomes. The effect of GnRH-a dosage was further analysed.

RESULTS

There were 212 GnRH-a pretreatment cases (45 single and 167 multiple polyps) and 448 HRT-only cases (228 single and 220 multiple polyps). The LBR of the GnRH-a pretreatment group (53.3%) was significantly higher than the HRT group (43.3%; P = 0.016). Logistic regression analysis showed that GnRH-a pretreatment significantly affected the LBR (odds ratio, OR 1.470, 95% confidence interval, Cl 1.046-2.065; P = 0.026). In the multiple polypectomy subgroup, the LBR with GnRH-a pretreatment was higher than with HRT-only (54.5% vs 43.6%; P = 0.034). However, the LBR was not different between the respective single polypectomy subgroups (48.9% vs 43.0%; P = 0.466). For patients with multiple polyps, two GnRH-a pretreatments produced a higher LBR than a single GnRH-a pretreatment (62.7% vs 47.8%), but without significant difference (P = 0.055).

CONCLUSION

GnRH-a pretreatment improved the LBR for FET cycles after hysteroscopic multiple polypectomies, independent of dose.

Tacrolimus treatment in women with repeated implantation failures

Background

Tacrolimus is an immunosuppressive drug that works as a calcineurin inhibitor to improve the reproductive outcomes for women who have experienced multiple implantation failures (RIF) and show elevated type 1 helper T (Th1)/Th2 cell ratios.

Methods

In the first part of this review, we indicate how we re-evaluated the cut-off index for selecting the participants in a tacrolimus regimen via transferred euploid blastocysts. In the second part, we cite cases where tacrolimus has improved the live birth rate for women who have experienced recurrent pregnancy losses (PRL) and we introduce the utility of tacrolimus treatment to prevent obstetrical complications.

Main Findings

After reconsideration of the cut-off index (Th1/Th2 ≥ 11.8), however, the pregnancy rates of women with tacrolimus were significantly higher than those of women without tacrolimus. The PRL women treated with tacrolimus showed significantly lower rates of biochemical pregnancy, but higher live-birth rates compared with women who were not treated with tacrolimus. Moreover, prior severe obstetrical complications could be controlled via the administration of tacrolimus during pregnancy.

Conclusion

Tacrolimus has become indispensable in the field of solid-organ transplantation, and in the near future, it should become an essential agent in the reproductive field, as well.

Assessing the Impact of Genratest on Women With Recurrent Implantation Failure: A Single-Center Study

Objective Recurrent implantation failure (RIF) is a significant challenge in assisted reproduction. Genratest has emerged as a potential tool to identify the displaced window of implantation (WOI). This study aimed to evaluate the impact of this test on the pregnancy outcomes of RIF patients. Methods A retrospective analysis was conducted on 143 RIF patients who were categorized into two groups: the personalized embryo transfer (pET, n=69) group and standard embryo transfer (sET, n=74) group. The main measured outcomes were clinical pregnancy, ongoing pregnancy, miscarriage, and live birth rates. Results Genratest effectively diagnoses the displaced WOI in 90% of RIF patients. The pET group exhibited a higher rate of clinical pregnancy (n=36/69, 52.2%) compared to the sET group (n=35/74, 47.3%), but this difference was not statistically significant (p=0.679). Ongoing pregnancy rates were comparable between the pET (n=28/69, 40.6%) and the sET (n=30/74, 40.5%) groups (p=0.996). Live birth rates showed no statistically significant difference between the two groups (n=26/69, 37.7% versus n=22/74, 29.7%, p=0.407). Miscarriage rates were similar in both groups (n=9/69, 13% versus n=11/74, 14.9%, p=0.942). Conclusions pET based on the results of the Genratest did not show a significant improvement in pregnancy outcomes, including clinical pregnancy, ongoing pregnancy, live birth, or miscarriage rates. Further research is needed to identify the role of Genratest in RIF patients.

Effect of intrauterine infusion of platelet-rich plasma for women with recurrent implantation failure: a systematic review and meta-analysis

This study evaluated the effect of intrauterine perfusion of autologous platelet-rich plasma (PRP) on pregnancy outcomes in women with recurrent implantation failure (RIF). Key biomedical databases were searched to identify relevant clinical trials and observational studies. Outcomes included clinical pregnancy rate, chemical pregnancy rate, implantation rate, live birth rate, and abortion rate. Data was extracted from ten studies (six randomised controlled trials, four cohort studies) involving 1555 patients. Pregnancy outcomes were improved in women treated with PRP compared to controls: clinical pregnancy rate (RR = 1.96, 95% CI [1.67, 2.31], p < 0.00001, I² = 46%), chemical pregnancy rate (RR = 1.79, 95% CI [1.54, 2.08], p < 0.00001, I² = 29%), implantation rate (RR = 1.90, CI [1.50, 2.41], p < 0.00001, I² = 0%), live birth rate (RR = 2.83, CI [1.45, 5.52], p = 0.0007, I² = 83%), abortion rate (RR = 0.40, 95% CI [0.18, 0.90], p = 0.03, I² = 59%). These data imply PRP has potential to improve pregnancy outcomes in women with RIF, suggesting a promising role in assisted reproductive technology.IMPACT STATEMENTWhat is already known on this subject? Platelet-rich plasma (PRP) is an autologous blood product that contains platelets, various growth factors, and cytokines at concentrations above the normal baseline level. Recent studies have shown that intrauterine infusion of autologous PRP can improve pregnancy outcomes in infertile women.What do the results of this study add? This systematic review and meta-analysis of data from ten studies (n = 1555; 775 cases and 780 controls) investigated the effect of intrauterine perfusion of autologous PRP on pregnancy outcomes in women with recurrent implantation failure (RIF). Findings suggest that pregnancy outcomes, including clinical pregnancy rate, chemical pregnancy rate, implantation rate, live birth rate and abortion rate were improved in women treated with PRP compared to controls.What are the implications of these findings for clinical practice and/or further research? RIF remains a challenge for researchers, clinicians, and patients. Our study identified PRP as a potential intervention in assisted reproduction. As an autologous blood preparation, PRP eliminates the risk of an immune response and transmission of disease. PRP is low cost and effective and may represent a new approach to the treatment of patients with RIF.

Recombinant human granulocyte colony stimulating factor (rhG-CSF) participates in the progression of implantation via the hsa_circ_0001550-miRNA-mRNA interaction network

Inadequate endometrial receptivity is a key factor affecting the successful implantation of embryos. Recombinant human granulocyte colony stimulating factor (rhG-CSF) can increase endometrial thickness and improve the outcomes of assisted reproductive technologies (ARTs). In this preliminary study, the function and possible molecular mechanisms of recombinant human granulocyte colony stimulating factor (rhG-CSF) which affects endometrial receptivity and implantation in human Embryonic Stem Cells (hESCs) were investigated. The cell viability of endometrial stromal cells treated with rhG-CSF 0.5 ng/ml for 24 h was significantly increased. Moreover, the expression of hsa_circ_0001550 was downregulated in endometrial stromal cells treated with rhG-CSF. Furthermore, the hsa_circ_0001550-miRNA-mRNA network was constructed and the downstream target genes (including 4 miRNAs and 117 mRNAs) of hsa_circ_0001550 were mainly involved in the cAMP and calcium signalling pathways, which play important roles in regulating endometrial receptivity and embryo implantation. We conclude that rhG-CSF participates in the regulation of embryo implantation by regulating the hsa_circ_0001550-miRNA-mRNA interaction network.

Stratified analysis of clinical pregnancy outcomes of sequential embryo transfer in frozen embryo transfer cycles based on different factors: a retrospective study

OBJECTIVE

To explore the effect of sequential embryo transfer (ET) on the pregnancy outcome of frozen-thawed embryo transfer (FET) cycle and the indications of sequential transfer.

METHODS

A total of 1440 FET cycles were enrolled in this retrospective study, of which 1080 patients received conventional ET and 360 patients received sequential ET. Further stratified analysis was performed according to the number of previous failed cycles, the number of embryos transferred and the stage of blastocyst (day 5 or 6, denoted D5 or D6) transferred. Comparison of pregnancy rates, implantation rate, miscarriage rate and multiple pregnancy rate among the groups of patients.

RESULTS

The clinical pregnancy rate and implantation rate of the sequential ET group were higher than those of the conventional ET group (P < 0.01); however, there was no statistical difference in multiple pregnancy rate and miscarriage rate (P > 0.05). In sequential transfer, the number of transferred embryos (2 or 3) and the stage of transferred blastocysts (D5 or D6) had no effect on clinical pregnancy rate, implantation rate, multiple pregnancy rate and miscarriage rate (P > 0.05). In patients with three or more previous failure cycles, the sequential ET group showed higher clinical pregnancy rate and implantation rate (P > 0.05).

CONCLUSIONS

Compared with conventional ET in FET cycle, sequential ET strategy could significantly improve the clinical pregnancy rate and implantation rate. In sequential transfer, patients with three embryos transferred don't have higher pregnancy rate and implantation rate. Besides, sequential transfer is more suitable for patients with repeated implantation failures (RIF), and increase the utilization rate of D6 blastocysts.

HIF-1α is positively associated with endometrial receptivity by regulating PKM2

PURPOSE

Numerous advancements have been introduced into the field of assisted reproductive technology (ART) in the past four decades. Nonetheless, implantation failure is still a key limiting step for a successful pregnancy. Building of endometrial receptivity (ER) is essential for successful implantation. However, the fundamental biological processes and mechanisms of ER remain elusive. Our study investigates the function of hypoxia inducible factor-1α (HIF-1α) during ER establishment and shed lights on the novel molecular mechanism by which HIF-1α regulates ER-related gene expression network.

METHODS

Levels of HIF-1α, homeobox A10 (HOXA10), insulin-like growth factor-binding protein 1 (IGFBP1), pyruvate kinase M2 (PKM2), and lactate dehydrogenase A (LDHA) in endometrial tissues were measured via real-time PCR, immunoblotting and immunohistochemistry. The correlation between HIF-1α and HOXA10, IGFBP1, PKM2, LDHA were analyzed separately. Ishikawa cells were treated with vector HIF-1α, HIF-1α-siRNA, and PKM2-siRNA. After transfection, the levels of HOXA10, IGFBP1, LDHA, and PKM2 were measured via real-time PCR and immunoblotting, and the lactate concentrations and cell migration of Ishikawa cells were measured.

RESULTS

Levels of HIF-1α, IGFBP1, HOXA10, LDHA, and PKM2 were significantly decreased in recurrent implantation failure (RIF) patients and levels of HOXA10, IGFBP1, PKM2, and LDHA were correlated with HIF-1α in endometrium. Then in a cellular model established by HIF-1α vector and HIF-1α-siRNA, the expression of HOXA10, IGFBP1, LDHA, PKM2, and lactate concentrations were dramatically upregulated and downregulated. And the expression of HOXA10, and IGFBP1 were dramatically decreased by PKM2-siRNA.

CONCLUSIONS

HIF-1α plays a crucial role in the building of ER through regulating glycolysis.

Uterine Nodal expression supports maternal immunotolerance and establishment of the FOXP3+ regulatory T cell population during the preimplantation period

Pregnancy success is dependent on the establishment of maternal tolerance during the preimplantation period. The immunosuppressive function of regulatory T cells is critical to limit inflammation arising from implantation of the semi-allogeneic blastocyst. Insufficient maternal immune adaptations to pregnancy have been frequently associated with cases of female infertility and recurrent implantation failure. The role of Nodal, a secreted morphogen of the TGFβ superfamily, was recently implicated during murine pregnancy as its conditional deletion (NodalΔ/Δ) in the female reproductive tract resulted in severe subfertility. Here, it was determined that despite normal preimplantation processes and healthy, viable embryos, NodalΔ/Δ females had a 50% implantation failure rate compared to NodalloxP/loxP controls. Prior to implantation, the expression of inflammatory cytokines MCP-1, G-CSF, IFN-γ and IL-10 was dysregulated in the NodalΔ/Δ uterus. Further analysis of the preimplantation leukocyte populations in NodalΔ/Δ uteri showed an overabundance of infiltrating, pro-inflammatory CD11bhigh Ly6C+ macrophages coupled with the absence of CD4+ FOXP3+ regulatory T cells. Therefore, it is proposed that uterine Nodal expression during the preimplantation period has a novel role in the establishment of maternal immunotolerance, and its dysregulation should be considered as a potential contributor to cases of female infertility and recurrent implantation failure.

AI, Borges Jr. E. Beetroot, watermelon and ginger juice supplementation may increase the clinical outcomes of Intracytoplasmic Sperm Injection cycles

OBJECTIVE

To prove the hypothesis that beetroot, watermelon and ginger juice supplementation improves the endometrial receptivity and clinical outcomes of intracytoplasmic sperm injection (ICSI) cycles.

METHODS

This prospective randomized study enrolled 436 female patients undergoing ICSI cycles from January/2018 to June/2021, in a private university-affiliated IVF center. Female patients were randomized in a 1:3 ratio to either Control (n=109) or Supplementation Group (n=327). All patients received nutritional orientation before the beginning of the treatment. Participants in the Supplementation Group were instructed to intake a daily dose of homemade juice, prepared with fresh beetroot, watermelon and ginger, from the day of embryo transfer until the day of pregnancy test, while patients in Control Group did not follow the juice protocol. Generalized Linear Models, adjusted for potential confounders (female age, body mass index - BMI, endometrial thickness upon embryo transfer, and number of transferred embryos), followed by Bonferroni post hoc test for the comparison of means between groups, were used to investigate the impact of juice supplementation on the clinical outcomes of ICSI.

RESULTS

Patients and cycles characteristics were equally distributed among Supplementation and Control groups. Implantation rate (25.2% vs. 20.5%, p<0.001) and clinical pregnancy rate (41.0% vs. 22.0%, p=0.039) were significantly higher in the Supplementation compared to the Control group.

CONCLUSIONS

The use of beetroot, watermelon and ginger juice may be considered a promising strategy for improving clinical outcomes in assisted reproductive technology (ART), without any side effects.

Anti-β2-glycoprotein I/HLA-DR antibody in infertility

To evaluate whether anti-β2-Glycoprotein I/HLA-DR (anti-β2GPI/HLA-DR) antibody is associated with pathophysiology of infertility, 224 women with infertility were enrolled from July 2020 to December 2021 in this prospective study. The serum levels of anti-β2GPI/HLA-DR antibody (normal < 73.3 U) were determined in 224 women with infertility. Backgrounds, causes and clinical factors were compared between women with and without anti-β2GPI/HLA-DR antibody. Forty (17.9 %) of the 224 women tested positive for anti-β2GPI/HLA-DR antibody. The prevalence of endometriosis was higher in women with anti-β2GPI/HLA-DR antibody than in women without the antibody (32.5 %, 13/40 vs. 17.4 %, 32/184; P = 0.048). Logistic regression analyses revealed that, among clinical factors and diseases, endometriosis was associated with anti-β2GPI/HLA-DR antibody positivity in infertile women (adjusted-odds ratio [OR] 3.01, 95 % confidence interval [CI] 1.30-6.99; P = 0.010). Twenty-three (15.5 %) of 148 women who underwent assisted reproductive technology (ART) tested positive for anti-β2GPI/HLA-DR antibody. The prevalence of recurrent implantation failure (RIF) defined as three or more implantation failures following in vitro fertilization and embryo transfers was higher in women with ART who tested positive for the antibody (43.5 %, 10/23) than in women with ART who tested negative (20.8 %, 26/125; P = 0.032). Logistic regression analyses revealed that RIF was associated with anti-β2GPI/HLA-DR antibody positivity in women with ART (adjusted-OR 2.92, 95 % CI 1.05-8.11; P = 0.040). Anti-β2GPI/HLA-DR antibody may be associated with the pathophysiology of infertility, endometriosis and RIF; and can be a potential therapeutic target in infertility.

The Role of Plasma Cells as a Marker of Chronic Endometritis: A Systematic Review and Meta-Analysis

Chronic endometritis (CE) is the persistent inflammation of the endometrial lining associated with infertility and various forms of reproductive failures. The diagnosis of CE is based on the histological evidence of stromal plasma cells; however, standardized methods to assess plasma cells are still lacking. In the present paper, we aimed to determine the most appropriate plasma cell threshold to diagnose CE based on pregnancy outcomes. Three electronic databases were searched from their inception to February 2022 for all studies comparing pregnancy outcomes between patients with CE and patients without CE. The relative risk (RR) of pregnancy, miscarriage, and/or live birth rates were calculated and pooled based on the plasma cell threshold adopted. A p-value < 0.05 was considered significant. Nine studies adopting different thresholds (1 to 50 plasma cells/10 HPF) were included. In the meta-analysis, we only found a significant association between miscarriage rate and a plasma cell count ≥ 5/10 HPF (RR = 2.4; p = 0.007). Among studies not suitable for meta-analysis, CE showed an association with worsened pregnancy only when high thresholds (10 and 50/10 HPF) were adopted. In conclusion, our study suggests that the presence of plasma cells at low levels (<5/10 HPF) may not predict worsened pregnancy outcomes. Based on these findings, a threshold of ≥5 plasma cells/10 HPF may be more appropriate to diagnose CE.

Effect of low-molecular-weight heparin in women undergoing frozen-thawed embryo transfer cycles: a retrospective cohort study

BACKGROUND

Recurrent pregnancy loss (RPL) and recurrent implantation failure (RIF) during in vitro fertilization (IVF) treatment are still tough problems without effective treatments; thus, they are important research topics. There is controversy on whether low molecular weight heparin (LMWH) improves pregnancy outcomes in women with unexplained RPL and RIF. Moreover, currently, there is a paucity of reports on the role of LMWH in the entire population undergoing frozen-thawed embryo transfer (FET) cycles. This study aimed to estimate the effects of LMWH on pregnancy outcomes in women undergoing FET cycles.

METHODS

There were 1881 female patients included in the study. Of the 1881 patients, 107 underwent preimplantation genetic diagnosis cycles, which were analyzed individually. The patients were divided into two groups: the LMWH group received injections of 4100 IU/d LMWH from the day of transfer until 14 ± 2 days posttransplant, the control group was the comparison group (without LMWH use). The baseline characteristics and reproductive outcomes of the patients were reviewed.

RESULTS

Of the 1774 women with normal FET cycles, no significant differences were found in the number of embryos implanted (1.31 ± 0.02 vs. 1.28 ± 0.02), embryo implantation rate, biochemical pregnancy rate, clinical pregnancy rate, live birth rate, late abortion rate, and ectopic pregnancy rate between the two groups. The LMWH group had a higher early abortion (17.8% [76/427] vs. 12.5% [55/439], p = 0.030). In the sub-group analysis, among the patients who underwent more than four transfers, the LMWH group had a lower late abortion rate (1.7% [1/60] vs. 13.2% [7/53], p = 0.043). Similarly, of the 107 women who underwent preimplantation genetic diagnosis cycles, the reproductive outcomes were comparable between the two groups.

CONCLUSION

In the general population and PGD patients, LMWH did not improve pregnancy outcomes. Therefore, the routine use of LMWH is not recommended for early treatment.

The value of platelet-rich plasma in women with previous implantation failure: a systematic review and meta-analysis

OBJECTIVE

To assess the value of intrauterine PRP to improve IVF outcome in women with previous implantation failure.

METHODS

Screening of Pubmed, Web of Science, and other databases from inception to August 2022 using the keywords related to "platelet-rich plasma" OR "PRP" AND "IVF" "implantation failure." Twenty-nine studies (3308 participants) were included in our analysis, 13 were RCTs, 6 were prospective cohorts, 4 were prospective single arm, and 6 were retrospective analyses. Extracted data included settings of the study, study type, sample size, participants' characteristics, route, volume, timing of PRP administration, and outcome parameters.

RESULTS

Implantation rate was reported in 6 RCTs (886 participants) and 4 non-RCTs (732 participants). The odds ratio (OR) effect estimate was 2.62 and 2.06, with 95% CI of 1.83, 3.76, and 1.03-4.11, respectively. Endometrial thickness was compared in 4 RCTs (307 participants) and 9 non-RCTs (675 participants), which showed a mean difference of 0.93 and 1.16, with 0.59-1.27 and 0.68-1.65 95% CI, respectively.

CONCLUSION

PRP administration improves implantation, clinical pregnancy, chemical pregnancy, ongoing pregnancy, live birth rates, and endometrial thickness in women with previous implantation failure.

Intrauterine Infusion of Leukocyte-Poor Platelet-Rich Plasma Is an Effective Therapeutic Protocol for Patients with Recurrent Implantation Failure: A Retrospective Cohort Study

BACKGROUND

The clinical application of autologous leukocyte-poor platelet-rich plasma (LP-PRP) in patients with recurrent implantation failure (RIF) is rare. This retrospective observational cohort study aimed to evaluate the efficacy of LP-PRP intrauterine infusion in patients with RIF.

METHODS

Patients with RIF undergoing frozen embryo transfer (FET) from January 2019 to December 2021 (n = 118) were enrolled, with those undergoing LP-PRP intrauterine infusion as the PRP group (n = 64), and those receiving no LP-PRP treatment as the control group (n = 54). The beta-human chorionic gonadotropin (β-hCG)-positive rate, clinical pregnancy rate (CPR), live birth rate (LBR), and miscarriage rate (MR) per ET cycle were compared.

RESULTS

The β-hCG-positive rate (57.8% vs. 38.9%, p = 0.041), CPR (45.3% vs. 24.5%, p = 0.022), and LBR per ET cycle (42.2% vs. 18.5%, p = 0.009) were higher in the PRP group than in the control group, and the three variables (62.5% vs. 41.2%, p = 0.040, 47.5% vs. 23.5%, p = 0.033, and 47.5% vs. 20.6%, p = 0.027) in the PRP group transferred with the blastocyst-stage embryos were also higher than those in the control group. The MR was similar in all groups.

CONCLUSIONS

The LP-PRP treatment could improve the β-hCG-positive rate, CPR, and LBR in RIF patients undergoing FET cycles.

Trophectoderm non-coding RNAs reflect the higher metabolic and more invasive properties of young maternal age blastocysts

Increasing female age is accompanied by a corresponding fall in her fertility. This decline is influenced by a variety of factors over an individual's life course including background genetics, local environment and diet. Studying both coding and non-coding RNAs of the embryo could aid our understanding of the causes and/or effects of the physiological processes accompanying the decline including the differential expression of sub-cellular biomarkers indicative of various diseases. The current study is a post-hoc analysis of the expression of trophectoderm RNA data derived from a previous high throughput study. Its main aim is to determine the characteristics and potential functionalities that characterize long non-coding RNAs. As reported previously, a maternal age-related component is potentially implicated in implantation success. Trophectoderm samples representing the full range of maternal reproductive ages were considered in relation to embryonic implantation potential, trophectoderm transcriptome dynamics and reproductive maternal age. The long non-coding RNA (lncRNA) biomarkers identified here are consistent with the activities of embryo-endometrial crosstalk, developmental competency and implantation and share common characteristics with markers of neoplasia/cancer invasion. Corresponding genes for expressed lncRNAs were more active in the blastocysts of younger women are associated with metabolic pathways including cholesterol biosynthesis and steroidogenesis.

Uterine NK cells underexpress KIR2DL1/S1 and LILRB1 in reproductive failure

A significant proportion of recurrent miscarriage, recurrent implantation failure and infertility are unexplained, and these conditions have been proposed to have an etiology of immunological dysfunction at the maternal-fetal interface. Uterine Natural Killer cells (uNK) comprise three subsets and are the most numerous immune cells found in the uterine mucosa at the time of implantation. They are thought to play an important role in successful pregnancy by regulation of extravillous trophoblast (EVT) invasion and spiral artery remodelling. Here, we examine the frequency, phenotype and function of uNK1-3 from the uterine mucosa of 16 women with unexplained reproductive failure compared to 11 controls with no reproductive problems, during the window of implantation. We report that KIR2DL1/S1 and LILRB1 expression is lower in the reproductive failure group for both uNK (total uNK, uNK 2 and 3) and pNK. We also show that degranulation activity is significantly reduced in total uNK, and that TNF-α production is lower in all uNK subsets in the reproductive failure group. Taken together, our findings suggest that reproductive failure is associated with global reduction in expression of uNK receptors important for interaction with HLA-C and HLA-G on EVT during early pregnancy, leading to reduced uNK activation. This is the first study to examine uNK subsets during the window of implantation in women with reproductive failure and will serve as a platform to focus on particular aspects of phenotype and function of uNK subsets in future studies. Further understanding of uNK dysregulation is important to establish potential diagnostic and therapeutic targets in the population of women with unexplained reproductive failure.

Gene profiling reveals the role of inflammation, abnormal uterine muscle contraction and vascularity in recurrent implantation failure

Objective: Recurrent implantation failure (RIF) is now disturbing numerous infertile couples accepting assisted reproductive technology (ART). And the endometrial factors are crucial causes of recurrent implantation failure. However, its mechanism is still unclear. Thus, the aim of this study is to identify altered biologic processes in endometrium that may contribute to recurrent implantation failure. Methods: We recruited two microarray datasets (GSE103465, GSE111974) from Gene Expression Omnibus database (GEO), which contain endometrium from RIF and normal women during implantation period. Using the online tools GEO2R and Venny, we identified Differentially Expressed Genes (DEGs) of selected datasets, and obtained common DEGs. Gene Ontology (GO) terms, Kyoto Encyclopedia of Genes and Genomes (KEGG) and BioCatar pathway enrichment were conducted with Enrichr platform, "ssgsea" and "ggplot2" package of RStudio. PPI networks and hub gene related TF-gene interaction and TF-miRNA co-regulation networks were built via online tools STRING and NetworkAnalyst. Immune infiltration analysis was performed by CIBERSORT platform. Recurrent implantation failure subgroup identification was achieved through "ConsensusClusterPlus," "tsne," "ssgsea", and "ggpubr" package in RStudio. Diagnostic characteristic ROC curves were constructed via "pROC" and "ggplot2" package of RStudio. Enrichr platform was utilized to find drugs targeting hub genes. Results: 26 common DEGs were confirmed. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes/BioCarta analysis determined common DEGs were mainly enriched in inflammation associated pathways including TNF, NF-κB, IL-4, IL-10, IL-6, and TGF-β signaling pathways. Five hub genes (PTGS2, VCAM1, EDNRB, ACTA2, and LIF) and related TF-gene and TF-miRNA interactions were identified. Immune infiltration analysis indicated the importance of macrophage M2 in recurrent implantation failure patients. Importantly, subgroup identification analysis highlighted that recurrent implantation failure patients can be divided into two subgroups with different phenotypes. Moreover, the ROC curves and drugs may provide new diagnostic and therapeutic thought for recurrent implantation failure.

Management of recurrent implantation failure: British Fertility Society policy and practice guideline

Recurrent implantation failure (RIF) is defined as the absence of a positive pregnancy test after three consecutive transfers of good quality embryos. There remains significant variation in clinical practice in the management of RIF. This British Fertility Society (BFS) Policy and Practice guideline analyses the evidence for investigations and therapies that are employed in RIF and provides recommendations for clinical practice and for further research. Evidence for investigations of sperm and egg quality, uterine and adnexal factors, immunological factors and thrombophilia, endocrine conditions and genetic factors and for associated therapies have been evaluated. This guideline has been devised to assist reproductive medicine specialists and patients in making shared decisions concerning management of RIF. Finally, suggestions for research towards improving understanding and management of RIF have also been provided.

Sequential (two-step) day 3/day 5 frozen-thawed embryo transfer: does it improve the pregnancy rate of patients suffering recurrent implantation failure?

The best time of endometrial receptivity is the missing part of the implantation puzzle in patients with recurrent in vitro fertilization (IVF) failure. There are various treatment plans and strategies to meet the best endometrial timing for implantation. However, the lack of synchronization of the good-quality embryo with the patient's individual "window of implantation" is the hypothesis for most IVF failures so far. Sequential embryo transfer (ET) theoretically extends the availability time of embryos on the window of implantation. The study aimed to evaluate the improvement of pregnancy rate in sequential (two-step) frozen-thawed embryo transfer (FET) on day 3/day 5 in individuals who suffer from repeated IVF failures. This randomized controlled trial study was done in a university-affiliated infertility center for women with repeated consecutive IVF failures. Two hundred women aged 20-39 years who met our inclusion criteria were included in the study between January 2020 and September 2021. Participants were allocated with a 1:1 ratio to either sequential (two-step) ET on day 3/day 5 (study group, n=100) and conventional day 5 FET (n=100, control group). The frozen-thawed embryos were transferred to hormone replacement therapy-prepared endometrium in both groups. The primary outcomes were clinical pregnancy and implantation rates. The secondary outcomes were early pregnancy loss and multiple pregnancies. The demographic and clinical characteristics of the two groups were comparable. Clinical pregnancy rates were significantly higher in the sequential (two-step) FET group (40%) compared to the day 5 group (19%) (P<0.001). The sequential transfer of frozen-thawed embryos on day 3/day 5 was more effective than regular day 5 for patients suffering from repeated IVF failure.

TOP2A deficit-induced abnormal decidualization leads to recurrent implantation failure via the NF-κB signaling pathway

BACKGROUND

Successful implantation is a complex process that is influenced by embryo quality, endometrial receptivity, immune factors, and the specific type of in vitro fertilization protocol used. DNA topoisomerase IIα (TOP2A) is a well-known protein involved in cell proliferation; however, its expression and effect on the endometrium in recurrent implantation failure (RIF) have not been fully elucidated.

METHODS

The human endometrial tissues of healthy controls and patients with RIF were collected. A proteomic analysis was performed to evaluate the differentially expressed proteins between the RIF group and the fertile control group. The expression patterns of TOP2A in the human preimplantation endometrium of the patients with RIF were determined by immunohistochemical staining, Western blotting and qRT-PCR. TOP2A knockdown (sh-TOP2A) T-HESCs were generated using lentiviruses. The expression of TOP2A in T-HESCs was manipulated to investigate its role in decidualization. The TOP2A-related changes in decidualization were screened by mRNA sequencing in decidualized TOP2A knockdown and control T-HESCs and then confirmed by Western blotting and immunofluorescence staining. TOP2A-deficient mice were generated by injection of TOP2A-interfering adenovirus on GD2.5 and GD3.5.

RESULTS

We performed a proteomic analysis of endometrial tissues to investigate the potential pathogenesis of RIF by comparing the patients with RIF and the matched controls and found that TOP2A might be a key protein in RIF. TOP2A is ubiquitously expressed in both stromal and glandular epithelial cells of the endometrium. The data indicate that TOP2A expression is significantly lower in the mid-secretory endometrium of women with RIF. TOP2A expression was downregulated under stimulation by 8-bromo-cAMP and MPA. Ablation of TOP2A resulted in upregulated expression of decidual biomarkers and morphological changes in the cells. Mechanistic analysis revealed that TOP2A regulates the NF-κB signaling pathway in decidualized T-HESCs. The TOP2A-deficient mice exhibited lower fetal weights.

CONCLUSIONS

Our findings revealed that abnormal expression of TOP2A affects decidualization and changes the "window of implantation", leading to RIF. TOP2A participates in the processes of decidualization and embryo implantation, functioning at least in part through the NF-κB pathway. Regulating the expression of TOP2A in the endometrium may become a new strategy for the prevention and treatment of RIF.

Role of endometrial microRNAs in repeated implantation failure (mini-review)

MicroRNAs (miRNAs) play various roles in the implantation and pregnancy process. Abnormal regulation of miRNAs leads to reproductive disorders such as repeated implantation failure (RIF). During the window of implantation, different miRNAs are released from the endometrium, which can potentially reflect the status of the endometrium for in vitro fertilization (IVF). The focus of this review is to determine whether endometrial miRNAs may be utilized as noninvasive biomarkers to predict the ability of endometrium to implant and provide live birth during IVF cycles. The levels of certain miRNAs in the endometrium have been linked to implantation potential and pregnancy outcomes in previous studies. Endometrial miRNAs could be employed as non-invasive biomarkers in the assisted reproductive technology (ART) cycle to determine the optimal time for implantation. Few human studies have evaluated the association between ART outcomes and endometrial miRNAs in RIF patients. This review may pave the way for more miRNA transcriptomic studies on human endometrium and introduce a specific miRNA profile as a multivariable prediction model for choosing the optimal time in the IVF cycle.

The Application of Artificial Intelligence in Predicting Embryo Transfer Outcome of Recurrent Implantation Failure

Background: Recurrent implantation failure (RIF) refers to that infertile patients have undergone multiple in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) cycles and transferred multiple embryos without embryo implantation or clinical pregnancy. Due to the lack of clear evidence-based medical guidelines for the number of embryos to be transferred in RIF patients, how to obtain the highest single cycle pregnancy success rate with as few embryos transferred as possible while avoiding multiple pregnancy as much as possible, that is, how to balance the pregnancy success rate and multiple pregnancy rate, is a great challenge for clinicians and RIF patients. We urgently need an effective and reliable assisted decision-making method to help clinicians find this balance, and an artificial intelligence (AI) system will provide an efficient solution.

Design and Methods: In this research, we filtered out the RIF data set (n = 45,921) from the Human Fertilisation and Embryology Authority (HFEA) database from 2005 to 2016. The data set was divided into two groups according to the number of embryos transferred, Group A and B. Group A included 34,175 cycles with two embryos transferred, while Group B included 11,746 cycles with only one embryo transferred, each containing 44 features and a prediction label (pregnancy). Four machine learning algorithms (RF, GBDT, AdaBoost, and MLP) were used to train Group A and Group B data set respectively and 10-folder cross validation method was used to validate the models.

Results: The results revealed that the AdaBoost model of Group A obtained the best performance, while the GBDT model in Group B was proved to be the best model. Both models had been proved to provide accurate prediction of transfer outcome.

Conclusion: Our research provided a new approach for targeted and personalized treatment of RIF patients to help them achieve efficient and reliable pregnancy. And an AI-assisted decision-making system will be designed to help clinicians and RIF patients develop personalized transfer strategies, which not only guarantees efficient and reliable pregnancy, but also avoids the risk of multiple pregnancy as much as possible.

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

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

Improved pregnancy outcomes of cyclosporine A on patients with unexplained repeated implantation failure in IVF/ICSI cycles: A retrospective cohort study

PROBLEM

Repeated implantation failure (RIF) is a daunting obstacle restricting the further improvement of embryo implantation rate (IR) and live birth rate (LBR). The beneficial effect of cyclosporine A (CsA) on reproductive outcomes of unexplained RIF(URIF) was explored after de novo embryo transfer (ET).

METHOD OF STUDY

A retrospective cohort study was conducted, comparing pregnancy outcomes of 146 cycles (CsA group, n = 62; control group, n = 84) at the IVF center of Suzhou Municipal Hospital from April 2016 to March 2020.

RESULTS

Baseline and transfer cycle characteristics of participants were comparable between groups. Overall, CsA exerted obvious improvement on IR (51.16% vs 31.97%, P = .006), clinical pregnancy rate (CPR) (58.06% vs 38.10%, P = .017), and LBR (48.39% vs 32.14%, P = .047). Especially, CsA showed remarkably enhancement on IR (41.38% vs 14.63%, P = .012), CPR (47.62% vs 17.24%, P = .021) of non-high quality embryos. No difference in obstetric and pediatric complications was observed, and no birth defects were reported under CsA application. CsA was found to be a predictor of clinical pregnancy [fine adjusted OR 2.360, 95 % CI 1.165-4.781; P = .017] and live birth [fine adjusted OR 2.339, 95% CI 1.124-4.867; P = .023] for multivariate logistic regression. Not surprisingly, the number of high quality embryos should also be considered as an independent predictor for clinical pregnancy [fine adjusted OR 1.637,95%CI 1.027-2.609; P = .038] and live birth [fine adjusted OR 1.890, 95% CI 1.165-3.068; P = .010].

CONCLUSION

CsA application in patients with URIF promotes the pregnancy outcomes and does not increase the risk of obstetric and pediatric complications.

Emerging trends and frontier research on recurrent implantation failure: a bibliometric analysis

Background

Recurrent implantation failure (RIF) has been recognized to be a major obstacle to the successful application of artificial reproduction technologies. In this study, the trends in RIF research were examined through a bibliometric analysis evaluating relevant literature quantitatively and qualitatively.

Methods

A total of 1,764 publications from 2000 to 2020 were downloaded from the Web of Science Core Collection (WoSCC). Relevant articles were searched using the term "recurrent implantation failure" and other synonyms of this term. Using Excel 2013, CiteSpace V, and VOSviewer 1.6.10 software, data extracted from the literature, including countries/regions, institutions, journals, keywords, and trends, were analyzed. Next, a clustered network was constructed based on 46,718 references cited by the 1,764 publications to determine the top 10 cocited articles.

Results

The annual number of publications on RIF progressively increased over time. The highest number of publications were from the United States. Analysis of the cocited reference cluster showed that "endometrial injury", "platelet-rich plasma", "chronic endometritis" and "extracellular vesicles" were the hotspots in RIF research. Burst detection analysis of the top keywords showed that "hysteroscopy" and "improvement" are emerging research foci.

Conclusions

This study clarifies the current research status and evolution of research in the field of RIF. New therapeutic interventions designed to improve pregnancy outcomes are the focus of current research and are expected to dominate future research in the field of RIF.

Preimplantation genetic testing for aneuploidy (PGT-A)-a single-center experience

PURPOSE

The aim of this study was to determine the prevalence and nature of human embryonic aneuploidy based on the preimplantation genetic testing for aneuploidy (PGT-A), the distribution of aneuploidy across the individual chromosomes, and their relationship to maternal age.

METHODS

This is a retrospective cohort study conducted at a single center. The study includes subjects who opted for PGT-A in their in vitro fertilization (IVF) cycle from 2016 to 2020. PGT-A was performed on 1501 embryos from 488 patients in 535 cycles. PGT-A was performed using NGS-based technique on Ion Torrent PGM (Life Technologies). Analysis was performed to determine the (i) frequency of the aneuploidy, (ii) the chromosome most commonly affected, (iii) relationship between maternal age and the rate of aneuploidy, and (iv) incidence of segmental aneuploidy.

RESULTS

The overall frequency of aneuploidy was observed to be 46.8%. The incidence of aneuploidy rate was ~ 28% at maternal age < 30 years which steadily increased to ~ 67% in women above 40 years. High frequency of aneuploidy was observed in chromosomes 16, 22, 21, and 15. Segmental abnormalities, involving loss or gain of chromosomal fragments, were observed at a frequency of 5.3%, and highest incidence of segmental gain was observed on the q-arm of chromosome 9.

CONCLUSION

The study provides important information regarding the frequency of the aneuploidy in IVF cohort and the most frequent chromosomal abnormality. The study further emphasizes the relationship between maternal age and aneuploidy. This study has important implications which help clinicians and genetic counselors in providing information in patient counseling.

The Role of Interleukins in Recurrent Implantation Failure: A Comprehensive Review of the Literature

Recurrent implantation failure (RIF) is a multifactorial condition affecting 10-15% of in vitro fertilization (IVF) couples. Data suggest that functional dysregulation of the endometrial immune system constitutes one of the main pathophysiological mechanisms leading to RIF. The aim of this article is to provide a thorough presentation and evaluation of the role of interleukins (ILs) in the pathogenesis of RIF. A comprehensive literature screening was performed summarizing current evidence. During implantation, several classes of ILs are secreted by epithelial and stromal endometrial cells, including IL-6, IL-10, IL-12, IL-15, IL-18, and the leukemia inhibitory factor. These ILs create a perplexing network that orchestrates both proliferation and maturation of uterine natural killer cells, controls the function of regulatory T and B cells inhibiting the secretion of antifetal antibodies, and supports trophoblast invasion and decidua formation. The existing data indicate associations between ILs and RIF. The extensive analysis performed herein concludes that the dysregulation of the ILs network indeed jeopardizes implantation leading to RIF. This review further proposes a mapping of future research on how to move forward from mere associations to robust molecular data that will allow an accurate profiling of ILs in turn enabling evidence-based consultancy and decision making when addressing RIF patients.

Gonadotropin-releasing hormone agonist downregulation combined with hormone replacement therapy improves the reproductive outcome in frozen-thawed embryo transfer cycles for patients of advanced reproductive age with idiopathic recurrent implantation failure

BACKGROUND

To determine whether gonadotropin-releasing hormone (GnRH) agonist downregulation combined with hormone replacement therapy (HRT) can improve the reproductive outcomes in frozen-thawed embryo transfer cycles for older patients (aged 36-43 years) with idiopathic recurrent implantation failure (RIF).

METHODS

This retrospective cohort study involved 549 older patients undergoing their third cleavage-stage embryo or blastocyst transfer over a 5-year period (January 2015-December 2020) at Northwest Women's and Children's Hospital after in vitro fertilization/intracytoplasmic sperm injection cycles. Patients with known endometriosis or adenomyosis were excluded from the study. The patients were divided into three groups according to the endometrial preparation protocol: the natural cycle (NC) group (n = 65), the HRT group (n = 194), and the GnRH agonist downregulation combined with HRT cycle (GnRH agonist-HRT) group (n = 290). The primary outcome was the live birth rate, and the secondary outcomes were the clinical pregnancy, miscarriage, and ongoing pregnancy rates.

RESULTS

The live birth rate in the GnRH agonist-HRT group (36.55%) was higher than that in the HRT group (22.16%) and NC group (16.92%) (P < 0.0001). Similarly, a logistic regression model adjusting for potential confounders showed that the live birth rate was higher in the GnRH agonist-HRT group than in the HRT group (odds ratio, 0.594; 95% confidence interval, 0.381-0.926; P = 0.021) and NC group (odds ratio, 0.380; 95% confidence interval, 0.181-0.796; P = 0.010).

CONCLUSIONS

The GnRH agonist-HRT protocol improves the live birth rate in frozen-thawed embryo transfer cycles for patients of advanced reproductive age with RIF. We hypothesize that the GnRH agonist-HRT protocol enhances implantation-related factors and promotes optimal endometrial receptivity, leading to an improved live birth rate. These findings are also useful for further investigating the underlying mechanism of the GnRH agonist-HRT protocol in improving the reproductive outcomes for patients of advanced reproductive age with RIF.

TRIAL REGISTRATION

This research protocol was approved by the hospital institutional ethics committee (No. 2021002).

Xiaoyao powder improves endometrial receptivity via VEGFR-2-mediated angiogenesis through the activation of the JNK and P38 signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Xiaoyao powder (XYP) is a traditional Chinese medicine formula which has wide scope of indications related to liver stagnation, reconcile qi and blood in TCM syndrome. Infertility can induce similar symptoms and signs to the clinical features of liver stagnation syndrome, the treatment of infertility by soothing the liver is obvious. XYP can increase the clinical pregnancy rate, follicle development, oocyte quality and improve endometrial receptivity. However, its underlying pharmacological mechanism of improving endometrial receptivity is unclear.

AIM OF THE STUDY

The aim of the study was to investigate the effect of XYP on pregnancy rates and endometrial angiogenesis, to determine the potent mechanism in association with the pro-angiogenic behavior which closely related to improving endometrial receptivity.

MATERIALS AND METHODS

We established an animal model exhibiting decreasing endometrial receptivity by controlled ovarian hyperstimulation and a human endometrial microvascular endothelial cell (HEMEC) model. Endometrial morphology was observed by hematoxylin-eosin staining and Scanning electron microscopy. Western blot and qRT-PCR analysis were used to detect expression of PCNA, Cyclin D1, MMP9 and MAPK signaling pathway. Scratch-wound assay and tube formation assay were used to observe HEMEC migration and tubulogenesis.

RESULTS

The results demonstrated that XYP pretreatment could improve endometrial receptivity, which leads to high pregnancy rates. In the endometrium, XYP facilitated angiogenesis by promoting tube formation. XYP could enhance HEMEC proliferation and migration induced by VEGF, which were observed by the microscope and Scratch-wound assays. XYP promoted HEMEC proliferation and migration via the p38 and JNK MAPK signaling pathways.

CONCLUSION

XYP promotes HEMEC proliferation and migration via the P38 and the JNK MAPK signaling pathways, which contribute to the endometrial angiogenesis mediated by VEGFR-2 that is favorable for endometrial receptivity. We firstly elucidated the molecular mechanisms by which XYP improved endometrial receptivity by promoting angiogenesis.

Intrauterine interventions for women with two or more implantation failures: A systematic review and network meta-analysis

OBJECTIVE

To compare the effectiveness of different intrauterine interventions for women with two or more unexplained implantation failures.

DESIGN

A systematic review and network meta-analysis of randomized controlled trials (RCTs).

PATIENTS

Women with two or more implantation failures undergoing fresh or frozen embryo transfer (ET).

INTERVENTIONS

An electronic search of the following databases: Pubmed, Cochrane Central Register of Controlled Trials (CENTRAL), and Embase.

MAIN OUTCOME MEASURES

Clinical pregnancy, live birth/ongoing pregnancy, and miscarriage.

RESULTS

We included 21 RCTs(3079 women) in the network meta-analysis. The network meta-analysis showed that compared with control treatment, platelet-rich plasma(PRP), peripheral blood mononuclear cells (PBMC), granulocyte colony-stimulating factor(G-CSF), human chorionic gonadotropin(HCG), and endometrial scratch(ES) significantly increased clinical pregnancy(OR 3.78, 95% CI 2.72 to 5.25; 2.79, 95% CI 1.75 to 4.45; 1.93, 95% CI 1.37 to 2.72; 1.80, 95% CI 1.18 to 2.72; 1.75, 95% CI 1.29 to 2.36, respectively). PRP ranked the highest in improving clinical pregnancy, followed by PBMC, G-CSF, HCG, and ES. Compared with control treatment, PRP, PBMC, and ES significantly increased live birth/ongoing pregnancy (OR 5.96, 95% CI 3.38 to 10.52; OR 2.55, 95% CI 1.27 to 5.11; OR 1.70, 95% CI 1.07 to 2.69, respectively). PRP ranked the highest in improving live birth/ongoing pregnancy, followed by PBMC, and ES.

CONCLUSIONS

PRP is the most effective intrauterine intervention in improving pregnancy outcome in women with two or more implantation failures.

Insight on Polyunsaturated Fatty Acids in Endometrial Receptivity

Endometrial receptivity plays a crucial role in fertilization as well as pregnancy outcome in patients faced with fertility challenges. The optimization of endometrial receptivity may help with normal implantation of the embryo, and endometrial receptivity may be affected by numerous factors. Recently, the role of lipids in pregnancy has been increasingly recognized. Fatty acids and their metabolites may be involved in all stages of pregnancy and play a role in supporting cell proliferation and development, participating in cell signaling and regulating cell function. Polyunsaturated fatty acids, in particular, are essential fatty acids for the human body that can affect the receptivity of the endometrium through in a variety of methods, such as producing prostaglandins, estrogen and progesterone, among others. Additionally, polyunsaturated fatty acids are also involved in immunity and the regulation of endometrial decidualization. Fatty acids are essential for fetal placental growth and development. The interrelationship of polyunsaturated fatty acids with these substances and how they may affect endometrial receptivity will be reviewed in this article.

Live Birth with or without Preimplantation Genetic Testing for Aneuploidy

BACKGROUND

Embryo selection with preimplantation genetic testing for aneuploidy (PGT-A) may improve pregnancy outcomes after initial embryo transfer. However, it remains uncertain whether PGT-A improves the cumulative live-birth rate as compared with conventional in vitro fertilization (IVF).

METHODS

In this multicenter, randomized, controlled trial, we randomly assigned subfertile women with three or more good-quality blastocysts to undergo either PGT-A or conventional IVF; all the women were between 20 and 37 years of age. Three blastocysts were screened by next-generation sequencing in the PGT-A group or were chosen by morphologic criteria in the conventional-IVF group and then were successively transferred one by one. The primary outcome was the cumulative live-birth rate after up to three embryo-transfer procedures within 1 year after randomization. We hypothesized that the use of PGT-A would result in a cumulative live-birth rate that was no more than 7 percentage points higher than the rate after conventional IVF, which would constitute the noninferiority margin for conventional IVF as compared with PGT-A.

RESULTS

A total of 1212 patients underwent randomization, and 606 were assigned to each trial group. Live births occurred in 468 women (77.2%) in the PGT-A group and in 496 (81.8%) in the conventional-IVF group (absolute difference, -4.6 percentage points; 95% confidence interval [CI], -9.2 to -0.0; P<0.001). The cumulative frequency of clinical pregnancy loss was 8.7% and 12.6%, respectively (absolute difference, -3.9 percentage points; 95% CI, -7.5 to -0.2). The incidences of obstetrical or neonatal complications and other adverse events were similar in the two groups.

CONCLUSIONS

Among women with three or more good-quality blastocysts, conventional IVF resulted in a cumulative live-birth rate that was noninferior to the rate with PGT-A. (Funded by the National Natural Science Foundation of China and others; ClinicalTrials.gov number, NCT03118141.).

A robust metabolomics approach for the evaluation of human embryos from in vitro fertilization

The identification of the most competent embryos for transfer to the uterus constitutes the main challenge of in vitro fertilization (IVF). We established a metabolomic-based approach by applying Fourier transform infrared (FTIR) spectroscopy on 130 samples of 3-day embryo culture supernatants from 26 embryos that implanted and 104 embryos that failed. On examining the internal structure of the data by unsupervised multivariate analysis, we found that the supernatant spectra of nonimplanted embryos constituted a highly heterogeneous group. Whereas ∼40% of these supernatants were spectroscopically indistinguishable from those of successfully implanted embryos, ∼60% exhibited diverse, heterogeneous metabolic fingerprints. This observation proved to be the direct result of pregnancy's multifactorial nature, involving both intrinsic embryonic traits and external characteristics. Our data analysis strategy thus involved one-class modelling techniques employing soft independent modelling of class analogy that identified deviant fingerprints as unsuitable for implantation. From these findings, we could develop a noninvasive Fourier-transform-infrared-spectroscopy-based approach that represents a shift in the fundamental paradigm for data modelling applied in assisted-fertilization technologies.

Identification of Uterine Microbiota in Infertile Women Receiving in vitro Fertilization With and Without Chronic Endometritis

In vitro fertilization (IVF) is an important assisted reproductive technology in treating infertility, whose failure rate is still high. Studies suggested that uterine microbiota are related to women’s reproductive diseases and persisting intrauterine bacterial infectious conditions, such as chronic endometritis (CE), impairing the pregnant processes. However, the relationship between uterine microbiota and IVF outcomes is still an open question. In the present study, 94 patients diagnosed with infertility were enrolled and were divided into CE (E group, n = 25) and non-CE (NE group, n = 69) groups depending on the hysteroscopy and immunohistochemistry. Subsequently, E (Ep, n = 8 and Enp, n = 17) and NE (NEp, n = 41 and NEnp, n = 28) groups were divided into pregnancy and non-pregnancy groups depending on the IVF outcomes, respectively. The uterine fluids were collected and microbial profiles were examined through the V4 region of 16S rRNA gene high-throughput sequencing. The results demonstrated that patients with CE had significantly lower clinical pregnancy rate compared with the non-CE patients (32 vs. 58.42%, p = 0.0014). The relative abundances of Proteobacteria and Acidobacteria were higher in the non-CE group, whereas high abundances of Actinobacteria and Fusobacteria were observed in the CE group at the phylum level. At the genus level, high relative abundances of Gardnerella were observed in the CE group and non-pregnancy groups, which significantly referred to the negative IVF outcome. In conclusion, CE may be a key factor for the negative outcome after IVF, of which the uterine microbiota plays a pivotal role, and the microbial diversity in uterine may serve as a biomarker to forecast the success of IVF outcome.

Reproductive outcomes of women with recurrent pregnancy losses and repeated implantation failures are significantly improved with immunomodulatory treatment

This study investigated if immunomodulatory treatment improves the in-vitro fertilization (IVF) success rates of women with two or more recurrent pregnancy losses (RPL) and repeated implantation failures (RIF) with cellular immune abnormalities and thrombophilia. We performed a retrospective cohort study of 197 RPL patients who received immunomodulatory and anticoagulation treatment undergoing IVF cycles (fresh or frozen embryo transfer). Patients were divided into four groups; Group 1: women with RPL but without RIF, Group 2: women with RPL and RIF (≥3), Group 3: women with RPL after IVF cycles (>2) and without RIF, and Group 4: women with RPL after IVF cycles and RIF. Patients received immunomodulatory treatment with prednisone-only or prednisone and intravenous immunoglobulin G (IVIG) and anticoagulation treatment with low molecular weight heparin and low dose aspirin. IVF success rates of study groups were compared to those of the historical controls. The pregnancy rate of IVF cycles with immunomodulatory treatment was significantly increased in all patients (48.2 % vs. 33.0 %, P < 0.001), Group 1 (54.2 % vs. 30.5 %, P < 0.005) and Group 2 (33.3 % vs. 11.0 %, P < 0.005) as compared to historical controls. The live birth rates per ET cycle were significantly improved for all patients (1.8 % vs. 39.6 %, P < 0.001), and study groups compared to their historical controls (Group 1, 43.1 % vs. 0 %; Group 2, 33.3 % vs. 2.5 %; Group 3, 45.5 % vs. 2.3 %; and Group 4, 16.7 % vs. 1.2 %, P < 0.001, respectively). Immunomodulatory and anticoagulation treatment significantly improved the reproductive outcomes of IVF cycles in women with a history of RPL and/or RIF of immune etiologies.

A comparative evaluation of subendometrial and intrauterine platelet-rich plasma treatment for women with recurrent implantation failure

OBJECTIVE

To compare the effectiveness of treatment with autologous activated platelet-rich plasma (PRP), administered to either the subendometrium (SE-PRP) or endometrial surface (intrauterine; IU-PRP), against controls.

DESIGN

Prospective observational cohort study.

SETTING

Tertiary fertility unit.

PATIENTS

Women aged <40 years with a history of recurrent implantation failure undergoing frozen embryo transfer (FET) (n = 318).

INTERVENTIONS

In SE-PRP, PRP was injected into the subendometrial space transvaginally in the luteal phase of the previous cycle of embryo transfer under ultrasound guidance (n = 55). In IU-PRP, PRP was administered during the index FET cycle when the endometrium was approximately 7 mm (n = 109). Both SE-PRP and IU-PRP groups were administered 300 μg of granulocyte colony-stimulating factor (G-CSF) subcutaneously once a day for 3 days to boost white blood cells (WBC) and growth factor production in the PRP sample. The control group consisted of women who did not choose PRP treatment and underwent standard FET with no intervention (n = 154).

MAIN OUTCOME MEASURES

Ongoing pregnancy rate or live birth rate (OPR/LBR) per transfer cycle, clinical pregnancy rate (CPR) per transfer cycle, and miscarriage rate.

RESULTS

As a result, OPR/LBR was higher in the SE-PRP (22/55, 40%) and IU-PRP (45/109, 41.3%) groups than that in the control group (34/154, 22.1%). It was similar between the SE-PRP and IU-PRP groups. Moreover, CPR showed a similar trend with a higher rate in the SE-PRP (28/55, 51%) and IU-PRP (57/109, 52.3%) groups than that in the controls (52/154, 33.8%). No statistical difference in the CPR was noted between the SE-PRP and IU-PRP groups. The miscarriage rate was similar in all three groups (14/55, 25.45%; 25/109, 22.23%; and 34/154, 22.07%, respectively).

CONCLUSION

In women with a history of recurrent implantation failure, PRP treatment appears to improve FET outcome with an increase in OPR/LBR. However, SE-PRP treatment does not offer any advantage over lesser invasive IU-PRP treatment.

Evaluation of Pregnancy Outcomes of Vitrified-Warmed Blastocyst Transfer before and after Endometrial Receptivity Analysis in Identical Patients with Recurrent Implantation Failure

Background: The clinical value of personalized embryo transfer (pET) guided by the endometrial receptivity analysis (ERA) tests for recurrent implantation failure (RIF) cases is still unclear. The aim of this study is to clarify the efficacy of ERA leading to personalization of the day of embryo transfer (ET) in RIF patients.

Methods: A retrospective study was performed for 94 patients with RIF who underwent ERA between July 2015 and December 2019. Pregnancy outcomes in a previous vitrified-warmed blastocyst transfer (previous VBT) and a personalized vitrified-warmed blastocyst transfer (pVBT) in identical patients were compared. The details of each pVBT were further analyzed between patients in a non-displaced group, which indicated “receptive” cases in ERA results and those who were in the displaced group, which indicated “non-receptive” cases.

Results: When the pregnancy rate, both per patient and per transfer cycle, of previous VBT and pVBT were compared, a significant increase in pVBT was observed between the two methods (5.3% vs. 62.8%, 4.4% vs. 47.9%, respectively). The pregnancy rates, implantation rates, and clinical pregnancy rates of the first pVBT were significantly higher in the displaced group than the non-displaced group. The cumulative ongoing pregnancy rate of the displaced group tended to be higher compared to that of the non-displaced group in the first pVBT, although the difference was not statistically significant (51.0% vs. 31.1%, [Formula: see text] = 0.06).

Conclusions: Our study demonstrates that pVBT guided by ERA tests may improve pregnancy outcomes in RIF patients whose window of implantation (WOI) is displaced, and its effect may be more pronounced at the first pVBT. The displacement of WOI may be considered to be one of the causes of RIF, and its adjustment may contribute to the improvement of pregnancy outcomes in RIF patients.

Hysteroscopic endometrial peeling as a different approach to endometrial scratching. Case series report

STUDY QUESTION

Does hysteroscopic endometrial peeling improve reproductive outcomes in women with implantation failure?

DESIGN

In this case series, 66 women underwent an hysteroscopic endometrial peeling and subsequently, a single frozen embryo transfer.

RESULTS

After the exclusion of patients with intraoperative incidental findings, pregnancy was achieved in 63% (42/66) of the women who underwent hysteroscopic endometrial peeling and subsequently a single frozen embryo transfer, clinical pregnancy rate was observed in 57% (38/66) of the patients and, clinical pregnancy loss occurred in 10% (4/38).

CONCLUSION

this novel surgical technique seems to increase implantation as well as clinical pregnancy rates in women with repeated implantation failure. We can hypothesize that the controlled and subtle degree of endometrial injury generated by the peeling generates an inflammatory cascade that enhances implantation.

Endometrial gene expression profiling of recurrent implantation failure after in vitro fertilization

Recurrent implantation failure (RIF) is diagnosed when good-quality embryos repeatedly fail to implant after transfer in several in vitro fertilization (IVF) treatment cycles. Different expression profiles in maternal mRNAs could be referring to many diseases including RIF. This study aimed to reveal significantly dysregulated selected genes expression between healthy fertile women and RIF patients in the implantation window days of the natural menstrual cycle. MME, WWC1, TNC, and FOXP3 genes were chosen as target genes regarding their possible relations with the implantation process. Pathways with these genes were identified and the relationship between these pathways and RIF was investigated. In this study, the endometrial biopsy samples were collected in the secretory phase (cycle day 20-24) of the menstrual cycle from RIF patients (n = 34) and healthy fertile controls (n = 34). After "Pathway and network-oriented GWAS analysis" (PANOGA) and "Kyoto Encyclopedia of Genes and Genomes" (KEGG) pathway analysis; "Membrane Metalloendopeptidase" (MME), "WW and C2 Domain Containing 1" (WWC1), "Tenascin C" (TNC) and "Forkhead Box P3" (FOXP3) genes were chosen as target genes by regarding their possible relation with implantation process. Detection of differences in mRNA expressions between the control group and RIF patients has been performed with the droplet digital PCR (ddPCR) method. Results of the study showed that MME and WWC1 genes expression levels are significantly (p < 0,05) up-regulated 4.9 and 5.2 times respectively and TNC gene expression level is significantly (p < 0,05) down-regulated 9 times in the RIF samples compared to the control group. However, no statistically significant difference was observed between the patient group and the control group in the expression of the FOXP3 gene (p < 0.05). Changes are observed in the expression of the renin-angiotensin system pathway in which the MME gene is involved in the implantation process. The increase in MME gene expression can be speculated to cause implantation failure by restricting the invasion of trophoblast cells. Increasing WWC1 gene expression in the Hippo signaling pathway inhibits "Yes-associated protein 1" (YAP) expression, which is a transcriptional cofactor. Inhibition of YAP protein expression may impair the implantation process by causing the failure of endometrial decidualization. The TNC gene is located in the focal adhesion pathway and this pathway reduces cell adhesion on the endometrial surface to facilitate the attachment of the embryo to the endometrium. The reason for implantation failure might be that the intercellular connections are not suitable for implantation as a result of decreased expression of the focal adhesion pathway in which the TNC gene is effective. Considering the relations between the pathways of the target genes and the implantation process, changes in the expression of target genes might be a cause of RIF.

Analysis of vaginal and endometrial microbiota communities in infertile women with a history of repeated implantation failure

PURPOSE

To identify specific bacterial communities in vaginal and endometrial microbiotas as biomarkers of implantation failure by comprehensively analyzing their microbiotas using next-generation sequencing.

METHODS

We investigated α- and β-diversities of vaginal and endometrial microbiotas using 16S rRNA gene sequencing and compared their profiles between 145 women with repeated implantation failure (RIF) and 21 controls who lacked the factors responsible for implantation failure with a high probability of being healthy and fertile to identify specific bacteria that induce implantation failure.

RESULTS

The endometrial microbiotas had higher α-diversities than did the vaginal microbiotas (P < .001). The microbiota profiles showed that vaginal and endometrial samples in RIF patients had significantly higher levels of 5 and 14 bacterial genera, respectively, than those in controls. Vaginal Lactobacillus rates in RIF patients were significantly lower at 76.4 ± 38.9% compared with those of the controls at 91.8 ± 22.7% (P = .018), but endometrial Lactobacillus rates did not significantly differ between the RIF patients and controls (56.2 ± 36.4% and 58.8 ± 37.0%, respectively, P = .79).

CONCLUSIONS

Impaired microbiota communities containing specific bacteria in both the endometrium and vagina were associated with implantation failure. The vaginal Lactobacillus rates, but not the endometrial, may be a biomarker for RIF.