An unbiased approach of molecular characterization of the endometrium: toward defining endometrial-based infertility.

Infertility is a complex condition affecting millions of couples worldwide. The current definition of infertility, based on clinical criteria, fails to account for the molecular and cellular changes that may occur during the development of infertility. Recent advancements in sequencing technology and single-cell analysis offer new opportunities to gain a deeper understanding of these changes. The endometrium has a potential role in infertility and has been extensively studied to identify gene expression profiles associated with (impaired) endometrial receptivity. However, limited overlap among studies hampers the identification of relevant downstream pathways that could play a role in the development of endometrial-related infertility. To address these challenges, we propose sequencing the endometrial transcriptome of healthy and infertile women at the single-cell level to consistently identify molecular signatures. Establishing consensus on physiological patterns in endometrial samples can aid in identifying deviations in infertile patients. A similar strategy has been used with great success in cancer research. However, large collaborative initiatives, international uniform protocols of sample collection and processing are crucial to ensure reliability and reproducibility. Overall, the proposed approach holds promise for an objective and accurate classification of endometrial-based infertility and has the potential to improve diagnosis and treatment outcomes.

The endometrial transcriptome of infertile women with and without implantation failure.

INTRODUCTION: Implantation failure after transferring morphologically "good-quality" embryos in in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) may be explained by impaired endometrial receptivity. Analyzing the endometrial transcriptome analysis may reveal the underlying processes and could help in guiding prognosis and using targeted interventions for infertility. This exploratory study investigated whether the endometrial transcriptome profile was associated with short-term or long-term implantation outcomes (ie success or failure). MATERIAL AND METHODS: Mid-luteal phase endometrial biopsies of 107 infertile women with one full failed IVF/ICSI cycle, obtained within an endometrial scratching trial, were subjected to RNA-sequencing and differentially expressed genes analysis with covariate adjustment (age, body mass index, luteinizing hormone [LH]-day). Endometrial transcriptomes were compared between implantation failure and success groups in the short term (after the second fresh IVF/ICSI cycle) and long term (including all fresh and frozen cycles within 12 months). The short-term analysis included 85/107 women (33 ongoing pregnancy vs 52 no pregnancy), excluding 22/107 women. The long-term analysis included 46/107 women (23 'fertile' group, ie infertile women with a live birth after ≤3 embryos transferred vs 23 recurrent implantation failure group, ie no live birth after ≥3 good quality embryos transferred), excluding 61/107 women not fitting these categories. As both analyses drew from the same pool of 107 samples, there was some sample overlap. Additionally, cell type enrichment scores and endometrial receptivity were analyzed, and an endometrial development pseudo-timeline was constructed to estimate transcriptomic deviations from the optimum receptivity day (LH + 7), denoted as ΔWOI (window of implantation). RESULTS: There were no significantly differentially expressed genes between implantation failure and success groups in either the short-term or long-term analyses. Principal component analysis initially showed two clusters in the long-term analysis, unrelated to clinical phenotype and no longer distinct following covariate adjustment. Cell type enrichment scores did not differ significantly between groups in both analyses. However, endometrial receptivity analysis demonstrated a potentially significant displacement of the WOI in the non-pregnant group compared with the ongoing pregnant group in the short-term analysis. CONCLUSIONS: No distinct endometrial transcriptome profile was associated with either implantation failure or success in infertile women. However, there may be differences in the extent to which the WOI is displaced.

Endometrial injury for pregnancy following sexual intercourse or intrauterine insemination.

BACKGROUND: Intentional endometrial injury is being proposed as a technique to improve the probability of pregnancy in women undergoing assisted reproductive technologies (ART) such as in vitro fertilisation (IVF). Endometrial injury is often performed by pipelle biopsy and is a common gynaecological procedure with established safety. However, it causes a moderate degree of discomfort/pain and requires an additional pelvic examination. The effectiveness of this procedure outside of ART, in women or couples attempting to conceive via sexual intercourse or with intrauterine insemination (IUI), remains unclear. OBJECTIVES: To assess the effectiveness and safety of intentional endometrial injury performed in infertile women or couples attempting to conceive through sexual intercourse or intrauterine insemination (IUI). SEARCH METHODS: The Cochrane Gynaecology and Fertility Group Specialised Register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, LILACS, ISI Web of Knowledge, and clinical trial registries were searched from inception to 21 May 2020, as were conference abstracts and reference lists of relevant reviews and included studies. SELECTION CRITERIA: We included randomised controlled trials (RCTs) that evaluated any kind of intentional endometrial injury in women planning to undergo IUI or attempting to conceive spontaneously (with or without ovarian stimulation (OS)) compared to no intervention, a mock intervention, or intentional endometrial injury performed at a different time. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures recommended by Cochrane. Primary outcomes were live birth/ongoing pregnancy and pain experienced during the procedure. Due to high risk of bias associated with many of the studies, primary analyses of all review outcomes were restricted to studies at low risk of bias. Sensitivity analysis including all studies was then performed. MAIN RESULTS: We included 22 RCTs (3703 women). Most of these studies included women with unexplained infertility. Intentional endometrial injury versus either no intervention or a sham procedure The primary analysis was restricted to studies at low risk of bias, which left only one study included. We are uncertain whether endometrial injury has an effect on the probability of live birth, as only one study is included in the analysis and the confidence interval is wide (risk ratio (RR) 1.11, 95% confidence interval (CI) 0.78 to 1.59; 1 RCT, 210 participants). Evidence suggests that if the chance of live birth with no intervention/a sham procedure is assumed to be 34%, then the chance with endometrial injury would be 27% to 55%. When all studies were included in the sensitivity analysis, we were uncertain whether endometrial injury improves live birth/ongoing pregnancy, as the evidence was of very low quality (RR 1.71, 95% CI 1.32 to 2.21; 8 RCTs, 1522 participants; I² = 16%). Evidence suggests that if the chance of live birth/ongoing pregnancy with no intervention/a sham procedure is assumed to be 13%, then the chance with endometrial injury would be 17% to 28%. A narrative synthesis conducted for the other primary outcome of pain during the procedure included studies measuring pain on a zero-to-ten visual analogue scale (VAS) or grading pain as mild/moderate/severe, and showed that most often mild to moderate pain was reported (6 RCTs, 911 participants; very low-quality evidence). Timing of intentional endometrial injury Four trials compared endometrial injury performed in the cycle before IUI to that performed in the same cycle as IUI. None of these studies reported the primary outcomes of live birth/ongoing pregnancy and pain during the procedure. One study compared endometrial injury in the early follicular phase (EFP; Day 2 to 4) to endometrial injury in the late follicular phase (LFP; Day 7 to 9), both in the same cycle as IUI. The primary outcome live birth/ongoing pregnancy was not reported, but the study did report the other primary outcome of pain during the procedure assessed by a zero-to-ten VAS. The average pain score was 3.67 (standard deviation (SD) 0.7) when endometrial injury was performed in the EFP and 3.84 (SD 0.96) when endometrial injury was performed in the LFP. The mean difference was -0.17, suggesting that on average, women undergoing endometrial injury in the EFP scored 0.17 points lower on the VAS as compared to women undergoing endometrial injury in the LFP (95% CI -0.48 to 0.14; 1 RCT, 110 participants; very low-quality evidence). AUTHORS' CONCLUSIONS: Evidence is insufficient to show whether there is a difference in live birth/ongoing pregnancy between endometrial injury and no intervention/a sham procedure in women undergoing IUI or attempting to conceive via sexual intercourse. The pooled results should be interpreted with caution, as the evidence was of low to very low quality due to high risk of bias present in most included studies and an overall low level of precision. Furthermore, studies investigating the effect of timing of endometrial injury did not report the outcome live birth/ongoing pregnancy; therefore no conclusions could be drawn for this outcome. Further well-conducted RCTs that recruit large numbers of participants and minimise bias are required to confirm or refute these findings. Current evidence is insufficient to support routine use of endometrial injury in women undergoing IUI or attempting to conceive via sexual intercourse.

Endometrial injury for pregnancy following sexual intercourse or intrauterine insemination.

BACKGROUND: Intentional endometrial injury is being proposed as a technique to improve the probability of pregnancy in women undergoing assisted reproductive technologies (ART) such as in vitro fertilisation (IVF). Endometrial injury is often performed by pipelle biopsy and is a common gynaecological procedure with established safety. However, it causes a moderate degree of discomfort/pain and requires an additional pelvic examination. The effectiveness of this procedure outside of ART, in women or couples attempting to conceive via sexual intercourse or with intrauterine insemination (IUI), remains unclear. OBJECTIVES: To assess the effectiveness and safety of intentional endometrial injury performed in infertile women or couples attempting to conceive through sexual intercourse or intrauterine insemination (IUI). SEARCH METHODS: The Cochrane Gynaecology and Fertility Group Specialised Register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, LILACS, ISI Web of Knowledge, and clinical trial registries were searched from inception to 21 May 2020, as were conference abstracts and reference lists of relevant reviews and included studies. SELECTION CRITERIA: We included randomised controlled trials (RCTs) that evaluated any kind of intentional endometrial injury in women planning to undergo IUI or attempting to conceive spontaneously (with or without ovarian stimulation (OS)) compared to no intervention, a mock intervention, or intentional endometrial injury performed at a different time or to a higher/lower degree. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures recommended by Cochrane. Primary outcomes were live birth/ongoing pregnancy and pain experienced during the procedure. Due to high risk of bias associated with many of the studies, primary analyses of all review outcomes were restricted to studies at low risk of bias. Sensitivity analysis including all studies was then performed. MAIN RESULTS: We included 23 RCTs (4035 women). Most of these studies included women with unexplained infertility. Intentional endometrial injury versus either no intervention or a sham procedure The primary analysis was restricted to studies at low risk of bias, which left only one study included. We are uncertain whether endometrial injury has an effect on the probability of live birth, as only one study is included in the analysis and the confidence interval is wide (risk ratio (RR) 1.11, 95% confidence interval (CI) 0.78 to 1.59; 1 RCT, 210 participants). Evidence suggests that if the chance of live birth with no intervention/a sham procedure is assumed to be 34%, then the chance with endometrial injury would be 27% to 55%. When all studies were included in the sensitivity analysis, we were uncertain whether endometrial injury improves live birth/ongoing pregnancy, as the evidence was of very low quality (RR 1.71, 95% CI 1.32 to 2.21; 8 RCTs, 1522 participants; I² = 16%). Evidence suggests that if the chance of live birth/ongoing pregnancy with no intervention/a sham procedure is assumed to be 13%, then the chance with endometrial injury would be 17% to 28%. A narrative synthesis conducted for the other primary outcome of pain during the procedure included studies measuring pain on a zero-to-ten visual analogue scale (VAS) or grading pain as mild/moderate/severe, and showed that most often mild to moderate pain was reported (6 RCTs, 911 participants; very low-quality evidence). Higher versus lower degree of intentional endometrial injury Evidence was insufficient to show whether there is a difference in ongoing pregnancy rates (RR 1.29, 95% CI 0.71 to 2.35; 1 RCT, 332 participants; low-quality evidence) between hysteroscopy with endometrial injury and hysteroscopy alone. Evidence suggests that if the chance of ongoing pregnancy with hysteroscopy alone is 10%, then the chance with hysteroscopy with endometrial injury would be 7% to 24%. This study did not report the primary outcomes of live birth and pain during the procedure. Timing of intentional endometrial injury Four trials compared endometrial injury performed in the cycle before IUI to that performed in the same cycle as IUI. None of these studies reported the primary outcomes of live birth/ongoing pregnancy and pain during the procedure. One study compared endometrial injury in the early follicular phase (EFP; Day 2 to 4) to endometrial injury in the late follicular phase (LFP; Day 7 to 9), both in the same cycle as IUI. The primary outcome live birth/ongoing pregnancy was not reported, but the study did report the other primary outcome of pain during the procedure assessed by a zero-to-ten VAS. The average pain score was 3.67 (standard deviation (SD) 0.7) when endometrial injury was performed in the EFP and 3.84 (SD 0.96) when endometrial injury was performed in the LFP. The mean difference was -0.17, suggesting that on average, women undergoing endometrial injury in the EFP scored 0.17 points lower on the VAS as compared to women undergoing endometrial injury in the LFP (95% CI -0.48 to 0.14; 1 RCT, 110 participants; very low-quality evidence). AUTHORS' CONCLUSIONS: Evidence is insufficient to show whether there is a difference in live birth/ongoing pregnancy between endometrial injury and no intervention/a sham procedure in women undergoing IUI or attempting to conceive via sexual intercourse. The pooled results should be interpreted with caution, as the evidence was of low to very low quality due to high risk of bias present in most included studies and an overall low level of precision. Furthermore, studies investigating the effect of timing of endometrial injury did not report the outcome live birth/ongoing pregnancy; therefore no conclusions could be drawn for this outcome. Further well-conducted RCTs that recruit large numbers of participants and minimise bias are required to confirm or refute these findings. Current evidence is insufficient to support routine use of endometrial injury in women undergoing IUI or attempting to conceive via sexual intercourse.

Organoids can be established reliably from cryopreserved biopsy catheter-derived endometrial tissue of infertile women.

RESEARCH QUESTION: Can organoids be established from endometrial tissue of infertile women and does tissue cryopreservation allow for establishment of organoids comparable to organoids derived from freshly biopsied endometrial tissue? DESIGN: Endometrial tissue was obtained from six infertile women through minimally invasive biopsy using a Pipelle catheter and subjected to organoid development, immediately after biopsy as well as after tissue cryopreservation. Organoid formation efficiency, morphology, expandability potential, endometrial marker expression (immunostaining and reverse transcription quantitative real-time polymerase chain reaction) and hormonal responsiveness (after oestradiol and progesterone treatment) were assessed. RESULTS: Organoids established from both fresh and frozen tissue at comparable efficiency could be passaged long-term and showed similar morphology, i.e. cystic with a central lumen lined by a single epithelial cell layer. They also exhibited comparable expression of endometrial markers and proliferative activity (Ki67 expression). Finally, organoids from freshly biopsied and cryopreserved endometrial tissue showed similar responses to oestradiol and progesterone treatment. CONCLUSIONS: Organoids can be established from cryopreserved endometrial tissue of infertile women and cryopreservation of the biopsy does not affect organoid formation and overall organoid characteristics. Cryopreservation of biopsies for later organoid development facilitates sample collection from any fertility clinic, not just the ones near an organoid laboratory.

The treatment of post-hysterectomy vaginal vault prolapse: a systematic review and meta-analysis.

INTRODUCTION AND HYPOTHESIS: The treatment of post-hysterectomy vaginal vault prolapse (VVP) has been investigated in several randomized clinical trials (RCTs), but a systematic review of the topic is still lacking. The aim of this study is to compare the effectiveness of treatments for VVP. METHODS: We performed a systematic review and meta-analysis of the literature on the treatment of VVP found in PubMed and Embase. Reference lists of identified relevant articles were checked for additional articles. A network plot was constructed to illustrate the geometry of the network of the treatments included. Only RCTs reporting on the treatment of VVP were eligible, conditional on a minimum of 30 participants with VVP and a follow-up of at least 6 months. RESULTS: Nine RCTs reporting 846 women (ranging from 95 to 168 women) met the inclusion criteria. All surgical techniques were associated with good subjective results, and without differences between the compared technique, with the exception of the comparison of vaginal mesh (VM) vs laparoscopic sacrocolpopexy (LSC). LSC is associated with a higher satisfaction rate. The anatomical results of the sacrocolpopexy (laparoscopic, robotic [RSC]. and abdominal [ASC]) are the best (62-91%), followed by the VM. However, the ranges of the anatomical outcome of VM were wide (43-97%). The poorest results are described for the sacrospinal fixation (SSF; 35-81%), which also correlates with the higher reoperation rate for pelvic organ prolapse (POP; 5-9%). The highest percentage of complications were reported after ASC (2-19%), VM (6-29%), and RSC (54%). Mesh exposure was seen most often after VM (8-21%). The rate of reoperations carried out because of complications, recurrence prolapse, and incontinence of VM was 13-22%. Overall, sacrocolpopexy reported the best results at follow-up, with an outlier of one trial reporting the highest reoperation rate for POP (11%). The results of the RSC are too small to make any conclusion, but LSC seems to be preferable to ASC. CONCLUSIONS: A comparison of techniques was difficult because of heterogeneity; therefore, a network meta-analysis was not possible. All techniques have proved to be effective. The reported differences between the techniques were negligible. Therefore, a standard treatment for VVP could not be given according to this review.

The endometrial microbiota of women with or without a live birth within 12 months after a first failed IVF/ICSI cycle.

The endometrial microbiota composition may be associated with implantation success. However, a 'core' composition has not yet been defined. This exploratory study analysed the endometrial microbiota by 16S rRNA sequencing (V1-V2 region) of 141 infertile women whose first IVF/ICSI cycle failed and compared the microbiota profiles of women with and without a live birth within 12 months of follow-up, and by infertility cause and type. Lactobacillus was the most abundant genus in the majority of samples. Women with a live birth compared to those without had significantly higher Lactobacillus crispatus relative abundance (RA) (p = 0.029), and a smaller proportion of them had ≤ 10% L. crispatus RA (42.1% and 70.4%, respectively; p = 0.015). A smaller proportion of women in the male factor infertility group had ≤ 10% L. crispatus RA compared to women in the unexplained and other infertility causes groups combined (p = 0.030). Women with primary infertility compared to secondary infertility had significantly higher L. crispatus RA (p = 0.004); lower proportions of them had ≤ 10% L. crispatus RA (p = 0.009) and > 10% Gardnerella vaginalis RA (p = 0.019). In conclusion, IVF/ICSI success may be associated with L. crispatus RA and secondary infertility with endometrial dysbiosis, more often than primary infertility. These hypotheses should be tested in rigorous well-powered longitudinal studies.