Endometrial scratching prior to IVF; does it help and for whom? A systematic review and meta-analysis

Enhancing uterine receptivity for embryo implantation through controlled collagenase intervention

Ineffective endometrial matrix remodeling, a key factor in infertility, impedes embryo implantation in the uterine wall. Our study reveals the cellular and molecular impact of human collagenase-1 administration in mouse uteri, demonstrating enhanced embryo implantation rates. Collagenase-1 promotes remodeling of the endometrial ECM, degrading collagen fibers and proteoglycans. This process releases matrix-bound bioactive factors (e.g., VEGF, decorin), facilitating vascular permeability and angiogenesis. Collagenase-1 elevates embryo implantation regulators, including NK cell infiltration and the key cytokine LIF. Remarkably, uterine tissue maintains structural integrity despite reduced endometrial collagen fiber tension. In-utero collagenase-1 application rescues implantation in heat stress and embryo transfer models, known for low implantation rates. Importantly, ex vivo exposure of human uterine tissue to collagenase-1 induces collagen de-tensioning and VEGF release, mirroring remodeling observed in mice. Our research highlights the potential of collagenases to induce and orchestrate cellular and molecular processes enhancing uterine receptivity for effective embryo implantation. This innovative approach underscores ECM remodeling mechanisms critical for embryo implantation.

Hysteroscopic Endometrial Fundal Incision versus Hysteroscopy Only in Oocyte Recipients: A Randomized Controlled Trial Assessing The Reproductive Outcomes

BACKGROUND

Endometrial scratching (ES) remains controversial regarding its potential effectiveness in improving pregnancy rates. The objective of the present study was to assess the impact of endometrial fundal incision (EFI) during hysteroscopy on reproductive outcomes in a population of oocyte recipients.

MATERIALS AND METHODS

A randomized controlled trial was conducted between 2020 and 2023 at the Third Department of Obstetrics and Gynecology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki and "Assisting Nature Centre of Reproduction and Genetics". The study population consisted of women who underwent hysteroscopy randomly assigned in a 1:1 ratio to either EFI (one to three months before embryotransfer with donor oocytes) or no intervention throughout office hysteroscopy. Clinical pregnancy and live birth rates were the primary outcomes.

RESULTS

After the exclusion of patients with intraoperative diagnosed endometrial pathology, a total of 124 women underwent randomization. The pregnancy test was positive in 79% (n=49/62) of the women in the EFI compared to 59.7% (n=37/62) in the hysteroscopy-only group (P=0.019), while the live birth rates did not differ between the two groups (58.1%, n=36/62 vs. 51.6%, n=32/62, P=0.470).

CONCLUSION

EFI during hysteroscopy seems to improve pregnancy rates in oocyte recipients without intrauterine pathology, while live birth rates are not affected by the EFI. These results should be interpreted with caution before the implementation of EFI in the routine in vitro fertilization (IVF) practice (registration number: NCT04580056).

Endometrial biopsy performed before the first in vitro fertilization does not impact the early pregnancy rate

Endometrial biopsy (EB) has been showed to increase the rate of clinical pregnancy in patients who underwent in vitro fertilization (IVF) failures. The purpose of this work was to assess the impact of an EB performed before the first in IVF on the early pregnancy rate. Be One study is a prospective, single-centre, randomized, open-label study. In this parallel study, patients were evenly split into two groups. In one group, patients underwent an EB between days 17 and 22 of the menstrual cycle that precedes the ovarian stimulation. In the other group (control), no EB was performed. The hCG-positive rate (early pregnancy rate) was evaluated on day 14 after the ovarian puncture. In total, 157 patients were randomized in the EB group and 154 patients were in the control group. The early pregnancy rate was 33.1% (52/157) in the EB group and 29.9% (46/154) in the control group (p = 0.54). Other parameters, including perforation, endometritis, or pain level were reassuring. An EB performed during the luteal phase of the menstrual cycle preceding the stimulation of the first IVF did not increase early pregnancy rate.

Hysteroscopic Endometrial Fundal Incision in Oocyte Recipients before Embryo Transfer May Improve Reproductive Outcomes: A Prospective Study

BACKGROUND

Induced endometrial injury is a technique described that have positive impact on implantation. The aim of this study was to investigate whether hysteroscopic endometrial fundal incision (EFI) in oocyte recipients before embryo transfer increases pregnancy and live birth rates or not.

MATERIALS AND METHODS

A prospective study was conducted between 2014 and 2019 at an in vitro fertilization (IVF) unit in Greece. As part of the protocol, hysteroscopy and EFI were offered to all the egg recipients and the outcomes compared with those from an older cohort from the same Unit not undergoing hysteroscopy.

RESULTS

In total, 332 egg recipients participated in the study; 114 of them underwent EFI prior to embryo transfer. Both groups were similar in terms of age, years of infertility, duration of hormone replacement treatment (HRT) and number of blastocysts transferred. In the EFI group, minor anomalies were detected and treated in 6.1% (n=7) of the participants. Moreover, pregnancy test was positive in 73.7% of the women in the hysteroscopy group compared to 57.8% in the nonhysteroscopy group (P=0.004). Live birth rate was also higher (56.1 vs. 42.2%, P=0.016) in the EFI group compared to the non-hysteroscopy one.

CONCLUSION

Apart from the obvious benefit of recognizing obscured anomalies, requiring surgical correction, it appears that in oocyte recipients prior to embryo transfer, EFI might improve uterine receptivity and reproductive outcomes.

Good practice recommendations on add-ons in reproductive medicine†

STUDY QUESTION

Which add-ons are safe and effective to be used in ART treatment?

SUMMARY ANSWER

Forty-two recommendations were formulated on the use of add-ons in the diagnosis of fertility problems, the IVF laboratory and clinical management of IVF treatment.

WHAT IS KNOWN ALREADY

The innovative nature of ART combined with the extremely high motivation of the patients has opened the door to the wide application of what has become known as 'add-ons' in reproductive medicine. These supplementary options are available to patients in addition to standard fertility procedures, typically incurring an additional cost. A diverse array of supplementary options is made available, encompassing tests, drugs, equipment, complementary or alternative therapies, laboratory procedures, and surgical interventions. These options share the common aim of stating to enhance pregnancy or live birth rates, mitigate the risk of miscarriage, or expedite the time to achieving pregnancy.

STUDY DESIGN, SIZE, DURATION

ESHRE aimed to develop clinically relevant and evidence-based recommendations focusing on the safety and efficacy of add-ons currently used in fertility procedures in order to improve the quality of care for patients with infertility.

PARTICIPANTS/MATERIALS, SETTING, METHODS

ESHRE appointed a European multidisciplinary working group consisting of practising clinicians, embryologists, and researchers who have demonstrated leadership and expertise in the care and research of infertility. Patient representatives were included in the working group. To ensure that the guidelines are evidence-based, the literature identified from a systematic search was reviewed and critically appraised. In the absence of any clear scientific evidence, recommendations were based on the professional experience and consensus of the working group. The guidelines are thus based on the best available evidence and expert agreement. Prior to publication, the guidelines were reviewed by 46 independent international reviewers. A total of 272 comments were received and incorporated where relevant.

MAIN RESULTS AND THE ROLE OF CHANCE

The multidisciplinary working group formulated 42 recommendations in three sections; diagnosis and diagnostic tests, laboratory tests and interventions, and clinical management.

LIMITATIONS, REASONS FOR CAUTION

Of the 42 recommendations, none could be based on high-quality evidence and only four could be based on moderate-quality evidence, implicating that 95% of the recommendations are supported only by low-quality randomized controlled trials, observational data, professional experience, or consensus of the development group.

WIDER IMPLICATIONS OF THE FINDINGS

These guidelines offer valuable direction for healthcare professionals who are responsible for the care of patients undergoing ART treatment for infertility. Their purpose is to promote safe and effective ART treatment, enabling patients to make informed decisions based on realistic expectations. The guidelines aim to ensure that patients are fully informed about the various treatment options available to them and the likelihood of any additional treatment or test to improve the chance of achieving a live birth.

STUDY FUNDING/COMPETING INTEREST(S)

All costs relating to the development process were covered from ESHRE funds. There was no external funding of the development process or manuscript production. K.L. reports speakers fees from Merck and was part of a research study by Vitrolife (unpaid). T.E. reports consulting fees from Gynemed, speakers fees from Gynemed and is part of the scientific advisory board of Hamilton Thorne. N.P.P. reports grants from Merck Serono, Ferring Pharmaceutical, Theramex, Gedeon Richter, Organon, Roche, IBSA and Besins Healthcare, speakers fees from Merck Serono, Ferring Pharmaceutical, Theramex, Gedeon Richter, Organon, Roche, IBSA and Besins Healthcare. S.R.H. declares being managing director of Fertility Europe, a not-for-profit organization receiving financial support from ESHRE. I.S. is a scientific advisor for and has stock options from Alife Health, is co-founder of IVFvision LTD (unpaid) and received speakers' fee from the 2023 ART Young Leader Prestige workshop in China. A.P. reports grants from Gedeon Richter, Ferring Pharmaceuticals and Merck A/S, consulting fees from Preglem, Novo Nordisk, Ferring Pharmaceuticals, Gedeon Richter, Cryos and Merck A/S, speakers fees from Gedeon Richter, Ferring Pharmaceuticals, Merck A/S, Theramex and Organon, travel fees from Gedeon Richter. The other authors disclosed no conflicts of interest.

DISCLAIMER

This Good Practice Recommendations (GPRs) document represents the views of ESHRE, which are the result of consensus between the relevant ESHRE stakeholders and are based on the scientific evidence available at the time of preparation.ESHRE GPRs should be used for information and educational purposes. They should not be interpreted as setting a standard of care or bedeemedinclusive of all proper methods of care, or be exclusive of other methods of care reasonably directed to obtaining the same results.Theydo not replace the need for application of clinical judgement to each individual presentation, or variations based on locality and facility type.Furthermore, ESHRE GPRs do not constitute or imply the endorsement, or favouring, of any of the included technologies by ESHRE.

Endometrial scratching in women undergoing IVF/ICSI: an individual participant data meta-analysis

BACKGROUND

In IVF/ICSI treatment, the process of embryo implantation is the success rate-limiting step. Endometrial scratching has been suggested to improve this process, but it is unclear if this procedure increases the chance of implantation and live birth (LB) and, if so, for whom, and how the scratch should be performed.

OBJECTIVE AND RATIONALE

This individual participant data meta-analysis (IPD-MA) aims to answer the question of whether endometrial scratching in women undergoing IVF/ICSI influences the chance of a LB, and whether this effect is different in specific subgroups of women. After its incidental discovery in 2000, endometrial scratching has been suggested to improve embryo implantation. Numerous randomized controlled trials (RCTs) have been conducted, showing contradicting results. Conventional meta-analyses were limited by high within- and between-study heterogeneity, small study samples, and a high risk of bias for many of the trials. Also, the data integrity of several trials have been questioned. Thus, despite numerous RCTs and a multitude of conventional meta-analyses, no conclusion on the clinical effectiveness of endometrial scratching could be drawn. An IPD-MA approach is able to overcome many of these problems because it allows for increased uniformity of outcome definitions, can filter out studies with data integrity concerns, enables a more precise estimation of the true treatment effect thanks to adjustment for participant characteristics and not having to make the assumptions necessary in conventional meta-analyses, and because it allows for subgroup analysis.

SEARCH METHODS

A systematic literature search identified RCTs on endometrial scratching in women undergoing IVF/ICSI. Authors of eligible studies were invited to share original data for this IPD-MA. Studies were assessed for risk of bias (RoB) and integrity checks were performed. The primary outcome was LB, with a one-stage intention to treat (ITT) as the primary analysis. Secondary analyses included as treated (AT), and the subset of women that underwent an embryo transfer (AT+ET). Treatment-covariate interaction for specific participant characteristics was analyzed in AT+ET.

OUTCOMES

Out of 37 published and 15 unpublished RCTs (7690 participants), 15 RCTs (14 published, one unpublished) shared data. After data integrity checks, we included 13 RCTs (12 published, one unpublished) representing 4112 participants. RoB was evaluated as 'low' for 10/13 RCTs. The one-stage ITT analysis for scratch versus no scratch/sham showed an improvement of LB rates (odds ratio (OR) 1.29 [95% CI 1.02-1.64]). AT, AT+ET, and low-RoB-sensitivity analyses yielded similar results (OR 1.22 [95% CI 0.96-1.54]; OR 1.25 [95% CI 0.99-1.57]; OR 1.26 [95% CI 1.03-1.55], respectively). Treatment-covariate interaction analysis showed no evidence of interaction with age, number of previous failed embryo transfers, treatment type, or infertility cause.

WIDER IMPLICATIONS

This is the first meta-analysis based on IPD of more than 4000 participants, and it demonstrates that endometrial scratching may improve LB rates in women undergoing IVF/ICSI. Subgroup analysis for age, number of previous failed embryo transfers, treatment type, and infertility cause could not identify subgroups in which endometrial scratching performed better or worse. The timing of endometrial scratching may play a role in its effectiveness. The use of endometrial scratching in clinical practice should be considered with caution, meaning that patients should be properly counseled on the level of evidence and the uncertainties.

Endometrial scratching in Australia, New Zealand and the United Kingdom (UK): a follow-up survey

Endometrial scratching is a common IVF add-on. In 2015, a survey in Australia, New Zealand and the United Kingdom (UK) reported that 83% of fertility specialists recommended endometrial scratching for IVF. Several large trials have since been published reporting no clear evidence for improved live birth rates following endometrial scratching before IVF. An online survey was undertaken to ascertain the current practices and views across Australia, New Zealand, and the UK. A total of 121 eligible responses were received between October and December 2020 (fertility specialists (n = 61), embryologists (n = 26) and fertility nurses (n = 24)). Among fertility specialists, 34% currently offer endometrial scratching, mostly in the case of recurrent implantation failure. Most respondents were neutral or did not believe endometrial scratching improved pregnancy and live birth rates (>90%), except for in women with recurrent implantation failure (29% believed it can increase pregnancy and live birth rates in this group). More than half of respondents viewed reducing psychological distress as a benefit of endometrial scratching (55%). Among fertility specialists not offering endometrial scratching, 51% previously offered it but no longer do. The decline in use over the last five years likely reflects a response to recent evidence reporting no benefit from the procedure.

Endometrial Injury Upregulates Expression of Receptivity Genes in Women with Implantation Failure

BACKGROUND

Homeobox genes A10 (HOXA10) and A11 (HOXA11), members of the abdominal B gene family, are responsible for embryonic survival and implantation. This study was planned to investigate whether endometrial injury alters the expression of both transcripts in women with implantation failure.

METHODS

A total of 54 women with implantation failure were divided into two equal groups as experimental (scratching) and sham (no scratching). Participants in the scratching group were exposed to endometrial injury in the mid-luteal phase, and those in the sham group were exposed to endometrial flushing. The scratching group, but not the sham group, underwent prior endometrial sampling. A second endometrial sampling was performed on the scratching group in the mid-luteal phase of the following cycle. The mRNA and protein levels of the HOXA10 and 11 transcripts were determined in endometrial samples collected before and after injury/flushing. Participants in each group underwent IVF/ET in the cycle after the second endometrial sampling.

RESULTS

Endometrial injury caused a 60.1-fold (p < 0.01) increase in HOXA10 mRNA and a 9.0-fold increase in HOXA11 mRNA (p < 0.02). Injury resulted in a significant increase in both HOXA10 (p < 0.001) and HOXA11 protein expression (p < 0.003). There was no significant change in HOXA10 and 11 mRNA expressions after flushing. Clinical pregnancy, live birth, and miscarriage rates of the both groups were similar.

CONCLUSIONS

Endometrial injury increases homeobox transcript expression at both mRNA and protein levels.

Subtle changes in perivascular endometrial mesenchymal stem cells after local endometrial injury in recurrent implantation failure

Improvements in reproductive techniques have resulted in the live birth rates from IVF procedures increasing from 5% to approximately 30% in recent decades but has plateaued since. Emerging preclinical and clinical data implicates endometrial receptivity deficiencies in patients with recurrent implantation failure (RIF) as the predominant factor hindering successful implantation. Mechanisms on how local endometrial injury (LEI) improves implantation rates in patients with RIF are currently unknown. We hypothesized that LEI may influence perivascular endometrial mesenchymal stem/progenitor cells (eMSCs) which are thought to regenerate the stromal vascular component of the functional layer every month. Here, we assessed the effect of LEI on the proportion and function of eMSCs present in consecutive LEI biopsies. Consecutive paired mid-luteal phase endometrial biopsies obtained from patients with RIF were digested to single cells and the proportion of SUSD2-expressing cells determined. Growth kinetics and decidualization were compared between the consecutive LEI samples. A mid-luteal LEI altered the decidualization capacity of SUSD2⁺ eMSCs in women with RIF, but not their proportion or clonogenicity. With the potential of LEI to improve IVF outcomes in women with RIF, additional investigations are needed to understand the impact of the altered decidualization response in eMSCs.

Additional dydrogesterone for the treatment of chronic endometritis treated with antibiotic in premenopausal women with endometrial polyps: a retrospective cohort study

Background

To assess the efficacy of dysdrogesterone in the treatment of chronic endometritis (CE) treated with antibiotic in premenopausal women with endometrial polyps (EPs).

Methods

Routine detection of endometrium was simultaneously conducted to determine whether there was CE by syndecan-1 (CD138), while women underwent hysteroscopic polypectomy in our hospital. Antibiotic was given for the treatment of CE. A total of 235 premenopausal women with CE who underwent hysteroscopic polypectomy were enrolled in the retrospective observational study. In the control group, single antibiotic was given for the treatment of CE form January 2016 to December 2018, and in the treatment group additional dydrogesterone was used from January 2019 to November 2020. Comparison of cure rates of CE with different treatment regimens was performed.

Results

The cure rates of CE in dydrogesterone and antibiotic combination group and the single antibiotic group were 85.2% and 74.3%, respectively, with overall cure rate of 80.0% (188/235). The combination group showed better effects regarding the cure rate of CE (P < .05). Multivariate analysis confirmed that the cure rate of CE was not affected by age, body mass index, number of EPs, the status of estrogen receptor and the status of progesterone receptor. Conversely, dydrogesterone and endometrial scratching were beneficial factors for cure rate increase with antibiotic treatment.

Conclusion

Combination of dydrogesterone and antibiotic was more effective for cure rate of CE than antibiotic alone in premenopausal women after hysteroscopic polypectomy. Endometrial scratching also contributed to the cure rate increase with antibiotic treatment.

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.

Impact of endometrial scratching on reproductive outcome in patients: A systematic review and meta-analysis

BACKGROUND

Endometrial scratching (ES) has demonstrated initial success in women with recurrent implantation failure, but the effect in women with 1 previous assisted reproductive technology (ART) failure is unknown. This meta-analysis aimed to evaluate the impact of ES as a treatment in clinical outcomes for women with at least 1 failed in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI)/Intrauterine Insemination (IUI).

METHODS

PubMed, Medline, Embase, Cochrane Library, Web of Science, CNKI, and EMCC databases were searched for randomized controlled trial studies utilizing endometrial scratching for infertility women with at least 1 failed assisted reproductive technology (ART) to collect pregnancy outcomes, including clinical pregnancy rate (CPR), embryo implantation rate (IR), miscarriage rate (MR), live birth rate (LBR), and multiple pregnancy rate (MPR).

RESULTS

Sixteen randomized controlled trial (RCT) studies were included in this meta-analysis, including 1770 women in the intervention group and 1934 women in the control group. Overall, the CPR, IR and LBR were significantly higher in the intervention group than in the control group (for CPR, n = 1430, 16 studies, P = .0002, risk ratio (RR) = 1.59, 95% confidence interval [CI] [1.24, 2.03]; for IR, n = 859, 10 studies, P = .0003, RR = 1.67, 95% CI [1.26, 2.21]; for LBR, n = 156, 6 studies, P = .0005, RR = 1.59, 95% CI [1.22, 2.06]). Nonetheless, there was no significant difference in MR (n = 344, 11 studies, P = .62, risk ratio (RR) = 0.92, 95% confidence interval [CI] [0.66, 1.29]) and MPR (n = 98, 3 studies, P = .39, risk ratio (RR) = 0.81, 95% confidence interval [CI] [0.51, 1.30]) between the intervention group and the control group.

CONCLUSION

Endometrial scratching is considered to enhance the reproductive outcomes of embryo implantation. Additional randomized controlled studies are recommended to identify the appropriate time of invasion and the applicable population to confirm whether it can become a routine operation.

Evaluating interventions and adjuncts to optimize pregnancy outcomes in subfertile women: an overview review

BACKGROUND

There is a wealth of information regarding interventions for treating subfertility. The majority of studies exploring interventions for improving conception rates also report on pregnancy outcomes. However, there is no efficient way for clinicians, researchers, funding organizations, decision-making bodies or women themselves to easily access and review the evidence for the effect of adjuvant therapies on key pregnancy outcomes in subfertile women.

OBJECTIVE AND RATIONALE

The aim was to summarize all published systematic reviews (SRs) of randomized controlled trials (RCTs) of interventions in the subfertile population, specifically reporting on the pregnancy outcomes of miscarriage and live birth. Furthermore, we aimed to highlight promising interventions and areas that need high-quality evidence.

SEARCH METHODS

We searched the Cochrane Database of Systematic Reviews and PubMed clinical queries SR filter (inception until July 2021) with a list of key words to capture all SRs specifying or reporting any miscarriage outcome. Studies were included if they were SRs of RCTs. The population was subfertile women (pregnant or trying to conceive) and any intervention (versus placebo or no treatment) was included. We adopted Grading of Recommendations, Assessment, Development and Evaluation (GRADE) for determining the quality of the evidence. Exclusion criteria were overview reviews, reviews that exclusively reported on women conceiving via natural conception, reviews including non-randomized study designs or reviews where miscarriage or live birth outcomes were not specified or reported.

OUTCOMES

The primary outcome was miscarriage, defined as pregnancy loss <24 weeks of gestation. Data were also extracted for live birth where available. We included 75 published SRs containing 121 251 participants. There were 14 classes of intervention identified: luteal phase, immunotherapy, anticoagulants, hCG, micronutrients, lifestyle, endocrine, surgical, pre-implantation genetic testing for aneuploidies (PGT-As), laboratory techniques, endometrial injury, ART protocols, other adjuncts/techniques in the ART process and complementary interventions. The interventions with at least moderate-quality evidence of benefit in reducing risk of miscarriage or improving the chance of a live birth are: intrauterine hCG at time of cleavage stage embryo transfer, but not blastocyst transfer, antioxidant therapy in males, dehydroepiandrosterone in women and embryo medium containing high hyaluronic acid. Interventions showing potential increased risk of miscarriage or reduced live birth rate are: embryo culture supernatant injection before embryo transfer in frozen cycles and PGT-A with the use of fluorescence in situ hybridization.

WIDER IMPLICATIONS

This review provides an overview of key pregnancy outcomes from published SRs of RCTs in subfertile women. It provides access to concisely summarized information and will help clinicians and policy makers identify knowledge gaps in the field, whilst covering a broad range of topics, to help improve pregnancy outcomes for subfertile couples. Further research is required into the following promising interventions: the dose of progesterone for luteal phase support, peripheral blood mononuclear cells for women with recurrent implantation failure, glucocorticoids in women undergoing IVF, low-molecular-weight heparin for unexplained subfertility, intrauterine hCG at the time of cleavage stage embryo or blastocyst transfer and low oxygen concentrations in embryo culture. In addition, there is a need for high-quality, well-designed RCTs in the field of reproductive surgery. Finally, further research is needed to demonstrate the integrated effects of non-pharmacological lifestyle interventions.

The effect of hysteroscopy and conventional curretage versus no hysteroscopy on live birth rates in recurrent in vitro fertilisation failure: a retrospective cohort study from a single referral centre experience

This retrospective cohort study aimed to evaluate the effect of hysteroscopy and endometrial scratching (ES) in patients with recurrent implantation failure (RIF) who do not have an intracavity pathology. The authors retrospectively collected data of patients between 2014 and 2019 from a single centre. The study analysed 350 unexplained RIF patients, of whom, 225 underwent hysteroscopy and endometrial scratching, and 125 did not have a hysteroscopy prior to an IVF cycle. Pregnancy rates among post endometrial scratching and no endometrial scratching cycles were 35.6% versus 27.2%, (p = .048), clinical pregnancy rates were 32.9% versus 21.6% (p = .026) and live birth rates were 26.2% versus 19.2% (p = .039). Although it is not possible to distinguish whether hysteroscopy or injury is effective in improving live birth results, the authors thought that endometrial injury with gentle conventional curettage is effective in patients with recurrent implantation failure.IMPACT STATEMENTWhat is already known on this subject? Hysteroscopy and endometrial injury improve pregnancy outcomes in IVF cycles, but definitive conclusions have been uncertain.What do the results of this study add? The study showed that endometrial injury with gentle conventional curettage during hysteroscopy significantly improved the pregnancy rates of RIF patients compared to the non-hysteroscopy group.What are the implications of these findings for clinical practice and/or further research? In cases of recurrent implantation failure, even if hysteroscopy findings are normal, endometrial scratching in the follicular phase increases pregnancy rates compared to the non-hysteroscopy group.

Endometrial scratch to increase live birth rates in women undergoing first-time in vitro fertilisation: RCT and systematic review

BACKGROUND

In vitro fertilisation is a widely used reproductive technique that can be undertaken with or without intracytoplasmic sperm injection. The endometrial scratch procedure is an in vitro fertilisation 'add-on' that is sometimes provided prior to the first in vitro fertilisation cycle, but there is a lack of evidence to support its use.

OBJECTIVES

(1) To assess the clinical effectiveness, safety and cost-effectiveness of endometrial scratch compared with treatment as usual in women undergoing their first in vitro fertilisation cycle (the 'Endometrial Scratch Trial') and (2) to undertake a systematic review to combine the results of the Endometrial Scratch Trial with those of previous trials in which endometrial scratch was provided prior to the first in vitro fertilisation cycle.

DESIGN

A pragmatic, multicentre, superiority, open-label, parallel-group, individually randomised controlled trial. Participants were randomised (1 : 1) via a web-based system to receive endometrial scratch or treatment as usual using stratified block randomisation. The systematic review involved searching electronic databases (undertaken in January 2020) and clinicaltrials.gov (undertaken in September 2020) for relevant trials.

SETTING

Sixteen UK fertility units.

PARTICIPANTS

Women aged 18-37 years, inclusive, undergoing their first in vitro fertilisation cycle. The exclusion criteria included severe endometriosis, body mass index ≥ 35 kg/m² and previous trauma to the endometrium.

INTERVENTIONS

Endometrial scratch was undertaken in the mid-luteal phase of the menstrual cycle prior to in vitro fertilisation, and involved inserting a pipelle into the cavity of the uterus and rotating and withdrawing it three or four times. The endometrial scratch group then received usual in vitro fertilisation treatment. The treatment-as-usual group received usual in vitro fertilisation only.

MAIN OUTCOME MEASURES

The primary outcome was live birth after completion of 24 weeks' gestation within 10.5 months of egg collection. Secondary outcomes included implantation, pregnancy, ectopic pregnancy, miscarriage, pain and tolerability of the procedure, adverse events and treatment costs.

RESULTS

One thousand and forty-eight (30.3%) women were randomised to treatment as usual (n = 525) or endometrial scratch (n = 523) and were followed up between July 2016 and October 2019 and included in the intention-to-treat analysis. In the endometrial scratch group, 453 (86.6%) women received the endometrial scratch procedure. A total of 494 (94.1%) women in the treatment-as-usual group and 497 (95.0%) women in the endometrial scratch group underwent in vitro fertilisation. The live birth rate was 37.1% (195/525) in the treatment-as-usual group and 38.6% (202/523) in the endometrial scratch group: an unadjusted absolute difference of 1.5% (95% confidence interval -4.4% to 7.4%; p = 0.621). There were no statistically significant differences in secondary outcomes. Safety events were comparable across groups. No neonatal deaths were recorded. The cost per successful live birth was £11.90 per woman (95% confidence interval -£134 to £127). The pooled results of this trial and of eight similar trials found no evidence of a significant effect of endometrial scratch in increasing live birth rate (odds ratio 1.03, 95% confidence interval 0.87 to 1.22).

LIMITATIONS

A sham endometrial scratch procedure was not undertaken, but it is unlikely that doing so would have influenced the results, as objective fertility outcomes were used. A total of 9.2% of women randomised to receive endometrial scratch did not undergo the procedure, which may have slightly diluted the treatment effect.

CONCLUSIONS

We found no evidence to support the theory that performing endometrial scratch in the mid-luteal phase in women undergoing their first in vitro fertilisation cycle significantly improves live birth rate, although the procedure was well tolerated and safe. We recommend that endometrial scratch is not undertaken in this population.

TRIAL REGISTRATION

This trial is registered as ISRCTN23800982.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 10. See the NIHR Journals Library website for further project information.

Economic evaluation of endometrial scratching before the second IVF/ICSI treatment: a cost-effectiveness analysis of a randomized controlled trial (SCRaTCH trial)

STUDY QUESTION

Is a single endometrial scratch prior to the second fresh IVF/ICSI treatment cost-effective compared to no scratch, when evaluated over a 12-month follow-up period?

SUMMARY ANSWER

The incremental cost-effectiveness ratio (ICER) for an endometrial scratch was €6524 per additional live birth, but due to uncertainty regarding the increase in live birth rate this has to be interpreted with caution.

WHAT IS KNOWN ALREADY

Endometrial scratching is thought to improve the chances of success in couples with previously failed embryo implantation in IVF/ICSI treatment. It has been widely implemented in daily practice, despite the lack of conclusive evidence of its effectiveness and without investigating whether scratching allows for a cost-effective method to reduce the number of IVF/ICSI cycles needed to achieve a live birth.

STUDY DESIGN, SIZE, DURATION

This economic evaluation is based on a multicentre randomized controlled trial carried out in the Netherlands (SCRaTCH trial) that compared a single scratch prior to the second IVF/ICSI treatment with no scratch in couples with a failed full first IVF/ICSI cycle. Follow-up was 12 months after randomization.Economic evaluation was performed from a healthcare and societal perspective by taking both direct medical costs and lost productivity costs into account. It was performed for the primary outcome of biochemical pregnancy leading to live birth after 12 months of follow-up as well as the secondary outcome of live birth after the second fresh IVF/ICSI treatment (i.e. the first after randomization). To allow for worldwide interpretation of the data, cost level scenario analysis and sensitivity analysis was performed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

From January 2016 until July 2018, 933 women with a failed first IVF/ICSI cycle were included in the trial. Data on treatment and pregnancy were recorded up until 12 months after randomization, and the resulting live birth outcomes (even if after 12 months) were also recorded.Total costs were calculated for the second fresh IVF/ICSI treatment and for the full 12 month period for each participant. We included costs of all treatments, medication, complications and lost productivity costs. Cost-effectiveness analysis was carried out by calculating ICERs for scratch compared to control. Bootstrap resampling was used to estimate the uncertainty around cost and effect differences and ICERs. In the sensitivity and scenario analyses, various unit costs for a single scratch were introduced, amongst them, unit costs as they apply for the United Kingdom (UK).

MAIN RESULTS AND THE ROLE OF CHANCE

More live births occurred in the scratch group, but this also came with increased costs over a 12-month period. The estimated chance of a live birth after 12 months of follow-up was 44.1% in the scratch group compared to 39.3% in the control group (risk difference 4.8%, 95% CI -1.6% to +11.2%). The mean costs were on average €283 (95% CI: -€299 to €810) higher in the scratch group so that the point average ICER was €5846 per additional live birth. The ICER estimate was surrounded with a high level of uncertainty, as indicated by the fact that the cost-effectiveness acceptability curve (CEAC) showed that there is an 80% chance that endometrial scratching is cost-effective if society is willing to pay ∼€17 500 for each additional live birth.

LIMITATIONS, REASONS FOR CAUTION

There was a high uncertainty surrounding the effects, mainly in the clinical effect, i.e. the difference in the chance of live birth, which meant that a single straightforward conclusion could not be ascertained as for now.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first formal cost-effectiveness analysis of endometrial scratching in women undergoing IVF/ICSI treatment. The results presented in this manuscript cannot provide a clear-cut expenditure for one additional birth, but they do allow for estimating costs per additional live birth in different scenarios once the clinical effectiveness of scratching is known. As the SCRaTCH trial was the only trial with a follow-up of 12 months, it allows for the most complete estimation of costs to date.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by ZonMW, the Dutch organization for funding healthcare research. A.E.P.C., F.J.M.B., E.R.G. and C.B. L. reported having received fees or grants during, but outside of, this trial.

TRIAL REGISTRATION NUMBER

Netherlands Trial Register (NL5193/NTR 5342).

Endometrial injury concurrent with hysteroscopy increases the expression of Leukaemia inhibitory factor: a preliminary study

OBJECTIVE

It is not known by which mechanism endometrial injury increases pregnancy rates. Leukaemia inhibitory factor (LIF) is a cytokine involved in wound healing and implantation. The aim of this study was to determine the change in endometrial LIF mRNA expression before and after mechanical injury during hysteroscopy.

METHODS

Forty patients with a history of two or more unsuccessful implantations who decided to undergo hysteroscopy in the proliferative phase were divided into two equal groups: one with endometrial injury (scratching group) and the other with noninjury (control group). Endometrial sampling was conducted before injury on the patients in the scratching group, and then injury was performed with monopolar needle forceps. Only diagnostic hysteroscopy was performed on the patients in the control group. Endometrial tissues were collected using a Pipelle catheter between Days 20 and 23 of the mid-luteal phase of the next cycles in both the scratching and control groups. Endometrial LIF mRNA expression was evaluated with the use of reverse-transcription polymerase chain reactions.

RESULTS

Relative changes in mRNA expression levels of the LIF gene in endometrial samples taken before and after injury were calculated using the 2-ΔΔCt method, and the fold changes obtained were compared between and within the groups. Compared with preinjury values, an 11.1-fold increase was found in postinjury LIF mRNA expression in patients with monopolar forceps injury (p < 0.001). There was a 3.9-fold significant increase in postinjury LIF mRNA levels compared with those in the control group (p < 0.02).

CONCLUSIONS

The fertility-promoting effect of hysteroscopy-guided mechanical endometrial injury may be mediated by LIF mRNA.

Uterine Cavity Irrigation With Office Hysteroscopy During Ovarian Stimulation for IVF: A Randomized Controlled Trial

OBJECTIVE

This was a non-blinded randomized controlled study to evaluate whether endometrial irrigation via office hysteroscopy during the early follicular phase would lead to a higher level of live birth rates compared to no irrigation in the fresh embryo transfer cycle.

METHOD

The study was conducted in Tehran university of medical sciences from June 2015 to June 2016. women under the age of 40 with primary infertility without history of previous IVF/ICSI or hysteroscopic examination, were included. Controlled ovarian hyperstimulation was done. Hysteroscopy was performed in the early mid-follicular phase of a stimulation cycle (day 5-7) with a vaginoscopy approach and saline irrigation in hysteroscopy group. Embryo-transfer was done in the same cycle.

RESULTS

228 patients completed their participation in the study. In the fresh cycle, clinical pregnancy rate was 46% in the hysteroscopy group and 40.43% in the control group. (p-value= 0.326, RR= 1.16 [95%CI: 0.862 to 1.56]). Live birth rate was 41.28% in the hysteroscopic group and 31.93% in the control group (p-value=0.143, RR= 1.293 [95%CI: 0.916 to 1.825]). For those patients having surplus cryopreserved embryos, after 2 months, a second embryo transfer was performed. The cumulative LBR was 44.05% in the hysteroscopic group and 32.25% in the control group (p-value=0.029, RR= 1.368 [95%CI: 1.031 to 1.815], RD= 11.9% [95%CI: 1.2% to 22.3%] and NNT= 8 [95%CI: 4 to 85]).

CONCLUSION

The current study clearly demonstrated a significantly higher cumulative live birth rate in the intervention group.

CLINICAL TRIAL REGISTRATION

[https://www.irct.ir/trial/19586], identifier IRCT2016011022795N2.

The Spiny Mouse—A Menstruating Rodent to Build a Bridge From Bench to Bedside

Menstruation, the cyclical breakdown of the uterine lining, is arguably one of evolution's most mysterious reproductive strategies. The complexity and rarity of menstruation within the animal kingdom is undoubtedly a leading contributor to our current lack of understanding about menstrual function and disorders. In particular, the molecular and environmental mechanisms that drive menstrual and fertility dysregulation remain ambiguous, owing to the restricted opportunities to study menstruation and model menstrual disorders in species outside the primates. The recent discovery of naturally occurring menstruation in the Egyptian spiny mouse (Acomys cahirinus) offers a new laboratory model with significant benefits for prospective research in women's health. This review summarises current knowledge of spiny mouse menstruation, with an emphasis on spiral artery formation, inflammation and endocrinology. We offer a new perspective on cycle variation in menstrual bleeding between individual animals, and propose that this is indicative of fertility success. We discuss how we can harness our knowledge of the unique physiology of the spiny mouse to better understand vascular remodelling and its implications for successful implantation, placentation, and foetal development. Our research suggests that the spiny mouse has the potential as a translational research model to bridge the gap between bench to bedside and provide improved reproductive health outcomes for women.

Differential expression of innate/adaptive immunity genes induced by endometrial scratching as a hopeful approach for implantation boosting in unexplained, repeated implantation failure: An RCT

BACKGROUND

Endometrial scratching (ES) has been proposed as a potential treatment for implantation improvement in unexplained repeated implantation failure (uRIF) patients, however, little is known about its exact molecular mechanisms.

OBJECTIVE

This randomized controlled trial (RCT) was conducted on twenty uRIF patients to investigate the expression of innate and adaptive immune signaling genes after ES.

METHODS

Ten uRIF patients in the intervention (twice endometrial sampling in follicular and luteal phases) and 10 uRIF patients in the control group (only luteal phase sampling) were randomly enrolled. Gene expression analysis with innate and adaptive immune response PCR-array kit between intervention and control groups were performed.

RESULTS

Among innate immune-associated genes, a significant decrease was observed in the expression of APCS, CPR, CCL2, NLRP3, HLA-A, TLR3 and TLR4 in the intervention group. In adaptive immune-related genes, the expression level of CD80, CD86, CXCR3, IFNγ, IFNα1, IFNβ, MBL2, CCR6, CCR8 and IL17A were decreased and CSF2, GATA3, and IL4 increased significantly in the intervention group (P < 0.05). Of 14 uRIF patients, five live birth (35.71 %) was achieved.

CONCLUSION

ES in uRIF patients may exert positive effects on the endometrial preparation which increases its receptivity for embryo implantation by modulating the expression of an array of immune signaling pathway genes.

The Effects of Autologous Platelet-Rich Plasma on Pregnancy Outcomes in Repeated Implantation Failure Patients Undergoing Frozen Embryo Transfer: A Randomized Controlled Trial

Repeated implantation failure (RIF) is a disorder in which good-quality embryos fail to implant in the endometrium following several in vitro fertilization (IVF) cycles. This study aimed to evaluate the efficiency and safety of intrauterine infusion of platelet-rich plasma (PRP) in improvement of pregnancy outcomes in RIF patients undergoing frozen embryo transfer (FET). A total of 438 women with a history of RIF undergoing FET were assessed for eligibility to enter the study. Patients were randomly assigned to the intervention (PRP) and control groups. The intervention group received an intrauterine infusion of 0.5 ml PRP 48 h before embryo transfer while the control group received standard treatment. The rates of chemical and clinical pregnancy were defined as the primary outcome values. All women were followed up until the study endpoints that included the number of neonates born and pregnancy-related complications. Three hundred and ninety-three participants accomplished the study and their data were analyzed. The chemical pregnancy, clinical pregnancy, and live birth rates were higher in the PRP group than control group (p value: <0.0001; p value: <0.0001; p value: <0.0001 respectively). However, there were no significant differences between the two groups in terms of multiple pregnancies and pregnancy complications except for spontaneous abortion. The spontaneous abortion rate was significantly higher in the control group compared to the PRP group (p value = 0.0262). These results suggest that intrauterine infusion of PRP is an effective and safe route to improve pregnancy outcomes in RIF patients undergoing FET.

Mucosal biomarkers for endometrial receptivity: A promising yet underexplored aspect of reproductive medicine

Annually, approximately 2 million assisted reproductive technology (ART) procedures are performed worldwide, of which, only ~25% lead to successful delivery. There are two major factors contributing to successful implantation: embryo quality and endometrial receptivity (ER). Although embryo quality might be assessed through morphological and genetic testing, no clinically approved techniques are available to evaluate ER. Mucus in different parts of the female reproductive tract contains many cytokines, chemokines, growth factors, and nucleic acids, which influence and reflect various implantation-related processes. Therefore, the aim of the present review was to summarize available data regarding noninvasively obtained mucosal biomarkers for ER and to investigate their ability to predict the outcome of ART procedures. A broad literature search was performed to define studies related to noninvasive ER assessments. More than 50 biomarkers detectable in endometrial fluid, embryo transfer cannula leftover cells and mucus, menstrual blood, cervicovaginal washings are discussed herein. The remarkable methodological heterogeneity of the reviewed studies complicates the comparison of their results. Nevertheless, certain promising analytical targets may already be identified, such as urocortin, activin A, IL-1β, TNF-α, IP-10, MCP-1, and several oxidative stress biomarkers. The present review contains a collection of currently available mucosal biomarker-related data, which may provide insights for future studies.Abbreviations: ART: assisted reproductive technology; ER: endometrial receptivity; IVF: in vitro fertilization; ICSI: intracytoplasmic sperm injection; IUI: intrauterine insemination; MeSH: Medical Subject Headings; hDP 200: human decidua-associated protein 200; ET: embryo transfer; IL-18: Interleukin-18; LRG: leucine-rich α2-glycoprotein; ROC: receiver operating characteristic; AUC: area under the ROC-curve; LH: luteinizing hormone; LIF: leukemia inhibitory factor; TNF-α: tumor necrosis factor alpha; IFN-γ: interferon γ; MCP-1: monocyte chemoattractant protein-1; VEGF: vascular endothelial growth factor; SOD: superoxide dismutase; CAT: catalase; LPO: lipid peroxidation; TTG: total thiol groups; TAP: total antioxidant power; CE: chronic endometritis.

Intentional endometrial injury enhances angiogenesis through increased production and activation of MMP-9 by TNF-α and MMP-3 in a mouse model

There have been reports of improved pregnancy rates after performing intentional endometrial injuries, also known as endometrial scratching, in patients with recurrent implantation failure. In our previous study on intentional endometrial injury, we found an increased expression of matrix metalloproteinase (MMP)-3 following induced injuries to the mice endometrium. In the current study, we further examine whether the rise in MMP-3 could contribute to increased angiogenesis. Female C57B1/6 mice were obtained at 12 weeks of age, and intentional endometrial injuries were induced mechanically in the left uterine horns. Using the appropriate media, uterine-washes were performed on the injured and uninjured (control) horns of the harvested uteri. The uterine tissues were further processed for tissue lysates, histopathology and immunohistochemistry. The results show that intentional endometrial injuries caused an increase in secreted LPA in the injured horns, which were detected in the uterine-washes. In addition, LPA induced increased production of TNF-α in human endometrial epithelial cells (hEEpCs). Furthermore, TNF-α appeared to induce differential and cell-specific upregulation of the MMPs: MMP-3 was upregulated in the epithelial (hEEpCs), while MMP-9 was upregulated in the endothelial cells (human endometrial endothelial cells; hEEnCs). The upregulation of MMP-3 appeared to be necessary for the activation of MMP-9, whose active form stimulated the formation of vessel-like structure by the hEEnCs. The results of this study suggest that there may be enhanced angiogenesis following intentional endometrial injuries, which is mediated in part by TNF-α-induced and MMP-3-activated MMP-9 production.

The effect of diagnostic hysteroscopy performed before fresh and frozen-thawed embryo transfer in IVF cycles on reproductive outcomes

Objective

Hysteroscopy is frequently performed in infertile women and thought to improve pregnancy rates. The data obtained from studies investigating the effect of hysteroscopy in in-vitro fertilization (IVF) cycles is variable. We aimed to evaluate the effect of hysteroscopy on pregnancy outcomes of fresh and frozen-thawed embryo transfers (FET) performed during IVF cycles.

Material and Methods

The data of the 765 patients, who had IVF treatment between January 2015 and July 2017 in an infertility center, were retrospectively analyzed. Of those, 586 (76.6%) patients underwent fresh embryo transfer, while 179 (23.4%) patients underwent FET. Hysteroscopy performed by a single experienced surgeon was scheduled two months before transfer. Hysteroscopy was performed in 101/586 (17.2%) in those undergoing fresh embryo transfer and 44/179 (24.6%) patients in the FET group. Pregnancy outcomes of the groups were compared respectively within their own group.

Results

The mean age was similar in patients in the fresh and FET groups (p=0.365, respectively). There was no difference in the number of transferred embryos between the groups (p=0.218). In the fresh embryo group there were 246 pregnancies, of which 44 had undergone diagnostic hysteroscopy while 202 had not, (p=0.516) and 79 pregnancies in the FET group, of which 20 had undergone diagnostic hysteroscopy while 59 had not (p=0.711). There was no statistical difference according to pregnancy rate between the groups (p=0.538).

Conclusion

Performing diagnostic hysteroscopy before fresh or FET does not improve the pregnancy rates.

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 injury in women undergoing in vitro fertilisation (IVF)

BACKGROUND

Implantation of an embryo within the endometrial cavity is a critical step in the process of in vitro fertilisation (IVF). Previous research has suggested that endometrial injury (also known as endometrial scratching), defined as intentional damage to the endometrium, can increase the chance of pregnancy in women undergoing IVF.

OBJECTIVES

To assess the effectiveness and safety of endometrial injury performed before embryo transfer in women undergoing in vitro fertilisation (IVF) including intracytoplasmic sperm injection (ICSI) and frozen embryo transfer.

SEARCH METHODS

In June 2020 we searched the Cochrane Gynaecology and Fertility Group Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL, LILACS, DARE and two trial registries. We also checked the reference sections of relevant studies and contacted experts in the field for any additional trials.

SELECTION CRITERIA

Randomised controlled trials comparing intentional endometrial injury before embryo transfer in women undergoing IVF, versus no intervention or a sham procedure.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane. Two independent review authors screened studies, evaluated risk of bias and assessed the certainty of the evidence by using GRADE (Grading of Recommendation, Assessment, Development and Evaluation) criteria. We contacted and corresponded with study investigators as required. Due to the high risk of bias associated with many of the studies, the primary analyses of all review outcomes were restricted to studies at a low risk of bias for selection bias and other bias. Sensitivity analysis was then performed including all studies. The primary review outcomes were live birth and miscarriage.

MAIN RESULTS

Endometrial injury versus control (no procedure or a sham procedure) A total of 37 studies (8786 women) were included in this comparison. Most studies performed endometrial injury by pipelle biopsy in the luteal phase of the cycle before the IVF cycle. The primary analysis was restricted to studies at low risk of bias, and included eight studies. The effect of endometrial injury on live birth is unclear as the result is consistent with no effect, or a small reduction, or an improvement (odds ratio (OR) 1.12, 95% confidence interval (CI) 0.98 to 1.28; participants = 4402; studies = 8; I² = 15%, moderate-certainty evidence). This suggests that if the chance of live birth with IVF is usually 27%, then the chance when using endometrial injury would be somewhere between < 27% and 32%. Similarly, the effect of endometrial injury on clinical pregnancy is unclear (OR 1.08, 95% CI 0.95 to 1.23; participants = 4402; studies = 8; I² = 0%, moderate-certainty evidence). This suggests that if the chance of clinical pregnancy from IVF is normally 32%, then the chance when using endometrial injury before IVF is between 31% and 37%. When all studies were included in the sensitivity analysis, we were unable to conduct meta-analysis for the outcomes of live birth and clinical pregnancy due to high risk of bias and statistical heterogeneity. Endometrial injury probably results in little to no difference in chance of miscarriage (OR 0.88, 95% CI 0.68 to 1.13; participants = 4402; studies = 8; I² = 0%, moderate-certainty evidence), and this result was similar in the sensitivity analysis that included all studies. The result suggests that if the chance of miscarriage with IVF is usually 6.0%, then when using endometrial injury it would be somewhere between 4.2% and 6.8%. Endometrial injury was associated with mild to moderate pain (approximately 4 out of 10), and was generally associated with some minimal bleeding. The evidence was downgraded for imprecision due to wide confidence intervals and therefore all primary analyses were graded as moderate certainty. Higher versus lower degree of injury Only one small study was included in this comparison (participants = 129), which compared endometrial injury using two different instruments in the cycle prior to the IVF cycle: a pipelle catheter and a Shepard catheter. This trial was excluded from the primary analysis due to risk of bias. In the sensitivity analysis, all outcomes reported for this study were graded as very-low certainty due to risk of bias, and as such we were not able to interpret the study results.

AUTHORS' CONCLUSIONS

The effect of endometrial injury on live birth and clinical pregnancy among women undergoing IVF is unclear. The results of the meta-analyses are consistent with an increased chance, no effect and a small reduction in these outcomes. We are therefore uncertain whether endometrial injury improves the chance of live birth or clinical pregnancy in women undergoing IVF. Endometrial injury does not appear to affect the chance of miscarriage. It is a somewhat painful procedure associated with a small amount of bleeding. In conclusion, current evidence does not support the routine use of endometrial injury for women undergoing IVF.

Endometrial stem cells: origin, biological function, and therapeutic applications for reproductive disorders

PURPOSE OF REVIEW

Endometrial stem cells (ESCs) are multipotent cells that are thought to originate locally in the endometrium as well as in the bone marrow (BM). They have remarkable plasticity and hold promise as an autologous source for regenerative medicine. This review focuses on recent studies that have advanced our understanding of the biology and function of ESCs and BM-derived stem cells (BMDSCs) as related to physiological reproductive processes and pathologies. Moreover, it reviews recent data on potential therapeutic applications of stem cells to endometrial disorders that lead to reproductive failure.

RECENT FINDINGS

Growing evidence from basic and preclinical studies suggests that ESCs participate in endometrial tissue regeneration and repair. Recent evidence also suggests that ESCs and BMDSCs play important roles in physiological reproductive functions including decidualization, implantation, pregnancy maintenance, and postpartum uterine remodeling. Initial preclinical and clinical studies with ESCs and BMDSCs suggest they have the potential to provide new therapies for various endometrial disorders associated with reproductive failure.

SUMMARY

Uterine ESCs and BMDSCs appear to play an important biological role in reproductive success and failure, and have the potential to become treatment targets for reproductive diseases including recurrent implantation failure, thin endometrium, Asherman, and recurrent pregnancy loss.

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.

Approaches to Improve Endometrial Receptivity in Case of Repeated Implantation Failures

Repeated implantation failures are a constant challenge in reproductive medicine with a significant impact both on health providers and on infertile couples. Several approaches have been proposed so far as effective; however, accumulative data have clarified that most of the treatment options do not have the evidence base for a generalized application to be suggested by the relevant societies. Implantation failures are attributed to either poor quality embryos or to defected endometrial receptivity. The current review aims to summarize in a systematic way all the new trends in managing RIF via interference with endometrial receptivity. The authors focus mainly, but not exclusively, on endometrial injury prior to embryo transfer and endometrial priming with autologous cells or biological agents. To this direction, a systematic search of the Pubmed database has been conducted taking into account the emerged evidence of the last two decades. All the suggested interventions are herein presented and analyzed in terms of reproductive outcomes. It is evident that properly powered and designed randomized trials are needed to support a new standard approach in RIF treatment that will safely be incorporated in national and international guidelines.

Endometrial scratching for poor responders based on the Bologna criteria in ICSI fresh embryo transfer cycles: a preliminary retrospective cohort study

Objective

This study evaluated the effect of endometrial injury on pregnancy outcomes in patients with a poor ovarian response (POR), based on the Bologna criteria, who underwent intracytoplasmic sperm injection (ICSI) cycles.

Material and Methods

Sixty-eight patients were enrolled in this retrospective cohort study. All patients in the endometrial scratching group (group 1, n=32) and control group (group 2, n=36) underwent office hysteroscopy in the early follicular phase of the cycle before controlled ovarian stimulation. Group 1 also underwent endometrial scratching. The main outcome measure was the ongoing pregnancy rate.

Results

The study groups had similar baseline demographics, including age, body mass index, duration of infertility, number of ICSI cycles, and hormone levels. However, the antral follicle count was significantly higher in group 1 than in group 2 (4.2±1.9 vs 3.3±1.8; p<0.05). There were no significant group differences in ovarian stimulation characteristics (ovarian stimulation time, trigger day endometrial thickness, number of metaphase II oocytes), number of embryos transferred, or the ratio of embryo transfer on days 3 and 5. Moreover, there were no significant differences between groups 1 and 2 in the rates of chemical pregnancy (25% vs 19.4%), clinical pregnancy (15.6% vs 11.1%) or ongoing pregnancy (9.4% vs 8.3%) (p>0.05 for all).

Conclusion

Endometrial scratching did not improve pregnancy outcomes for patients meeting the Bologna criteria for a POR to ICSI cycles using fresh embryo transfer and the GnRH antagonist protocol.

Efficacy of therapies and interventions for repeated embryo implantation failure: a systematic review and meta-analysis

The aim of the present systematic review and meta-analysis was to assess the effect of the different therapeutic options for repeated embryo implantation failure (RIF) on a subsequent IVF cycle outcome. Twenty-two RCTs and nineteen observational studies were included. Pooling of results showed a beneficial effect of intrauterine PBMC infusion on both CPR (RR 2.18; 95% CI 1.58-3.00; p < 0.00001; OR 2.03; 95% CI 1.22-3.36; p = 0.006) and LBR (RR 2.41; 95% CI 1.40-4.16; p = 0.002; OR 3.73; 95% CI 1.13-12.29; p = 0.03), of subcutaneous G-CSF administration on CPR (RR 2.29; 95% CI 1.58-3.31; p < 0.0001) and of intrauterine PRP infusion on CPR (RR 2.45; 95% CI 1.55-3.86; p = 0.0001). Observational studies also demonstrated a positive effect of IVIG and intrauterine hCG infusion on both CPR and LBR and of atosiban on CPR. Studies investigating intrauterine G-CSF infusion, LMWH, intravenous intralipid, hysteroscopy, blastocyst-stage ET, ZIFT, PGT-A and AH failed to observe an impact on IVF outcome. The quality of the evidence that emerged from RCTs focused on intrauterine PBMC infusion and subcutaneous G-CSF administration was moderate. For all other therapies/interventions it varied from low to very low. In conclusion, intrauterine PBMC infusion and subcutaneous G-CSF administration are the most promising therapeutic options for RIF. However, further well conducted RCTs are necessary before their introduction into clinical practice.

Endometrial scratching in women with one failed IVF/ICSI cycle-outcomes of a randomised controlled trial (SCRaTCH)

STUDY QUESTION

Does endometrial scratching in women with one failed IVF/ICSI treatment affect the chance of a live birth of the subsequent fresh IVF/ICSI cycle?

SUMMARY ANSWER

In this study, 4.6% more live births were observed in the scratch group, with a likely certainty range between -0.7% and +9.9%.

WHAT IS KNOWN ALREADY

Since the first suggestion that endometrial scratching might improve embryo implantation during IVF/ICSI, many clinical trials have been conducted. However, due to limitations in sample size and study quality, it remains unclear whether endometrial scratching improves IVF/ICSI outcomes.

STUDY DESIGN, SIZE, DURATION

The SCRaTCH trial was a non-blinded randomised controlled trial in women with one unsuccessful IVF/ICSI cycle and assessed whether a single endometrial scratch using an endometrial biopsy catheter would lead to a higher live birth rate after the subsequent IVF/ICSI treatment compared to no scratch. The study took place in 8 academic and 24 general hospitals. Participants were randomised between January 2016 and July 2018 by a web-based randomisation programme. Secondary outcomes included cumulative 12-month ongoing pregnancy leading to live birth rate.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women with one previous failed IVF/ICSI treatment and planning a second fresh IVF/ICSI treatment were eligible. In total, 933 participants out of 1065 eligibles were included (participation rate 88%).

MAIN RESULTS AND THE ROLE OF CHANCE

After the fresh transfer, 4.6% more live births were observed in the scratch compared to control group (110/465 versus 88/461, respectively, risk ratio (RR) 1.24 [95% CI 0.96-1.59]). These data are consistent with a true difference of between -0.7% and +9.9% (95% CI), indicating that while the largest proportion of the 95% CI is positive, scratching could have no or even a small negative effect. Biochemical pregnancy loss and miscarriage rate did not differ between the two groups: in the scratch group 27/153 biochemical pregnancy losses and 14/126 miscarriages occurred, while this was 19/130 and 17/111 for the control group (RR 1.21 (95% CI 0.71-2.07) and RR 0.73 (95% CI 0.38-1.40), respectively). After 12 months of follow-up, 5.1% more live births were observed in the scratch group (202/467 versus 178/466), of which the true difference most likely lies between -1.2% and +11.4% (95% CI).

LIMITATIONS, REASONS FOR CAUTION

This study was not blinded. Knowledge of allocation may have been an incentive for participants allocated to the scratch group to continue treatment in situations where they may otherwise have cancelled or stopped. In addition, this study was powered to detect a difference in live birth rate of 9%.

WIDER IMPLICATIONS OF THE FINDINGS

The results of this study are an incentive for further assessment of the efficacy and clinical implications of endometrial scratching. If a true effect exists, it may be smaller than previously anticipated or may be limited to specific groups of women undergoing IVF/ICSI. Studying this will require larger sample sizes, which will be provided by the ongoing international individual participant data-analysis (PROSPERO CRD42017079120). At present, endometrial scratching should not be performed outside of clinical trials.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by ZonMW, the Dutch organisation for funding healthcare research. J.S.E. Laven reports grants and personal fees from AnshLabs (Webster, Tx, USA), Ferring (Hoofddorp, The Netherlands) and Ministry of Health (CIBG, The Hague, The Netherlands) outside the submitted work. A.E.P. Cantineau reports 'other' from Ferring BV, personal fees from Up to date Hyperthecosis, 'other' from Theramex BV, outside the submitted work. E.R. Groenewoud reports grants from Titus Health Care during the conduct of the study. A.M. van Heusden reports personal fees from Merck Serono, personal fees from Ferring, personal fees from Goodlife, outside the submitted work. F.J.M. Broekmans reports personal fees as Member of the external advisory board for Ferring BV, The Netherlands, personal fees as Member of the external advisory board for Merck Serono, The Netherlands, personal fees as Member of the external advisory for Gedeon Richter, Belgium, personal fees from Educational activities for Ferring BV, The Netherlands, grants from Research support grant Merck Serono, grants from Research support grant Ferring, personal fees from Advisory and consultancy work Roche, outside the submitted work. C.B. Lambalk reports grants from Ferring, grants from Merck, grants from Guerbet, outside the submitted work.

TRIAL REGISTRATION NUMBER

Registered in the Netherlands Trial Register (NL5193/NTR 5342).

TRIAL REGISTRATION DATE

31 July 2015.

DATE OF FIRST PATIENT’S ENROLMENT

26 January 2016.

Concordance between systematic reviews of randomized controlled trials in assisted reproduction: an overview

STUDY QUESTION

Are systematic reviews published within a 3-year period on interventions in ART concordant in their conclusions?

SUMMARY ANSWER

The majority of the systematic reviews published within a 3-year period in the field of assisted reproduction on the same topic had discordant conclusions.

WHAT IS KNOWN ALREADY

Systematic reviews and meta-analyses have now replaced individual randomized controlled trials (RCTs) at the top of the evidence pyramid. There has been a proliferation of systematic reviews and meta-analyses, many of which suffer from methodological issues and provide varying conclusions.

STUDY DESIGN SIZE DURATION

We assessed nine interventions in women undergoing ART with at least three systematic reviews each, published from January 2015 to December 2017.

PARTICIPANTS/MATERIALS SETTING METHODS

The systematic reviews which included RCTs were considered eligible for inclusion. The primary outcome was extent of concordance between systematic reviews on the same topic. Secondary outcomes included assessment of quality of systematic reviews, differences in included studies in meta-analyses covering the same search period, selective reporting and reporting the quality of evidence.

MAIN RESULTS AND THE ROLE OF CHANCE

Concordant results and conclusions were found in only one topic, with reviews in the remaining eight topics displaying partial discordance. The AMSTAR grading for the majority of the non-Cochrane reviews was critically low whilst it was categorized as high for all of the Cochrane reviews. For three of the nine topics, none of the included systematic reviews assessed the quality of evidence. We were unable to assess selective reporting as most of the reviews did not have a pre-specified published protocol.

LIMITATIONS REASONS FOR CAUTION

We were limited by the high proportion of reviews lacking a pre-specified protocol, which made it impossible to assess for selective reporting. Furthermore, many reviews did not specify primary and secondary outcomes which made it difficult to assess reporting bias. All the authors of this review were Cochrane review authors which may introduce some assessment bias. The categorization of the review's conclusions as beneficial, harmful or neutral was subjective, depending on the tone and wording of the conclusion section of the review.

WIDER IMPLICATIONS OF THE FINDINGS

The majority of the systematic reviews published within a 3-year period on the same topic in the field of assisted reproduction revealed discordant conclusions and suffered from serious methodological issues, hindering the process of informed healthcare decision-making.

STUDY FUNDING/COMPETING INTERESTS

All the authors are Cochrane authors. M.S.K. is an editorial board member of Cochrane Gynaecology and Fertility group. No grant from funding agencies in the public, commercial or not-for-profit sectors was obtained.

Tubal Flushing Treatment for Unexplained Infertility

Tubal patency testing was initially introduced as a diagnostic test. However, it has been observed that some tubal patency tests also have a therapeutic effect. This therapeutic effect can be influenced by the contrast medium used during tubal flushing. In this review, we discuss current evidence associated with different methods for tubal flushing and their potential impact on reproductive outcomes in women with unexplained infertility. Furthermore, we discuss their diagnostic accuracy, safety, and cost-effectiveness.

Uterine bathing with sonography gel prior to IVF/ICSI-treatment in patients with endometriosis, a multicentre randomised controlled trial

STUDY QUESTION

What is the effect of uterine bathing with sonography gel prior to IVF/ICSI-treatment on live birth rates after fresh embryo transfer in patients with endometriosis?

SUMMARY ANSWER

After formal interim analysis and premature ending of the trial, no significant difference between uterine bathing using a pharmacologically neutral sonography gel compared to a sham procedure on live birth rate after fresh embryo transfer in endometriosis patients (26.7% vs. 15.4%, relative risk (RR) 1.73, 95% confidence interval (CI) 0.81-3.72; P-value 0.147) could be found, although the trial was underpowered to draw definite conclusions.

WHAT IS KNOWN ALREADY

Impaired implantation receptivity contributes to reduced clinical pregnancy rates after IVF/ICSI-treatment in endometriosis patients. Previous studies have suggested a favourable effect of tubal flushing with Lipiodol^® on natural conceptions. This benefit might also be explained by enhancing implantation through endometrial immunomodulation. Although recent studies showed no beneficial effect of endometrial scratching, the effect of mechanical stress by intrauterine infusion on the endometrium in endometriosis patients undergoing IVF/ICSI-treatment has not been investigated yet.

STUDY DESIGN SIZE DURATION

We performed a multicentre, patient-blinded, randomised controlled trial in which women were randomly allocated to either a Gel Infusion Sonography (GIS, intervention group) or a sham procedure (control group) prior to IVF/ICSI-treatment. Since recruitment was slow and completion of the study was considered unfeasible, the study was halted after inclusion of 112 of the planned 184 women.

PARTICIPANTS/MATERIALS SETTING METHODS

We included infertile women with surgically confirmed endometriosis ASRM stage I-IV undergoing IVF/ICSI-treatment. After informed consent, women were randomised to GIS with intrauterine instillation of ExEm-gel^® or sonography with gel into the vagina (sham). This was performed in the cycle preceding the embryo transfer, on the day GnRH analogue treatment was started. The primary endpoint was live birth rate after fresh embryo transfer. Analysis was performed by both intention-to-treat and per-protocol.

MAIN RESULTS AND THE ROLE OF CHANCE

Between July 2014 to September 2018, we randomly allocated 112 women to GIS (n = 60) or sham procedure (n = 52). The live birth rate after fresh embryo transfer was 16/60 (26.7%) after GIS versus 8/52 (15.4%) after the sham (RR 1.73, 95% CI 0.81-3.72; P-value 0.147). Ongoing pregnancy rate was 16/60 (26.7%) after GIS versus 9/52 (17.3%) in the controls (RR 1.54, 95% CI 0.74-3.18). Miscarriage occurred in 1/60 (1.7%) after GIS versus 5/52 (9.6%) in the controls (RR 0.17, 95% CI 0.02-1.44) women. Uterine bathing resulted in a higher pain score compared with a sham procedure (visual analogue scale score 2.7 [1.3-3.5] vs. 1.0 [0.0-2.0], P < 0.001). There were two adverse events after GIS compared with none after sham procedures.

LIMITATIONS REASONS FOR CAUTION

The study was terminated prematurely due to slow recruitment and trial fatigue. Therefore, the trial is underpowered to draw definite conclusions regarding the effect of uterine bathing with sonography gel on live birth rate after fresh embryo transfer in endometriosis patients undergoing IVF/ICSI-treatment.

WIDER IMPLICATIONS OF THE FINDINGS

We could not demonstrate a favourable effect of uterine bathing procedures with sonography gel prior to IVF/ICSI-treatment in patients with endometriosis.

STUDY FUNDING/COMPETING INTERESTS

Investigator initiated study. IQ Medical Ventures provided the ExEm FOAM^® kits free of charge, they were not involved in the study design, data management, statistical analyses and/or manuscript preparation, etc. C.B.L. reports receiving grants from Ferring, Merck and Guerbet, outside the submitted work. C.B.L. is Editor-in-Chief of Human Reproduction. V.M. reports grants and other from Guerbet, outside the submitted work. B.W.M. reports grants from NHMRC (GNT1176437), personal fees from ObsEva, Merck and Merck KGaA, Guerbet and iGenomix, outside the submitted work. N.P.J. reports research funding from Abb-Vie and Myovant Sciences and consultancy for Vifor Pharma, Guerbet, Myovant Sciences and Roche Diagnostics, outside the submitted work. K.D. reports personal fees from Guerbet, outside the submitted work. The other authors do not report any conflicts of interest. No financial support was provided.

TRIAL REGISTRATION NUMBER

NL4025 (NTR4198).

TRIAL REGISTRATION DATE

7 October 2013.

DATE OF FIRST PATIENT’S ENROLMENT

22 July 2014.

The impact of accurately timed mid-luteal endometrial injury in nulligravid women undergoing their first or second embryo transfer

INTRODUCTION

Endometrial injury or 'scratch' preceding an assisted reproductive therapy (ART) cycle has recently been shown not to improve livebirth rates among women undergoing ART. The objective of this study was to compare pregnancy outcomes in nulliparous women who underwent an accurately timed mid-luteal scratch biopsy prior to ART with those who did not.

METHODS

This was a prospective cohort study. Women were recruited between October 2016 and February 2018 inclusive. Women who met the inclusion criteria and who did not undergo an endometrial scratch in the study period were used as a comparison group. Patients underwent a cycle of ART in the menstrual cycle following endometrial scratch.

RESULTS

Ninety-eight women were eligible for participation in the study. There were no differences in rates of implantation (35.7% (n = 20/56) vs. 35.4% (n = 17/48); p = 1.00), clinical pregnancy (40.0% (n = 20/50) vs. 39.5% (n = 17/43); p = 1.00) or live birth (34.0% (n = 17/50) vs. 25.6% (n = 11/43); p = 0.50) per embryo transfer between those who underwent a scratch and those who did not.

CONCLUSION

Endometrial scratch is a simple, inexpensive and low-risk procedure. However, in this relatively small cohort study, no differences in rates of implantation, clinical pregnancy or live birth in women with primary infertility were determined between those who underwent a scratch and those who did not.

IVF, from the past to the future: the inheritance of the Capri Workshop Group

Today IVF use is booming all over the world and has even started to play a role in demographic analyses. Prognosis-adjusted estimates suggest that up to two-thirds of couples could achieve a live birth. However, the scenario is less exciting in reality. Discontinuation during the cycles is common, and age and ovarian response continue to be crucial in modulating this rate of success. A growing interest is now given to the risk of abuses and in particular to overtreatment and to prescriptions of useless, if not harmful, expensive additional treatments ('add-ons'). A more rational, evidence-based and wise approach is needed. From a scientific perspective, several obscure aspects remain and warrant future investigations. Of particular interest are the neglected role of sperm selection, the potential adult implications of early embryo life in vitro and the issue of sustainability.

The impact of endometrial injury on reproductive outcomes: results of an updated meta-analysis

Background

It is still unclear whether endometrial injury (EI) has a beneficial effect on reproductive outcomes, and if so, the optimal procedure characteristics are not clear. All previous papers concluded that more research is needed, and as additional studies were recently published, the insights on EI have changed significantly.

Methods

Searches were conducted in MEDLINE, Embase, Web of Science, and Cochrane Library, to identify randomized controlled trials examining the EI effect on IVF outcomes in women at least one previous failed cycle.

Results

2015 references were identified through database searching. Ultimately, 17 studies were included, involving 3016 patients. Clinical pregnancy rate (CPR) (RR = 1.19, [95% CI 1.06-1.32], P = .003) and live birth rate (LBR) (RR = 1.18, [95%CI 1.04-1.34], P = .009) were significantly improved after EI. Number of previous failed cycles, maternal age, and hysteroscopy were found to be relevant confounders. Higher CPR and LBR were found when EI was performed twice, while performing EI once did not significantly improve reproductive rates.

Conclusion

According to the present meta-analysis, EI may be offered to younger patients with few previous failed cycles and should be additionally studied in an RCT comparing different timing and more than one EI before treatment.

Recurrent implantation failure in IVF: A Canadian Fertility and Andrology Society Clinical Practice Guideline

Recurrent implantation failure (RIF) after IVF is a challenging topic for clinicians and can be a devastating reality for some patients with infertility. The purpose of this guideline from the Canadian Fertility and Andrology Society (CFAS) is to provide the most relevant evidence to date for the assessment and management of RIF. This guideline was developed using the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach. This guideline recognizes the presence of heterogeneity in the definition of RIF. Recommendations are offered here on the investigation of RIF and management options that may increase the chance of a live birth.

[Endometrial receptivity in assisted reproductive techniques: An aspect to investigate in embryo implantation failure]

Infertility affects between 8 and 12% of reproductive-age couples worldwide. Despite improvements in assisted reproductive techniques (ART), live birth rates are still limited. In clinical practice, imaging and microscopy are currently widely used, but their diagnostic effectiveness remains limited. In research, the emergence of innovative techniques named OMICS would improve the identification of the implantation window, while progressing in the understanding of the pathophysiological mechanisms involved in embryo implantation failures. To date, transcriptomic analysis seems to be the most promising approach in clinical research. The objective of this review is to present the results obtained with the different approaches available in clinical practice and in research to assess endometrial receptivity in patients undergoing ART.

Endometrial scratch injury with office hysteroscopy before IVF/ICSI: A randomised controlled trial

OBJECTIVE

Endometrial scratch injury (ESI) has been proposed to improve endometrial receptivity and thereby increase implantation rates in assisted reproductive technology (ART) treatment. ESI has been widely incorporated into clinical practice despite inconclusive evidence of its effect on reproductive outcomes. We aimed to assess pregnancy and live birth rates in subfertile women receiving ESI before IVF treatment in comparison to controls.

STUDY DESIGN

This was a randomised controlled trial (RCT) with no blinding of participants, investigators or health care personnel. Women in ART treatment were allocated to either office hysteroscopy with ESI (ESI group) or no intervention (control group). In total 184 women in IVF/ICSI treatment with minimum one previous failed IVF/ICSI cycle, were included in the final analysis. The primary outcome was positive serum hCG (s-hCG). Secondary outcomes were ongoing pregnancy and live birth rate. Only per-protocol analyses were performed as all patients included at one centre had to be excluded. The trial is registered at ClinicalTrials.gov, NCT01743391.

RESULTS

Our results showed a non-significant increase in positive s-hCG (OR 1.23, 95 % CI (0.65-2.33)), ongoing pregnancy (OR 1.52, 95 % CI (0.73-3.17)), and live birth rates (OR 1.69, 95 % CI (0.78-3.64)) per randomised woman between the ESI and the control group.

CONCLUSION

We observed no significant differences in positive s-hCG or other reproductive outcomes in the ESI vs. the control group. While the crude estimates of positive reproductive outcomes were higher in the ESI group, statistical significance was not reached, and the study was not powered to show smaller differences. However, data from this study will be re-evaluated in the context of an individual participant data meta-analysis (IPD-MA) of RCTs on ESI.

Endometrial Immune Profiling: A Method to Design Personalized Care in Assisted Reproductive Medicine

Objective: To assess the efficiency of the endometrial immune profiling as a method to design personalized care to enhance the pregnancy rate in a large heterogeneous infertile population. We hypothesized that some reproductive failures could be induced by a uterine immune dysregulation which could be identified and corrected with a targeted plan. Design: Prospective cohort study. Setting: Multicentric study. Intervention(s) and Main outcome measure(s): One thousand and seven hundred thirty-eight infertile patients had an immune profiling on a timed endometrial biopsy between 2012 and 2018. This test documented the absence or the presence of an endometrial immune dysregulation and identified its type. In case of dysregulation, a targeted personalized plan was suggested to the treating clinician aiming to supply the anomaly. One year after the test, the clinician was contacted to provide the outcome of the subsequent embryo transfer with the applied suggested plan. Result(s): After testing, 16.5% of the patients showed no endometrial immune dysregulation, 28% had a local immune under-activation, 45% had a local immune over-activation, and 10.5% had a mixed endometrial immune profile. In patients with a history of repeated implantation failures (RIF) or recurrent miscarriages (RM), the pregnancy rate was significantly higher if an endometrial dysregulation was found and the personalized plan applied, compared to the patients with an apparent balanced immune profile (respectively 37.7 and 56% vs. 26.9 and 24%, p < 0.001). In contrast, in good prognosis IVF (in vitro fertilization) subgroup and patients using donor eggs, this difference was not significant between dysregulated and balanced subgroups, but higher pregnancy rates were observed in absence of dysregulation. For patients with immune over-activation, pregnancy rates were significantly higher for patients who had a test of sensitivity, regarding the type of immunotherapy introduced, when compared to the ones who did not (51 vs. 39.9%, p = 0.012). Conclusion(s): Local endometrial immunity appears to be a new and important parameter able to influence the prognosis of pregnancy. Targeted medical care in case of local immune dysregulation resulted in significantly higher pregnancy rates in RIF and RM patients.

Effect of endometrial injury during menstruation on clinical outcomes in frozen-thawed embryo transfer cycles: A randomized control trial

Aim

To explore the clinical effect of endometrial injury (EI) on the third day of the menstrual cycle before frozen–thawed embryo transfer (frozen–thawed ET) on patients experienced two or more implantation failures.

Methods

A total of 200 patients who suffered at least two failed hormone‐replacement therapies and frozen–thawed ET were randomly divided into two groups: EI group and control group (n = 100 in each group). Patients in the EI group received local EI with a Pipelle catheter on the third day of the menstrual cycle before frozen–thawed ET. Primary outcomes were live birth, clinical pregnancy and implantation rates. Secondary outcomes were biochemical, multiple and ectopic pregnancy rates and abortion rates.

Results

The rate of live birth in EI group (51.00%) was significantly higher than that of control group (36.00%) (P = 0.032). Clinical pregnancy and implantation rates in EI group were significantly higher comparing to control group (64.00% vs 48.00%, P = 0.023 and 46.74% vs 30.11%, P = 0.001). The rate of multiple pregnancy in EI group (37.50%) was significantly higher than that of control group (18.75%) (P = 0.031). No significant difference in ectopic pregnancy rate and abortion rate was observed between EI group and control group.

Conclusion

Applying EI to patients experienced two or more implantation failures on the third day of the menstrual cycle before frozen–thawed ET can improve clinical outcomes.

Randomised controlled trials evaluating endometrial scratching: assessment of methodological issues

STUDY QUESTION

Do randomised controlled trials (RCTs) evaluating endometrial scratching suffer from methodological issues including insufficient trial registration, statistical errors or irreproducibility, randomisation errors or miscellaneous issues?

SUMMARY ANSWER

The majority of RCTs investigating endometrial scratching have methodological issues.

WHAT IS KNOWN ALREADY

A large number of small RCTs investigating the effectiveness of endometrial scratching prior to in vitro fertilisation (IVF) and intrauterine insemination (IUI)/intercourse have reported favourable findings. Subsequently, systematic reviews incorporating these RCTs yielded meta-analyses in favour of endometrial scratching. Endometrial scratching has been widely adopted by infertility specialists around the world. Recently, an international RCT including 1364 women reported no benefit from endometrial scratching before IVF.

STUDY DESIGN, SIZE, DURATION

We evaluated several methodological issues of RCTs investigating the effectiveness of endometrial scratching prior to IVF and IUI/intercourse. We identified 25 RCTs for IVF and 12 RCTs for IUI/intercourse with full-text publication.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We assessed the RCTs on the following criteria: adequacy of trial registration, statistical issues (description of statistical methods and reproducibility of univariable statistical analysis), excessive similarity or difference in baseline characteristics that is not compatible with chance (Monte Carlo simulations and Kolmogorov–Smirnov test) and miscellaneous methodological issues.

MAIN RESULTS AND THE ROLE OF CHANCE

Of 25 RCTs evaluating endometrial scratching prior to IVF, only eight (32%) had adequate trial registration. In total, 10 (40%) RCTs had issues regarding statistical methods. Nine (69%, 13 applicable) RCTs had at least one inconsistency between reported and reproduced univariable statistical analysis for categorical baseline/intermediate characteristics. Statistical results of at least one outcome were not reproducible in 14 (74%, 19 applicable) RCTs. Only two (8%) RCTs had none of the above issues. Suggested by the simulations, these RCTs did not significantly violate the null hypothesis that the baseline characteristics were the results of a properly conducted randomisation process (P = 0.4395).

Of 12 IUI/intercourse RCTs, only 2 (17%) had adequate trial registration. In total, five (42%) studies had issues of statistical methods. Inconsistency between reported and reproduced univariable analysis for baseline/intermediate categorical variable(s) was found in four (57%, 7 applicable) RCTs. Statistical analysis was not reproducible for at least one outcome in eight (80%, 10 applicable) studies. All RCTs had at least one of the above issues. These RCTs were inconsistent with the null hypothesis that their baseline characteristics were the results of proper randomised allocation (P = 1.659*10−7).

LIMITATIONS, REASONS FOR CAUTION

We were unable to assess RCTs which were not published as full-text papers. We could not analyse individual participant data to investigate possible reasons for statistical inconsistencies. The method to infer the likelihood of proper random sampling rests on assumptions including independent baseline characteristics, simple randomisation and no publication bias.

WIDER IMPLICATIONS OF THE FINDINGS

The methodological issues common to RCTs evaluating endometrial scratching may have biased the results of the trials. Further development and validation of these novel methods may be helpful for the critical appraisal of RCTs.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was sought to support this work. B.W.M. is supported by a National Health Medical Research Council (NHMRC) Practitioner Fellowship (GNT1082548). B.W.M. reports consultancy for ObsEva, Merck and Guerbet. D.W. is supported by a grant from the Paracelsus Medical University Salzburg, Austria (PMU Research Fund—PMU FFF Number: L-18/02/006-WET) and by Drs Haackert Foundation, Germany. S.L. is an author of a trial included in this study, an author of an included systematic review and a Cochrane editor. All other authors have no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A