Is there a treatable cause of repeated implantation failure, or is it simply treatment failure by chance?

RESEARCH QUESTION

Does repeated implantation failure (RIF) sometimes have a cause, or is it simply treatment failure by chance?

DESIGN

A hypothetical model of a cohort of 1000 women undergoing four repeated IVF attempts was constructed. A proportion of women with RIF carried an underlying risk factor negatively affecting implantation, compared with women without the factor. In strategy A, women had standard IVF without additional treatment; in strategy B, the women received standard IVF plus an additional treatment. The sensitivity analysis varied the prevalence of the underlying risk factor from 5% to 50%. The model was compared with literature studies where a treatment strategy had been applied.

RESULTS

With strategy A, the clinical pregnancy rate decreased with subsequent IVF attempts (31% in the first transfer with a risk factor prevalence of 5%, to 8% in the fourth transfer with a risk factor prevalence of 50%). As the prevalence increased, the clinical pregnancy rate was higher with strategy A. For strategy B, the clinical pregnancy rates for the modelled cohort decreased with each subsequent IVF attempt. Regardless of the prevalence of the risk factor, the decline in clinical pregnancy rate was less strong (from 32% in the first transfer with a prevalence of 5%, to 25% in the fourth transfer with a prevalence of 50%). When applying the model to the literature studies, the trends expected for strategy B (decreasing clinical pregnancy rates) were not expressed.

CONCLUSIONS

RIF might therefore be of iatrogenic origin due to the low success rate of IVF and might be triggered by the increasing female age associated with higher numbers of RIF.

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.

Outcome of Different Endometrial Preparation Protocols Prior to Frozen-Thawed Embryo Transfer on Pregnancy Outcomes in Women with Repeated Implantation Failure

Aim

To compare the pregnancy outcomes of frozen-thawed embryo transfer (FET) cycles among women with repeated implantation failure (RIF) treated with various endometrial preparation protocols.

Methods

A total of 605 women with RIF were retrospectively recruited between January 2017 and December 2020 from Northern Theater General Hospital. Patients were divided into natural cycles, hormone replacement therapy (HRT) cycles, depot gonadotropin-releasing hormone (GnRH) agonist-HRT, and endometrial scratching (ES) plus depot GnRH agonist-HRT. The primary endpoint was clinical pregnancy rate, while secondary endpoints included live birth rate and pain assessment.

Results

Of the 605 recruited patients, 63 were undergoing natural cycles, 281 were treated with HRT cycles, 141 treated with depot GnRH agonist-HRT, and 120 treated with ES combined with depot GnRH agonist-HRT. There were significant differences among protocols on clinical pregnancy rate (P=0.029), while no significant difference was observed among protocols on live birth rates (P=0.108). Multivariate analyses suggested that HRT (odds ratio [OR]: 0.50; 95% confidence interval [CI]: 0.28-0.89; P=0.019) and depot GnRH agonist-HRT (OR: 0.49; 95% CI: 0.27-0.91; P=0.021) cycles were associated with a lower clinical pregnancy rate as compared with natural cycles, while no significant difference between ES combined with depot GnRH agonist-HRT and natural cycles for clinical pregnancy rates (OR: 0.72; 95% CI: 0.38-1.36; P=0.313). Moreover, the HRT (OR: 0.70; 95% CI: 0.39-1.28; P=0.239), depot GnRH agonist-HRT (OR: 0.67; 95% CI: 0.35-1.29; P=0.229), and ES combined with depot GnRH agonist-HRT (OR: 1.11; 95% CI: 0.58-2.14; P=0.754) cycles had no significant effects on live birth rate as compared with natural cycles. A total of 87.50% patients treated with ES combined with depot GnRH agonist-HRT reported pain during the procedure.

Conclusion

ES and depot GnRH agonists could be considered for RIF women with high-quality blastocysts, 14 days after verified transplantation failure.

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.

The role of endometrial scratching prior to in vitro fertilization: an updated systematic review and meta-analysis

RESEARCH QUESTION

To evaluate the role of endometrial scratching performed prior to an embryo transfer cycle on the probability of pregnancy compared to placebo/sham or no intervention.

DESIGN

A computerized literature (using a specific search strategy) search was performed across the databases MEDLINE, EMBASE, COCHRANE CENTRAL, SCOPUS and WEB OF SCIENCE up to June 2023 in order to identify randomized controlled trials (RCTs) evaluating the effect of endometrial scratching prior to an embryo transfer cycle on the probability of pregnancy, expressed either as live birth, ongoing pregnancy or clinical pregnancy (in order of significance) compared to placebo/sham or no intervention. Data were pooled using random-effects or fixed-effects model, depending on the presence or not of heterogeneity. Heterogeneity was assessed using the I2 statistic. Subgroup analyses were performed based on the population studied in each RCT, as well as on the timing and method of endometrial biopsy. Certainty of evidence was assessed using the GRADEPro tool.

RESULTS

The probability of live birth was significantly higher in embryo transfer cycles after endometrial scratching as compared to placebo/sham or no intervention (relative risk-RR: 1.12, 95% CI: 1.05-1.20; heterogeneity: I2=46.30%, p<0.001, 28 studies; low certainty). The probability of ongoing pregnancy was not significantly difference between the two groups (RR: 1.07, 95% CI: 0.98-1.18; heterogeneity: I2=27.44%, p=0.15, 11 studies; low certainty). The probability of clinical pregnancy was significantly higher in embryo transfer cycles after endometrial scratching as compared to placebo/sham or no intervention (RR: 1.12, 95% CI: 1.06-1.18; heterogeneity: I2=47.48%, p<0.001, 37 studies; low certainty). A subgroup analysis was performed based on the time that endometrial scratching was carried out. When endometrial scratching was performed during the menstrual cycle prior to the embryo transfer cycle a significantly higher probability of live birth was present (RR: 1.18, 95% CI:1.09-1.27; heterogeneity: I2=39.72%, p<0.001, 21 studies; moderate certainty). On the contrary, no effect on the probability of live birth was present when endometrial injury was performed during the embryo transfer cycle (RR: 0.87, 95% CI: 0.67-1.15; heterogeneity: I2=65.18%, p=0.33, 5 studies; low certainty). In addition, a higher probability of live birth was only present in women with previous IVF failures (RR: 1.35, 95% CI: 1.20-1.53; heterogeneity: I2=0%, p<0.001, 13 studies; moderate certainty) with evidence suggesting that the more IVF failures the more likely endometrial scratching to be beneficial (p=0.004). The number of times endometrial scratching was performed, as well as the type of instrument used did not appear to affect the probability of live birth.

CONCLUSIONS

Endometrial scratching during the menstrual cycle prior to an embryo transfer cycle can lead to a higher probability of live birth in patients with previous IVF failures.

PROSPERO REGISTRATION

PROSPERO CRD42023433538 (18 Jun 2023).

The impact of endometrial scratch performed in mid-luteal phase on the endometrium whole genome transcriptomic profiles in following menstrual cycle

The value of endometrial scratch in women with recurrent embryo transfer has been controversial. Endometrial scratch is often performed in the mid-luteal phase of the cycle preceding embryo transfer but there is little scientific evidence if it affects the whole genome transcriptomic profile of peri-implantation endometrium in the following cycle. A prospective longitudinal cohort study was conducted in a university assisted reproductive unit. A total of eight women with recurrent implantation failure (RIF) were included. Each participant had endometrial biopsy twice, first biopsy on day LH + 7 in natural cycle and second on day LH + 7 of the following cycle. R package was used to identify differentially expressed genes between the sample and enriched gene ontology. However, the paired sample showed no significant difference, neither known endometrial receptive gene set nor other genes, before and after the endometrial scratch. It suggests that endometrial scratch performed during previous mid-luteal phase did not affect the transcriptomic profiles of endometrium on day LH + 7 in women with RIF.

Closer to the Reality-Proteome Changes Evoked by Endometrial Scratching in Fertile Females

Endometrial scratching (ES) has been widely used in assisted reproductive technology to possibly improve pregnancy rates, but its exact mechanism is still not understood or investigated, and its benefits are controversially discussed. Hypothetically, ES may trigger a local immune response, leading to an improved endometrial receptivity. So far, it has been shown that ES affects the gene expression of cytokines, growth factors, and adhesive proteins, potentially modulating inflammatory pathways and adhesion molecule expression. Our pilot study applying proteomic analysis reveals that ES probably has an impact on the proteins involved in immune response pathways and cytoskeleton formation, which could potentially increase endometrial receptivity. Specifically, proteins that are involved in the immune response and cytoskeleton regulation showed a trend toward higher abundance after the first ES. On the other hand, proteins with a decreasing abundance after the first ES play roles in the regulation of the actin cytoskeleton and cellular processes such as intracellular transport, apoptosis, and autophagy. These trends in protein changes suggest that ES may affect endometrial tissue stiffness and extracellular matrix remodeling, potentially enhancing the embryos' implantation. To our knowledge, this pilot study provides, for the first time, data investigating potential changes in the endometrium due to the scratching procedure that might explain its possible benefit for patients in infertility treatment. Furthermore, the proteome of a group of patients suffering from repeated implantation failure was compared to that of the fertile group in order to transfer the basic science to clinical routine and application.

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.

The effect of endometrial scratching on reproductive outcomes in infertile women undergoing IVF treatment cycles

This study was a Randomised Controlled Trial aiming to evaluate the effect of Endometrial Scratching (ES) on fertility rate. Participants were primary infertile women undergoing IVF treatment. ES for the intervention group was done using endometrial aspiration in the luteal phase of the cycle before embryo transfer. In both groups, 2-3 8-celled embryos were transferred after endometrial preparation by Oestrogen and Progesterone. There were no significant differences between the two groups in terms of age, BMI and endometrial thickness (ET). No significant differences were found between intervention and control groups in chemical pregnancy rate (p = 0.410), clinical pregnancy (p = 0.822), the number of abortions (p = 0.282) and the implantation rate (p = 0.777). Local ES had no significant effects in improving the IVF success rate and reducing the embryo abortion rate.Impact statementWhat is already known on this subject? Endometrial scratching (ES) is a local injury to the endometrium that was assumed to affect implantation in IVF and IUI cycles positively. However, various studies have shown conflicting results on this matter.What do the results of this study add? Local ES had no significant effects on improving the IVF success rate and reducing the embryo abortion rate in patients with the first IVF cycle.What are the implications of these findings for clinical practice and/or further research? Larger clinical trials can measure the usefulness of ES with higher powers. However, this study, along with other clinical trials, can help evaluate the ES effect in future meta-analyses.

Correlation between Endometrial Vascular Endothelial Growth Factor Expression and Pregnancy Outcome of Frozen-Thawed Embryo Transfer in Patients with Repeated Implantation Failure

Objective

Vascular endothelial growth factor (VEGF) is a well-known angiogenic factor that is essential to numerous physiological and pathological processes. VEGF also contributes to embryo implantation by promoting embryo development, enhancing endometrial receptivity (ER), and promoting interactions between the endometrium and developing embryo. Changes in VEGF expression are linked to repeated implantation failure (RIF). Control endometrial tissues demonstrated an increase in VEGF expression during the implant window period, which promoted early villous vascularization and embryo implantation. The purpose of this study is to investigate the relationship between RIF and the expression of ER markers, such as VEGF during the implantation window stage.

Methods

The Yinchuan Maternal and Child Health Hospital collected 192 cases of FET endometrial tissues in the implantation window stage between January 2019 and December 2021. Immunohistochemistry was utilized to measure the levels of VEGF expression in patients with RIF (RIF group, n = 82) and patients with a successful pregnancy (control group, n = 110). The relationship between VEGF and the RIF group was analyzed using Spearman's correlation coefficient.

Results

VEGF levels were significantly lower during the implantation window stage (P < 0.05).

Conclusion

VEGF was expressed in planting window stage. The decrease of VEGF during the implantation window was correlated with RIF.

GnRH agonist as a luteal support in IVF cycle: mini-review—is there a role?

Background

It has been established that assisted reproductive technology (ART) cycles are usually accompanied by a defective luteal phase, and that luteal phase support (LPS) is mandatory to improve reproductive outcomes. This review aims to summarize the hypothesis, safety and current evidence about GnRH agonist as a luteal phase support in ART.

Main body

There are many regimens of luteal phase support to improve ART outcomes in women undergoing fresh and thawed cycles. Luteal phase support drugs include progesterone, human chorionic gonadotropin, gonadotropin-releasing hormone agonist, estradiol, and recombinant luteinizing hormone. There is some debate about optimal drugs and timing for start of LPS in ART cycles.

Conclusion

Although most centers support luteal phase by vaginal progesterone, GnRH agonist is a debatable drug for luteal support cycles.

Autologous platelet-rich plasma improves the endometrial thickness and live birth rate in patients with recurrent implantation failure and thin endometrium

PURPOSE

The aim of this study was to evaluate the effects of intrauterine platelet-rich plasma (PRP) infusion on endometrial thickness and pregnancy outcomes in a population of patients with either recurrent implantation failure (RIF), thin endometrium (TE), or both (RIF + TE) METHODS: This retrospective study included patients attending the CReATe Fertility Centre between October 2018 and July 2021 who received intrauterine PRP infusion to prepare the endometrium for frozen embryo transfer. PRP was prepared from 21 cc of whole blood using the 2-step centrifugation method to yield 0.5-0.75 cc of concentrated platelets. Endometrial thickness was measured before infusion and within 72 h after infusion. All embryos transferred were tested for genetic abnormalities using next-generation sequencing.

RESULTS

A total of 85 patients, 133 cycles, and 211 infusions were included. The majority of patients (56.5%) were diagnosed with RIF, some with TE (27.0%), and the remainder with both RIF and TE (16.5%). The majority of patients received one PRP infusion per cycle (55%). The endometrial thickness significantly increased across all diagnoses with a significant increase of 1.0 mm (0.5-1.7), which was also significantly greater than in previous cycles. The clinical pregnancy rate per embryo transfer after intrauterine PRP infusion was significantly greater compared to previous cycles (37% vs 20%, odds ratio 2.2) as was the live birth rate (19% vs 2%, odds ratio 11.6).

CONCLUSION

Our study suggests that PRP should be considered a noninvasive front-line therapy for improving endometrial thickness and implantation in patients with RIF, a TE, or both.

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.

Cumulative live birth rates in egg donor IVF cycles with or without endometrial scratching: is there a residual effect in subsequent embryo transfers? Follow-up results of a RCT in clinical practice

INTRODUCTION

Endometrial scratching (ES) is a simple technique that has been claimed to improve pregnancy rates in patients undergoing assisted reproduction techniques. Our objective was to acknowledge the effects of ES in subsequent embryo transfers by assessing the cumulative live birth rates (LBR) in patients undergoing egg-donor in vitro fertilization (IVF).

MATERIAL AND METHODS

We performed a follow-up analysis of the cumulative reproductive outcomes of the 352 patients included in the Endoscratch Trial (NCT03108157) during the twelve months following the randomization date. We compared the outcomes of patients who underwent an ES for the second and/or successive embryo transfers versus those who did not have an ES performed, in order to determine a possible carry over effect that could lead to different LBR in these groups.

RESULTS

Our analysis reveals that both groups (with and without ES performed before the first embryo transfer) had similar cumulative LBR (69.9% vs 65.9% in group A and B respectively, RR: 1.20, 95% confidence interval (CI): 0.92 - 1.22, p= 0.42). When we analyzed the results comparing patients who had received at least an ES before any of the embryo transfers during that period, we did not find any differences in LBR either (68.0% in patients with at least an ES and 67.8% in patients without ES, RR 1.00, 95%CI 0.87 - 1.16, p= 0.96).

CONCLUSION

According to our results, we cannot state that ES has a long term effect on endometrial receptivity of egg recipients as cumulative LBR do not differ from those of patients who do not receive it.

Comparing the effects of endometrial injury in the luteal phase and follicular phase on in vitro fertilization treatment outcomes

BACKGROUND

Several studies have shown that endometrial injury improves clinical pregnancy outcomes in patients undergoing in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) treatment with a history of implantation failure. However, endometrial injury can be performed in the follicular phase (FP) followed by embryo transfer in the same menstrual cycle or in the luteal phase (LP) before the embryo transfer cycle.

METHOD

This prospective cohort study was conducted from January 2015 to September 2021, and a total of 487 patients were included. All included patients had a history of a failed implantation cycle. They were divided into two groups: the FP group (N = 330), in which endometrial injury was performed on menstrual day 3-5, and the LP group (N = 157), in which endometrial injury was performed in the cycle preceding embryo transfer 7 days after ovulation.

RESULTS

First, in unselected patients, the implantation rate and clinical pregnancy rate were comparable between the LP and FP groups. However, in patients with a history of ≥ 2 failed transfer cycles, the implantation rate was significantly higher in the LP group than in FP group (43.09% versus 33.33%, P = 0.03). Moreover, the clinical pregnancy rate was also significantly higher in patients in the LP group than in patients in the FP group (60.17% versus 46.15%, P=0.02). In addition, logistic regression analysis showed that endometrial injury in the LP group was an independent factor affecting clinical pregnancy outcome in patients with a history of ≥ 2 failed transfer cycles (aOR = 2.05, 90% CI:1.22-3.47, P=0.01).

CONCLUSION

Endometrial injury improves pregnancy outcomes when performed in the luteal phase compared with the follicular phase in patients with a history of ≥ 2 failed transfer cycles but not in unselected patients.

The effect of endometrial scratch on pregnancy outcomes of frozen-thawed embryo transfer: a propensity score-matched study

AIMS

To study the effect of endometrial scratch (ES) performed on Days 2 to 5 of the menstrual cycle on pregnancy outcomes of frozen-thawed embryo transfer (FET).

MATERIALS AND METHODS

We conducted a retrospective study including 5769 women undergoing FET from January 2018 to August 2019. The endometrial scratching group (group ES) consisted of 827 patients and the control group (group non-ES) comprised 4942 patients. A propensity score matching (PSM) method using the nearest neighbor matching at a proportion of 1:1 was performed. Subsequently, we compared the pregnancy outcomes of each group after PSM.

RESULTS

After PSM, there were significant differences in implantation (36.1% vs. 47.0%, p = .005), clinical pregnancy (45.4% vs. 58.3%, p = .007), and live birth (33.5% vs. 47.2%, p = .003) rates in matched patients with two previous implantation failures. In the matched patients with at least three previous implantation failures, we also detected increase rates of implantation (31.0% versus 40.1%, p = .028), clinical pregnancy (39.8% versus 57.0%, p = .019), live birth (32.3% versus 47.3%, p = .036). In contrast, no significant difference in pregnancy outcomes was found in women with no previous implantation failure or only one failure.

CONCLUSIONS

Endometrial scratch on day 2 to day 5 of the menstrual cycle in women with at least two previous implantation failures who underwent FET increased their implantation, clinical pregnancy, and live birth rates, and did not increase miscarriage or ectopic pregnancy rates compared to the non-ES group.

Endometrial scratch in women undergoing first-time IVF treatment: a systematic review and meta-analysis of randomized controlled trials

The endometrial scratch procedure is an IVF ‘add-on’ sometimes provided prior to the first IVF cycle. A 2019 systematic review concluded that there was insufficient evidence to show whether endometrial scratch has a significant effect on pregnancy outcomes (including live birth rate, LBR) when undertaken prior to the first IVF cycle. Further evidence was published following this review, including the Endometrial Scratch Trial (ISRCTN23800982). The objective of the current review was to synthesize and critically appraise the evidence for the clinical effectiveness and safety of the endometrial scratch procedure in women undergoing their first IVF cycle. Databases searched include MEDLINE, Embase, CINAHL and ClinicalTrials.gov. Eligible randomized controlled trials included women undergoing IVF for the first time that reported the effectiveness and/or safety of the endometrial scratch procedure; 12 studies were included. Meta-analysis showed no evidence of a significant effect of the endometrial scratch on LBR (10 trials, odds ratio [OR] 1.17, 95% confidence interval [CI] 0.76–1.79) or other pregnancy outcomes. This review confirms that there is a lack of evidence that endometrial scratch improves pregnancy outcomes, including LBR, for women undergoing their first IVF cycle. Clinicians are recommended not to perform this procedure in individuals undergoing their first cycle of IVF.

The Current Role of Induced Endometrial Trauma (Endometrial Scratch) in Women Undergoing Infertility Treatment

Induced endometrial trauma, otherwise known as endometrial scratch is a simple technique that has been rapidly adopted into clinical practice, mainly for women having IVF treatment, in an attempt to increase pregnancy rates. The introduction of endometrial scratch followed early reports of improved clinical pregnancy rates in women with repetitive implantation failure after having the procedure and follows on from evidence from animal models in the early 20^th century suggesting that mechanical trauma to the endometrium can induce decidual changes. Due to the ease and low cost of the procedure, it has been rapidly adopted as an add-on to fertility treatments, in many cases where evidence is still lacking. Despite the initial publication of a large number of studies that demonstrated encouraging improvements in pregnancy rates in women who underwent this procedure, these studies were mainly limited by the small sample sizes and heterogeneity of their study populations, leading to limited validity of the evidence provided by these studies. More recently, three large randomized controlled studies have been published that paint a different picture regarding the value of this procedure. This article explores the evolution of the evidence and the current state of endometrial scratch as an adjuvant therapy for women undergoing IVF treatment.

Fertility Preservation Programme in a Tertiary-Assisted Reproduction Unit in Hong Kong

Background: Fertility preservation is increasingly important with improving cancer survival rates and the delay in childbearing in modern societies. The objective of our study was to review the experience of the fertility preservation programme in a tertiary-assisted reproduction unit in Hong Kong.

Methods: This is a retrospective study involving men and women who were seen at a tertiary-assisted reproduction unit for fertility preservation counselling before gonadotoxic treatment from January 2005 to December 2020. Their medical records in paper and electronic forms were reviewed.

Results: There were 75 consultations for female fertility preservation from 2010 to 2020 involving 72 women. Twenty women underwent 22 cycles of ovarian stimulation for oocyte or embryo cryopreservation, two of whom subsequently transported their oocytes abroad for further management and another two achieved natural conception. Additional four women who did not have oocyte or embryo cryopreservation achieved natural conception after cancer treatment. Eleven (15.2%) women were followed up at a reproductive endocrinology clinic after their cancer treatment. From 2005 to 2020, 265 men had sperm cryopreserved. Twenty-six (9.8%) came back to use the cryopreserved sperms, the wives of 13 (50.0%) of whom achieved an on-going pregnancy. Six of them transferred out and 40 discarded the cryopreserved sperms.

Conclusions: There was generally an increasing number of patient consultations for fertility preservation in our Centre over the past decade but a consistently low rate of utilisation of cryopreserved gametes for both women and men. Post-cancer treatment fertility evaluation and monitoring was a major area of deficiency in Hong Kong. More structured post-cancer treatment fertility follow-up is needed.

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.

A randomised controlled trial to assess the clinical effectiveness and safety of the endometrial scratch procedure prior to first-time IVF, with or without ICSI

STUDY QUESTION

What is the clinical-effectiveness and safety of the endometrial scratch (ES) procedure compared to no ES, prior to usual first time in vitro fertilisation (IVF) treatment?

SUMMARY ANSWER

ES was safe but did not improve pregnancy outcomes when performed in the mid-luteal phase prior to the first IVF cycle, with or without intracytoplasmic sperm injection (ICSI).

WHAT IS KNOWN ALREADY

ES is an ‘add-on’ treatment that is available to women undergoing a first cycle of IVF, with or without ICSI, despite a lack of evidence to support its use.

STUDY DESIGN, SIZE, DURATION

This pragmatic, superiority, open-label, multi-centre, parallel-group randomised controlled trial involving 1048 women assessed the clinical effectiveness and safety of the ES procedure prior to first time IVF, with or without ICSI, between July 2016 and October 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants aged 18–37 years undergoing their first cycle of IVF, with or without ICSI, were recruited from 16 UK fertility clinics and randomised (1:1) by a web-based system with restricted access rights that concealed allocation. Stratified block randomisation was used to allocate participants to TAU or ES in the mid-luteal phase followed by usual IVF with or without ICSI treatment. The primary outcome was live birth after completing 24 weeks gestation within 10.5 months of egg collection.

MAIN RESULTS AND THE ROLE OF CHANCE

In total, 1048 women randomised to TAU (n = 525) and ES (n = 523) were available for intention to treat analysis. In the ES group, 453 (86.6%) received the ES procedure. IVF, with or without ICSI, was received in 494 (94.1%) and 497 (95.0%) of ES and TAU participants respectively. Live birth rate was 37.1% (195/525) in the TAU and 38.6% (202/523) in the ES: an unadjusted absolute difference of 1.5% (95% CI −4.4% to 7.4%, P = 0.621). There were no statistical differences in secondary outcomes. Adverse events were comparable across groups.

LIMITATIONS, REASONS FOR CAUTION

A sham ES procedure was not undertaken in the control group, however, we do not believe this would have influenced the results as objective fertility outcomes were used.

WIDER IMPLICATIONS OF THE FINDINGS

This is the largest trial that is adequately powered to assess the impact of ES on women undergoing their first cycle of IVF. ES was safe, but did not significantly improve pregnancy outcomes when performed in the mid-luteal phase prior to the first IVF or ICSI cycle. We recommend that ES is not undertaken in this population.

STUDY FUNDING/COMPETING INTEREST(S)

Funded by the National Institute of Health Research. Stephen Walters is an National Institute for Health Research (NIHR) Senior Investigator (2018 to present) and was a member of the following during the project: National Institute for Health Research (NIHR) Health Technology Assessment (HTA) Clinical Trials and Evaluation Committee (2011–2017), NIHR HTA Commissioning Strategy Group (2012 to 2017); NIHR Programme Grants for Applied Research Committee (2020 to present); NIHR Pre doctoral Fellowship Committee (2019 to present). Dr. Martins da Silva reports grants from AstraZeneca, during the conduct of the study; and is Associate editor of Human Reproduction and Editorial Board member of Reproduction and Fertility. Dr. Bhide reports grants from Bart's Charity and grants and non-financial support from Pharmasure Pharmaceuticals outside the submitted work.

TRIAL REGISTRATION NUMBER

ISRCTN number: ISRCTN23800982.

TRIAL REGISTRATION DATE

31 May 2016

DATE OF FIRST PATIENT’S ENROLMENT

04 July 2016

Is Endometrial Scratching Beneficial for Patients Undergoing a Donor-Egg Cycle with or without Previous Implantation Failures? Results of a Post-Hoc Analysis of an RCT

Endometrial scratching (ES) has been proposed as a useful technique to improve outcomes in in vitro fertilization (IVF) cycles, particularly in patients with previous implantation failures. Our objective was to determine if patients undergoing egg-donor IVF cycles had better live birth rates after ES, according to their previous implantation failures. Secondary outcomes were pregnancy rate, clinical pregnancy rate, ongoing pregnancy rate, miscarriage rate, and multiple pregnancy rate. We analysed the results of 352 patients included in the Endoscratch Trial (NCT03108157). A total of 209 were patients with one or no previous implantation failures (105 with an ES done in the previous cycle, group A1, and 104 without ES, group B1), and 143 were patients with at least two previous failed implantations (71 patients with ES, group A2, and 72 without ES, group B2). We found an improvement in pregnancy rates (62.9% in group A1 vs. 55.8% in group B1 vs. 70.4% in group A2 vs. 76.4% in group B2, p = 0.028) in patients with at least two previous implantation failures, but this difference was not statistically different when we compared clinical pregnancy rates (59.1% vs. 51.0% vs. 64.8% vs. 68.1% in groups A1, B1, A2 and B2, respectively, p = 0.104) and live birth rates (52.4% vs. 43.3% vs. 57.8% vs. 55.6% in groups A1, B1, A2 and B2, respectively, p = 0.218). According to these results, we conclude that there is no evidence to recommend ES in egg-donor IVF cycles, regardless of the number of previous failed cycles.

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 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.

The Addition of Endometrial Injury to Freeze-All Strategy in Women with Repeated Implantation Failures

(1) Background: Recurrent implantation failure (RIF) after IVF remains a challenging topic for fertility specialists and a frustrating reality for patients with infertility. Various approaches have been investigated and applied towards the improvement of clinical outcomes. Through a nonrandomized clinical trial, we evaluated the effect of the combination of hysteroscopic endometrial injury and the freeze-all technique on pregnancy parameters in a cohort of RIF patients; (2) Methods: The study group comprised of 30 patients with RIF that underwent a hysteroscopic endometrial injury prior to a frozen embryo transfer cycle; another 30 patients with RIF, comprising the control group, underwent a standard frozen cycle with no adjuvant treatment before. Live birth comprised the primary outcome. Logistic and Poisson regression analyses were implemented to reveal potential independent predictors for all outcomes. (3) Results: Live birth rates were similar between groups (8/30 vs. 3/30, p = 0.0876). Biochemical and clinical pregnancy and miscarriages were also independent of the procedure (p = 0.7812, p = 0.3436 and p = 0.1213, respectively). The only confounding factor that contributed to biochemical pregnancy was the number of retrieved oocytes (0.1618 ± 0.0819, p = 0.0481); (4) Conclusions: The addition of endometrial injury to the freeze-all strategy in infertile women with RIF does not significantly improve pregnancy rates, including live birth. A properly conducted RCT with adequate sample size could give a robust answer.

Follicular-phase endometrial scratching: a truncated randomized controlled trial

STUDY QUESTION

Does intentional endometrial injury (scratching) during the follicular phase of ovarian stimulation (OS) increase the clinical pregnancy rate (CPR) in ART?

SUMMARY ANSWER

CPR did not vary between the endometrial injury and the control group, but the trial was underpowered due to early termination because of a higher clinical miscarriage rate observed in the endometrial injury arm after a prespecified interim analysis.

WHAT IS KNOWN ALREADY

Intentional endometrial injury has been put forward as an inexpensive clinical tool capable of enhancing endometrial receptivity. However, despite its widespread use, the benefit of endometrial scratching remains controversial, with several recent randomized controlled trials (RCTs) being unable to confirm its added value. So far, most research has focused on endometrial scratching during the luteal phase of the cycle preceding the one with embryo transfer (ET), while only a few studies investigated in-cycle injury during the follicular phase of OS. Also, the persistence of a scratch effect in subsequent treatment cycles remains unclear and possible harms have been insufficiently studied.

STUDY DESIGN, SIZE, DURATION

This RCT was performed in a tertiary hospital setting between 3 April 2014 and 8 October 2017. A total of 200 women (100 per study arm) undergoing IVF/ICSI in a GnRH antagonist suppressed cycle followed by fresh ET were included.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants were randomized with a 1:1 allocation ratio to either undergo a pipelle endometrial biopsy between Days 6 and 8 of OS or to be in the control group.The primary outcome was CPR. Secondary outcomes included biochemical pregnancy rate, live birth rate (LBR), early pregnancy loss (biochemical pregnancy losses and clinical miscarriages), excessive procedure pain/bleeding and cumulative reproductive outcomes within 6 months of the study cycle.

MAIN RESULTS AND THE ROLE OF CHANCE

The RCT was stopped prematurely by the trial team after the second prespecified interim analysis raised safety concerns, namely a higher clinical miscarriage rate in the intervention group. The intention-to-treat CPR was similar between the biopsy and the control arm (respectively, 44 versus 40%, P = 0.61, risk difference = 3.6 with 95% confidence interval = -10.1;17.3), as was the LBR (respectively, 32 versus 36%, P = 0.52). The incidence of a biochemical pregnancy loss was comparable between both groups (10% in the intervention group versus 15% in the control, P = 0.49), but clinical miscarriages occurred significantly more frequent in the biopsy group (25% versus 8%, P = 0.032). In the intervention group, 3% of the patients experienced excessive procedure pain and 5% bleeding. The cumulative LBR taking into account all conceptions (spontaneous or following ART) within 6 months of randomization was not significantly different between the biopsy and the control group (54% versus 60%, respectively, P = 0.43).

LIMITATIONS, REASONS FOR CAUTION

The trial was stopped prematurely due to safety concerns after the inclusion of 200 of the required 360 patients. Not reaching the predefined sample size implies that definite conclusions on the outcome parameters cannot be drawn. Furthermore, the pragmatic design of the study may have limited the detection of specific subgroups of women who may benefit from endometrial scratching.

WIDER IMPLICATIONS OF THE FINDINGS

Intentional endometrial injury during the follicular phase of OS warrants further attention in future research, as it may be harmful. These findings should be taken in consideration together with the growing evidence from other RCTs that scratching may not be beneficial.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by 'Fonds Wetenschappelijk Onderzoek' (FWO, Flanders, Belgium, 11M9415N, 1524417N). None of the authors have a conflict of interest to declare with regard to this study.

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.

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.

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.

Improving reproductive outcomes of intrauterine insemination: Does endometrial scratch injury help? A randomised controlled trial

OBJECTIVE(S)

Current evidence suggests that endometrial injury improves clinical pregnancy rate while having no effect on miscarriages in women undergoing IVF/ICSI. However, there is no substantial evidence to advocate the use of endometrial injury to benefit the outcomes of IUI treatment. Additionally, there is no clear consensus about the ideal timing, underlying mechanism and optimum intensity of endometrial injury required. The study examines the effect of intentional endometrial injury/scratch in the early proliferative phase of stimulated cycle on reproductive outcomes (clinical and ongoing pregnancy rates and miscarriage occurrence) of intra-uterine insemination treatment (IUI).

STUDY DESIGN, SIZE, DURATION

This prospective, randomized control interventional study was conducted in a tertiary level teaching institution from April 2018 to February 2020. 150 eligible couples requiring IUI treatment who agreed to participate were randomly allocated on 1:1 basis to either control or intervention group. The trial participants received up to 3 cycles ovulation induction with clomiphene citrate and intra-uterine insemination. In addition, women in intervention group were subjected to endometrial scratch injury on day 6-7 of their stimulated cycle. 154 cycles in control arm and 128 cycles in intervention group were analyzed for clinical pregnancy, miscarriages and pain experienced by the women during endometrial scratch injury using the statistical package SPSS (version 21).

RESULT

Similar cumulative clinical pregnancy rates (12.5% Vs 13.6%, RR 1.21, 95% CI 0.44-3.37, p = 0.713), biochemical pregnancy rates (17.1% vs 22.9%, RR 1.43, CI 0.59-3.47, p = 0.421) and ongoing pregnancy rates (10.93% Vs 11.47%, RR 1.05, CI 0.35-3.21, p = 924) were observed in control and intervention arms. Likewise, the relative risk of miscarriage occurrence in the intervention arm was 1.32 (95% CI 0.39-4.32, p = 1.000) which was not statistically different from control group. Mean pain score of 6.93 on numerical pain rating scale was experienced by women whilst having endometrial scratch injury.

CONCLUSIONS

There is insufficient evidence to defend the use of endometrial scratch injury in intra-uterine insemination treatment, as it is moderately painful and have uncertain beneficial influence on reproductive outcomes.

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 "Scratching" An update and overview of current research

About one in every six couples is affected by sterility. Assisted reproduction procedures are currently the treatment of choice for a number of patients who desire children. Many causes of sterility can be overcome with the aid of in vitro fertilization, but successful implantation of the embryos is the major limiting factor. Failure of implantation may occur repetitively. In the treatment of sterility, many approaches have been used to overcome the barrier of implantation failure and improve the chances of successful nidation. Scratching the endometrium prior to embryo transfer has been suggested as one means of enhancing the likelihood of implantation. The current literature was examined to investigate if there was any possible benefit from endometrial scratching. The studies were divided according to whether the women suffered from recurrent implantation failure or not. In summary, it was found that unselected subfertile women generally benefit less from endometrial scratching, but scratching appears to be successful in women who have experienced repeated implantation failure. Although the heterogeneous body of data on the subject deserves further clarification. The latest data presented at “European Society of Human Reproduction and Embryology” 2018 in Barcelona suggested that the method should be abandoned.

Endometrial scratch vs no intervention in egg donation cycles: the ENDOSCRATCH trial protocol

Background

The effects of endometrial scratching (ES) on embryo implantation have been studied for many years. Several studies have shown better outcomes when performed on patients undergoing intrauterine insemination and in vitro fertilization (IVF) cycles, but many other reports have not been able to find these differences. As far as cycles with donor eggs are concerned, reported evidence is scarce. Our aim in this trial is to determine if ES is useful for those patients undergoing IVF cycles with donor eggs, in order to assure a greater homogeneity in embryo quality and endometrial preparation.

Methods

This single centre randomized controlled trial will include patients undergoing an egg donation cycle, meeting the inclusion criteria and who accept to participate in the study. Once informed consent is signed, patients will be randomly allocated to the study arm (group A) and then receive ES in the luteal phase of the cycle prior to embryo transfer, or the control arm (group B) without any intervention. All cycle data will be collected and analyzed to obtain the clinical pregnancy and the live birth rates in the two groups.

Discussion

Several studies have tried to determine the effectiveness of an ES in IVF cycles, but it is still unclear due to the heterogeneity of these reports. The aim of this study is to determine if there are differences in clinical pregnancy rate and live birth rate in egg donor cycles, when comparing an ES performed in the preceding luteal phase versus no intervention, given that embryo quality and endometrial preparation protocols will be comparable.

Trial registration

Ethical approval of version 2.0 of this trial was obtained on the 13th January 2017. It was retrospectively registered on the 5th April 2017 as the ENDOSCRATCH Trial (NCT03108157) in ClinicalTrials.gov.

Endometrial Scratching Effect on Clinical Pregnancy Rates in Patients Undergoing Egg Donor In Vitro Fertilization Cycles: the ENDOSCRATCH Randomized Clinical Trial (NCT03108157)

The potential benefit of endometrial scratching (ES) on embryo implantation is still a controversial subject. At present, the single retrospective study in egg donor IVF cycles concluded that ES has no beneficial effect. Our objective was to determine if there are differences in clinical pregnancy rates (CPR) in egg donor cycles when an ES is performed. This is a randomized controlled trial (RCT) in egg donor IVF patients conducted at ProcreaTec Fertility Center in Madrid. Three hundred fifty-two patients were included in total. One hundred sixty-one patients completed the protocol in group A and 172 patients in group B. Patients allocated to group A received an ES in the luteal phase of the cycle preceding the embryo transfer cycle. Group B patients did not receive any intervention. Primary outcome of this RCT was CPR. Secondary outcomes were implantation (IR), miscarriage (MR), ongoing pregnancy (OPR), multiple pregnancy (MulPR), and live birth rates (LBR). CPR was 104 of 161 (64.6%) in group A and 102 of 172 (59.3%) in group B (RR 1.09, 95% confidence interval (CI) (0.92-1.29); p = 0.378). OPR, MR, MulPR, and LBR were also comparable. No major complications were detected after ES and pregnancy complications were comparable. Our results show that there is no beneficial role of ES in egg donor IVF cycles, considering these patients as the ideal model as they share homogeneous embryo quality and endometrial preparation protocols. This trial was registered on April 5, 2017, as the ENDOSCRATCH trial (NCT03108157).

Therapeutic endometrial scratching and implantation after in vitro fertilization: a multicenter randomized controlled trial

OBJECTIVE

To study whether endometrial scratching in the luteal phase before ovarian stimulation increases clinical pregnancy rates in women with one or more previous implantation failures.

DESIGN

A nonblinded multicenter randomized clinical trial.

SETTING

Fertility clinics.

PATIENT(S)

Three hundred four eligible patients scheduled for IVF/intracytoplasmic sperm injection were randomized. The intervention group (n = 151) underwent endometrial scratching in the luteal phase before controlled ovarian stimulation, while no intervention was performed in the control group (n = 153).

INTERVENTION(S)

Endometrial scratching with a Pipelle de Cornier catheter in the luteal phase before ovarian stimulation.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy rate and prenatal and birth data.

RESULT(S)

There was no overall significant improvement in clinical pregnancy rates between the control and intervention groups (38.5% vs. 44.4%; relative risk = 1.15; confidence interval [0.86-1.55]). However, subgroup analyses revealed that women with three or more previous implantation failures had a significant increase in clinical pregnancy rate (31.1% vs. 53.6%; relative risk = 1.72; confidence interval [1.05-2.83]) after scratching. No difference was seen as regards prenatal and birth data between the two groups.

CONCLUSION(S)

Endometrial scratching in the luteal phase before ovarian stimulation significantly enhances the clinical pregnancy rate in women with three or more prior implantation failures. This result seems to corroborate previous reports, which found that particularly women with repeated implantation failure seem to gain a positive effect from endometrial scratching. Importantly, there were no significant differences in prenatal data and birth data between the groups.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01963819.

Vaginal versus intramuscular progesterone for luteal phase support in assisted reproductive techniques: a systematic review and meta-analysis of randomized controlled trials

We aimed to compare the efficacy of vaginal progesterone versus intramuscular progesterone (IMP) for luteal phase support in assisted reproductive techniques (ART). A comprehensive electronic search of four electronic databases (PubMed, Cochrane Library, Scopus, and ISI Web of Science) was performed from inception till August 2019 for randomized controlled trials (RCTs). We included studies performed different ART with the use of vaginal progesterone versus IMP for luteal phase support. Our primary outcome was clinical pregnancy rate. Our secondary outcomes were ongoing pregnancy, miscarriage, live birth rates, and satisfaction in both groups. 15 RCTs met our inclusion criteria with a total of 5656 patients. Our analysis indicated no significant differences between vaginal progesterone and IMP regarding clinical and ongoing pregnancies (RR = 0.90, 95% CI [0.80, 1.00], p = .06), (RR = 0.90, 95% CI [0.76, 1.06], p = .21), respectively. No significant differences were found between both routes of progesterone in miscarriage (p = .98) and live birth (p = .99). Subgroup analysis between fresh and frozen embryo transfer cycles in above outcomes showed no difference between progesterone routes. Vaginal progesterone was significantly associated with more satisfaction compared to IMP (p < .00001). In conclusion, vaginal progesterone can be used an alternative method for luteal phase support instead of IMP in ART.

MODERN METHODS OF DIAGNOSIS AND TREATMENT OF CHRONIC ENDOMETRITIS, IN PREPARING PATIENTS FOR ASSISTED REPRODUCTIVE TREATMENT TECHNOLOGIES (LIT ERATURE REVIEW)

Since the chronic endometritis often leads to impaired reproductive function causing infertility, failed IVF attempts, miscarriage, and complicated pregnancy and childbirth, it has become not only medically relevant but also socially significant. For successful embryo implantation, the thickness of the endometrium should be at least 7 cm. Even though there is always a chance for embryo implantation, despite the endometrial hypoplasia, the attachment may be fragile, and such pregnancy may cease its development further on. Recently, in connection with an increase in the rate of developing allergic reactions, dysbacteriosis, and the emergence of drug-resistant strains of microorganisms, a search for new treatment methods to avoid these complications has begun. One of such methods in treating chronic endometritis, satisfying several requirements (efficiency, comfort, accessibility, safety), is the ultrasonic cavitation of the uterine cavity.

Intentional endometrial injury increases embryo implantation potentials through enhanced endometrial angiogenesis†

Embryo implantation rates have been found to be enhanced by precedent endometrial injuries, but the underlying mechanism is not fully investigated. Endometrial inflammation occurs both at peri-implantation period and after endometrial injury, in which vascular reaction is a distinctive feature of inflammation. In this study, intentional endometrial injury was done with a 0.7-mm-diameter brush inserted into the left uterine horn of female ICR mice, then turned around 720° (group 2), and the right uterine horn served as the controls without endometrial injuries (group 1). Intraperitoneal equine chorionic gonadotropin 2.5 IU was injected, followed by human chorionic gonadotropin 10 IU injection, and the uterus was dissected 5 days later, roughly at the peri-implantation period. The peri-implantation endometrium was obtained, and angiogenesis protein array revealed that matrix metalloproteinase-3 (MMP-3), plasminogen activator inhibitor-1 (PAI-1), insulin-like growth factor binding protein 1 (IGFBP-1), and IL-1α were more strongly expressed in injured endometrium (group 2) than in the controls (group 1). Immunohistochemical CD34 staining was more prominently expressed in group 2 uterus, and the treatment with LY294002, a phosphoinositide 3-kinase (PI3K) inhibitor, significantly decreased CD34 immunopositive cells. The capabilities of permeability, proliferation, tube formation, and migration of mouse endometrial endothelial cells were significantly enhanced in group 2 than in group 1. Our results demonstrate that enhanced endometrial angiogenesis is a possible mechanism accounting for the increased endometrial receptivity after endometrial injury.

The impact of intentional endometrial injury on reproductive outcomes: a systematic review and meta-analysis

BACKGROUND

Endometrial injury is an intentional damage made to the endometrium, usually produced by a Pipelle catheter. Over the last two decades, endometrial injury has been studied to improve implantation rates and decrease the incidence of implantation failure in invitro fertilization (IVF) cycles. Recently, additional studies of endometrial injury, performed not only in patients with implantation failure but also in intrauterine insemination cycles, have been conducted, and the endometrial injury made by hysteroscopy has been researched. The evidence describing the impact of endometrial injury is controversial; therefore, we conducted a systematic review and meta-analysis to examine the issue.

OBJECTIVE AND RATIONALE

Our objective is to review the research that has been done until now and perform a meta-analysis regarding endometrial injury and its influence on implantation success and pregnancy rates in patients with at least one failed IVF cycle. In particular, we aim to study the efficacy of the procedure and look for confounding factors, such as maternal age, in assessing the efficacy of endometrial injury.

SEARCH METHODS

The systematic review of the literature was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement. Study protocol can be assessed at PROSPERO International prospective register of systematic reviews (registration number CRD42018092773). Searches were conducted by an experienced research librarian in the following databases: MEDLINE(R) using the OvidSP interface and PUBMED, Embase, Web of Science and Cochrane Library. This review considered for inclusion randomized-controlled trials examining the success of performing local endometrial injury on IVF outcomes in women with previous failed IVF cycles.

OUTCOMES

Ten studies, comprising a total of 1260 patients, were selected. Overall, when studying the effect of endometrial injury on clinical pregnancy rates (CPRs) and live birth rates (LBRs), higher rates were shown in the endometrial injury group. However, endometrial injury did not significantly improve CPRs and LBRs, when considering sub-group analyses of studies including patients with two or more failed IVF cycles, studies examining older patients or studies which did not include hysteroscopy. There was no significant difference found regarding multiple pregnancy rates, while a handful of studies showed an improvement in miscarriage rates.

WIDER IMPLICATIONS

Endometrial injury should be used restrictively and not routinely in clinics. Maternal age and number of previous failed treatment cycles may be contributing factors which can influence the results when studying the effect of endometrial local injury. It is possible that the relative contribution of endometrial receptivity to the chances of implantation decreases with any additional failed cycle. The optimal study to prove the efficacy of local endometrial injury on implantation and pregnancy rates, should be a random-controlled trial studying the effect of local endometrial injury in oocyte donation cycles, in recipients with repeated implantation failure. This kind of study will conclude whether local endometrial injury is an efficient procedure with minimum confounding factors, and may assist in defining the population, even outside of donation cycles, that will benefit from the procedure.

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

The effect of performing hysteroscopy prior to the first in vitro fertilization (IVF) cycle on live birth rate

In this retrospective cohort study, a total of 707 couples underwent in vitro fertilization (IVF) at Hacettepe University Hospital between 01 January 2010 and 01 November 2014 with their chronologically first cycle were evaluated. Patients who have diagnostic hysteroscopy prior to first IVF cycle served as a study group (n = 42) and patients without diagnostic hysteroscopy served as control group (n = 282). In study group in all patients, diagnostic hysteroscopy was performed at the follicular phase of previous menstrual cycle, namely immediately before ovarian stimulation (OS) cycle. Demographic features, clinical characteristics and treatment outcomes were compared between the groups. The logistic regression analysis was performed in order to assess independent predictors of live birth rates (LBRs). There was no statistically significant difference between the groups for demographic features and OS cycle characteristics. Implantation rate (22.2% vs. 21.5%, p=.840), clinical pregnancy rate (33.3% vs. 28.7%, p=.541), and LBRs (23.8% vs. 18.5%, p=.420) were comparable. In logistic regression analysis, performing hysteroscopy prior to first IVF cycles per se without correcting anatomic abnormalities was not an independent predictor of LBRs (OR: 0.72, 95% CI: 0.310-1.68, p=.45). In conclusion, performing diagnostic hysteroscopy prior to first IVF treatment cycle without correcting any anatomic abnormalities did not improve LBRs.

Systematic and standardized hysteroscopic endometrial injury for treatment of recurrent implantation failure

RESEARCH QUESTION

To investigate the effect of hysteroscopic endometrial injury for treatment of recurrent implantation failure (RIF).

DESIGN

This prospective and randomized controlled trial included 239 patients who had failed to achieve a clinical pregnancy after the transfer of at least four good-quality embryos in a minimum of three fresh or frozen-thawed embryo transfer cycles and were under the age of 40 years, who were randomized into two groups. The injury group (n = 124) received endometrial injury during their hysteroscopic procedure, whereas the control group (n = 115) did not. Patients who had endometrial pathologies were excluded from the study.

RESULTS

There were no statistically significant differences in duration of gonadotrophin use (8.23 versus 8.30 days), total dose of gonadotrophins (2330 versus 2338 IU), number of oocytes (7.03 versus 8.21), number of mature oocytes (5.27 versus 6.02), number of fertilized oocytes (4.19 versus 4.55), number of good-quality embryos (2.07 versus 2.43), number of embryos transferred (1.97 versus 1.93) or endometrial thickness (9.04 versus 9.35 mm) between the injury group and control group, respectively. Clinical pregnancy rates (25.8% versus 15.6%, P = 0.047), live birth rates (21.8% versus 12.2%, P = 0.049) and implantation rates (14.2% versus 8.8%, P = 0.036) were significantly different, favouring the injury group.

CONCLUSION

This study suggests that endometrial injury is beneficial in RIF patients to increase the odds of implantation, clinical pregnancy and live birth.