Investigation and current management of recurrent IVF treatment failure in the UK

Autologous platelet-rich plasma for assisted reproduction

BACKGROUND

Autologous platelet-rich plasma (PRP) consists of plasma and a concentrate of platelets extracted from fresh whole blood of the person being treated. Research has suggested that intrauterine or intraovarian infusion/injection of PRP before embryo transfer may improve endometrial receptivity and response to ovarian stimulation in women undergoing assisted reproduction. We compared these interventions to standard treatment, placebo, or other interventions (mechanical or pharmacological).

OBJECTIVES

To assess the effectiveness and safety of intrauterine and intraovarian infusion/injection of platelet-rich plasma in infertile women undergoing assisted reproductive technology cycles.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility Group's Specialised Register, CENTRAL, MEDLINE, Embase, and the Epistemonikos database in January 2023. We also searched the reference lists of relevant articles and contacted the trial authors and experts in the field for any additional trials.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that evaluated the application of PRP in the uterine cavity, ovaries, or both versus no intervention, placebo, or any other intervention (either mechanical or pharmacological) in women undergoing in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) cycles.

DATA COLLECTION AND ANALYSIS

We followed standard methodological procedures recommended by Cochrane, including use of the updated risk of bias tool (RoB 2). The primary outcomes were live birth (or ongoing pregnancy) and miscarriage. The secondary outcomes were clinical pregnancy, complications of the procedure, multiple pregnancy, ectopic pregnancy, fetal growth restriction, preterm delivery, and fetal abnormality. We estimated the average effect of the interventions by fitting a Der Simonian-Laird's random-effects meta-analysis model. We reported pooled odds ratios (ORs) with 95% confidence intervals (CIs). We restricted the primary analyses to trials at low risk of bias for the outcomes and performed sensitivity analyses that included all studies.

MAIN RESULTS

We included 12 parallel-group RCTs that recruited a total of 1069 women. We identified three different comparison groups. Using GRADE, we assessed the certainty of evidence as very low for almost all outcomes. Intrauterine injection/infusion of platelet-rich plasma versus no intervention or placebo Nine studies evaluated intrauterine PRP versus no intervention or placebo. Eight included women with at least two or three previous implantation failures. Only one was assessed at low risk of bias for each outcome. This study provided very low-certainty evidence about the effect of intrauterine PRP injection versus no intervention on live birth (OR 1.10, 95% CI 0.38 to 3.14; 94 women) and miscarriage (OR 0.96, 95% CI 0.13 to 7.09; 94 women). If the likelihood of live birth following no intervention is assumed to be 17%, then the likelihood following intrauterine PRP would be 7% to 40%; and if the risk of miscarriage following no intervention is 4%, then the risk following intrauterine PRP would be 1% to 24%. When we analyzed all studies (regardless of risk of bias), we found very low-certainty evidence about the effect of intrauterine PRP compared with placebo or no intervention on live birth or ongoing pregnancy (OR 2.38, 95% CI 1.16 to 4.86; I² = 54%; 6 studies, 564 women) and miscarriage (OR 1.54, 95% CI 0.59 to 4.01; I² = 0%; 5 studies, 504 women). The study at low risk of bias provided very low-certainty evidence about the effect of intrauterine PRP compared with no intervention on clinical pregnancy (OR 1.55, 95% CI 0.64 to 3.76; 94 women) and ectopic pregnancy (OR 2.94, 95% CI 0.12 to 73.95; 94 women). The synthesis of all studies provided very low-certainty evidence about the effect of intrauterine PRP compared with placebo or no intervention on clinical pregnancy (OR 2.22, 95% CI 1.50 to 3.27; I² = 24%; 9 studies, 824 women), multiple pregnancy (OR 2.68, 95% CI 0.81 to 8.88; I² = 0%; 2 studies, 240 women), and ectopic pregnancy (OR 2.94, 95% CI 0.12 to 73.95; 1 study, 94 women; very low-certainty evidence). Intrauterine infusion of PRP may increase the risk of preterm delivery compared with no intervention (OR 8.02, 95% CI 1.72 to 37.33; 1 study, 120 women; low-certainty evidence). No studies reported pain, infection, allergic reaction, fetal growth restriction, or fetal abnormality. Intrauterine infusion of platelet-rich plasma versus intrauterine infusion of granulocyte colony-stimulating factor Two RCTs evaluated intrauterine PRP versus intrauterine granulocyte colony-stimulating factor (G-CSF); both included women with thin endometrium, and neither was judged at low risk of bias for any outcome. We are uncertain about the effect of intrauterine PRP compared with intrauterine G-CSF on live birth (OR 0.88, 95% CI 0.43 to 1.81; 1 study, 132 women; very low-certainty evidence), miscarriage (OR 1.94, 95% CI 0.63 to 5.96; 1 study, 132 women; very low-certainty evidence), and clinical pregnancy (OR 1.24, 95% CI 0.66 to 2.35; 2 studies, 172 women; very low-certainty evidence). Neither study reported adverse outcomes other than miscarriage. Intraovarian injection of platelet-rich plasma versus no intervention One RCT evaluated PRP injection into both ovaries versus no intervention; it was judged at high risk of bias for the two outcomes it reported. We are uncertain about the effect of intraovarian PRP injection compared with no intervention on ongoing pregnancy (OR 1.09, 95% CI 0.33 to 3.63; 73 women; very low-certainty evidence) and clinical pregnancy (OR 0.90, 95% CI 0.31 to 2.60; 73 women; very low-certainty evidence). The study examined no safety outcomes.

AUTHORS' CONCLUSIONS

We are uncertain about the effect of intrauterine or intraovarian administration of PRP on outcomes of assisted reproduction technology in infertile women. The pooled results should be interpreted with caution. Only one of the 12 included studies was judged at low risk of bias. Other limitations of the included trials were failure to report live birth, poor reporting of methods, lack of prospective protocol registration, low precision due to the small number of enrolled participants, indirectness due to the specific subpopulations and settings studied, and insufficient or absent safety data.

Clinical Relevance of Vaginal and Endometrial Microbiome Investigation in Women with Repeated Implantation Failure and Recurrent Pregnancy Loss

Recent studies have investigated if and how the vaginal and endometrial microbiome might affect endometrial receptivity and reproductive health. Although there is no consensus on the existence of a core uterine microbiome yet, evidence shows that the dominance of Lactobacillus spp. in the female reproductive tract is generally associated with eubiosis and improved chances of successful implantation and an ongoing pregnancy. Conversely, vaginal and endometrial dysbiosis can cause local inflammation and an increase of pro-inflammatory cytokines, compromising the integrity and receptivity of the endometrial mucosa and potentially hampering successful embryonic implantation. This review provides a critical appraisal of the influence of the vaginal and endometrial microbiome as parts of the female reproductive tract on fertility outcomes, focusing on repeated implantation failure (RIF) and recurrent pregnancy loss (RPL). It seems that RIF as well as RPL are both associated with an increase in microbiome diversity and a loss of Lactobacillus dominance in the lower female reproductive system.

The Effect of CoQ10 supplementation on ART treatment and oocyte quality in older women

A significant problem associated with assisted reproductive technologies (ART) is recurrent treatment failure which can be attributed to the age-associated decline in oocyte quality. Co-enzyme Q10 (CoQ10) is an antioxidant and essential component of the mitochondrial electron transport chain. It is reported that de novo CoQ10 production declines with ageing and coincides with age-related decline in fertility, leading to CoQ10 supplementation being advocated to enhance response to ovarian stimulation and improve oocyte quality. CoQ10 supplementation was found to improve fertilization rates, embryo maturation rates and embryo quality when used before and during in vitro fertilization (IVF) and in vitro maturation (IVM) treatment in women aged 31 and over. Regarding oocyte quality, CoQ10 was able to reduce high rates of chromosomal abnormalities and oocyte fragmentation, as well as improve mitochondrial function. Proposed mechanisms of CoQ10 function include restoration of reactive oxygen species imbalance, preventing DNA damage and oocyte apoptosis, as well as restoration of Krebs cycle downregulation from ageing. In this literature review, we provide an overview of the use of CoQ10 in improving the success of IVF and IVM in older women, and additionally assess the impact of CoQ10 on oocyte quality and discuss potential mechanisms of action by CoQ10 on the oocyte.

Low Molecular Weight Heparin-Aspirin-Prednisolone Combination Does Not Increase the Live Birth Rate in Recurrent Implantation Failure: A Retrospective Cohort Study

This study investigates the triple combination of adjuvants (low molecular weight heparin (LMWH)-aspirin-prednisolone) whether it improves the live birth rates of IVF&ICSI patients with previous implantation failure. This retrospective study included 1095 patients with >2 failed either fresh or frozen single embryo transfer cycles between 2014 Jan and 2021 Jan. Patients were divided into two subgroups. Group A consisted of patients with only vaginal progesterone for luteal phase support. Group B consisted of patients with triple (daily subcutaneous LMWH, daily 150 mg aspirin, and daily 16 mg prednisolone) luteal phase supplementation to vaginal progesterone. Demographic parameters, cycle characteristics, embryology, and pregnancy outcomes were compared, and the study's primary outcome was the live birth rate. Demographic parameters were similar between the groups. Positive b-hCG, miscarriage, and live birth rates were similar between groups as Group A vs. Group B, positive b-hCG 30.8% (190/617) vs. 35.4% (169/478), miscarriage rates 4.4% (27/617) vs. 6.7% (32/478), and live birth rates 20.4% (126/617) vs. 23.8% (114/478), respectively. When patients were stratified according to previous failures, live birth rates were still similar. Pregnancy outcomes were significantly improved in only patients with diminished ovarian reserve (Group A vs. Group B, positive b-hCG 24.2% vs. 34.3%, live birth rate 12.1% vs. 21.9%, p < 0.01). Whether the embryo transfer was fresh or frozen-thawed did not affect the results. A combined supplementation of LMWH, aspirin, and prednisolone in the luteal phase does not improve live birth rates of IVF&ICSI patients with previous implantation failure except potentially for patients with diminished ovarian reserve.

Association of Polymorphisms in FSHR, INHA, ESR1, and BMP15 with Recurrent Implantation Failure

Recurrent implantation failure (RIF) refers to two or more unsuccessful in vitro fertilization embryo transfers in the same individual. Embryonic characteristics, immunological factors, and coagulation factors are known to be the causes of RIF. Genetic factors have also been reported to be involved in the occurrence of RIF, and some single nucleotide polymorphisms (SNPs) may contribute to RIF. We examined SNPs in FSHR, INHA, ESR1, and BMP15, which have been associated with primary ovarian failure. A cohort of 133 RIF patients and 317 healthy controls consisting of all Korean women was included. Genotyping was performed by Taq-Man genotyping assays to determine the frequency of the following polymorphisms: FSHR rs6165, INHA rs11893842 and rs35118453, ESR1 rs9340799 and rs2234693, and BMP15 rs17003221 and rs3810682. The differences in these SNPs were compared between the patient and control groups. Our results demonstrate a decreased prevalence of RIF in subjects with the FSHR rs6165 A>G polymorphism [AA vs. AG adjusted odds ratio (AOR) = 0.432; confidence interval (CI) = 0.206-0.908; p = 0.027, AA+AG vs. GG AOR = 0.434; CI = 0.213-0.885; p = 0.022]. Based on a genotype combination analysis, the GG/AA (FSHR rs6165/ESR1 rs9340799: OR = 0.250; CI = 0.072-0.874; p = 0.030) and GG-CC (FSHR rs6165/BMP15 rs3810682: OR = 0.466; CI = 0.220-0.987; p = 0.046) alleles were also associated with a decreased RIF risk. Additionally, the FSHR rs6165GG and BMP15 rs17003221TT+TC genotype combination was associated with a decreased RIF risk (OR = 0.430; CI = 0.210-0.877; p = 0.020) and increased FSH levels, as assessed by an analysis of variance. The FSHR rs6165 polymorphism and genotype combinations are significantly associated with RIF development in Korean women.

Establishment of reference intervals of endometrial immune cells during the mid-luteal phase

This study aimed to develop reference intervals (RIs) of endometrial immune cells in control infertile women during the mid-luteal phase, and compare with the proportion of endometrial immune cells in recurrent reproductive failure (RRF) patients. Endometrial tissue sections were obtained from 113 fertile women and 79 patients with RRF, including 40 patients who had suffered recurrent miscarriage (RM) and 39 patients with repeated implantation failure (RIF) during the mid-luteal phase of the menstrual cycle. Immunohistochemical staining and quantitative analysis of CD56⁺, Foxp3⁺, CD163⁺, CD1a⁺ and CD8⁺ cells were performed in endometriums. RIs of endometrial immune cells in control infertile women were as follows: CD56⁺ uterine natural killer cells (uNK) cells, 1.785-8.712%, forkhead box P3 (Foxp3)⁺ Tregs, 0.041-0.154%, CD163⁺ M2 macrophages, 0.298-1.492%, CD1a⁺ dendritic cells (DCs), 0.006-0.081% and CD8⁺ T cells, 0.674-2.504%. Compared with control infertile women, the percentage of endometrial CD56⁺ uNK cells, CD163⁺ M2 macrophages, CD1a⁺ DCs and CD8⁺ T cells were significantly increased in patients with RRF. Moreover, Foxp3⁺ Tregs levels were decreased in patients with RRF, and were statistically significant only in patients with RM. In conclusion, the RIs of endometrial immune cells were established in control infertile women during the mid-luteal phase, and a disordered endometrial immune microenvironment was observed in patients with RRF. The RIs of endometrial immune cells may be of important clinical significance for the treatment of RRF.

Efficacy of atosiban for repeated embryo implantation failure: A systematic review and meta-analysis

BACKGROUND

Repeated embryo implantation failure (RIF) posed a significant challenge in assisted reproduction. Evidence of its therapeutic effectiveness including atosiban used around embryo transfer to improve pregnancy outcomes in RIF patients undergoing in vitro fertilization-embryo transfer (IVF-ET) remained inconsistent. This study aimed to explore the efficacy of atosiban on pregnancy outcomes of patients with RIF who received IVF-ET.

METHODS

The research was designed using the PICOS format. A systematic search of four English databases, PubMed, EMBASE, Web of Science, Cochrane Library, and one Chinse database, China National Knowledge Infrastructure (CNKI) was conducted. The time range was from inception to December 10, 2022. Then trials comparing the efficacy of atosiban and control group on pregnancy outcomes in RIF patients who receive IVF-ET were included. Subgroup analysis and sensitivity analysis were performed to reduce the influence of heterogeneity between included studies. Risk ratio (RR) and 95% confidence interval (CI) were calculated. The main outcome measure was clinical pregnancy rate (CPR). For the analyses, StataMP 17.0 (Stata Corporation, USA) was used.

RESULTS

Two prospective randomized controlled trials (RCTs), one prospective cohort study and four retrospective cohort studies were included. Our results showed that atosiban was associated with higher clinical pregnancy rate (RR=1.54, 95% CI: 1.365-1.735, P < 0.001, I^{2 =} 0.0%). The results of subgroup analysis based on study types (prospective randomized controlled clinical trial, retrospective cohort study and prospective cohort study) showed that in all types of studies, CPR of atosiban group was significantly higher than controlled group. The results of subgroup analysis based upon the diagnostic criteria of number of previous embryo transfer failures showed that the intervention of atosiban improved the CPR whether in participants with 2 previous ET failures or in participants with 3 previous ET failures. Nevertheless, the incidence of ectopic pregnancy, multiple pregnancy, and miscarriages were not significantly different between the case and control groups.

CONCLUSION

For women who are undergoing IVF-ET and have experienced repeated embryo implantation failure, atosiban may be an important factor in enhancing pregnancy outcomes. To confirm this conclusion, more thorough, prospective randomized controlled studies of sizable sample sizes with well design are required.

The role of thrombophilias in reproduction: A swot analysis

Thrombophilia is a group of inherited or acquired coagulation disorders that have been associated with reproductive failure. However, there are still no clear recommendations on whether its inclusion in the initial study of the infertile couple or patients with recurrent implantation failure is necessary. In this discussion paper, based on a SWOT (strengths, weaknesses, opportunities, threats) analysis, the different aspects of the repercussions of thrombophilia screening and treatment in reproduction are evaluated. To avoid possible subjectivity in the analysis and results of this study, researchers followed Oxford criteria for the evaluation of evidence. The results from the evaluation of the reviewed bibliography seem to indicate that, pending new evidence, it would be advisable not to include thrombophilia screening in the initial baseline study of the infertile couple. There is no evidence to support a clear association between thrombophilia and implantation failure or infertility. Thrombophilia testing in this setting may increase cost, with minimal potential benefit and lead to inappropriate use of anticoagulants with possible deleterious adverse effects. Future well-designed studies are needed to assess the possible benefit of anticoagulant therapy in infertile thrombophilic patients with implantation failure.

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

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

A novel lncRNA lncSAMD11-1: 1 interacts with PIP4K2A to promote endometrial decidualization by stabilizing FoxO1 nuclear localization

Decidualization is essential for a successful pregnancy and determines embryo implantation and pregnancy maintenance. Abnormal decidualization is one of the main causes of recurrent implantation failure (RIF). Studies have shown that large amounts of long noncoding RNAs (lncRNAs) are abnormally expressed in endometrial samples from patients with RIF. However, the functional contributions of lncRNAs to decidualization in RIF have not been explored. In this study, we found that lncSAMD11-1:1 was significantly declined in the endometria of patients with RIF. The knockdown of lncSAMD11-1:1 in human endometrial stromal cells (hESCs) restrained decidualization and embryo implantation in vitro, while the overexpression of lncSAMD11-1:1 facilitated hESC decidualization and embryo implantation in vitro and ameliorated decidualization in RIF patients. Mechanistically, lncSAMD11-1:1 and phosphatidylinositol-5-phosphate 4-kinase type 2 alpha (PIP4K2A) translocated out of nucleus and bound to each other during decidualization, thereby inhibiting the phosphorylation of AKT and promoting FoxO1 nuclear localization. These data suggest that lncSAMD11-1:1 might be a critical novel lncRNA functionally required for human decidualization, and the dysregulation of lncSAMD11-1:1 in the endometrium may be a new predisposing factor of RIF.

The outcomes of sequential embryo transfer in patients undergoing in vitro fertilization with frozen-thawed embryos: A retrospective study

AIM

To explore whether sequential embryo transfer benefits patients with repeated implantation failure (RIF) undergoing frozen-thawed embryo transfer (FET) cycles.

METHODS

We included 311 patients with a history of RIF in this retrospective study. We did sequential transfers with a cleavage embryo on day 3 and a blastocyst on day 5 in 77 patients; blastocyst transfers with two blastocysts on day 5 in 80 patients; and cleavage embryo transfers with two cleavage embryos on day 3 in 154 patients. We compared clinical outcomes between the three groups.

RESULTS

The clinical pregnancy rate was comparable between the blastocyst transfer group (48.8%), the sequential transfer group(48.1%) and the cleavage embryo transfer group (48.1%). There was no statistically significant difference found (p > 0.05). The ongoing pregnancy and multipregnancy rates were also comparable between the three groups (p > 0.05). The early miscarriage rate was significantly higher in the sequential transfer group (32.4%) compared with the blastocyst group (12.8%) and the cleavage embryo group (12.2%) (p < 0.05). However, after adjusting for confounders, there was no significant difference in early miscarriage rates in the sequential transfer group compared with the blastocyst group (odds ratio [OR], 2.97; 95% confidence interval [CI], 0.85-9.24; p = 0.07) and the cleavage embryo group (OR, 3.03; 95% CI, 0.94-8.06; p = 0.08).

CONCLUSIONS

Sequential embryo transfer failed to improve clinical outcomes for patients with RIF.

Defining recurrent implantation failure: a profusion of confusion or simply an illusion?

Recurrent implantation failure (RIF) is a poorly defined clinical scenario marked by failure to achieve pregnancy after multiple embryo transfers. The causes and definitions of implantation failure are heterogeneous, posing limitations on study design as well as the interpretation and application of findings. Recent studies suggest a novel, personalized approach to defining RIF. Here, we review the implantation physiology and definitions of the implantation rate, failure, and RIF.

Interaction Between Chronic Endometritis Caused Endometrial Microbiota Disorder and Endometrial Immune Environment Change in Recurrent Implantation Failure

Objective

To investigate the Interaction between chronic endometritis (CE) caused endometrial microbiota disorder and endometrial immune environment change in recurrent implantation failure (RIF).

Method

Transcriptome sequencing analysis of the endometrial of 112 patients was preform by using High-Throughput Sequencing. The endometrial microbiota of 43 patients was analyzed by using 16s rRNA sequencing technology.

Result

In host endometrium, CD4 T cell and macrophage exhibited significant differences abundance between CE and non-CE patients. The enrichment analysis indicated differentially expressed genes mainly enriched in immune-related functional terms. Phyllobacterium and Sphingomonas were significantly high infiltration in CE patients, and active in pathways related to carbohydrate metabolism and/or fat metabolism. The increased synthesis of lipopolysaccharide, an important immunomodulator, was the result of microbial disorders in the endometrium.

Conclusion

The composition of endometrial microorganisms in CE and non-CE patients were significantly different. Phyllobacterium and Sphingomonas mainly regulated immune cells by interfering with the process of carbohydrate metabolism and/or fat metabolism in the endometrium. CE endometrial microorganisms might regulate Th17 response and the ratio of Th1 to Th17 through lipopolysaccharide (LPS).

Human chorionic gonadotropin improves endometrial receptivity by increasing the expression of homeobox A10

Homeobox A10 (HOXA10) is a characterized marker of endometrial receptivity. The mechanism by which hCG intrauterine infusion promotes embryo implantation is still unclear. This study seeks to investigate whether hCG improves endometrial receptivity by increasing expression of HOXA10. HOXA10 expression with human chorionic gonadotropin stimulation was analyzed in vitro and in vivo. Our results demonstrate that HOXA10 was decreased in the endometria of recurrent implantation failure patients compared to that in the healthy control fertile group, also we observed that hCG intrauterine infusion increased endometrial HOXA10 expression. HOXA10, blastocyst-like spheroid expansion area was increased, whereas DNA (cytosine-5-)-methyltransferase 1 was decreased when human endometrial stromal cells (hESCs) were treated with 0.2 IU/ml of hCG for 48 h. HOXA10 promoter methylation was also reduced after hCG treatment. Collagen XV (ColXV) can repress the expression of DNA (cytosine-5-)-methyltransferase 1, and hCG treatment increased the expression of ColXV. However, when the hESCs were treated with LH/hCG receptor small interfering RNA to knock down LH/hCG receptor, hCG treatment failed to repress DNA (cytosine-5-)-methyltransferase 1 expression or to increase ColXV expression. Our findings suggest that hCG may promote embryo implantation by increasing the expression of HOXA10.

Definition, diagnostic and therapeutic options in recurrent implantation failure: an international survey of clinicians and embryologists

STUDY QUESTION

What is the global variability in recurrent implantation failure (RIF) definition, investigation and therapy, currently offered to patients undergoing IVF?

SUMAMRY ANSWER

Definitions, diagnostic investigations and treatments offered to RIF patients differ widely amongst assisted reproduction healthcare professionals and clinical guidelines on RIF are urgently needed.

WHAT IS KNOWN ALREADY

RIF affects around 10% of patients undergoing IVF worldwide. There is no consensus on the definition of RIF, its diagnostic investigations or the therapeutic options, which leads to inconsistencies in clinical practice.

STUDY DESIGN, SIZE, DURATION

A cross-sectional study of clinicians and embryologists was conducted between May and June 2020. The survey included 43 questions aimed at understanding participants' background and their current practice with regards to defining, investigating and managing RIF. The questions were designed by the European Society of Human Reproduction and Embryology (ESHRE) Special Interest Group (SIG) on implantation and early pregnancy following three consensus meetings.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 8579 ESHRE members from 6916 IVF centers were invited to participate using two global email calls based on their pre-specified interest in implantation and early pregnancy. SurveyMonkey and SPSS were used for data collection and analysis, respectively. Furthermore, differences were reported in the answers of European and non-European professionals, as well as between public and private settings and among clinicians clustered according to the average number of RIF patients treated per year.

MAIN RESULTS AND THE ROLE OF CHANCE

The final data set included 735 clinicians and 300 embryologist or IVF-biologists. The majority defines RIF based on the number of failed embryo transfers (ETs) with the most common threshold adopted being three ETs both fresh and frozen. More than two-thirds take lifestyle factors into account, mainly drugs, smoking and BMI. The highest consensus on which diagnostic investigations should be performed was reached for anatomical malformations and gynecological aspects focusing on hydrosalpinx, Asherman's syndrome, endometrial thickness and endometriosis. Concerning treatment of RIF patients, the highest consensus was reached for preconceptional therapies, including BMI adjustment, smoking and endometritis followed by therapies during IVF procedures.

LIMITATIONS, REASONS FOR CAUTION

The response rate was relatively low, but comparable to other surveys.

WIDER IMPLICATIONS OF THE FINDINGS

A consensus on definition, diagnosis and treatment of RIF would help to reduce costly, time-consuming and poorly validated approaches.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was used. B.T. received support from Bayer for Clinical trials concerning endometriosis and Ferring for clinical trials concerning ovarian stimulation. She received reimbursement for travel expenses from Astropharm, Ferring. Dr Kade and is a shareholder of Reprognostics. She is a board member of the Austrian Society for Obstetrics and Gynecology (OEGGG), the associate head of the 'Reproduktionsmedizinische Zentren Baden-Württemberg' (RZBW), a member of guideline group of the German Society for Obstetrics and Gynecology (DGGG) and an editorial board member of the following journals: American Journal of Reproductive Immunology (AJRI), Archives of Gynecology and Obstetrics. All the other authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Endometrial delay is found to be part of a normal individual dynamic transformation process

Purpose

Limited information is clinically available concerning endometrial receptivity; assessing endometrial transformation status is therefore an urgent topic in assisted reproductive technology. This study aimed to investigate individual endometrial transformation rates during the secretory phase in subfertile patients using personal endometrial transformation analysis.

Methods

Monitoring was carried out during the secretory phase to obtain endometrial receptivity profiles. For the investigation, two endometrial biopsies were taken within one menstrual cycle. The extended endometrial dating was based on the Noyes criteria, combined with immunohistochemical analyses of hormone receptors and proliferation marker Ki-67. Biopsies were taken mainly at days ovulation (OV, n = 76)/hormone replacement therapy (HRT, n = 58) + 5 and + 10.

Results

The results of the two biopsies were correlated with the clinically expected day of the cycle and showed temporal delays or hypercompensations, diverging from the expected cycle days by 0.5–5 days. In comparison with the first biopsies, the transformation rate in the second biopsies showed compensation, augmented delay, or constant transformation in 48.69, 22.37, and 28.94% of cases for ovulation in natural cycles and 56.89, 25.85, and 17.26% for HRT cycles, respectively.

Conclusion

The study revealed an individually dynamic transformation process of the endometrium, with the ability to compensate or enlarge an initial “delay”, which is now identified as a normal individual transformation process during the secretory phase. This information is of great importance for the scientific investigation of dynamic changes in endometrial tissue, as well as for the timing of embryo transfers.

A novel platform for discovery of differentially expressed microRNAs in patients with repeated implantation failure

OBJECTIVE

To identify predictor microRNAs (miRNAs) from patients with repeated implantation failure (RIF).

DESIGN

Systemic analysis of miRNA profiles from the endometrium of patients undergoing in vitro fertilization (IVF).

SETTING

University research institute, private IVF center, and molecular testing laboratory.

PATIENT(S)

Twenty five infertile patients in the discovery cohort and 11 patients in the validation cohort.

INTERVENTIONS(S)

None.

MAIN OUTCOME MEASURE(S)

A signature set of miRNA associated with the risk of RIF.

RESULT(S)

We designed a reproductive disease-related PanelChip to access endometrium miRNA profiles in patients undergoing IVF. Three major miRNA signatures, including hsa-miR-20b-5p, hsa-miR-155-5p, and hsa-miR-718, were identified using infinite combination signature search algorithm analysis from 25 patients in the discovery cohort undergoing IVF. These miRNAs were used as biomarkers in the validation cohort of 11 patients. Finally, the 3-miRNA signature was capable of predicting patients with RIF with an accuracy >90%.

CONCLUSION(S)

Our findings indicated that specific endometrial miRNAs can be applied as diagnostic biomarkers to predict RIF. Such information will definitely help to increase the success rate of implantation practice.

Association between HOX Transcript Antisense RNA Single-Nucleotide Variants and Recurrent Implantation Failure

Recurrent implantation failure (RIF) refers to the occurrence of more than two failed in vitro fertilization–embryo transfers (IVF-ETs) in the same individual. RIF can occur for many reasons, including embryo characteristics, immunological factors, and coagulation factors. Genetics can also contribute to RIF, with some single-nucleotide variants (SNVs) reported to be associated with RIF occurrence. We examined SNVs in a long non-coding RNA, homeobox (HOX) transcript antisense RNA (HOTAIR), which is known to affect cancer development. HOTAIR regulates epigenetic outcomes through histone modifications and chromatin remodeling. We recruited 155 female RIF patients and 330 healthy controls, and genotyped HOTAIR SNVs, including rs4759314, rs920778, rs7958904, and rs1899663, in all participants. Differences in these SNVs were compared between the patient and control groups. We identified significant differences in the occurrence of heterozygous genotypes and the dominant expression model for the rs1899663 and rs7958904 SNVs between RIF patients and control subjects. These HOTAIR variants were associated with serum hemoglobin (Hgb), luteinizing hormone (LH), total cholesterol (T. chol), and blood urea nitrogen (BUN) levels, as assessed by analysis of variance (ANOVA). We analyzed the four HOTAIR SNVs and found significant differences in haplotype patterns between RIF patients and healthy controls. The results of this study showed that HOTAIR is not only associated with the development of cancer but also with pregnancy-associated diseases. This study represents the first report showing that HOTAIR is correlated with RIF.

Reproductive health research in Australia and New Zealand: highlights from the Annual Meeting of the Society for Reproductive Biology, 2019

The 2019 meeting of the Society for Reproductive Biology (SRB) provided a platform for the dissemination of new knowledge and innovations to improve reproductive health in humans, enhance animal breeding efficiency and understand the effect of the environment on reproductive processes. The effects of environment and lifestyle on fertility and animal behaviour are emerging as the most important modern issues facing reproductive health. Here, we summarise key highlights from recent work on endocrine-disrupting chemicals and diet- and lifestyle-induced metabolic changes and how these factors affect reproduction. This is particularly important to discuss in the context of potential effects on the reproductive potential that may be imparted to future generations of humans and animals. In addition to key summaries of new work in the male and female reproductive tract and on the health of the placenta, for the first time the SRB meeting included a workshop on endometriosis. This was an important opportunity for researchers, healthcare professionals and patient advocates to unite and provide critical updates on efforts to reduce the effect of this chronic disease and to improve the welfare of the women it affects. These new findings and directions are captured in this review.

Clinical utility of the endometrial receptivity analysis in women with prior failed transfers

PURPOSE

To determine the utility of the endometrial receptivity analysis (ERA) in women with prior failed embryo transfers (ET).

METHODS

This was a retrospective study of patients who underwent an ERA test with a subsequent frozen ET. Women were classified based on their indication for an ERA test: (1) ≥ 1 prior failed ET (cases), or (2) as a prophylactic measure (controls). A subset analysis of women with ≥ 3 prior failed transfers was performed. Pregnancy outcomes of the subsequent cycle were examined, including conception, clinical pregnancy, and ongoing pregnancy/live birth.

RESULTS

A total of 222 women were included, 131 (59%) women with ≥ 1 prior failed ET and 91 (41%) controls. Among the 131 women with ≥ 1 prior failed ET, 20 women (9%) had ≥ 3 prior failed ETs. The proportion of non-receptive ERA tests in the three groups were the following: 45% (≥ 1 prior failed ET), 40% (≥ 3 prior failed ETs), and 52% (controls). The results did not differ between cases and controls. The pregnancy outcomes did not differ between women with ≥ 1 prior failed ET and controls. In women with ≥ 3 prior failed ETs, there was a lower ongoing pregnancy/live birth rate (28% vs 54%, P = 0.046).

CONCLUSION

Women with ≥ 1 prior failed ET and ≥ 3 prior failed ETs had a similar prevalence of non-receptive endometrium compared to controls. Women with ≥ 3 prior failed ETs had a lower ongoing pregnancy/live birth rate despite a personalized FET, suggesting that there are additional factors in implantation failure beyond an adjustment in progesterone exposure.

Maternal and paternal carriage of the annexin A5 M2 haplotype: a possible risk factor for recurrent implantation failure (RIF)

OBJECTIVE

This study was carried out to determine the potential role of the M2/ANXA5 haplotype as a risk factor for recurrent implantation failure (RIF). Carriage of the M2/ANXA5 haplotype that induces prothrombotic changes has been implicated in failure of early pregnancies and placenta-mediated complications (preeclampsia, IUGR, preterm birth).

MATERIAL AND METHODS

In the present case control study, 63 couples (females and males) with RIF presenting for IVF/ICSI to the Fertility Center of [masked] were analyzed. RIF was defined as ≥ 4 consecutive failed ART-transfers of ≥ 4 blastocysts or ≥ 8 cleavage-stage embryos of optimal quality and maternal age ≤ 41. Fertile female controls (n = 90) were recruited from the same center. Population controls (n = 533) were drafted from the PopGen biobank, UKSH Kiel.

RESULTS

Couples carrying the M2/ANXA5 haplotype turned out to have a significantly increased relative risk (RR) for RIF. Compared with female fertile controls, RR was 1.81 with p = 0.037 (OR 2.1, 95%CI 1.0-4.3) and RR was 1.70, with p = 0.004 (OR 2.0, 95%CI 1.2-3.1) compared with population controls (15.4% M2 carriers). Male partners were comparable with RIF females for M2/ANXA5 haplotypes (28.6% vs. 23.8%, p = 0.54). RIF females compared with population controls had a RR of 1.55 (p = 0.09) and RIF males compared with population controls had a RR of 1.9 (p = 0.01). Couples with ≥ 7 failed transfers showed a RR of 1.82 (p = 0.02) compared with population controls.

CONCLUSION

Our findings suggest that maternal as well as paternal M2/ANXA5 haplotype carriages are risk factors for RIF. These results allow new insights into the pathogenesis of RIF and might help to identify relevant risk groups.

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.

Assessing endometrial receptivity after recurrent implantation failure: a prospective controlled cohort study

RESEARCH QUESTION

What is the prevalence of disrupted markers of endometrial function among women experiencing recurrent implantation failure (RIF), and does the prevalence differ from a control cohort?

DESIGN

Prospective controlled cohort study. In total, 86 women with a history of RIF and 37 women starting their first fertility treatment were recruited for this study. Endometrial and blood profiling were carried out in a hormone-substituted cycle using oestradiol and progesterone. Endometrial biopsies were analysed by histology, immune cell profiling, and the endometrial receptivity array (ERA®) test (Igenomix, Valencia, Spain). The vaginal microbiome was analysed using a NGS-based technology (ArtPRED, Amsterdam, the Netherlands). Blood tests included oestradiol, progesterone, prolactin, thyroid-stimulating hormone, vitamin D and anti-phospholipid antibody levels.

RESULTS

Patients who had experienced RIF produced a range of test abnormalities. Compared with controls, women with RIF had a higher prevalence of chronic endometritis (24% versus 6%), a lower vitamin D level and a borderline lower progesterone level. Women who had experienced RIF had a more favourable vaginal microbiome compared with controls. Although the RIF cohort was older than the controls (mean age 33.8 years versus 30.2 years), no differences between the groups were observed in immune cell profiling and the ERA test.

CONCLUSION

These data demonstrate that a single test or treatment for the endometrial factor in RIF is unlikely to be clinically effective. Diagnosing the endometrium in women with RIF permits targeted rather than blind interventions. Relative vitamin D deficiency, lower mid-luteal progesterone and chronic endometritis are ready targets for treatment. Understanding the role and treatment of an unfavourable vaginal microbiome in RIF needs further investigation.

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.

Alterations in Vaginal Microbiota and Associated Metabolome in Women with Recurrent Implantation Failure

In vitro fertilization-embryo transfer (IVF-ET) is now widely applied for treating infertility, and unexplained recurrent implantation failure (RIF) has become a substantial challenge. We hypothesize that vaginal microbial dysbiosis is associated with RIF, as it is linked to many female reproductive diseases. In this study, we characterized the vaginal microbiota and metabolomes of patients with unexplained RIF, while patients who achieved clinical pregnancy in the first IVF cycle were set as controls. In general, significant differences were discovered in the vaginal microbiota and metabolomes between the two groups. This study is the first detailed elaboration of the vaginal microbiota and metabolites associated with RIF. We believe that our findings will inspire researchers to consider the dynamics of microbiomes related to the microenvironment as a critical feature for future studies of nosogenesis not only for RIF but also for other reproductive diseases.

Recurrent implantation failure (RIF) refers to repeated failure to become pregnant after transferring embryos with normal morphology. However, the pathogenesis of RIF remains unrevealed, especially for those without any pathological features. In this study, we characterized the vaginal microbiota and metabolomes of patients with unexplained RIF, while patients who achieved clinical pregnancy in the first frozen embryo transfer (FET) cycle were used as controls. Based on 16S rRNA gene sequencing of the vaginal microbiota, the vaginal Lactobacillus showed a significant positive correlation with the pregnancy rate, and the RIF group presented higher microbial α-diversity than the control group (P value = 0.016). The metabolomic profile identified 2,507 metabolites, of which 37 were significantly different between the two groups (P value < 0.05, variable importance for the projection [VIP] > 1). Among them, 2′,3-cyclic UMP and inositol phosphate were the top two metabolites that were higher in the RIF group, while glycerophospholipids and benzopyran were important metabolites that were lower in the RIF group. A lack of lysobisphosphatidic acid and prostaglandin metabolized from glycerophospholipids will lead to deferred implantation and embryo crowding. Benzopyran, as a selective estrogen receptor modulator, may affect the outcome of pregnancy. All of the changes in metabolite profiles may result in or from the differential microbiota compositions in RIF patients. In conclusion, significant differences were presented in the vaginal microbiota and metabolomes between patients with unexplained RIF and women who became pregnant in the first FET cycle. For the first time, this study elaborates the possible pathogenesis of RIF by investigating the vaginal microbiota and metabolites in RIF patients.

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.

The effect of platelet-rich plasma on the achievement of pregnancy during frozen embryo transfer in women with a history of failed implantation

Objective

The aim of this study was to evaluate the effect of platelet-rich plasma (PRP) on the rate of implantation and pregnancy in women with repeated failed implantation during frozen embryo transfer.

Methods

This study was conducted on 50 infertile women candidates (who were referred to the Infertility Treatment Center of Besat Hospital in Sanandaj) with a history of failed implantation for the purpose of frozen embryo transfer. The participants were randomly divided into two groups (n = 25). In the first group (control), the intrauterine infusion of 0.5 ml of Ringer serum was done 48 h before embryo transfer. In the second group (treatment), the intrauterine infusion of 0.5 ml of PRP was performed 48 h before embryo transfer.

Results

In this study, there was no significant difference between the two groups in the rate of chemical and clinical pregnancy. The rate of chemical pregnancy was 28% in the treatment group and 36% in the control group, while the rate of clinical pregnancy was 28% in the treatment group and 24% in the control group.

Conclusion

The intrauterine infusion of PRP before frozen embryo transfer in infertile women with a history of failed implantation will not make any significant effect on the result of pregnancy.

Recurrent implantation failure: which patients benefit from endometrial scratching prior to IVF?

PURPOSE

Endometrial scratching (ES) using a biopsy catheter prior to the IVF cycle in the repeated implantation failure (RIF) population has been suggested, but no convincing evidence of its benefit has been presented until now.

METHODS

A retrospective mono-center study among 300 consecutive IVF-RIF cycles following evaluation of the ovarian reserve, hysterosalpingography or hysteroscopy, pelvic ultrasound, thrombophilia evaluation, karyotyping and assessment of male sperm parametrs. The findings within normal limits. All the patients offered ES, 78 consented and underwent ES prior to their next IVF cycle.

RESULTS

A comparison of treatment outcomes between the post-ES cycles (n = 78) and the non-ES cycles (222) demonstrated the following: 34 (43.5%) versus 14 (6.3%) conceptions, respectively (p = 0.001) and 30 (38.4%) versus 2 (0.9%) clinical pregnancies, respectively (p < 0.001%), emphasizing an extremely high biochemical pregnancy rate among the non-ES cycles. Implantation rate was 19.7% versus 0.4%, respectively (p < 0.001) and live birth rate was 33.33% (26 newborns) versus 0.45% (1 newborn), respectively (p < 0.001). Since there were more embryos available for transfer and more top-quality embryos in the post-ES-IVF conception cycles, the role of ES became questionable. A multivariate analysis that included ES and the percentage of top-quality embryos demonstrated that ES was an independent factor highly correlated with conception in this particular RIF population.

CONCLUSIONS

ES proved to be an efficient tool in a particular subgroup of RIF patients with fertility investigation results within normal limits, an optimal ovarian response to gonadotropins, and a high percentage of top-quality embryos. Nevertheless, the results should not be overestimated, since the study has limitations related to its retrospective model.

Associations between microRNA (miR-25, miR-32, miR-125, and miR-222) polymorphisms and recurrent implantation failure in Korean women

Background

Recurrent implantation failure (RIF) is the failure of embryos to implant more than two times in a given individual. There is debate about a precise definition for RIF, but we consider more than two implantation failures for individuals who undergo in vitro fertilization-embryo transfer (IVF-ET) to constitute RIF. There are many potential reasons for RIF, including embryonic factors, immunological factors, uterine factors, coagulate factors, and genetic factors. Genetic variation has been suggested as one of the contributing factors leading to RIF, and a number of single-nucleotide polymorphisms (SNPs) have been reported to be associated with RIF. The recent elucidation of miRNA functions has provided new insight into the regulation of gene expression.

Methods

We investigated associations between polymorphisms in four miRNAs and RIF in 346 Korean women: 118 patients with RIF and 228 controls. We determined the genotypes of the miRNAs in the study participants by polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) analysis. We analyzed the effects of genotypes, allele combinations, and environmental and clinical factors on the risk of RIF.

Results

The miR-25 T/miR-125aT/miR-222G (odds ratio (OR), 0.528; 95% confidence interval (CI), 0.282–0.990; P = 0.044) and miR-25 T/miR-125aT allele combinations were associated with a reduced risk of RIF. The miR-25 T/miR-32C/miR-125aC/miR-222 T allele combination was associated with an increased risk of RIF. The miR-222GT+TT genotypes interacted with high prothrombin time (≥ 12 s) to increase the risk of RIF.

Conclusions

MicroRNA polymorphisms are significantly different between patients that experience RIF and healthy controls. Combinations of microRNA polymorphisms were associated with the risk of RIF. Interactions between environmental factors and genotypes increased the risk of RIF in Korean women.

Frozen blastocyst embryo transfer vs. frozen cleavage-stage embryo transfer in couples with recurrent implantation failure: a cohort study

The objective of this prospective cohort study was to investigate whether cryopreservation of cleavage or blastocyst stage embryos improves in vitro fertilization outcomes in recurrent implantation failure (RIF) patients. The study comprised 575 patients who were allocated to receive either single frozen/thawed blastocyst-stage transfer (SBT) or frozen/thawed double-cleavage-stage embryo transfer (DET). The clinical pregnancy rate, implantation rate, and ongoing pregnancy rate were higher in the SBT group compared with the DET group (41.15% vs. 27.11%, p < 0.001; 41.15% vs. 19.28%, p < 0.001; 40.03% vs. 25.9%, p < 0.001), but the miscarriage rate did not differ between the two groups. It was concluded that frozen/thawed SBT could be a preferred strategy for RIF patients.

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

STUDY QUESTION

What is the effect of endometrial scratching in patients with or without prior failed ART cycles on live birth (LBR) and clinical pregnancy rates (CPR)?

SUMMARY ANSWER

It remains unclear if endometrial scratching improves the chance of pregnancy and, if so, for whom.

WHAT IS KNOWN ALREADY

Endometrial scratching is hypothesized to improve embryo implantation in ART. Multiple studies have been published, but it remains unclear if endometrial scratching actually improves pregnancy rates and, if so, for which patients.

STUDY DESIGN, SIZE, DURATION

For this review, a systematic search for published articles on endometrial scratching and ART was performed on 12 February 2018, in Pubmed, Embase and the Cochrane Library.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Randomized controlled trials (RCTs) that evaluated endometrial scratching in the cycle prior to the stimulation cycle and reported CPR or LBR were included. RCTs investigating the effect of scratching during the stimulation cycle, or prior to cryo-thaw cycles were excluded. Studies were assessed using the Cochrane Risk of Bias tool. The effect of scratching was assessed for three different patient groups: patients with no prior IVF/ICSI treatment (Group 0), patients with one failed full IVF/ICSI cycle, including cryo-thaw cycles (Group 1) and patients with two or more failed full IVF/ICSI cycles (Group 2). A meta-analysis was performed when statistical heterogeneity was low; otherwise, a descriptive analysis was performed.

MAIN RESULTS AND THE ROLE OF CHANCE

Fourteen RCTs involving 2537 participants were included. Most RCTs contained a high or unclear risk of bias on one or more items. Substantial clinical and statistical heterogeneity was present; therefore meta-analysis for LBR and CPR could only be performed on Group 1. For this group, no differences between scratch and control were found for both LBR (risk ratio (RR) 1.01 [95%CI 0.68–1.51]) and CPR (RR 1.04 [95%CI 0.74–1.45]). For Groups 0 and 2, pooled analysis could not be performed, and for both groups the results of the individual RCTs were negative, neutral and positive. Miscarriage and multiple pregnancy rates were evaluated for the three groups (0, 1 and 2) together. Both outcomes were not significantly different between scratch and control (miscarriage rate RR 0.82 [95%CI 0.57–1.17] and multiple pregnancy rate RR 1.06 [95%CI 0.84–1.35]). Subgroup analysis, excluding trials with a risk of unintentional endometrial injury in the control group, was performed for Group 0 and 2 for LBR and CPR, and for the overall groups for miscarriage rate and multiple pregnancy rate. This reduced the heterogeneity and allowed for pooled analysis in these subgroups. Results of pooled analysis for the subgroups of Group 0 and 2 showed no significant difference for LBR, but CPR was significantly improved after endometrial scratching (Group 0 RR 1.28 [95%CI 1.02–1.62] and Group 2 RR 2.03 [95%CI 1.20–3.43]). Subgroup analysis of the overall groups showed no significant difference for miscarriage and multiple pregnancy rate.

LIMITATIONS REASONS FOR CAUTION

The main limitations were that many RCTs had a high or unclear risk of bias on one or several items, clinical heterogeneity was still present despite categorizing into three populations, and that not all RCTs could be included in the analyses because separate data for our three groups could not be provided.

WIDER IMPLICATIONS OF THE FINDINGS

It remains unclear if endometrial scratching improves the chance of pregnancy for women undergoing ART and, if so, for whom. This means endometrial scratching should not be offered in daily practice until results from large and well-designed RCTs and an individual patient data analysis become available.

STUDY FUNDING/COMPETING INTERESTS

No specific funding was sought for the study. The Department of Reproductive Medicine and Gynaecology funds of the University Medical Center of Utrecht were used to support the authors throughout the study period and preparation of the manuscript. None of the authors has a conflict of interest to declare.

REGISTRATION NUMBER

Not applicable.

Preliminary functional inquiry of lncRNA ENST00000433673 in embryo implantation using bioinformatics analysis

Long non-coding RNAs (lncRNAs), a class of non-coding RNA, have been shown to be essential in many diseases, such as infertility. Here, we found three candidate lncRNAs, ENST00000414116, ENST00000433673, and ENST00000448179, that are highly expressed in the uterus endometrial tissues of normal patients compared to the tissues of patients with adenomyosis, endometriosis, and recurrent implantation failure. lncRNAs ENST00000414116 and ENST00000433673 showed high expression in endometrial stromal cells (ESCs) and endometrial epithelial cells (EECs), respectively, and lncRNA ENST00000448179 was specifically expressed in ESCs. The bioinformatics analysis results indicated that the target mRNAs of lncRNA ENST00000433673 were related to biological adhesion. Interestingly, intercellular adhesion molecule 1 (ICAM1), an interacting mRNA of the target mRNA integrin subunit alpha L (ITGAL), has been reported be an important regulator of embryo implantation. Further studies found that the target mRNA ITGAL and the interacting mRNA ICAM1 were highly expressed in the uterus endometrial tissues and EECs of normal patients. Based on our results, our study indicates that lncRNA ENST00000433673 might mediate the high expression of the target mRNA ITGAL, thereby promoting the expression of the interacting mRNA ICAM1 and the adhesion of EECs, which facilitates adhesion and implantation between the embryo and the mater. Abbreviations: AMs: adenomyosis; EMs: endometriosis; RIF: recurrent implantation failure; miRNAs: microRNAs; lncRNAs: Long non-coding RNAs; RT-qPCR: real-time quantitative PCR; ESCs: endometrial stromal cells; EECs: endometrial epithelial cells; BFE: free binding energy; PCDHB9: protocadherin beta 9; PARVG: parvin gamma; MAPK6: mitogen-activated protein kinase 6; LAF1: lymphocyte function-associated antigen 1.

Asynchronous and pathological windows of implantation: two causes of recurrent implantation failure

STUDY QUESTION

Is endometrial recurrent implantation failure (RIF) only a matter of an asynchronous (displaced) window of implantation (WOI), or could it also be a pathological (disrupted) WOI?

SUMMARY ANSWER

Our predictive results demonstrate that both displaced and disrupted WOIs exist and can present independently or together in the same RIF patient.

WHAT IS KNOWN ALREADY

Since 2002, many gene expression signatures associated with endometrial receptivity and RIF have been described. Endometrial transcriptomics prediction has been applied to the human WOI in two previous studies. One study describes endometrial RIF to be the result of a temporal displacement of the WOI. The other indicates that endometrial RIF can also result from a molecularly disrupted WOI without temporal displacement.

STUDY DESIGN, SIZE, DURATION

Retrospective analysis was undertaken to compare WOI endometrial transcriptomics predictions in controls (n = 72) and RIF patients (n = 43). RIF was clinically designated by the absence of implantation after four or more transfers of high quality embryos or after the placement of 10 or more embryos in multiple transfers. Endometrial tissue samples were collected from LH + 5 to LH + 8. We compared the two molecular causes of RIF to signatures currently described in the literature. We propose a new transcriptomic RIF taxonomy to fill the gap between the two hypotheses and to guide the development of clinical detection and determination of both types of RIF.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Utilizing 115 gene expression profiles, two different predictive designs were developed: one considering RIF versus controls removing menstrual cycle timing, called the disrupted or pathological model, and another stratifying the WOI in transcriptomic profiles related to timing for predicting displacements. The predictive value of each model was compared between all signatures selected. We propose a new genomic approach that distinguishes between both types of RIF in the same sample cohort.

MAIN RESULTS AND THE ROLE OF CHANCE

From the 16 signatures analysed, we clearly predicted two causes of RIF-both a displaced WOI and an on-time but pathologically disrupted WOI. A high predictive value related to WOI profiles associated with menstrual cycle timing was found in most of the signatures. Specifically, 69% of the signatures analysed presented an accuracy higher than expected by chance in a range from 0.87 to 0.97. Displacements and disruptions were not molecularly independent, as some signatures were moderately associated with both causes. The gene and functional comparison between signatures revealed that they were not similar, although we did find functions in common and a cluster of moderate functional concordance between some of the signatures that predicted displacements (the highest Cohen's Kappa index were between 0.55 and 0.62 depending on the functional database). We propose a new transcriptomic RIF taxonomy to fill the gap between these prior studies and to establish methodology for detecting and distinguishing both types of RIF in clinical practice. Our findings indicate these two phenotypes could present independently or together in the same RIF patient. RIF patients designated by clinical criteria have been stratified transcriptomically as 18.6% with only a displaced WOI, 53.5% with a displaced and pathological WOI, 23.3% with only a disrupted WOI, and 4.7% could be a clinical RIF with non-endometrial origin. The new RIF transcriptomic taxonomy avoids menstrual cycle timing as a confounding variable that should be controlled for, distinguishing clearly between a disrupted and a displaced WOI for precision medicine in RIF.

LIMITATIONS REASONS FOR CAUTION

The main objective of this study was to use transcriptomics to detect both RIF causes and to understand the role of transcriptomic signatures in these phenotypes. The predictive value in absolute terms for each signature was not indicative in these prediction designs; instead, the comparison between signatures was most important for prediction capability in the same sample cohort for both RIF causes. Clinical follow up of the RIF taxonomies proposed has not been analysed in this study, so further prospective clinical studies are necessary to determine the prevalence and penetrance of these phenotypes.

WIDER IMPLICATIONS OF THE FINDINGS

The main insight from this study is a new understanding of RIF taxonomy. Understanding how to classify RIF patients to distinguish clinically between a patient who could benefit from a personalized embryo transfer day and a patient with a disrupted WOI will enable identification and stratification for the research and development of new treatments. In addition, we demonstrate that basic research designs in endometrial transcriptomics cause masking of the study variable by the menstrual cycle timing.

STUDY FUNDING/COMPETING INTEREST(S)

This research has been funded by IVI-RMA; the authors do not have any competing interests.

Administration of low-molecular-weight heparin in patients with two or more unsuccessful IVF/ICSI cycles: a multicenter cohort study

To compare the effects of the administration of low-molecular-weight heparin (LMWH) in subfertile patients with two or more unsuccessful IVF/ICSI cycles. In this six-center two-arm retrospective cohort study, the study population (230 women) underwent a GnRH-antagonist protocol and was classified into two groups, according to the couse of LMWH or not. Groups were compared regarding the clinical and IVF/ICSI cycle characteristics and reproductive outcomes, whereas clinical pregnancy and miscarriage constituted the primary endpoints. Logistic regression analysis was performed to determine the potential predictors of clinical pregnancy, miscarriage and live birth rates using the Enter method. Baseline characteristics were comparable in the two groups. There was no statistically significant difference between the two study groups with regard neither to clinical pregnancy and miscarriage rates (33/133 vs. 20/97, p = .456 and 15/133 vs. 9/97, p = .624, respectively), nor to the secondary outcomes preset for this study (all p values >.05). Logistic regression revealed that age of the woman and ICSI and dose of gonadotrophins used were predictors of clinical pregnancy and live birth, respectively. In conclusion, there is no evidence to support the standard addition of LMWH in patients with two or more unsuccessful IVF/ICSI cycles.

Increased Krüppel-like factor 12 impairs embryo attachment via downregulation of leukemia inhibitory factor in women with recurrent implantation failure

Recurrent implantation failure (RIF) caused by various etiological factors remains a challenge for fertility clinicians using assisted reproductive technology (ART) worldwide. Dysregulation of leukemia inhibitory factor (LIF) in the endometria of women with RIF is involved in impaired endometrial receptivity and embryo adhesion. However, the mechanism through which LIF expression is regulated in women with RIF is still poorly understood. Our previous study noted that the abnormally increased endometrial Krüppel-like factor 12 (KLF12) in RIF women led to impaired decidualization and embryo implantation. Here, we further found that KLF12 inhibited embryo adhesion in vivo and in vitro by repressing LIF expression. Mechanistically, KLF12 bound to conserved sites (CAGTGGG, −6771 to −6765 and −7115 to −7109) within the LIF promoter region and repressed LIF transcription directly. Exogenous LIF significantly reversed the KLF12-mediated repression of BeWo spheroid adhesion. KLF12 expression was reduced significantly in Ishikawa cells treated with progestogen, which was due to the activation of Akt signaling. These findings may provide novel potential therapeutic regimens for patients with RIF and disrupted endometrial receptivity.

Scratching and IVF: any role?

PURPOSE OF REVIEW

To review updated information on the influence of endometrial scratching on IVF.

RECENT FINDINGS

Endometrial receptivity remains an important rate-limiting step affecting the success of IVF. The current evidence on the effect of endometrial scratching on IVF ranges from marked improvement, no difference to a potentially negative impact. The heterogeneity of studies presents a challenge in interpretation of data for routine clinical practice.

SUMMARY

Endometrial scratching performed in the preceding cycle is associated with improved clinical pregnancy and live birth rates in women with recurrent implantation failure, but not in unselected subfertile women undergoing IVF. Most of the current literature are underpowered and at high risk of bias.

Association between vascular endothelial growth factor promoter polymorphisms and the risk of recurrent implantation failure

The objective of the present study was to investigate the association between recurrent implantation failure (RIF) and vascular endothelial growth factor (VEGF) gene polymorphisms that are associated with various female infertility disorders. A total of 116 women diagnosed with RIF and 218 control subjects were genotyped for the VEGF -2578C>A, -1154G>A, -634C>G and 936C>T polymorphisms using a polymerase chain reaction-restriction fragment length polymorphism assay. The VEGF -2578AA genotype was associated with an increased prevalence (≥4) of RIF [adjusted odds ratio (AOR)=2.77; 95% confidence interval (CI)=1.10-7.02; P=0.031], whereas the VEGF -634CG+GG genotype was associated with an increased incidence of total RIF (AOR=2.03; 95% CI=1.02-4.05; P=0.044) and ≥4 RIF (AOR=3.16; 95% CI=1.19-8.37; P=0.021). The results of the haplotype analysis indicated that -2578A/-1154A/-634G/936C (AOR=1.76; 95% CI=1.03-3.00; P=0.040 for total RIF and AOR=2.11; 95% CI=1.12-3.97; P=0.021 for ≥4 RIF) was associated with the occurrence of RIF. In addition, it was revealed that there was a significant difference in serum prolactin level associated with the VEGF -634C>G polymorphism (P=0.013). Therefore the findings of the present study indicate that the VEGF -2578AA genotype, -634G allele and -2578A/-1154A/-634G/936C haplotype may be genetic markers for susceptibility to RIF. However, further studies on VEGF promoter polymorphisms that include an independent randomized-controlled population are required to confirm these results.

Increased levels of CCR7(lo)PD-1(hi) CXCR5+ CD4+ T cells, and associated factors Bcl-6, CXCR5, IL-21 and IL-6 contribute to repeated implantation failure

In vitro fertilization-embryo transfer (IVF-ET) can be used by infertile couples to assist with reproduction; however, failure of the embryo to implant into the endometrial lining results in failure of the IVF treatment. The present study investigated the expression of chemokine receptor 7 (CCR7)(lo) programmed death-1(PD-1)(hi) chemokine receptor type 5 (CXCR5)⁺ cluster of differentiation 4 (CD4)⁺ T cells and associated factors in patients with repeated implantation failure (RIF). A total of 30 females with RIF and 30 healthy females were enrolled in the current study. Flow cytometry was used to detect the proportion of CCR7(lo)PD-1(hi) CXCR5⁺ CD4⁺ T cells in the peripheral blood. Cytokine bead arrays were performed to detect the levels of interleukin (IL)-6, −4 and −2 in the serum. ELISAs were used to detect the level of IL-21 in the serum. Quantitative real time polymerase chain reaction analysis and immunohistochemistry were used to investigate the expression of B-cell lymphoma 6 (Bcl-6), chemokine receptor type 5 (CXCR5) and IL-21 in the endometrium. The results revealed that the percentage of CCR7(lo)PD-1(hi) CXCR5⁺ CD4⁺ T cells was increased in the RIF group compared with the control group during the mid luteal phase. The mRNA and protein levels of Bcl-6, IL-21 and CXCR5 in the endometrium and the concentrations of IL-21 and IL-6 in the serum were significantly increased in the RIF group; however, no significant difference was observed between the two groups in regards to the expression of IL-4 and IL-2. Furthermore, a significant positive correlation was identified between the percentage of CCR7(lo)PD-1(hi) CXCR5⁺ CD4⁺ T cells and IL-21 and IL-6 levels. The expression of IL-21 also had a positive correlation with Bcl-6 and CXCR5 expression in the RIF group. These results suggest that increased levels of CCR7(lo)PD-1(hi) CXCR5⁺ CD4⁺ T cells and associated factors contribute to RIF and could therefore be a potential therapeutic target.

Thrombophilia and assisted reproduction technology-any detrimental impact or unnecessary overuse?

PURPOSE

The aim of this study is to provide an overview of the studies investigating a possible association between thrombophilia and assisted reproductive technology (ART) outcome.

METHODS

This is a literature review.

RESULTS

Congenital thrombophilias (CoT) are reported to be associated with pregnancy loss. However, the association between CoT and early pregnancy loss is weak and does not necessarily support causation. CoT are more likely to be associated with late fetal loss. Even though data pooled from case-control and cohort studies suggest an increased risk of ART failure in women with CoTs, there seems no association when the analysis is confined to better quality cohort studies. The evidence supporting anticoagulation to improve ART outcome in CoT carriers is weak. Likewise, studies on antiphospholipid antibodies (APAs) and ART outcome suffer from multiple methodological limitations and a detrimental impact of APA positivity is controversial. Empirical administration of heparin or low molecular weight heparin to women with recurrent ART failures is supported by weak evidence. Importantly, thrombophilias are likely to increase thrombotic complications after ovarian stimulation for ART.

CONCLUSIONS

Current evidence does not support routinely testing for or treatment of thrombophilia in the setting of ART nor in couples with implantation failure. A careful personal and family history should be obtained and a risk assessment for thrombotic complications should be made in every woman undergoing ovarian stimulation. If positive, testing for thrombophilia is warranted.

Integrative Analyses of Uterine Transcriptome and MicroRNAome Reveal Compromised LIF-STAT3 Signaling and Progesterone Response in the Endometrium of Patients with Recurrent/Repeated Implantation Failure (RIF)

Intimate two-way interactions between the implantation-competent blastocyst and receptive uterus are prerequisite for successful embryo implantation. In humans, recurrent/repeated implantation failure (RIF) may occur due to altered uterine receptivity with aberrant gene expression in the endometrium as well as genetic defects in embryos. Several studies have been performed to understand dynamic changes of uterine transcriptome during menstrual cycles in humans. However, uterine transcriptome of the patients with RIF has not been clearly investigated yet. Here we show that several signaling pathways as well as many genes and microRNAs are dysregulated in the endometrium of patients with RIF (RIFE). Whereas unsupervised hierarchical clustering showed that overall mRNA and microRNA profiles of RIFE were similar to those of endometria of healthy women, many genes were significantly dysregulated in RIFE (cut off at 1.5 fold change). The majority (~75%) of differentially expressed genes in RIFE including S100 calcium binding protein P (S100P), Chemokine (C-X-C motif) ligand 13 (CXCL13) and SIX homeobox 1 (SIX1) were down-regulated, suggesting that reduced uterine expression of these genes is associated with RIF. Gene Set Enrichment analyses (GSEA) for mRNA microarrays revealed that various signaling pathways including Leukemia inhibitory factor (LIF) signaling and a P4 response were dysregulated in RIFE although expression levels of Estrogen receptor α (ERα) and Progesterone receptor (PR) were not significantly altered in RIFE. Furthermore, expression and phosphorylation of Signal transducer and activator of transcription 3 (STAT3) are reduced and a gene set associated with Janus kinase (JAK)-STAT signaling pathway is systemically down-regulated in these patients. Pairwise analyses of microRNA arrays with prediction of dysregulated microRNAs based on mRNA expression datasets demonstrated that 6 microRNAs are aberrantly regulated in RIFE. Collectively, we here suggest that dysregulation of several major signaling pathways and genes critical for uterine biology and embryo implantation may lead to uterine abnormalities in patients with RIF.

Association of miR-146aC>G, miR-149C>T, miR-196a2T>C, and miR-499A>G polymorphisms with risk of recurrent implantation failure in Korean women

OBJECTIVE

The aim of this study was to investigate the association of microRNA polymorphisms (miR-146aC>G, miR-149T>C, miR-196a2T>C, and miR-499A>G) in Korean patients with recurrent implantation failure (RIF).

METHODS

We conducted a case-control study of 354 Korean women: 120 patients with RIF and 234 healthy controls with at least one live birth and no history of pregnancy loss.

RESULTS

The combined miR-146aCG+GG/miR-196a2CC genotype was more frequent in patients than in controls (P<0.05), and apparently conferred increased susceptibility. Conversely, genotype-based multifactor dimensionality reduction analysis, revealed that the G-T-T-A (miR-146a/-149/-196a2/-499) and G-T-T inferred genotypes (miR-146a/-149/-196a2) were significantly less frequent in patients, which suggested potential protective effects. The expression of miR-146a for the GG homozygote was significantly lower (P<0.05) than expression of the CC homozygote from both the pre, mature and sequences of miR-146a-3p (P<0.05 each). The expression of miR-196a2 for the CC homozygote was also lower than the TT homozygote from the mature sequence of miR-196a2-3p (P<0.05).

CONCLUSIONS

These results suggest that the polymorphisms in miR-146a and miR-196a2 could alter their target mRNA expression. Our findings suggest that expression levels of miR-146aC>G, miR-196a2T>C and putative gene-gene interaction between miR-146a, miR-196a2, miR-149 may be involved in RIF development in Korean women.