Effect of Timing by Endometrial Receptivity Testing vs Standard Timing of Frozen Embryo Transfer on Live Birth in Patients Undergoing In Vitro Fertilization: A Randomized Clinical Trial

Personalized embryo transfer guided by rsERT with hourly precision improves pregnancy outcomes in patients with a receptive window of implantation: a pilot study

PURPOSE

To investigate whether personalized embryo transfer (pET) predicted by a modified RNA-sequencing-based endometrial receptivity test (rsERT) model can improve intrauterine pregnancy rate (IPR) in patients with a receptive window of implantation (WOI).

DESIGN

A retrospective pilot study was conducted in the Center for Reproductive Medicine, Central South University, from January 2018 to December 2023. A total of 524 patients with receptive WOI results from rsERT were assigned into two groups based on whether they underwent conventional embryo transfer (conventional ET) or pET. Patients in the conventional ET were matched with those in the pET group at a 1:1 ratio using propensity score matching (PSM).

RESULTS

Before PSM, the IPR (55.73% vs. 46.19%, P = 0.032) and implantation rate (IR) (47.51% vs. 34.03%, P = 0.000) in the pET group were significantly higher than that in the conventional ET group. However, the number and types of transferred embryos differed significantly between the two groups. After adjusting for confounding factors, IPR (57.38% vs. 44.81, P = 0.016) and IR (46.81% vs. 33.10%, P = 0.001) remained significantly higher in the pET group compared to the conventional ET group. The implantation failure rate was significantly lower in the pET group compared to controls (42.62% vs. 55.19%, P = 0.016). Additionally, the multiple-pregnancy rate was significantly higher in the pET group compared to the conventional ET group (10.29% vs. 1.68%, P = 0.001).

CONCLUSIONS

Women with receptive WOI results could benefit from the receptivity-timed pET predicted by the newly refined rsERT. These findings provide a basis for future research in precision medicine for embryo transfer.

Effect of intravenous immunoglobulin therapy in recurrent implantation failure: A Systematic review and meta-analysis

BACKGROUND

IVIg is a pooled donor immunoglobulin preparation, used for auto-immune and inflammatory diseases. In assisted reproduction it receives considerable scepticism. Clinical data is expanding, but individual studies may be perceived as weak, meaning an updated appraisal of evidence in implantation failure is needed.

OBJECTIVE

To assess the efficacy of IVIg in Recurrent Implantation Failure (RIF) following assisted reproductive technology.

DESIGN

Systematic review and meta-analysis of randomized controlled trials and observational studies comparing IVIg therapy against placebo in a defined RIF population.

MATERIALS AND METHODS

A comprehensive literature search, identifying studies involving RIF following ART, using pre-conception IVIg. Primary outcomes were clinical pregnancy (CPR), live birth (LBR), implantation (IR), and miscarriage rates (MR). The selection process yielded twelve studies, including 1023 cases and 2276 controls.

RESULTS

A significant increase in CPR (OR=5.14, 95 % CI: 2.33-11.30, p<0.001) and LBR (OR=4.60, 95 % CI:2.44-8.68, p<0.001) is demonstrated in IVIG-treated patients, with an improvement in IR (OR=2.35, 95 % CI: 1.04-5.29, p=0.039) and reduction in MR (OR=0.60, 95 % CI: 0.37-0.97, p=0.036). Substantial heterogeneity was identified across studies, which was addressed through subgroup analyses, assessing if the variability in may be attributed to study-specific factors.

CONCLUSIONS

IVIg may enhance implantation, clinical pregnancy, and live birth rates in RIF patients, underscoring benefit for specific populations. Positive immunological risk factors may predict potential candidates, but it could also be of use in unexplained RIF with high-grade embryos. These findings highlight the importance of personalized therapeutic strategies to improve ART outcomes for complex cases.

Predicting risk of endometrial failure: a biomarker signature that identifies a novel disruption independent of endometrial timing in patients undergoing hormonal replacement cycles

OBJECTIVE

To propose a new gene expression signature that identifies endometrial disruptions independent of endometrial luteal phase timing and predicts if patients are at risk of endometrial failure.

DESIGN

Multicentric, prospective study.

SETTING

Reproductive medicine research department in a public hospital affiliated with private fertility clinics and a reproductive genetics laboratory.

PATIENTS

Caucasian women (n = 281; 39.4 ± 4.8 years old with a body mass index of 22.9 ± 3.5 kg/m2) undergoing hormone replacement therapy between July 2018 and July 2021. Endometrial samples from 217 patients met RNA quality criteria for signature discovery and analysis.

INTERVENTION(S)

Endometrial biopsies collected in the mid-secretory phase.

MAIN OUTCOME MEASURE(S)

Endometrial luteal phase timing-corrected expression of 404 genes and reproductive outcomes of the first single embryo transfer (SET) after biopsy collection to identify prognostic biomarkers of endometrial failure.

RESULTS

Removal of endometrial timing variation from gene expression data allowed patients to be stratified into poor (n = 137) or good (n = 49) endometrial prognosis groups on the basis of their clinical and transcriptomic profiles. Significant differences were found between endometrial prognosis groups in terms of reproductive rates: pregnancy (44.6% vs. 79.6%), live birth (25.6% vs. 77.6%), clinical miscarriage (22.2% vs. 2.6%), and biochemical miscarriage (20.4% vs. 0%). The relative risk of endometrial failure for patients predicted as a poor endometrial prognosis was 3.3 times higher than those with a good prognosis. The differences in gene expression between both profiles were proposed as a biomarker, coined the endometrial failure risk (EFR) signature. Poor prognosis profiles were characterized by 59 upregulated and 63 downregulated genes mainly involved in regulation (17.0%), metabolism (8.4%), immune response, and inflammation (7.8%). This EFR signature had a median accuracy of 0.92 (min = 0.88, max = 0.94), median sensitivity of 0.96 (min = 0.91, max = 0.98), and median specificity of 0.84 (min = 0.77, max = 0.88), positioning itself as a promising biomarker for endometrial evaluation.

CONCLUSION(S)

The EFR signature revealed a novel endometrial disruption, independent of endometrial luteal phase timing, present in 73.7% of patients. This EFR signature stratified patients into 2 significantly distinct and clinically relevant prognosis profiles providing opportunities for personalized therapy. Nevertheless, further validations are needed before implementing this gene signature as an artificial intelligence (AI)-based tool to reduce the risk of patients experiencing endometrial failure.

Precise hourly personalized embryo transfer significantly improves clinical outcomes in patients with repeated implantation failure

Purpose

This study investigated whether RNA-Seq-based endometrial receptivity test (rsERT)-which provides precision for the optimal hour of the window of implantation (WOI)-can improve clinical outcomes of frozen embryo transfer (FET) cycles in patients with a history of repeated implantation failure (RIF).

Methods

Patients with a history of RIF who received at least one autologous high-quality blastocyst during the subsequent FET cycle were retrospectively enrolled and divided into two groups: rsERT and FET, comprising patients who underwent rsERT-guided pET (n=115) and standard FET without rsERT (n=272), respectively.

Results

In the rsERT group, 39.1% (45/115) of patients were receptive. rsERT patients showed a higher probability of achieving both positive human chorionic gonadotropin (63.5% vs. 51.5%, P=0.03) and clinical pregnancy (54.8% vs. 38.6%, P=0.003) rates. In subgroup analysis, rsERT patients with non-receptive results had higher clinical pregnancy rates than patients undergoing FET (58.6% vs. 38.6%, P=0.003). rsERT patients with receptive results guided by rsERT with a precise WOI time had higher, although non-significant, clinical pregnancy rates (48.9% vs. 38.6%, P=0.192) than patients who underwent standard-time FET.

Conclusion

Hourly precise rsERT can significantly improve the probability of achieving clinical pregnancy in patients with RIF, especially in those with non-receptive rsERT results.

High-impact journal publishing: the devil is in the detail!

Research in medicine is an indispensable tool to advance knowledge and improve patient care. This may be particularly true in the field of human reproduction as it is a relatively new field and treatment options are rapidly evolving. This is of particular importance in an emerging field like 'human reproduction', where treatment options evolve fast.The cornerstone of evidence-based knowledge, leading to evidence-based treatment decisions, is randomized controlled trials as they explore the benefits of new treatment approaches. The study design and performance are crucial and, if they are carried out correctly, solid conclusions can be drawn and be implemented in daily clinical routines. The dissemination of new findings throughout the scientific community occurs in the form of publications in scientific journals, and the importance of the journal is reflected in part by the impact factor. The peer review process before publication is fundamental in preventing flaws in the study design. Thus, readers of journals with a high impact factor usually rely on a thorough peer review process and therefore might not question the published data. However, even papers published in high-impact journals might not be free of flaws, so the aim of this paper is to encourage readers to be aware of this fact and critically read scientific papers as 'the devil lies in the details'.

Avoiding weekend frozen embryo transfer in modified natural cycles: is it possible?

In this era of the freeze-all strategy, the prevalence of frozen embryo transfer (FET) cycles is increasing rapidly. Although still quite often used, the hormone replacement therapy cycle to prepare a FET should now belong to the past, unless strictly necessary. This raises questions about possible flexible protocols for the preparation of an FET cycle in a (modified) natural cycle. In this viewpoint, an overview of the different options is discussed, stressing the importance of the corpus luteum.

Current Status of Ovarian and Endometrial Biomarkers in Predicting ART Outcomes

This review evaluates the role of ovarian and endometrial biomarkers in predicting outcomes in assisted reproductive technology (ART). It highlights established ovarian biomarkers such as the anti-Müllerian hormone (AMH) and follicle-stimulating hormone (FSH), alongside emerging ones like growth differentiation factor 9 (GDF9), bone morphogenetic protein 15 (BMP15), connexin, and granulosa cell gene profiles. Additionally, the paper explores endometrial biomarkers such as ERA, BCL6, and immune markers, as well as the potential for genomic and proteomic technologies in customizing implantation. It concludes that while many of these biomarkers show promise, their clinical integration requires rigorous research and validation to confirm their safety and utility in ART.

Inflammatory Changes after Medical Suppression of Suspected Endometriosis for Implantation Failure: Preliminary Results

Unexplained euploid embryo transfer failure (UEETF) is a frustrating and unanswered conundrum accounting for 30 to 50% of failures in in vitro fertilization using preimplantation genetic testing for aneuploidy (PGT-A). Endometriosis is thought by many to account for most of such losses and menstrual suppression or surgery prior to the next transfer has been reported to be beneficial. In this study, we performed endometrial biopsy in a subset of women with UEETF, testing for the oncogene BCL6 and the histone deacetylase SIRT1. We compared 205 PGT-A cycles outcomes and provide those results following treatment with GnRH agonist versus controls (no treatment). Based on these and previous promising results, we next performed a pilot randomized controlled trial comparing the orally active GnRH antagonist, elagolix, to oral contraceptive pill (OCP) suppression for 2 months before the next euploid embryo transfer, and monitored inflammation and miRNA expression in blood, before and after treatment. These studies support a role for endometriosis in UEETF and suggest that medical suppression of suspected disease with GnRH antagonist prior to the next transfer could improve success rates and address underlying inflammatory and epigenetic changes associated with UEETF.

A Novel Method to Repair Thin Endometrium and Restore Fertility Based on Menstruation-Derived Stem Cell

Thin endometrium (TE), which mainly occurs as a result of severe damage to the endometrial basalis, is one of the prominent etiologies of menstrual abnormalities, infertility, and recurrent miscarriage in women. Previous studies have demonstrated that mesenchymal stem cells (MSCs) are considered ideal cells with multipotency for regenerative medicine and exhibit therapeutic effects on TE through their cellular secretions. However, there is limited research on strategies to enhance MSC secretion to improve their therapeutic efficacy. Herein, we isolated menstrual blood-derived mesenchymal stem cells (MenSCs) from menstruation and transformed them into decidualized stromal cells (DSCs), which are specialized cells with enhanced secretory functions. To assess the therapeutic potential of DSCs compared to MenSCs, we conducted a series of experiments in cells and animals. The results demonstrated that DSCs exhibited changes in morphology compared to MenSCs, with a decrease in cell proliferation but a significant improvement in secretion function. Furthermore, DSCs facilitated the restoration of endometrial thickness and increased the number of glands and blood vessel formation. Most importantly, the pregnancy rates in rats were effectively restored, bringing them closer to normal levels. These findings greatly contribute to our understanding of stem cell therapy for TE and strongly suggest that DSCs could hold significant promise as a potential treatment option for TE.

A Comprehensive Review of the Endometrial Receptivity Array in Euploid Embryo Transfer Cycles

The Endometrial Receptivity Array (ERA) is a revolutionary molecular diagnostic tool that determines the optimal timing for embryo transfer by analyzing the gene expression profile of endometrial tissue. This comprehensive review examines the significance and application of ERA in euploid embryo transfer cycles, where the implantation of embryos with the correct number of chromosomes is critical for achieving successful pregnancy outcomes. This review underscores its role in enhancing implantation rates and reducing pregnancy loss by assessing the evolution, methodology, clinical applications, efficacy, and challenges associated with ERA. Key findings highlight ERA's superior accuracy in identifying the window of implantation compared to traditional methods, resulting in improved clinical outcomes in assisted reproductive technology (ART) cycles. Despite its benefits, the review acknowledges challenges such as cost, accessibility, and the need for standardization. Recommendations for clinical practice emphasize the integration of ERA into routine ART protocols, comprehensive patient counseling, and the importance of multidisciplinary collaboration. The review outlines promising prospects, including technological advancements to make ERA more cost-effective, the development of refined gene expression profiles, and the potential integration with other emerging ART technologies. Further research directions include long-term studies on the outcomes of ERA-guided pregnancies and exploring its application in cases of recurrent implantation failure and unexplained infertility. Overall, ERA represents a significant advancement in reproductive medicine, offering a personalized approach to embryo transfer timing that can significantly improve the success rates of euploid embryo transfers.

Clinical Management of Infertility Associated with Endometriosis

OBJECTIVE

This study aimed to review recent data that affected the clinical management of infertility associated with endometriosis.

DATA SOURCES

We completed a PubMed review of all articles that included the following keywords: endometriosis, infertility, IVF, and ART.

STUDY SELECTION

A study was selected based on the pertinence of the topic addressed in relation to the study's set objectives.

DATA EXTRACTION AND SYNTHESIS

All identified articles were first assessed based on a review of the abstract. Pertinent articles were reviewed in depth.

CONCLUSION

Endometriosis interferes with natural conception primarily by altering the quality of gametes-oocytes and sperm-and early-stage embryos. On the contrary, recent data indicate that gametes and early-stage embryos are not altered in the case of ART. Surgery-a classical approach in yesteryears-does appear to improve ART outcomes and may affect ovarian reserve and the number of oocytes retrieved in ART. Surgery is thus more rarely opted for today and only when necessary; proceeding to fertility preservation prior to surgery is recommended. When ART is performed in women with endometriosis, it is recommended to use an antagonist or progesterone-primed ovarian stimulation approach followed by deferred embryo transfer. In this case, GnRH (gonadotropin releasing hormone) agonist is preferred for triggering ovulation, as it limits the risk of cyst formation as well as ovarian hyperstimulation syndrome. Frozen embryo transfers are best performed in E2 (estradiol) and progesterone replacement cycle.

Efficacy of endometrial receptivity testing for recurrent implantation failure in patients with euploid embryo transfers: study protocol for a randomized controlled trial

BACKGROUND

Embryo implantation remains a critical barrier in assisted reproductive technologies. One of the main causes of unsuccessful embryo implantation is window of implantation (WOI) displacement, particularly in patients with recurrent implantation failure (RIF). Therefore, a reliable diagnostic tool for identifying the optimal WOI is essential. Previous data has suggested that a novel RNA-Seq-based endometrial receptivity testing (ERT) can diagnose WOI, guide personalized embryo transfer (pET), and improve pregnancy outcomes in patients with RIF compared to standard embryo transfer (sET). However, there is still a lack of evidence from randomized controlled trials (RCT) with sufficient power to determine whether pET based on ERT can increase the rate of live births as the primary outcome.

METHODS

This trial is a prospective, single-blind, parallel-group RCT (1:1 ratio of pET versus sET). Infertile women with RIF who intend to undergo frozen-thawed embryo transfer (FET) after preimplantation genetic testing for aneuploidy (PGT-A) with the availability of at least one euploid blastocyst for transfer will be enrolled and assigned into two parallel groups randomly. Participants in the intervention group will undergo ERT and then pET based on the results of ERT, while those in the control group will undergo sET. The primary outcome is live birth rate.

DISCUSSION

The findings of this study will provide evidence for the effect of pET guided by ERT on pregnancy outcomes in patients with RIF.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2100049041. Registered on 20 July 2021.

Does recurrent implantation failure exist? Prevalence and outcomes of five consecutive euploid blastocyst transfers in 123 987 patients

STUDY QUESTION

What are the clinical pregnancy and live birth rates in women who underwent up to two more euploid blastocyst transfers after three failures in the absence of another known factor that affects implantation?

SUMMARY ANSWER

The fourth and fifth euploid blastocyst transfers resulted in similar live birth rates of 40% and 53.3%, respectively, culminating in a cumulative live birth rate of 98.1% (95% CI = 96.5-99.6%) after five euploid blastocyst transfers.

WHAT IS KNOWN ALREADY

The first three euploid blastocysts have similar implantation and live birth rates and provide a cumulative live birth rate of 92.6%.

STUDY DESIGN, SIZE, DURATION

An international multi-center retrospective study was conducted at 25 individual clinics. The study period spanned between January 2012 and December 2022. A total of 123 987 patients with a total of 64 572 euploid blastocyst transfers were screened for inclusion.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Patients with a history of any embryo transfer at another clinic, history of any unscreened embryo transfer at participating clinics, parental karyotype abnormalities, the use of donor oocytes or a gestational carrier, untreated intracavitary uterine pathology (e.g. polyp, leiomyoma), congenital uterine anomalies, adenomyosis, communicating hydrosalpinx, endometrial thickness <6 mm prior to initiating of progesterone, use of testicular sperm due to non-obstructive azoospermia in the male partner, transfer of an embryo with a reported intermediate chromosome copy number (i.e. mosaic), preimplantation genetic testing cycles for monogenic disorders, or structural chromosome rearrangements were excluded. Ovarian stimulation protocols and embryology laboratory procedures including trophectoderm biopsy followed the usual practice of each center. The ploidy status of blastocysts was determined with comprehensive chromosome screening. Endometrial preparation protocols followed the usual practice of participating centers and included programmed cycles, natural or modified natural cycles.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 105 (0.085% of the total population) patients met the criteria and underwent at least one additional euploid blastocyst transfer after failing to achieve a positive pregnancy test with three consecutive euploid blastocyst transfers. Outcomes of the fourth and fifth euploid blastocyst transfers were similar across participating centers. Overall, the live birth rate was similar with the fourth and fifth euploid blastocysts (40% vs 53.3%, relative risk = 1.33, 95% CI = 0.93-1.9, P value = 0.14). Sensitivity analyses excluding blastocysts biopsied on Day 7 postfertilization, women with a BMI >30 kg/m2, cycles using non-ejaculate or donor sperm, double-embryo transfer cycles, and cycles in which the day of embryo transfer was modified due to endometrial receptivity assay test result yielded similar results. Where data were available, the fourth euploid blastocyst had similar live birth rate with the first one (relative risk = 0.84, 95% CI = 0.58-1.21, P = 0.29). The cumulative live birth rate after five euploid blastocyst transfers was 98.1% (95% CI = 96.5-99.6%).

LIMITATIONS, REASONS FOR CAUTION

Retrospective design has its own inherent limitations. Patients continuing with a further euploid embryo transfer and patients dropping out from treatment after three failed euploid transfers can be systematically different, perhaps with regard to ovarian reserve or economic status.

WIDER IMPLICATION OF THE FINDINGS

Implantation failure seems to be mainly due to embryonic factors. Given the stable and high live birth rates up to five euploid blastocysts, unexplained recurrent implantation failure should have a prevalence of <2%. Proceeding with another embryo transfer can be the best next step once a known etiology for implantation failure is ruled out.

STUDY FUNDING/COMPETING INTEREST(S)

None.

TRIAL REGISTRATION NUMBER

N/A.

Immediate Effect of Electro-acupuncture on Endometrial Blood Flow in Patients with Recurrent Implantation Failure: A Randomized Controlled Trial

OBJECTIVE

To investigate the immediate effects of electro-acupuncture (EA) on endometrial blood flow among recurrent implantation failure (RIF) patients.

METHODS

Eighty RIF patients, enrolled from March 2022 to December 2022, were randomly allocated into either the EA group (40 cases) or the waiting-list (WL) group (40 cases) by using a random number table. The EA group underwent acupuncture at points of Shenting (GV 24), Baihui (GV 4), Benshen (GB 13), bilateral Zigong (EX-CA 1), Huangshu (KI 16), Sanyinjiao (SP 6) and Xuehai (SP10), and electric acupuncture apparatus was connected to EX-CA 1, KI 16, SP 6, and SP 10 with disperse-dense waves at 4/20 Hz frequencies for 30 min after transvaginal ultrasound, while the WL group received no intervention. The primary outcome measured was the endometrial volume blood flow. The secondary outcomes included the bilateral uterine artery index, endometrial volume, endometrial blood flow type, vascular distribution index (VIMV) for endometrial and ovary, clinical pregnancy rate, and embryo implantation rate.

RESULTS

In the EA group, there was a notable decrease in the bilateral pulsatility index and a significant improvement in the endometrial blood flow type post-EA (P<0.05). Both the endometrial blood flow type and VIMV for the endometrium and right ovary were markedly higher in the EA group compared to the WL group post-treatment (P<0.05). Conversely, no significant disparities were observed in vascular index, flow index, vascular blood flow index, uterine arterial blood flow indices, endometrial volume, clinical pregnancy rate and embryo implantation rate between the two groups after treatment (P>0.05). Besides, no adverse events related to EA were observed.

CONCLUSIONS

EA can promptly ameliorate VIMV for the endometrial and right ovary, and endometrial blood flow type. Future randomized controlled trials are warranted to investigate the long-term effects of EA on blood flow of RIF patients and its implications for pregnancy outcomes. (Trial registration No. ChiCTR2200057377).

Cellular heterogeneity and dynamics of the human uterus in healthy premenopausal women

The human uterus is a complex and dynamic organ whose lining grows, remodels, and regenerates in every menstrual cycle or upon tissue damage. Here we applied single-cell RNA sequencing to profile more the 50,000 uterine cells from both the endometrium and myometrium of 5 healthy premenopausal individuals, and jointly analyzed the data with a previously published dataset from 15 subjects. The resulting normal uterus cell atlas contains more than 167K cells representing the lymphatic endothelium, blood endothelium, stromal, ciliated epithelium, unciliated epithelium, and immune cell populations. Focused analyses within each major cell type and comparisons with subtype labels from prior studies allowed us to document supporting evidence, resolve naming conflicts, and to propose a consensus annotation system of 39 subtypes. We release their gene expression centroids, differentially expressed genes, and mRNA patterns of literature-based markers as a shared community resource. We find many subtypes show dynamic changes over different phases of the cycle and identify multiple potential progenitor cells: compartment-wide progenitors for each major cell type, transitional cells that are upstream of other subtypes, and potential cross-lineage multipotent stromal progenitors that may be capable of replenishing the epithelial, stromal, and endothelial compartments. When compared to the healthy premenopausal samples, a postpartum and a postmenopausal uterus sample revealed substantially altered tissue composition, involving the rise or fall of stromal, endothelial, and immune cells. The cell taxonomy and molecular markers we report here are expected to inform studies of both basic biology of uterine function and its disorders.

SIGNIFICANCE

We present single-cell RNA sequencing data from seven individuals (five healthy pre-menopausal women, one post-menopausal woman, and one postpartum) and perform an integrated analysis of this data alongside 15 previously published scRNA-seq datasets. We identified 39 distinct cell subtypes across four major cell types in the uterus. By using RNA velocity analysis and centroid-centroid comparisons we identify multiple computationally predicted progenitor populations for each of the major cell compartments, as well as potential cross-compartment, multi-potent progenitors. While the function and interactions of these cell populations remain to be validated through future experiments, the markers and their "dual characteristics" that we describe will serve as a rich resource to the scientific community. Importantly, we address a significant challenge in the field: reconciling multiple uterine cell taxonomies being proposed. To achieve this, we focused on integrating historical and contemporary knowledge across multiple studies. By providing detailed evidence used for cell classification we lay the groundwork for establishing a stable, consensus cell atlas of the human uterus.

Endometrial Receptivity Array (ERA) Test in a 32-Year-Old Female With Refractory Infertility: A Case Report

We report a successful case for the clinical efficacy of the endometrial receptivity array (ERA) test for a 32-year-old female patient with refractory infertility. After our careful treatment, the patient gave birth to a male baby (3390 g) in November 2021. To our knowledge, though the clinical efficacy of the ERA test is controversial until March 2024, we think that the age of the patients, the number of IVF cycles, and the racial differences may have an impact on the clinical efficacy of the ERA test.

Luteal phase support in assisted reproductive technology

Infertility affects one in six couples, with in vitro fertilization (IVF) offering many the chance of conception. Compared to the solitary oocyte produced during the natural menstrual cycle, the supraphysiological ovarian stimulation needed to produce multiple oocytes during IVF results in a dysfunctional luteal phase that can be insufficient to support implantation and maintain pregnancy. Consequently, hormonal supplementation with luteal phase support, principally exogenous progesterone, is used to optimize pregnancy rates; however, luteal phase support remains largely 'black-box' with insufficient clarity regarding the optimal timing, dosing, route and duration of treatment. Herein, we review the evidence on luteal phase support and highlight remaining uncertainties and future research directions. Specifically, we outline the physiological luteal phase, which is regulated by progesterone from the corpus luteum, and evaluate how it is altered by the supraphysiological ovarian stimulation used during IVF. Additionally, we describe the effects of the hormonal triggers used to mature oocytes on the degree of luteal phase support required. We explain the histological transformation of the endometrium during the luteal phase and evaluate markers of endometrial receptivity that attempt to identify the 'window of implantation'. We also cover progesterone receptor signalling, circulating progesterone levels associated with implantation, and the pharmacokinetics of available progesterone formulations to inform the design of luteal phase support regimens.

When the Embryo Meets the Endometrium: Identifying the Features Required for Successful Embryo Implantation

Evaluation of the optimal number of embryos, their quality, and the precise timing for transfer are critical determinants in reproductive success, although still remaining one of the main challenges in assisted reproduction technologies (ART). Indeed, the success of in vitro fertilization (IVF) treatments relies on a multitude of events and factors involving both the endometrium and the embryo. Despite concerted efforts on both fronts, the overall success rates of IVF techniques continue to range between 25% and 30%. The role of the endometrium in implantation has been recently recognized, leading to the hypothesis that both the "soil" and the "seed" play a central role in a successful pregnancy. In this respect, identification of the molecular signature of endometrial receptivity together with the selection of the best embryo for transfer become crucial in ART. Currently, efforts have been made to develop accurate, predictive, and personalized tests to identify the window of implantation and the best quality embryo. However, the value of these tests is still debated, as conflicting results are reported in the literature. The purpose of this review is to summarize and critically report the available criteria to optimize the success of embryo transfer and to better understand current limitations and potential areas for improvement.

Factors affecting the ongoing pregnancy rate in women with repeated implantation failure undergoing an endometrial receptivity array

OBJECTIVE

In this retrospective study, we analyzed factors influencing the ongoing pregnancy rate (PR) in women with repeated implantation failure (RIF) undergoing embryo transfer with endometrial receptivity array (ERA).

METHODS

Eighty-three consecutive personalized embryo transfers (pETs) with ERA, from 54 women with RIF, were selected from June 2020 to April 2022. Vitrified blastocyst transfer was timed based on ERA results.

RESULTS

The ongoing PR per pET was 33.7%. Using ERA, the endometrium was identified as pre-receptive in 26 cycles, early receptive in 25 cycles, receptive in 31 cycles, and late receptive in one cycle. With cycles categorized into three receptivity phases (pre-receptive, early receptive, or receptive), no significant differences were found in the clinical PR (27.3%, 55.6%, and 40%, respectively) or ongoing PR (9.1%, 55.6%, and 40%, respectively) after a single blastocyst transfer. Similarly, no significant differences were observed in the clinical PR or ongoing PR after the transfer of two or more blastocysts. Among women with ongoing pregnancy relative to those without, age at first pET was significantly lower (35 years vs. 39 years, p=0.001), while blastocyst score (23 vs. 18, p=0.012) and the proportion of blastocyst scores >18 (71.4% vs. 38.9%, p=0.005) were significantly higher. In multiple logistic regression analysis, the woman's age (odds ratio [OR], 0.814; 95% confidence interval [CI], 0.706 to 0.940; p=0.005) and blastocyst score >18 (OR, 3.052; 95% CI, 1.075 to 8.665; p=0.036) were identified as significant factors influencing ongoing pregnancy.

CONCLUSION

In pET with ERA, ongoing pregnancy was closely associated with woman's age and blastocyst quality.

Progress on the Endometrium

The endometrium is a dynamic tissue that facilitates mammalian internal reproduction and thus, the ability to deliver live born progeny that are more easily protected from predators. This tissue is unique in its ability to undergo cyclic regeneration and destruction in the absence of pregnancy. Ovarian steroids guide endometrial proliferation and maturation promoting its receptivity and selectivity with regards to blastocyst implantation. It is decidualization, terminal stromal maturation, that prevents the trophoblast from breeching containment of the uterus and allows for endometrial sloughing should pregnancy not occur. Endometrial pathology is highly variable and therefore a wide array of diagnostic measures are required for its interrogation. There remains no single test that can distinguish between all potential issues and it is critical that appropriate and evidence-based endometrial assessment is carried out. Emerging data on developmental markers, inflammatory mediators, and bacterial profiling offer hope that conditions including endometriosis, cancer, infertility, and implantation failure will be more easily and less invasively diagnosed. This will allow for a more timely and targeted approach to intervention. Accordingly, assessing novel measures requires an evidence-based approach prior to their mass utilization.

Good practice recommendations on add-ons in reproductive medicine†

STUDY QUESTION

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

SUMMARY ANSWER

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

WHAT IS KNOWN ALREADY

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

STUDY DESIGN, SIZE, DURATION

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

PARTICIPANTS/MATERIALS, SETTING, METHODS

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

MAIN RESULTS AND THE ROLE OF CHANCE

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

LIMITATIONS, REASONS FOR CAUTION

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

WIDER IMPLICATIONS OF THE FINDINGS

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

STUDY FUNDING/COMPETING INTEREST(S)

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

DISCLAIMER

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

Does endometrial receptivity array improve reproductive outcomes in euploid embryo transfer cycles? a systematic review

Besides chromosomal normality, endometrial receptivity is an important factor in determining successful pregnancies. Endometrial receptivity array (ERA), a promising endometrial receptivity test, was speculated to improve the reproductive outcomes. However, its effectiveness is controversial in clinical practice. Therefore, we conducted this review to investigate its role in in vitro fertilization (IVF) treatment. To eliminate the interference of embryo quality, we only analyzed studies that originally reported the reproductive outcomes of patients who underwent ERA-guided euploid embryo transfer (EET). Unexpectedly, it revealed that ERA could not optimize the reproductive outcomes in EET cycles, no matter in general infertile population or in patients with a history of previous failed embryo transfers.

Finding of the optimal preparation and timing of endometrium in frozen-thawed embryo transfer: a literature review of clinical evidence

Frozen-thawed embryo transfer (FET) has been a viable alternative to fresh embryo transfer in recent years because of the improvement in vitrification methods. Laboratory-based studies indicate that complex molecular and morphological changes in endometrium during the window of implantation after exogenous hormones with controlled ovarian stimulation may alter the interaction between the embryo and endometrium, leading to a decreased implantation potential. Based on the results obtained from randomized controlled studies, increased pregnancy rates and better perinatal outcomes have been reported following FET. Compared to fresh embryo transfer, fewer preterm deliveries, and reduced incidence of ovarian hyperstimulation syndrome were found after FETs, yet there is a trend of increased pregnancy-related hypertensive diseases in women receiving FET. Despite the increased application of FET, the search for the most optimal priming protocol for the endometrium is still undergoing. Three available FET protocols have been proposed to prepare the endometrium: i) natural cycle (true natural cycle and modified natural cycle) ii) artificial cycle (AC) or hormone replacement treatment cycle iii) mild ovarian stimulation (mild-OS) cycle. Emerging evidence suggests that the optimal timing for FET using warmed blastocyst transfer is the LH surge+6 day, hCG administration+7 day, and the progesterone administration+6 day in the true natural cycle, modified natural cycle, and AC protocol, respectively. Although still controversial, better clinical pregnancy rates and live birth rates have been reported using the natural cycle (true natural cycle/modified natural cycle) compared with the AC protocol. Additionally, a higher early pregnancy loss rate and an increased incidence of gestational hypertension have been found in FETs using the AC protocol because of the lack of a corpus luteum. Although the common clinical practice is to employ luteal phase support (LPS) in natural cycles and mild-OS cycles for FET, the requirement for LPS in these protocols remains equivocal. Recent findings obtained from RCTs do not support the routine application of endometrial receptivity testing to optimize the timing of FET. More RCTs with rigorous methodology are needed to compare different protocols to prime the endometrium for FET, focusing not only on live birth rate, but also on maternal, obstetrical, and neonatal outcomes.

Targeted gene expression profiling for accurate endometrial receptivity testing

Expressional profiling of the endometrium enables the personalised timing of the window of implantation (WOI). This study presents and evaluates a novel analytical pipeline based on a TAC-seq (Targeted Allele Counting by sequencing) method for endometrial dating. The expressional profiles were clustered, and differential expression analysis was performed on the model development group, using 63 endometrial biopsies spanning over proliferative (PE, n = 18), early-secretory (ESE, n = 18), mid-secretory (MSE, n = 17) and late-secretory (LSE, n = 10) endometrial phases of the natural cycle. A quantitative predictor model was trained on the development group and validated on sequenced samples from healthy women, consisting of 52 paired samples taken from ESE and MSE phases and five LSE phase samples from 31 individuals. Finally, the developed test was applied to 44 MSE phase samples from a study group of patients diagnosed with recurrent implantation failure (RIF). In validation samples (n = 57), we detected displaced WOI in 1.8% of the samples from fertile women. In the RIF study group, we detected a significantly higher proportion of the samples with shifted WOI than in the validation set of samples from fertile women, 15.9% and 1.8% (p = 0.012), respectively. The developed model was evaluated with an average cross-validation accuracy of 98.8% and an accuracy of 98.2% in the validation group. The developed beREADY screening model enables sensitive and dynamic detection of selected transcriptome biomarkers, providing a quantitative and accurate prediction of endometrial receptivity status.

Endometrial receptivity tests in reproduction: a SWOT analysis

Endometrial receptivity and its management in assisted reproduction is now a significant focus of research interest. Endometrial receptivity tests, which analyze different panels of gene expression, are usually offered in fertility clinics to determine the women's individual 'window of implantation', providing a personalized timing for embryo transfer. However, there are still no definite indications on whether its inclusion in the study of the infertile couple or the study of patients with repeated implantation failure is essential.

Investigation for Anxiety and Depression Situation in Couples Receiving in vitro Fertilization and Embryo Transfer (IVF-ET) with Donor Sperm and Associated Influencing Factors

Background

This study aimed to explore the current situation of anxiety and depression on day of transfer in couples receiving in vitro fertilization and embryo transfer (IVF-ET) with donor sperm and analyze its influencing factors.

Methods

This study selected 187 IVF-ET administered couples who received donor sperm from our Hospital from August 2021 to July 2022. On the day of IVF-ET with donor sperm transplantation, patients were investigated with general data questionnaire, self-rating anxiety scale (SAS) and self-rating depression scale (SDS) to analyze their anxiety and depression scores and their influencing factors.

Results

Scores of anxiety and depression on the day of transplantation in patients receiving IVF-ET with donor sperm were 43.98±6.80 and 46.03±10.61 respectively, which were higher compared to levels of Chinese health norm (P<0.05). The anxiety score of patients' spouses was 41.23±6.69 and depression score was 44.23±11.65, which were higher compared to levels of Chinese health norm (P<0.05). Score of anxiety and depression of women was significantly higher compared to those of their spouse (P<0.05). Anxiety and depression scores of women in non-pregnant group were significantly higher compared to those in pregnant group (P<0.05). Regression analysis showed that education level and annual family income were influencing factors of anxiety and depression scores of IVF-ET with donor sperm couples on the day of transfer, and number of eggs taken and transfer times were influencing factors of depression scores of IVF-ET with donor sperm patients on the day of transfer.

Conclusion

Psychological state of couples receiving IVF-ET with donor sperm was significantly affected, especially in female side. Medical staff should focus on patients with low education level, low family income, and more times of transfer and egg retrieval, and take targeted intervention measures to keep them in good psychological state, which is conducive to improving pregnancy outcome.

One center experience with a personalized frozen-thawed embryo transfer in patients with recurrent implantation failure

PURPOSE

Displaced endometrial receptivity has been discussed as a possible cause of recurrent implantation failure in patients undergoing assisted reproductive technology. The aim of this study was to document our experience with the endometrial receptivity analysis in patients with recurrent implantation failure.

METHODS

This retrospective cohort study, conducted at the Fertility Centre of the University Hospital, Duesseldorf Germany, presents the results of the endometrial receptivity analysis in 67 patients with recurrent implantation failure and compares the clinical outcome between these 67 patients who underwent a personalized frozen-thawed embryo transfer guided by the results of the endometrial receptivity analysis and 32 patients with recurrent implantation failure who performed a standardized frozen-thawed embryo transfer.

RESULTS

The data analysis revealed a displaced endometrial receptivity in 73% (49/67) of all tested patients. Out of these patients, 24% (12/49) were early receptive, 74% (36/49) were pre-receptive, and 2% (1/49) were post-receptive. Comparison of pregnancy rate, clinical pregnancy rate, and live-birth rate between personalized (49%, 39%, 27%, respectively) and standardized embryo transfer (44%, 31%, 19%, respectively) reveals no statistically significant difference. In both groups, patients had an average of four unsuccessful embryo transfers.

CONCLUSION

In this cohort of patients with recurrent implantation failure, the endometrial receptivity analysis showed a high incidence of displaced endometrial receptivity. However, a personalized embryo transfer did not increase reproductive outcome. Displaced endometrial receptivity might not be the main cause for recurrent implantation failure in this cohort.

Prednisone vs Placebo and Live Birth in Patients With Recurrent Implantation Failure Undergoing In Vitro Fertilization: A Randomized Clinical Trial

Importance

Implantation failure remains a critical barrier to in vitro fertilization. Prednisone, as an immune-regulatory agent, is widely used to improve the probability of implantation and pregnancy, although the evidence for efficacy is inadequate.

Objective

To determine the efficacy of 10 mg of prednisone compared with placebo on live birth among women with recurrent implantation failure.

Design, Setting, and Participants

A double-blind, placebo-controlled, randomized clinical trial conducted at 8 fertility centers in China. Eligible women who had a history of 2 or more unsuccessful embryo transfer cycles, were younger than 38 years when oocytes were retrieved, and were planning to undergo frozen-thawed embryo transfer with the availability of good-quality embryos were enrolled from November 2018 to August 2020 (final follow-up August 2021).

Interventions

Participants were randomized (1:1) to receive oral pills containing either 10 mg of prednisone (n = 357) or matching placebo (n = 358) once daily, from the day at which they started endometrial preparation for frozen-thawed embryo transfer through early pregnancy.

Main Outcomes and Measures

The primary outcome was live birth, defined as the delivery of any number of neonates born at 28 or more weeks' gestation with signs of life.

Results

Among 715 women randomized (mean age, 32 years), 714 (99.9%) had data available on live birth outcomes and were included in the primary analysis. Live birth occurred among 37.8% of women (135 of 357) in the prednisone group vs 38.8% of women (139 of 358) in the placebo group (absolute difference, -1.0% [95% CI, -8.1% to 6.1%]; relative ratio [RR], 0.97 [95% CI, 0.81 to 1.17]; P = .78). The rates of biochemical pregnancy loss were 17.3% in the prednisone group and 9.9% in the placebo group (absolute difference, 7.5% [95% CI, 0.6% to 14.3%]; RR, 1.75 [95% CI, 1.03 to 2.99]; P = .04). Of those in the prednisone group, preterm delivery occurred among 11.8% and of those in the placebo group, 5.5% of pregnancies (absolute difference, 6.3% [95% CI, 0.2% to 12.4%]; RR, 2.14 [95% CI, 1.00 to 4.58]; P = .04). There were no statistically significant between-group differences in the rates of biochemical pregnancy, clinical pregnancy, implantation, neonatal complications, congenital anomalies, other adverse events, or mean birthweights.

Conclusions and Relevance

Among patients with recurrent implantation failure, treatment with prednisone did not improve live birth rate compared with placebo. Data suggested that the use of prednisone may increase the risk of preterm delivery and biochemical pregnancy loss. Our results challenge the value of prednisone use in clinical practice for the treatment of recurrent implantation failure.

Trial Registration

Chinese Clinical Trial Registry Identifier: ChiCTR1800018783.

Endometrial receptivity in adenomyosis and/or endometriosis

A narrative review of endometrial receptivity in adenomyosis and/or endometriosis revealed that this parameter is difficult to assess in natural conception because both disorders alter natural fertility. Recent data emanating from assisted reproductive technology have allowed the study of endometrial receptivity in women affected by adenomyosis and endometriosis. This has upended our views on the effects of these 2 disorders on embryo implantation. Today, the very existence of altered receptivity in assisted reproductive technology is questioned. In this context, we now know that frozen euploid blastocyst transfers in estradiol and progesterone cycles have unaltered outcomes in both adenomyosis and endometriosis.

Personalized embryo transfer reduces success rates because endometrial receptivity analysis fails to accurately identify the window of implantation

After more than a decade of increasingly widespread clinical use, personalized embryo transfer guided by endometrial receptivity analysis (ERA) remains controversial and unproven. One key element missing from the historical literature is the recognition that potential benefits from personalized embryo transfer are entirely dependent on the accuracy and predictive value of the ERA test. Results from the first comprehensive clinical trial, designed in a way that allowed independent evaluation of both potential benefits of personalized embryo transfer and the predictive value of the ERA test upon which it is based, were recently published. However, the authors failed to conduct an appropriate analysis or recognize the significance of their results. Here, we present a simple reanalysis of data from this otherwise excellent randomized controlled trial, demonstrating for the first time that the ERA was unable to identify the window of implantation as purported and that, as a result, personalized embryo transfer based on the ERA actually reduced rather than increased the birth rates. Based on these results and the lack of any contradictory evidence, it is our opinion that all clinical use of ERA-guided personalized embryo transfer should be discontinued immediately, outside of a controlled experimental setting with appropriate informed consent of all participating patients.

Deep learning analysis of endometrial histology as a promising tool to predict the chance of pregnancy after frozen embryo transfers

PURPOSE

Endometrial histology on hematoxylin and eosin (H&E)-stained preparations provides information associated with receptivity. However, traditional histological examination by Noyes' dating method is of limited value as it is prone to subjectivity and is not well correlated with fertility status or pregnancy outcome. This study aims to mitigate the weaknesses of Noyes' dating by analyzing endometrial histology through deep learning (DL) algorithm to predict the chance of pregnancy.

METHODS

Endometrial biopsies were taken during the window of receptivity from healthy volunteers in natural menstrual cycles (group A) and infertile patients undergoing mock artificial cycles (group B). H&E staining was performed followed by whole slide image scanning for DL analysis.

RESULTS

In a proof-of-concept trial to differentiate group A (n=24) vs. B (n=37), a DL-based binary classifier was trained, cross-validated, and achieved 100% for accuracy. Patients in group B underwent subsequent frozen-thawed embryo transfers (FETs) and were further categorized into "pregnant (n=15)" or "non-pregnant (n=18)" sub-groups based on the outcomes. In the following trial to predict pregnancy outcome in group B, the DL-based binary classifier yielded 77.8% for accuracy. Its performance was further validated by an accuracy of 75% in a "held-out" test set where patients had euploid embryo transfers. Furthermore, the DL model identified histo-characteristics including stromal edema, glandular secretion, and endometrial vascularity as important features related to pregnancy prediction.

CONCLUSIONS

DL-based endometrial histology analysis demonstrated its feasibility and robustness in pregnancy prediction for patients undergoing FETs, indicating its value as a prognostic tool in fertility treatment.