Improved endometrial assessment using cyclin E and p27

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.

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.

OUP accepted manuscript

STUDY QUESTION

Can the accuracy of timing of luteal phase endometrial biopsies based on urinary ovulation testing be improved by measuring the expression of a small number of genes and a continuous, non-categorical modelling approach?

SUMMARY ANSWER

Measuring the expression levels of six genes (IL2RB, IGFBP1, CXCL14, DPP4, GPX3 and SLC15A2) is sufficient to obtain substantially more accurate timing estimates and to assess the reliability of timing estimates for each sample.

WHAT IS KNOWN ALREADY

Commercially available endometrial timing approaches based on gene expression require large gene sets and use a categorical approach that classifies samples as pre-receptive, receptive or post-receptive.

STUDY DESIGN, SIZE, DURATION

Gene expression was measured by RTq-PCR in different sample sets, comprising a total of 664 endometrial biopsies obtained 4–12 days after a self-reported positive home ovulation test. A further 36 endometrial samples were profiled by RTq-PCR as well as RNA-sequencing.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A computational procedure, named ‘EndoTime’, was established that models the temporal profile of each gene and estimates the timing of each sample. Iterating these steps, temporal profiles are gradually refined as sample timings are being updated, and confidence in timing estimates is increased. After convergence, the method reports updated timing estimates for each sample while preserving the overall distribution of time points.

MAIN RESULTS AND THE ROLE OF CHANCE

The Wilcoxon rank-sum test was used to confirm that ordering samples by EndoTime estimates yields sharper temporal expression profiles for held-out genes (not used when determining sample timings) than ordering the same expression values by patient-reported times (GPX3: P < 0.005; CXCL14: P < 2.7e−6; DPP4: P < 3.7e−13). Pearson correlation between EndoTime estimates for the same sample set but based on RTq-PCR or RNA-sequencing data showed a high degree of congruency between the two (P = 8.6e−10, R² = 0.687). Estimated timings did not differ significantly between control subjects and patients with recurrent pregnancy loss or recurrent implantation failure (P > 0.05).

LARGE SCALE DATA

The RTq-PCR data files are available via the GitHub repository for the EndoTime software at https://github.com/AE-Mitchell/EndoTime, as is the code used for pre-processing of RTq-PCR data. The RNA-sequencing data are available on GEO (accession GSE180485).

LIMITATIONS, REASONS FOR CAUTION

Timing estimates are informed by glandular gene expression and will only represent the temporal state of other endometrial cell types if in synchrony with the epithelium. Methods that estimate the day of ovulation are still required as these data are essential inputs in our method. Our approach, in its current iteration, performs batch correction such that larger sample batches impart greater accuracy to timing estimations. In theory, our method requires endometrial samples obtained at different days in the luteal phase. In practice, however, this is not a concern as timings based on urinary ovulation testing are associated with a sufficient level of noise to ensure that a variety of time points will be sampled.

WIDER IMPLICATIONS OF THE FINDINGS

Our method is the first to assay the temporal state of luteal-phase endometrial samples on a continuous domain. It is freely available with fully shared data and open-source software. EndoTime enables accurate temporal profiling of any gene in luteal endometrial samples for a wide range of research applications and, potentially, clinical use.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by a Wellcome Trust Investigator Award (Grant/Award Number: 212233/Z/18/Z) and the Tommy's National Miscarriage Research Centre. None of the authors have any competing interests. J.L. was funded by the Biotechnology and Biological Sciences Research Council (UK) through the Midlands Integrative Biology Training Partnership (MIBTP, BB/M01116X/1).

Decidualization score identifies an endometrial dysregulation in samples from women with recurrent pregnancy losses and unexplained infertility

OBJECTIVE

To study decidualization-associated endometrial factors.

DESIGN

Retrospective cohort study to compare endometrial gene expression patterns in women experiencing reproductive failure including recurrent pregnancy loss or unexplained infertility versus fertile controls.

SETTING

University Reproductive Medicine Center.

PATIENTS

Women experiencing recurrent reproductive failure including recurrent pregnancy loss or unexplained infertility (n = 42) and fertile controls (n = 18).

INTERVENTIONS

Endometrial biopsy samples were analyzed with targeted ribonucleic acid sequencing via next-generation sequencing.

MAIN OUTCOME MEASURES

The primary end point measurements were the expression of genes important for endometrial transformation during decidualization measured singly and in a combined/cumulative score approach. The secondary end point measurements were receiver operating curve analysis and comparisons between the specific biomarkers.

RESULTS

The comparison revealed differential expression of factors associated with decidualization, tissue homeostasis, and immune regulation: FOXO1, GZMB, IL15, SCNN1A, SGK1, and SLC2A1. A combined evaluation of these 6 signature factors was designated as a decidualization score in which the maximal score was "6" and the minimal was "0". Among controls, 89% of the samples had a score ≥5 and 11% had a score of "4". A total of 76% of samples in the patient group had scores ≤4 and 19% had the lowest score of "0". A decidualization score <4 provided evidence of abnormality in the decidualization process with a sensitivity of 76% (95% CI 61%-88%) and specificity of 89% (95% CI 65%-99%).

CONCLUSIONS

Decidualization scoring can determine whether the endometrial molecular profile is implantation-friendly. Further validation of this testing approach is necessary to determine a particular patient population in whom it could be used for selecting patients that require therapeutic actions to improve endometrial conditions prior to the in vitro fertilization procedure.

Identifying biomarkers for predicting successful embryo implantation: applying single to multi-OMICs to improve reproductive outcomes

BACKGROUND

Successful embryo implantation is a complex process that requires the coordination of a series of events, involving both the embryo and the maternal endometrium. Key to this process is the intricate cascade of molecular mechanisms regulated by endocrine, paracrine and autocrine modulators of embryonic and maternal origin. Despite significant progress in ART, implantation failure still affects numerous infertile couples worldwide and fewer than 10% of embryos successfully implant. Improved selection of both the viable embryos and the optimal endometrial phenotype for transfer remains crucial to enhancing implantation chances. However, both classical morphological embryo selection and new strategies incorporated into clinical practice, such as embryonic genetic analysis, morphokinetics or ultrasound endometrial dating, remain insufficient to predict successful implantation. Additionally, no techniques are widely applied to analyse molecular signals involved in the embryo-uterine interaction. More reliable biological markers to predict embryo and uterine reproductive competence are needed to improve pregnancy outcomes. Recent years have seen a trend towards 'omics' methods, which enable the assessment of complete endometrial and embryonic molecular profiles during implantation. Omics have advanced our knowledge of the implantation process, identifying potential but rarely implemented biomarkers of successful implantation.

OBJECTIVE AND RATIONALE

Differences between the findings of published omics studies, and perhaps because embryonic and endometrial molecular signatures were often not investigated jointly, have prevented firm conclusions being reached. A timely review summarizing omics studies on the molecular determinants of human implantation in both the embryo and the endometrium will help facilitate integrative and reliable omics approaches to enhance ART outcomes.

SEARCH METHODS

In order to provide a comprehensive review of the literature published up to September 2019, Medline databases were searched using keywords pertaining to omics, including 'transcriptome', 'proteome', 'secretome', 'metabolome' and 'expression profiles', combined with terms related to implantation, such as 'endometrial receptivity', 'embryo viability' and 'embryo implantation'. No language restrictions were imposed. References from articles were also used for additional literature.

OUTCOMES

Here we provide a complete summary of the major achievements in human implantation research supplied by omics approaches, highlighting their potential to improve reproductive outcomes while fully elucidating the implantation mechanism. The review highlights the existence of discrepancies among the postulated biomarkers from studies on embryo viability or endometrial receptivity, even using the same omic analysis.

WIDER IMPLICATIONS

Despite the huge amount of biomarker information provided by omics, we still do not have enough evidence to link data from all omics with an implantation outcome. However, in the foreseeable future, application of minimally or non-invasive omics tools, together with a more integrative interpretation of uniformly collected data, will help to overcome the difficulties for clinical implementation of omics tools. Omics assays of the embryo and endometrium are being proposed or already being used as diagnostic tools for personalised single-embryo transfer in the most favourable endometrial environment, avoiding the risk of multiple pregnancies and ensuring better pregnancy rates.

Novel predictive and therapeutic options for better pregnancy outcome in frozen embryo transfer cycles

Since 1978, in the first decades of in vitro fertilization (IVF), the use of ovarian hyperstimulation allowed for the development and transfer of multiple embryos. As IVF technology improved, the number of multiple pregnancies increased, which led to gradual reduction in the number of embryos that were transferred. Embryo freezing (vitrification) was recommended to allow subsequent transfer if the fresh cycle was unsuccessful. However, experimentation has continued to improve pregnancy outcomes. We discuss here the significance of frozen embryo transfer cycle and the impact of uterine and peripheral immunity dominated by NK cells and regulatory T cells and human chorionic gonadotropin on pregnancy outcome in this innovative mode of IVF therapy.

Endometrial receptivity and pregnancy outcome

Human implantation is a highly complex and multifactorial process. Successful implantation requires the presence of a healthy embryo, a receptive endometrium, and a synchronized molecular dialogue between the two, as well as immune tolerance/protection from the host. The endometrial receptivity refers to a hormonally limited period in which the endometrial tissue acquires a transient functional status allowing blastocyst implantation and pregnancy initiation. Global knowledge of endometrial receptivity grew up in recent years. Improvements in genetics, new biomarkers, noninvasive methods, new advanced techniques (Endometrial receptivity assay - the ERA system, proteomic analysis) offer the possibility to evaluate the endometrial status and to manage patients with infertility problems, especially women undergoing assisted reproductive treatment. This overview reports the most relevant knowledge and recent advances in the study of implantation processes from the perspective of the endometrium, often considered as being the main barrier for a successful pregnancy initiation. Endometrial receptivity is a topic of great interest and further studies are needed for the early identification of endometrial abnormalities and the discovery of new strategies for increasing the chance for the establishment of pregnancy.

Micronized vaginal progesterone to prevent miscarriage: a critical evaluation of randomized evidence

Progesterone is essential for the maintenance of pregnancy. Several small trials have suggested that progesterone supplementation may reduce the risk of miscarriage in women with recurrent or threatened miscarriage. Cochrane Reviews summarized the evidence and found that the trials were small with substantial methodologic weaknesses. Since then, the effects of first-trimester use of vaginal micronized progesterone have been evaluated in 2 large, high-quality, multicenter placebo-controlled trials, one targeting women with unexplained recurrent miscarriages (the PROMISE [PROgesterone in recurrent MIScarriagE] trial) and the other targeting women with early pregnancy bleeding (the PRISM [PRogesterone In Spontaneous Miscarriage] trial). The PROMISE trial studied 836 women from 45 hospitals in the United Kingdom and the Netherlands and found a 3% greater live birth rate with progesterone but with substantial statistical uncertainty. The PRISM trial studied 4153 women from 48 hospitals in the United Kingdom and found a 3% greater live birth rate with progesterone, but with a P value of .08. A key finding, first observed in the PROMISE trial, and then replicated in the PRISM trial, was that treatment with vaginal micronized progesterone 400 mg twice daily was associated with increasing live birth rates according to the number of previous miscarriages. Prespecified PRISM trial subgroup analysis in women with the dual risk factors of previous miscarriage(s) and current pregnancy bleeding fulfilled all 11 conditions for credible subgroup analysis. For the subgroup of women with a history of 1 or more miscarriage(s) and current pregnancy bleeding, the live birth rate was 75% (689/914) with progesterone vs 70% (619/886) with placebo (rate difference 5%; risk ratio, 1.09, 95% confidence interval, 1.03–1.15; P=.003). The benefit was greater for the subgroup of women with 3 or more previous miscarriages and current pregnancy bleeding; live birth rate was 72% (98/137) with progesterone vs 57% (85/148) with placebo (rate difference 15%; risk ratio, 1.28, 95% confidence interval, 1.08–1.51; P=.004). No short-term safety concerns were identified from the PROMISE and PRISM trials. Therefore, women with a history of miscarriage who present with bleeding in early pregnancy may benefit from the use of vaginal micronized progesterone 400 mg twice daily. Women and their care providers should use the findings for shared decision-making.

Diagnostic and therapeutic options in recurrent implantation failure

Recurrent implantation failure (RIF) is an uncommon, imprecisely defined clinical disorder characterized by failure to achieve pregnancy after repeated embryo transfers. The diverse etiologies and incomplete understanding of RIF provide significant diagnostic and therapeutic challenges to patients and providers. Careful clinical evaluation prior to assisted reproduction can uncover many treatable causes, including thyroid dysfunction, submucosal myomas, and tobacco use. The more-subtle causes often require a more-targeted assessment. Undetected, small polyps or small areas of intrauterine synechiae are relatively common and easily treated contributors to RIF. Molecular and cellular abnormalities pose a greater therapeutic challenge. Putative causes of RIF, including progesterone resistance, shifted window of receptivity, decreased integrin expression, and immunologic disturbances, should be considered in the evaluation of a patient with otherwise unexplained RIF. It may also be true that a more complex and standardized definition of RIF would be helpful in these cases. In this paper, we review the diagnostic and therapeutic approaches to RIF, with emphasis on disorders of endometrial receptivity.

Clinical approach to recurrent implantation failure: evidence-based evaluation of the endometrium

The endometrium is a dynamic, repetitively cycling tissue that mediates the implantation of the blastocyst. Evaluation of this complex tissue necessitates sophisticated methods that can assess its functional potential. Beginning in the 1950s with simple histological endometrial "dating," these methods have crossed into the molecular era with the use of arrays aimed at dating, functional tests that assess for proliferation and differentiation, and tests that screen for inflammatory markers. In addition to these specialized tests, histologic evaluation for pathologic conditions-such as growth disorders (i.e. polyps and hyperplasia), inflammatory lesions, and retained products of conception-are critical for a complete assessment of the patient with recurrent implantation failure. Whatever the means of testing, the goal is to reveal actionable findings that can assist in offering the best options to patients who have failed multiple transfers with high quality embryos.

Diverse endometrial mRNA signatures during the window of implantation in patients with repeated implantation failure

High endometrial receptivity in the window of implantation (WOI) is essential for successful implantation. However, a diagnostic tool with high specificity for impaired endometrial receptivity remains to be developed. We collected endometrium specimens during the WOI from patients with RIF and women who conceived after one IVF/ICSI attempt. We conducted mRNA microarray on the samples followed by relevant comparative and functional analysis. Microarray analysis revealed 357 dysregulated mRNAs between the two groups. The majority of these mRNAs were found to encode membrane proteins by Gene Ontology (GO) analysis. The major functional biological pathways associated with the down-regulated mRNAs were cytokine-cytokine receptor interaction, the p53 signalling pathway and the complement and coagulation cascades. Up-regulated mRNAs were found mainly to participate in pathways such as PPAR signalling, hematopoietic cell lineage, phosphatidylinositol signalling system, ECM-receptor interaction and notch signalling. AQP3, DPP4 and TIMP3 whose expression patterns were down-regulated in RIF patients both by microarray and real-time PCR had a high correspondence with previous studies demonstrating that these genes may contribute to the defects in endometrial receptivity in RIF patients. Overall, these RIF-associated mRNAs may help devise new diagnostic tools for endometrial receptivity.

Both slowly developing embryos and a variable pace of luteal endometrial progression may conspire to prevent normal birth in spite of a capable embryo

Embryonic implantation requires synchrony between the endometrium and the embryo. When analyzed in isolation, competent embryos may be unsuccessful when placed on a nonreceptive endometrium or vice versa, contributing to the "black box" of implantation failure. It is when the two are assessed together that dyssynchrony becomes evident, due to premature progesterone stimulus on the endometrium, physiologic displacement of the window of implantation or late blastulation of the embryo, or all combined. From the embryonic component, detailed assessment of the timing of blastulation is essential. The molecular diagnosis of endometrial receptivity based on its transcriptomic signature could be superior to other techniques used in the past for defining the endometrial window of implantation.

Local and systemic factors and implantation: what is the evidence?

Significant progress has been made in the understanding of embryonic competence and endometrial receptivity since the inception of assisted reproductive technology. The endometrium is a highly dynamic tissue that plays a crucial role in the establishment and maintenance of normal pregnancy. In response to steroid sex hormones, the endometrium undergoes marked changes during the menstrual cycle that are critical for acceptance of the nascent embryo. There is also a wide body of literature on systemic factors that impact assisted reproductive technology outcomes. Patient prognosis is impacted by an array of factors that tip the scales in her favor or against success. Recognizing the local and systemic factors will allow clinicians to better understand and optimize the maternal environment at the time of implantation. This review will address the current literature on endometrial and systemic factors related to impaired implantation and highlight recent advances in this area of reproductive medicine.

Reproductive outcome is optimized by genomic embryo screening, vitrification, and subsequent transfer into a prepared synchronous endometrium

PURPOSE

The aim of this study is to compare implantation and live birth rates (LBR) between fresh euploid embryo transfers versus cryo-all cycles with a subsequent embryo transfer into a prepared endometrium.

MATERIAL AND METHODS

This is a retrospective cohort study. Patients who underwent an IVF cycle with PGS with trophectoderm biopsy from January 2011 to July 2015 were included. Patients were divided into three groups: "Fresh Only," "Frozen Embryo Transfer ('FET) Only," and "Fresh ET then FET." For "Fresh Only" group (n = 345), PGS results were received within 24 h. For "FET Only" group (n = 514), results were expected after 24 h, and embryos were cryopreserved after biopsy; only FET was performed in this group (no fresh transfer). For "FET with a previous fresh ET" (n = 139) group, patients underwent a fresh ET with a subsequent FET, in which the same cohort of embryos was utilized. The main outcome measures were pregnancy rate (PR), clinical PR, implantation rate (IR), LBR, and early pregnancy loss rate.

RESULTS

IRs were statistically higher in the "FET Only" group when compared to the "Fresh Only" group (59.5 vs. 50.6%, p < 0.01) and the "FET with a previous fresh ET" (59.5 vs. 50.6%, p < 0.05). LBR was statistically significant in the "FET Only" group when compared to the "Fresh Only" group (57.6 vs. 46.5 %, p < 0.005) but not when compared to "FET with a previous fresh ET" group (57.6 vs. 47.7%, p = 0.07).

CONCLUSIONS

This analysis suggests euploid embryos to be more likely to implant and achieve a LBR in a synthetic FET cycle than in a fresh cycle.

Estrogen signaling in the proliferative endometrium: implications in endometriosis

SUMMARY Even though the physiological role of estrogen in the female reproductive cycle and endometrial proliferative phase is well established, the signaling pathways by which estrogen exerts its action in the endometrial tissue are still little known. In this regard, advancements in cell culture techniques and maintenance of endometrial cells in cultures enabled the discovery of new signaling mechanisms activated by estrogen in the normal endometrium and in endometriosis. This review aims to present the recent findings in the genomic and non-genomic estrogen signaling pathways in the proliferative human endometrium specifically associated with the pathogenesis and development of endometriosis.

Evolutionary forward genomics reveals novel insights into the genes and pathways dysregulated in recurrent early pregnancy loss

STUDY QUESTION

Are the genes that gained novel expression in the endometria of Eutherian (placental) mammals more likely to be dysregulated in patients with endometrial-associated recurrent early pregnancy loss (REPL)?

SUMMARY ANSWER

There was a significant enrichment of genes dysregulated in REPL patients among the Eutherian-specific endometrial genes.

WHAT IS KNOWN ALREADY

Pregnancy loss is the most common complication of human pregnancy. REPL has multiple etiologies, including dysregulation of endometrial function, leading to 'suboptimal' implantation. Although the implantation process is tightly regulated in Eutherian (placental) mammals, the molecular factors contributing to dysregulated endometrial gene expression patterns in women with REPL are largely unknown.

STUDY DESIGN, SIZE, DURATION

Endometrial biopsies were obtained from 32 REPL patients during the mid-luteal phase, and evaluated for glandular development arrest based on elevated nuclear cyclin E levels in gland cells, and for out-of-phase endometrial development based on histology. Gene expression levels were measured using Illumina Human HT-12v4 BeadChip arrays.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Differentially expressed genes were identified between patients with (i) out-of-phase (n = 10) versus normal (n = 22) histological dating and (ii) abnormally elevated (n = 9) versus normal (n = 23) cyclin E levels in the nuclei of endometrial glands, using a likelihood ratio test. Enrichment of dysregulated genes in REPL endometria among Eutherian-specific genes was tested by permutation. Gene ontology and pathway enrichment analyses were carried out for the dysregulated genes.

MAIN RESULTS AND THE ROLE OF CHANCE

Fifty-eight and eighty-one genes were identified as differentially expressed at P < 0.001 in women with out-of-phase histological dating and abnormally elevated glandular cyclin E levels, respectively. Genes that were recruited into endometrial expression during the evolution of pregnancy in Eutherian mammals were significantly enriched for dysregulated genes (P = 0.002 for histology, P = 0.021 for cyclin E), as well as for genes involved in immune response and signaling pathways with essential roles in implantation and endometrial biology.

LIMITATIONS, REASONS FOR CAUTION

Small sample size limits the statistical power to detect dysregulated genes, and the lack of non-REPL control women does not allow us to test for the contribution of these genes to overall risk of REPL.

WIDER IMPLICATIONS OF THE FINDINGS

Enrichment of functional gene categories, as well as genes gained expression in the Eutherian endometria, help to identify molecular etiologies that contribute to normal functioning of the endometrium. These pathways are also strong candidates for successful pregnancy outcomes. Using the evolutionary history of mammalian gene expression in the endometrial tissue may be a promising approach to discover genes involved in female reproductive disorders.

STUDY FUNDING/COMPETING INTERESTS

This work is supported by National Institutes of Health (NIH) grant R01 HD21244 to C.O. Authors declare no competing interests.

Chronic endometritis in women with recurrent early pregnancy loss and/or fetal demise

OBJECTIVE

To assess the prevalence of chronic endometritis in women with a history of recurrent early pregnancy loss (REPL) and/or fetal demise (FD).

DESIGN

Observational cohort study using prospectively collected data.

SETTING

Recurrent pregnancy loss program in an academic medical center.

PATIENT(S)

Three hundred ninety-five women with a history of two or more pregnancy losses of less than 10 weeks' size or a fetal demise of 10 or more weeks' size.

INTERVENTION(S)

All women had an endometrial biopsy. Chronic endometritis was treated with antibiotics, and a second endometrial biopsy was recommended as a "test of cure."

MAIN OUTCOME MEASURE(S)

Subsequent live-birth rate (LBR).

RESULT(S)

The overall prevalence of chronic endometritis was 9% (35/395) in this cohort; 7% (21/285) in the REPL group, 14% (8/57) in the FD group, and 11% (6/53) in the combined REPL/FD group. The cure rate was 100% after a course(s) of antibiotics. The subsequent cumulative LBR was 88% (21/24) for the treated chronic endometritis group versus 74% (180/244) for the group without chronic endometritis. The per-pregnancy LBR for the treated chronic endometritis group was 7% (7/98) before treatment versus 56% (28/50) after treatment.

CONCLUSION(S)

There was a high prevalence of chronic endometritis in this cohort. The test of cure was 100% with antibiotics. Subsequent LBRs after treatment were encouraging.

"Information-rich" reproductive outcomes in carriers of a structural chromosome rearrangement ascertained on the basis of recurrent pregnancy loss

OBJECTIVE

To determine whether evaluation and management of concomitant recurrent pregnancy loss (RPL) factors, followed by close monitoring in the first trimester, improved subsequent live birth rate, in carriers of a structural chromosome rearrangement ascertained on the basis of RPL.

DESIGN

Prospective tabulation and analysis of subsequent pregnancy outcomes.

SETTING

Academic medical center.

PATIENT(S)

Carriers of a structural chromosome rearrangement with a history of RPL, defined as two or more pregnancy losses at any gestational age.

INTERVENTION(S)

Evaluation and treatment for concomitant factors and close monitoring in the first trimester.

MAIN OUTCOME MEASURE(S)

Live birth rate, defined as term, preterm, and ongoing pregnancies. Secondary outcomes include number of cycles to conception, and miscarriage chromosome results.

RESULT(S)

Live birth rate was 6.7% before evaluation and 63% subsequent. The proportion of women with at least one live birth increased significantly from 25%-90%. The mean number of cycles to conception was 1.7 (SD 1.3). Miscarriage chromosome results revealed that 13% were unbalanced structural chromosome rearrangements.

CONCLUSION(S)

This study provides further evidence that evaluation and treatment of concomitant RPL factors and close monitoring in the first trimester leads to a high subsequent live birth rate in carriers of a structural chromosome rearrangement ascertained on the basis of RPL. The number of cycles needed to conceive was less than two, indicating that infertility is not associated with carrier status. The low percentage of miscarriages or ongoing pregnancies with an unbalanced structural chromosome rearrangement suggests that there is natural selection against an unbalanced rearrangement.

Implantation failure: molecular mechanisms and clinical treatment

BACKGROUND

Implantation is a complex initial step in the establishment of a successful pregnancy. Although embryo quality is an important determinant of implantation, temporally coordinated differentiation of endometrial cells to attain uterine receptivity and a synchronized dialog between maternal and embryonic tissues are crucial. The exact mechanism of implantation failure is still poorly understood.

METHODS

This review summarizes the current knowledge about the proposed mechanisms of implantation failure in gynecological diseases, the evaluation of endometrial receptivity and the treatment methods to improve implantation.

RESULTS

The absence or suppression of molecules essential for endometrial receptivity results in decreased implantation rates in animal models and gynecological diseases, including endometriosis, hydrosalpinx, leiomyoma and polycystic ovarian syndrome. The mechanisms are diverse and include abnormal cytokine and hormonal signaling as well as epigenetic alterations.

CONCLUSIONS

Optimizing endometrial receptivity in fertility treatment will improve success rates. Evaluation of implantation markers may help to predict pregnancy outcome and detect occult implantation deficiency. Treating the underlying gynecological disease with medical or surgical interventions is the optimal current therapy. Manipulating the expression of key endometrial genes with gene or stem cell-based therapies may some day be used to further improve implantation rates.

Intravenous immunoglobulin and idiopathic secondary recurrent miscarriage: a multicentered randomized placebo-controlled trial

BACKGROUND

Idiopathic secondary recurrent miscarriage may be associated with an abnormal maternal immune response to subsequent pregnancies. Intravenous immunoglobulin (IVIG) has been studied in randomized controlled trials (RCTs) with conflicting results. Therefore, a definitive trial was proposed.

METHODS

We conducted an investigator-initiated, multicentered, randomized, double-blinded, placebo-controlled trial comparing IVIG with saline in women with idiopathic secondary recurrent miscarriage, defined as a history of at least one prior ongoing pregnancy followed by three or more consecutive unexplained miscarriages. Subjects received either IVIG 500 mg/kg or the equivalent volume of normal saline. Preconception infusions were administered 14-21 days from the projected next menstrual period. With documentation of pregnancy, the subject received the same infusion every 4 weeks until 18-20 weeks of gestation. The primary outcome was an ongoing pregnancy of at least 20 weeks of gestation.

RESULTS

A total of 82 patients enrolled, of whom 47 had an index pregnancy. All ongoing pregnancies resulted in live births. Therefore, the live birth rates were 70% (16/23) in the IVIG group and 63% (15/24) in the control group (P = 0.760); odds ratio (OR) 1.37 [95% confidence interval (CI) 0.41-4.61]. Including only clinical pregnancies (embryo with cardiac activity at 6 weeks of gestation), the live birth rates were equivalent, 94% (16/17) and (15/16), respectively (P > 0.999); OR 1.07 (95% CI 0.06-18.62). Meta-analysis of randomized controlled trials (RCTs) evaluating IVIG for idiopathic secondary recurrent miscarriage revealed live birth rates of 70% (31/44) in the IVIG group and 62% (28/45) in the control group (P = 0.503); common OR 1.44 (95% CI 0.59-3.48).

CONCLUSIONS

This is the largest RCT to date in which IVIG was evaluated in women with idiopathic secondary recurrent miscarriage; no treatment benefit was found. The meta-analysis, which combined our study results with two prior RCTs, also showed no significant effect of treatment with IVIG.

Estrogen and the endometrium: lessons learned from gene expression profiling in rodents and human

To date, research into the biological processes and molecular mechanisms associated with endometrial receptivity and embryo implantation has been a focus of attention, whereas the complex events that occur in the human endometrium during the menstrual and proliferative phase under the influence of estrogen have received little attention. The objective of this review is to provide an update of our current understanding of the actions of estrogen on both human and rodent endometrium, with special emphasis on the regulation of uterine growth and cell proliferation, and the value of global gene expression analysis, in increasing understanding of these processes.

Assessment of the proliferative status of epithelial cell types in the endometrium of young and menopausal transition women

BACKGROUND

We determined protein and mRNA expressions of markers of normal human endometrial proliferation and hypothesized that dysregulation of the endometrial response to estradiol (E(2)) and progesterone would be observed in the older menopausal transition (MT) women compared with mid-reproductive age (MRA) controls.

METHODS

Endometrial biopsies were prospectively obtained from MRA and MT non-randomized healthy volunteers during proliferative (+/- exogenous E(2)) and secretory (MRA only) menstrual cycle phases. mRNA and/or nuclear protein expressions of proliferative markers (MKI67, PCNA and MCM2), cell-cycle regulators (cyclins A1, E1 and D1 and cyclin dependent kinase Inhibitor B; CCNA1, CCNE1, CCND1 and CDKN1B) and sex-steroid receptors [estrogen receptor (ER) and progesterone receptor (PR)] were assessed in endometrial lumen, gland and stroma.

RESULTS

MRA women had significantly higher proliferative than secretory expression of MKI67, PCNA, MCM2, CCNA1, CCNE1, ESR1 and PGR in lumen and gland (minimal stromal changes), whereas CDKN1B protein expression was higher during the secretory phase. E(2)-treatment of MT women led to relatively less MKI67 glandular protein expression compared with MRA women; no other age-related differences were observed.

CONCLUSION

Although the MT does not appear to alter the proliferative cell phenotype of endometrial epithelium and stroma, the data suggest that prior to the MT, age is associated with a decrease in some proliferative markers and steroid receptor expression status within different endometrial cell types.

Biomarkers of ovulation, endometrial receptivity, fertilisation, implantation and early pregnancy progression

Increasing interest in early preconception and periconception exposures and human developmental outcomes has led to studies that monitor subjects from before conception to gestation, birth and childhood. Monitoring ovulation, endometrial receptivity, fertilisation, implantation and gestation requires the non-invasive collection of biological information and samples, and the measurement of biochemical and biological markers (biomarkers) that are associated with the aforementioned physiological events. This paper describes some of the key features of biomarkers needed for epidemiological studies, identifies some existing and potential biomarkers and available measurement devices, and suggests some directions for identification and development of new biomarkers that might be employed in longitudinal studies involving the analysis of female reproductive function and of embryonic development.

Optimization of endometrial preparation results in a normal endometrial function test® (EFT®) and good reproductive outcome in donor ovum recipients

PURPOSE

Numerous studies have investigated potential markers of endometrial receptivity as predictors of successful implantation. Cyclin E and p27 have recently been studied using the endometrial function test (EFT). Our objective is to determine the correlation between the expression of cyclin E and p27 and the adequacy of uterine preparation of recipients using donor oocytes.

METHODS

Twenty recipients undergoing preparatory cycles with leuprolide acetate, estrogen, and progesterone. Endometrial biopsies were obtained 10-12 days after progesterone supplementation following the course of estrogen. The tissue was prepared for histological analysis and immunohistochemical staining for cyclin E assessment. The outcome of their subsequent ovum donation cycle was blinded to the reviewer of the EFT.

RESULTS

All recipients showed normal luteal transformation. Nineteen (95%) of the recipients had a normal EFT. This is significantly higher than what we demonstrated, previously, in unexplained infertility patients, where only 40% of such patients had a normal EFT. Thirteen recipients with a normal EFT had a clinical pregnancy, while 6 did not become pregnant in their subsequent transfer cycles. The sole patient with an abnormal EFT did not conceive on 2 subsequent cycles.

CONCLUSIONS

While a normal EFT does not guarantee a successful pregnancy, an abnormal EFT appears to be associated with pregnancy failure. This may be useful in identifying women who need adjustments to their stimulation protocols prior to progressing to a physically, emotionally, and financially costly cycle.

Mouse ascites Golgi mucin expression abnormalities in natural cycle endometrial biopsies predict subsequent in vitro fertilization–embryo transfer (IVF-ET) failure in patients with previous IVF-ET failures

We performed a double-blinded retrospective cohort study to determine whether endometrial expression of mouse ascites Golgi mucin in a natural, unmedicated cycle predicts subsequent IVF-ET outcome among women with prior IVF-ET failure and poor pre-embryo quality. We found a statistically significant decrease in clinical pregnancy rate among women with abnormal mouse ascites Golgi expression, a test which was found to have high positive predictive value for failed IVF-ET.

Significantly decreased P27 expression in endometrial carcinoma compared to complex hyperplasia with atypia (correlation with p53 expression)

P27 expression was examined on paraffin-embedded specimens in proliferative, secretory, hyperplastic and neoplastic human endometrium by immunohistochemistry. The results of p27 immunoreactivity in endometrial carcinomas were compared with clinicopathological indicators as well as with p53 expression. Thirty-eight cases of endometrial carcinoma, 30 normal functional (15 proliferative, 15 secretory), 24 hyperplastic endometrium (12 without atypia, 12 with atypia) specimens were studied by using monoclonal p27 and p53 antibodies. The streptavidin-biotin-peroxidase detection system was used and the intensity and the distribution of immunoreactivity was evaluated semiquantitatively. p27 expression was present both in the proliferative and secretory phases; the expression being stronger in the secretory period. In complex hyperplasia with atypia, p27 expression was even higher and it was significantly reduced in the endometrial carcinoma group (p<0.05). No significant correlation was found between p27 expression and any of the clinicopathologic prognostic parameters (p>0.05). Nuclear p53 expression was detected in 13 (34.2%) patients with endometrial carcinoma and was higher in non-endometrioid carcinomas and in tumors with increasing FIGO grade (p<0.05). High expression of p53 was not found to be a significant prognostic indicator of survival (p>0.05). No p53 expression was detected in the endometria with proliferation, secretion or hyperplasia either simple without atypia or complex with atypia. Surprisingly, tumors with absent/low p27 expression showed absent/low p53 expression. Our data suggest that p27 is necessary to control the proliferation of endometrium and its loss of expression seems to play a role in some aspects of endometrial carcinogenesis.

Hertig and beyond: a systematic and practical approach to the endometrial biopsy

Evaluation of the endometrial biopsy is a challenge to practicing pathologists, largely due to the wide range of morphologic patterns resulting from both normal and abnormal cyclic changes, exogenous hormones, infections, and intrauterine tumors. Successfully addressing these challenges requires that the practitioner (i) understand the clinical questions being asked, (ii) have a realistic expectation for answering these questions, and (iii) have a systematic approach to resolving these questions in the context of these expectations. The approach outlined begins with the subdividing of women with endometrial alterations into three general categories: (i) women in their fourth decade undergoing evaluation for infertility, (ii) women in their fifth decade who experience abnormal uterine bleeding, and (iii) women in their sixth decade and beyond who experience postmenopausal bleeding. The clinical expectations for each group are unique, as are the morphologic patterns most commonly encountered. Algorithms for the laboratory management of cyclic changes, dysfunctional bleeding, and mixed-pattern endometria are provided, as are pitfalls in interpretation and exclusion of neoplasia.