Overexpression of Endometrial Estrogen Receptor-Alpha in The Window of Implantation in Women with Unexplained Infertility

Evaluation of endometrial receptivity in women with unexplained infertility by shear wave elastography

OBJECTIVES

The endometrium of most unexplained infertility (UI) patients has been altered histologically. Shear wave elastography (SWE) is utilized to assess the signature of living tissue. This study aimed to explore the value of SWE in evaluating endometrial receptivity (ER) in UI patients.

METHODS

In total, 59 UI patients (UI group) and 52 normal control women (NC group) who received fertility consultation in our hospital were included between January 2022 and June 2023. We divided them into the late-proliferative phase of UI group (LPUI; n = 59), mid-secretory phase of UI group (MPUI; n = 41), late-proliferative phase of NC group (LPNC; n = 52), and mid-secretory phase of NC group (MPNC; n = 45). Transvaginal ultrasonography and SWE were performed during the LP and MP. Endometrial thickness (EMT), uterine artery pulsatility index (UA-PI), endometrial mean elasticity (E-mean), and mean shear wave velocities (SWV-mean) were measured.

RESULTS

There were significant differences in E-mean, SWV-mean, EMT, and UA-PI between the UI group and the NC group during both the LP and MP (p MPNC vs MPUI < 0.05, p LPNC vs LPUI < 0.05). E-mean and SWV-mean decreased with increasing EMT but increased with increasing UA-PI (p < 0.05). The most effective parameter for evaluating ER in UI patients is the E-mean (AUC = 0.89).

CONCLUSIONS

UI patients exhibited thinner endometrium, increased endometrial stiffness, and poor endometrial blood perfusion. E-mean was the most effective parameter to evaluate ER in UI patients. The study preliminarily proved that SWE is a promising non-invasive tool for evaluating the condition of endometrium.

CRITICAL RELEVANCE STATEMENT

This study aimed to explore the significance of endometrial elasticity measured by SWE in evaluating patients with UI. The findings revealed a correlation between EMT, UA-PI, and E-mean. Endometrial elasticity can serve as an effective indicator for predicting ER.

KEY POINTS

1. To explore the significance of endometrial elasticity in assessing patients with UI. 2. The endometrium of UI patient exhibited thinness, stiffness, and poor blood perfusion. 3. Endometrial elasticity serves as a valuable indicator for evaluating endometrial receptivity.

Assisted reproductive technology outcomes and gene expression in unexplained infertility patients

Background: Unexplained infertility (UI) can be a frustrating and challenging diagnosis for doctors and couples as it can be difficult to understand why they are unable to conceive despite increasing diagnostic tools. Assisted reproductive technology (ART) procedures have been successfully applied to many couples aiming to overcome UI. However, they can be not only expensive but also require multiple cycles to achieve a successful pregnancy. The endometrium and the follicular fluid have been investigated as target tissues not only to determine the cause of UI but also to increase conception rates. Results: In this study, we analyzed the outcomes of ART in 223 UI couples and gene expression associated with DNA modification, cell death, immune response and senescence (TET1, TET2, BCL2, BAK1, HMGA2, IL-6, IL-8) in infertile women's endometrium and follicular fluid. We found significant differences in women who successfully got pregnant compared to women unable to conceive depending on age, duration of infertility, number of retrieved oocytes, zygotes, transferred embryos. Further, the expression of genes BAK1 (pro-apoptotic), TET2 (associated with epigenetic DNA modification) and IL-6 (associated with immune responses) were significantly higher in the endometrium of women who successfully got pregnant. Conclusion: Younger parental age couples showed higher ART success rates, shorter duration of infertility, higher number of retrieved oocytes, zygotes and transferred embryos. The gene expression analysis revealed significant changes in the endometrium depending on genes associated with cell death and immune response which were upregulated in females with diagnosed unexplained infertility.

Uterine deficiency of Dnmt3b impairs decidualization and causes consequent embryo implantation defects

Uterine deficiency of Dnmt3b impairs decidualization and consequent embryo implantation defects. Recent advances in molecular technologies have allowed the unprecedented mapping of epigenetic modifications during embryo implantation. DNA methyltransferase 3a (DNMT3A) and DNMT3B are responsible for establishing DNA methylation patterns produced through their de novo-type DNA methylation activity in implantation stage embryos and during germ cell differentiation. It was reported that conditional knockout of Dnmt3a in the uterus does not markedly affect endometrial function during embryo implantation, but the tissue-specific functions of Dnmt3b in the endometrium during embryo implantation remain poorly understood to investigate the role of Dnmt3b during peri-implantation period. Here, we generated Dnmt3b conditional knockout (Dnmt3bd/d) female mice using progesterone receptor-Cre mice and examined the role of Dnmt3b during embryo implantation. Dnmt3bd/d female mice exhibited compromised fertility, which was associated with defective decidualization, but not endometrial receptivity. Furthermore, results showed loss of Dnmt3b did not lead to altered genomic methylation patterns of the decidual endometrium during early pregnancy. Transcriptome sequencing analysis of uteri from day 6 pregnant mice identified phosphoglycerate kinase 1 (Pgk1) as one of the most variable genes in Dnmt3bd/d decidual endometrium. Potential roles of PGK1 in the decidualization process during early pregnancy were confirmed. Lastly, the compromised decidualization upon the downregulation of Dnmt3b could be reversed by overexpression of Pgk1. Collectively, our findings indicate that uterine deficiency of Dnmt3b impairs decidualization and consequent embryo implantation defects.

Optimization of estrogen dosage for uterine receptivity for implantation in post-coital bilaterally ovariectomized mice

Estrogens and progesterone, in unison and/or separately, synchronize the distinct events of blastocyst development, uterine priming and receptivity induction for implantation. In contrast to high implantation failure rates, the mechanistic concepts regarding the uterine receptivity for implantation still remain elusive. The present study aims to define the minimum estradiol (E₂) dose to induce uterine receptivity for successful implantation in post-coitus bilaterally ovariectomized (BLO) progesterone-primed uterus of mice. Post-coital sperm-positive adult female mice were divided into two groups. In both the groups, delayed implantation was induced by BLO on post-coitus Day 4 (D4). Group 1 received 2 mg of progesterone (P₄) from D5 until sacrifice, and E₂ injection of 3.0, 10.0, 25.0 and 50.0 ng on D7. On D8, all mice of this group were sacrificed except the mice that received second dose of 25.0 ng of E₂ on D8 and were sacrificed on D9. Group 2 followed the same doses, but were given simultaneously on D4, and sacrificed on D5. The mice that received second doses of 25.0 ng E₂ were sacrificed on D6. The minimum dose of E₂ required to induce uterine receptivity for implantation is a single dose of 50.0 ng E₂. The uterus remained refractory following short receptive period at E₂ doses lower than 50.0 ng, which is just sufficient to establish desired uterine receptivity. However, repeated administration of sub-threshold doses of 25.0 ng of E₂ could also not effectively sustain uterine receptivity towards successful implantation.

Effectiveness of Gamma Oryzanol on prevention of surgical induced endometriosis development in rat model

Infertility is believed to be triggered by endometriosis whose pathophysiology and the etiology is still unknown. Certain genes play pivotal roles in pathogenesis of endometriosis. Natural products and plants are used as important sources for production of new drugs. The current study assesses the effects of gamma-oryzanol (GO) in a rat model with surgically induced endometriosis. The experimental endometriosis was induced in 24 wistar rats, and the animals were subsequently subdivided into endometriosis-sole (endom group), 3000 and 6000 µg/kg GO (GO-3000 and GO-6000) and Vit C groups. The protein levels of estrogen receptor-alpha (ER-α), Steroidogenic factor 1 (SF1), Sirtuin 1 (SIRT1), heme oxygenase 1 (HO1), light chain 3 (LC3B) and Beclin1 (BECN1) were assessed. TUNEL staining was used for detecting the apoptosis rate. The results revealed that protein levels of SF1, HO1, and total LC3B significantly (P < 0.05) decreased in GO-6000-treated groups compared to endom group. Moreover, the protein level of BECN1 and SIRT-1 significantly (P < 0.05) increased in GO-6000-treated groups compared to endom group. GO treatment did not imply any significant difference (P > 0.05) concerning the protein levels of ER-α. The TUNEL staining results showed higher TUNEL-positive cells reactions in the rats treated with GO-6000 and Vit C. Thus, GO is involved in improving condition rats involved with endometriosis through modulation in the protein levels of some molecules and also induction of apoptosis.

Should intrauterine inseminations still be proposed in cases of unexplained infertility? Retrospective study and literature review

OBJECTIVE

Unexplained infertility is defined by the absence of identifiable causes of infertility. The results of randomized studies and meta-analysis regarding the treatment of unexplained infertility are discordant due to methodological problems.

DESIGN

The aim of this study is to compare the clinical pregnancy rate per cycle (CPR/c) in IUI and IVF/ICSI in cases of unexplained infertility, according to the woman's age group and to identify the factors which predict success.

INTERVENTIONS

We performed a retrospective study in two ART centers, comparing overall clinical pregnancy, ongoing pregnancy and live birth rates in IVF/ICSI and IUI. We also compared pregnancy and birth rates according to different female age groups.

RESULTS

855 IVF/ICSI and 804 IUI cycles were compared. We found a significant difference (p < 0.001) in the pregnancy and live birth rates per cycle between IUI and IVF/ICSI, overall and in the different female age groups, except in women aged 40 and over. The greatest chances of pregnancy with IUI are found in women with secondary unexplained infertility, during the first two cycles and with a bi-follicular response to stimulation. In IVF/ICSI, pregnancy rates are higher in women with secondary unexplained infertility, in the first two cycles, in IVF and in women receiving a transfer of two embryos regardless of the embryonic stage.

CONCLUSION

We recommend IVF/ICSI treatment rather than IUI for unexplained infertility (OR CPR/c 4.20 with 95% CI [3.72-4.68]). This is in accordance with NICE, which advises the use of IVF after 2 years.

[Receptive status of the endometrium in patients with benign ovarian tumors before and after organ-preserving operations]

Background. Benign ovarian tumors (BOT) occupy the 2^nd place in the structure of diseases of the female genital organs. In 20% of women of reproductive age, BOT are associated with infertility. One of the causes of infertility caused by ovarian tumors is morphofunctional inferiority with impaired endometrial receptivity.

OBJECTIVE

To reveal the morphological and functional features of the endometrium and the level of receptivity to sex hormones in patients with BOT before and after organ-preserving operations.

MATERIAL AND METHODS

The study included 77 patients with epithelial ovarian tumors (EOT) - I group, 52 with mature teratomas (MT) - II group. Before and 6-12 months after laparoscopic cystectomy aspiration biopsy of endometrium was performed in the middle stage of secretory phase. The percentage and degree of maturity of pinopodes were determined, and the level of expression of estrogen (ER) and progesterone (PR) receptors in the glands and stroma of the endometrium was assessed.

RESULTS

At the preoperative stage, a decrease in the number of mature pinopodes in patients with EOT was revealed. Normal levels of ER were determined in glands and stroma of endometrium, PR was reduced both in stroma and glands of uterine mucosa. In patients with MT all markers corresponded to those of healthy women. In the postoperative period an increase in the number of developed pinopodes on the apical surface of endometrium in patients of I group was found. The ER level did not differ from control values, PR remained reduced in stroma. In II group a persistent decrease in quantity of mature pinopodes, ER in stroma, PR in glands and stroma of uterine mucosa was recorded.

CONCLUSION

The presence of BOT and unintentional intraoperative removal of healthy ovarian tissue lead to indirect disorders of the morphofunctional state and endometrial receptivity.

Effects of FSH treatment and withdrawal during proestrus on uterine proliferation and steroid hormone receptor expression in beef heifers

To determine the effects of Follicle Stimulating Hormone (FSH) treatment and subsequent withdrawal on uterine proliferation and estrogen receptor (ESR), Brahman crossbred heifers (n = 12) were twice daily injected with FSH (4, 3, and 2 mg/injection) on Days 17-19 of the estrous cycle (FSH 3 days) and (4 and 3 mg/injection) on Days 17-18 (FSH 2 days) and withdrawal with saline on Day 19 and (4 mg/injection) on Day 17 (FSH 1 day) and withdrawal with saline on Days 18-19. Uterine tissue was subjectively collected on Day 20 and microscopically classified to four regions: endometrial stroma (ES), surface endometrial gland (EG), deep endometrial gland (DG), and myometrium (Myo). The cell proliferation marker, Ki-67, was quantified as labeling index (LI) in uterine regions, and tissues were immunostained to detect ESR2 followed by image analysis. The LI of ES, EG, and DG was greater (P = 0.0018, P = 0.0005, and P = 0.0103; respectively) in heifers received FSH for 3 days. The expression of ESR2 protein on ES and EG was greatest (P < 0.0001 and P = 0.0036, respectively) in FSH 3 days-treated group. Thus, FSH administration during proestrus stimulates uterine cell proliferation, and ESR2 expressions are affected by FSH during proestrus and differentially distributed in the uterine regions.

Current Knowledge on Endometriosis Etiology: A Systematic Review of Literature

Objective

To review the mechanisms of endometriosis development, including those related to epigenetic mutations, cellular dysregulation, inflammatory processes, and oxidative stress.

Methods

A systematic literature review regarding current aspects of endometriosis etiology, genesis and development was performed using the PubMed, Google Scholar, and eLibrary databases. Keywords included endometriosis, etiology, development, genesis, associations and mechanisms. A multilingual search was performed.

Results

Several mechanisms underline the pathophysiological pathways for endometriosis development. Epigenetic mutations, external and internal influences, and chronic conditions have a significant impact on endometriosis development, survival and regulation. Several historically valid theories on endometriosis development were discussed, as well as updated findings.

Conclusion

Despite recent advances, fundamental problems in understanding endometriosis remain unresolved. The identification of unknown circulating epithelial progenitors or stem cells that are responsible for epithelial growth in both the endometrium and endometriotic foci seems to be the next step in solving these questions.

AMPK is required for uterine receptivity and normal responses to steroid hormones

We previously demonstrated that 5'-AMP-activated protein kinase (AMPK) is essential for normal reproductive functions in female mice. Conditional ablation of Prkaa1 and Prkaa2, genes that encode the α1 and α2 catalytic domains of AMPK, resulted in early reproductive senescence, faulty artificial decidualization, uterine inflammation and fibrotic postparturient endometrial regeneration. We also noted a delay in the timing of embryo implantation in Prkaa1/2d/d female mice, suggesting a role for AMPK in establishing uterine receptivity. As outlined in new studies here, conditional uterine ablation of Prkaa1/2 led to an increase in ESR1 in the uteri of Prkaa1/2d/d mice, resulting in prolonged epithelial cell proliferation and retention of E2-induced gene expression (e.g. Msx1, Muc1, Ltf) through the implantation window. Within the stromal compartment, stromal cell proliferation was reduced by five-fold in Prkaa1/2d/d mice, and this was accompanied by a significant decrease in cell cycle regulatory genes and aberrant expression of decidualization marker genes such as Hand2, Bmp2, Fst and Inhbb. This phenotype is consistent with our prior study, demonstrating a failure of the Prkaa1/2d/d uterus to undergo decidualization. Despite these uterine defects, ovarian function seemed to be normal following ablation of Prkaa1/2 from peri-ovulatory follicles in which ovulation, luteinization and serum progesterone levels were not different on day 5 of pregnancy or pseudopregnancy between Prkaa1/2fl/fl and Prkaa1/2d/d mice. These cumulative findings demonstrate that AMPK activity plays a prominent role in mediating several steroid hormone-dependent events such as epithelial cell proliferation, uterine receptivity and decidualization as pregnancy is established.

Evaluation of Expression and Phosphorylation of Progesterone Receptor in Endometrial Stromal Cells of Patients with Recurrent Implantation Failure Compared to Healthy Fertile Women

Recurrent implantation failure (RIF) is the repeated failure of good-quality embryos in implantation process following several assisted reproduction cycles. Disruption of the endometrial receptivity is one of the main causes of RIF. Progesterone plays a pivotal role in the endometrial receptivity through the regulation of gene expression pattern by binding to its receptors in the endometrial cells. The aim of this study was to evaluate the expression level of progesterone receptor (PR) and its phosphorylated form in the endometrial stromal cells (eSC) of RIF patients and compare it to the eSC of healthy fertile women as control group. After isolation of the eSC from biopsy samples of RIF patients and healthy fertile women and their characterization, expression levels of PR mRNA, PR protein, and phospho-Ser294 PR protein were evaluated by quantitative real-time PCR and immunofluorescence staining, respectively. The results demonstrated a significant reduction in PR mRNA expression (P < 0.01.) and phospho-Ser294 PR protein (P < 0.05) level in RIF patients compared to the control group. These data for the first time suggest that the expression of PR and its phosphorylated form are impaired in RIF patients. Therefore, designing therapeutic methods for improving PR expression status and its regulation in the endometrium of RIF patients may help in improving the final reproductive outcomes of these cases.

Effect of antithyroid antibodies on women with recurrent miscarriage: A meta-analysis

Problem

The effect of thyroid autoimmunity (TAI) on the prevalence of recurrent miscarriage (RM) is highly debatable. No meta‐analysis has been published in the past decade to investigate the impact of TAI on women with RM.

Method of Study

Systemic literature search was conducted on PubMed, Embase, Cochrane, and Web of Science databases. English language literatures published between 1993 and 2019 were selected. We assessed the relationship between the prevalence of RM and thyroid peroxidase antibodies (TPO‐Ab) or antithyroid antibodies (ATA) and evaluated the thyroid‐stimulating hormone (TSH) level in TPO‐Ab‐positive women with RM. We also observed the treatment effect with levothyroxine (LT4) for RM. Review Manager 5.3 software was used to obtain the pooled odds ratios (OR).

Results

Analysis of 22 eligible studies revealed significant association between TPO‐Ab and the prevalence of RM (OR = 1.85; 95% CI, 1.38 to 2.49; P < .001)(n ≥ 3), (OR = 1.82; 95% CI, 1.13 to 2.92; P = .01) (n ≥ 3). Women with ATA + had higher risk of RM (OR = 2.36; 95% CI, 1.71 to 3.25; P < .00001)(n ≥ 3), (OR = 2.34; 95% CI, 1.70 to 3.22; P < .00001)(n ≥ 2). RM women with TPO‐Ab had higher TSH level when compared with those negative for TPO‐Ab (random‐effect SMD = 0.60; 95% CI, 0.31 to 0.90; P < .0001). We also found beneficial effects of LT4 supplementation on the outcome of live birth rate (LBR) among pregnant women with TPO‐Ab (OR = 3.04; 95% CI, 0.69 to 13.36; P = .14).

Conclusion

The presence of serum antithyroid antibodies does harms to women and can even lead to recurrent miscarriage; LT4 treatment may have beneficial to RM women.

Human Endometrial Transcriptome and Progesterone Receptor Cistrome Reveal Important Pathways and Epithelial Regulators

CONTEXT

Poor uterine receptivity is one major factor leading to pregnancy loss and infertility. Understanding the molecular events governing successful implantation is hence critical in combating infertility.

OBJECTIVE

To define Progesterone Receptor (PGR)-regulated molecular mechanisms and epithelial roles in receptivity.

DESIGN

RNA-sequencing and PGR-ChIP-seq were conducted in parallel to identify PGR-regulated pathways during the Window of implantation (WOI) in endometrium of fertile women.

SETTING

Endometrial biopsies from the proliferative and mid-secretory phases were analyzed.

PATIENTS OR OTHER PARTICIPANTS

Participants were fertile, reproductive aged (18-37 years) women with normal cycle length, and without any history of dysmenorrhea, infertility, or irregular cycles. In total, 42 endometrial biopsies obtained from 42 women were analyzed in this study.

INTERVENTIONS

There were no interventions during this study.

MAIN OUTCOME MEASURES

Here we measured the alterations in gene expression and PGR occupancy in the genome during the WOI, based on the hypothesis that PGR binds uterine chromatin cycle dependently to regulate genes involved in uterine cell differentiation and function.

RESULTS

653 genes were identified with regulated PGR binding and differential expression during the WOI. These were involved in regulating inflammatory response, xenobiotic metabolism, epithelial mesenchymal transition, cell death, interleukin/Signal Transducer And Activator Of Transcription (STAT) signaling, estrogen response, and Mammalian target of rapamycin complex 1 (MTORC1) response. Transcriptome of the epithelium identified 3052 differentially expressed genes, of which 658 were uniquely regulated. Transcription factors Interferon Regulatory Factor 8 (IRF8) and Myocyte Enhancer Factor 2C (MEF2C) were found to be regulated in the epithelium during the WOI at the protein level, suggesting potentially important functions that are previously unrecognized.

CONCLUSION

PGR binds the genomic regions of genes regulating critical processes in uterine receptivity and function.

Integrated miRNA-seq analysis reveals the molecular mechanism underlying the effect of acupuncture on endometrial receptivity in patients undergoing fertilization: embryo transplantation

Endometrial receptivity (ER) is the main factor affecting in vitro fertilization (IVF) and embryo transplantation. Previous studies have shown that acupuncture might be useful for increasing ER. However, the underlying microRNA (miRNA) molecular mechanisms deserve to be further elucidated. In this study, we performed small RNA sequencing of endometrial samples from infertile women who either underwent acupuncture therapy or did not. Differentially expressed microRNAs (DEmiRNAs) were identified and used to predict target genes. Then, the functional and pathway were analyzed for the target genes. Moreover, quantitative reverse transcription PCR (qRT-PCR) was performed to validate the RNA-seq results. Finally, the miRNA-gene network was conducted by Cytoscape. A total of 39 DEmiRNAs were identified between the acupuncture group and the control group. The functional enrichment analysis suggested that the target genes of the DEmiRNAs were significantly enriched in GO biological process (BP) terms associated with transcription, such as regulation of DNA-templated transcription and positive regulation of DNA-templated transcription. The pathway analysis showed that DEmiRNAs might be involved in acupuncture therapy via Endocytosis, Axon guidance, Oxytocin signaling, the Hippo pathway, and Estrogen signaling pathways. Significant downregulation of hsa-miR-449a and hsa-miR-449b-3p, and significant upregulation of hsa-miR-3135b and hsa-miR-345-3p in the RNA-seq results were validated by qRT-PCR. Besides, these four DEmiRNAs and their 34 target genes conducted a miRNA-gene network. Our results predict that hsa-miR-449a, hsa-miR-3135b and hsa-miR-345-3p may underly mechanisms by which acupuncture therapy help increase ER and promote endometrium receptivity in preparation for in vitro fertilization and embryo transplantation.

Should single embryo transfer be used in patients with any kind of infertility factor? Preliminary outcomes

OBJECTIVE

Multiple embryos have been transferred to compensate for low implantation rates, which in turn, increase the likelihood of multiple pregnancies. Despite the publication of clinical guidelines and a reduction in the number of embryos transferred, double embryo transfer still is the most common practice. There is no clear evidence of who should receive the single embryo transfer (SET), and it is more commonly indicated for patients of good prognosis. However, it is not clear how much the presence of other infertility factors can affect the SET prognosis. The aim of this study was to evaluate differences in clinical pregnancy rates (CPR) of frozen-thawed SET cycles for women presenting with different infertility factors.

METHODS

Retrospective cohort study evaluating 305 frozen-thawed SET cycles performed in the last 10 years in a private IVF center. We included patients undergoing ovarian stimulation cycles, using ejaculated sperm and a frozen-thawed ET. Embryos were routinely vitrified and warmed up, and the blastocysts were transferred after endometrium preparation. The cycles were categorized according to the infertility factor classified by the Society for Assisted Reproductive Technologies (SART) as anatomic female factor (n=55), endocrine female factor (n=26), endometriosis (n=37), male factor (n=60), ovarian insufficiency (n=26), unexplained (n=24), multiple factors (n=45) and other (n=32). CPR were compared between the groups and the multivariate analysis was performed to evaluate the association of each infertility factor and the CPR, adjusted for confounders.

RESULTS

The women varied in age from 18 to 44 years (35.9±3.8), presented Body Mass Index of 22.4±3.1kg/m², baseline serum FSH of 7.4±8.3 IU/ml, and had a mean of 11.0±8.4 MII oocytes recovered and 6.4±5.3 embryos cryopreserved. The CPR, according to infertility factors were: anatomic female factor (25.9%), endocrine female factor (30.8%), endometriosis (27.8%), male factor (20.7%), ovarian insufficiency (21.7%), unexplained (9.5%), multiple factors (17.1%) and other (20.7%). Multivariate analysis did not show significant association of infertility factors and CPR adjusted for confounders.

CONCLUSIONS

Patients presenting different infertility factors seem to have a satisfactory CPR for a SET cycle, except those with unexplained infertility. This is a preliminary outcome and the number of patients by category is small; in addition, the retrospective characteristics of the study are its limitations. Overall, our findings suggest that patients presenting any infertility factor, except unexplained infertility, are suitable to receive a SET with satisfactory outcomes.

Genetics and Epigenetics of Infertility and Treatments on Outcomes

CONTEXT

Infertility affects 10% of the reproductive-age population. Even the most successful treatments such as assisted reproductive technologies still result in failed implantation. In addition, adverse pregnancy outcomes associated with infertility have been attributed to these fertility treatments owing to the presumed epigenetic modifications of in vitro fertilization and in vitro embryo development. However, the diagnosis of infertility has been associated with adverse outcomes, and the etiologies leading to infertility have been associated with adverse pregnancy and long-term outcomes.

EVIDENCE ACQUISITION

We have comprehensively summarized the data available through observational, experimental, cohort, and randomized studies to better define the effect of the underlying infertility diagnosis vs the epigenetics of infertility treatments on treatment success and overall outcomes.

EVIDENCE SYNTHESIS

Most female infertility results from polycystic ovary syndrome, endometriosis, and unexplained infertility, with some cases resulting from a polycystic ovary syndrome phenotype or underlying endometriosis. In addition to failed implantation, defective implantation can lead to problems with placentation that leads to adverse pregnancy outcomes, affecting both mother and fetus.

CONCLUSION

Current research, although limited, has suggested that genetics and epigenetics of infertility diagnosis affects disease and overall outcomes. In addition, other fertility treatments, which also lead to adverse outcomes, are aiding in the identification of factors, including the supraphysiologic hormonal environment, that might affect the overall success and healthy outcomes for mother and child. Further studies, including genome-wide association studies, epigenomics studies, and experimental studies, are needed to better identify the factors leading to these outcomes.

Inside the Endometrial Cell Signaling Subway: Mind the Gap(s)

Endometrial cells perceive and respond to their microenvironment forming the basis of endometrial homeostasis. Errors in endometrial cell signaling are responsible for a wide spectrum of endometrial pathologies ranging from infertility to cancer. Intensive research over the years has been decoding the sophisticated molecular means by which endometrial cells communicate to each other and with the embryo. The objective of this review is to provide the scientific community with the first overview of key endometrial cell signaling pathways operating throughout the menstrual cycle. On this basis, a comprehensive and critical assessment of the literature was performed to provide the tools for the authorship of this narrative review summarizing the pivotal components and signaling cascades operating during seven endometrial cell fate “routes”: proliferation, decidualization, implantation, migration, breakdown, regeneration, and angiogenesis. Albeit schematically presented as separate transit routes in a subway network and narrated in a distinct fashion, the majority of the time these routes overlap or occur simultaneously within endometrial cells. This review facilitates identification of novel trajectories of research in endometrial cellular communication and signaling. The meticulous study of endometrial signaling pathways potentiates both the discovery of novel therapeutic targets to tackle disease and vanguard fertility approaches.