Can endometrial infection/inflammation explain implantation failure, spontaneous abortion, and preterm birth after in vitro fertilization?

Systematic Comparison of Bacterial Colonization of Endometrial Tissue and Fluid Samples in Recurrent Miscarriage Patients: Implications for Future Endometrial Microbiome Studies

BACKGROUND

A recent study has reported that the microbiota in endometrial fluid of patients receiving in vitro fertilization and embryo transfer (IVF-ET) may predict implantation and pregnancy rates. However, studies are lacking that simultaneously compare the microbiota between endometrial fluid and tissue samples. Whether the microbiota composition in endometrial fluid reflects that in the endometrial tissue remains unclear.

METHODS

We systematically profiled the microbiota in endometrial fluid and tissue samples of IVF-ET patients using massively parallel sequencing. The bacterial 16S ribosomal RNA gene (V4 region) was PCR-amplified. Sequencing reads with >98% nucleotide identity were clustered as a bacterial taxon. To account for the different number of reads per sample, we normalized the read counts of each taxon before comparing its relative abundances across samples.

RESULTS

Thirteen taxa, including Verrucomicrobiaceae, Brevundimonas, Achromobacter, Exiguobacterium, and Flavobacterium, were consistently detected only in endometrial tissue samples but not fluid samples. Eight taxa were detected in fluid but not tissue. Twenty-two taxa were differentially abundant between fluid and tissue samples (adjusted P values, 4.1 × 10^-25 to 0.025). The numbers of taxa identified per 1000 sequencing reads, diversity, and evenness in fluid samples were smaller than those in tissue samples.

CONCLUSIONS

Our data suggest that the microbiota composition in endometrial fluid does not fully reflect that in endometrial tissue. Sampling from both endometrial fluid and biopsy allows a more comprehensive view of microbial colonization. Further efforts are needed to identify the preanalytical effects, including sampling sites, methods, and sequencing depth, on profiling endometrial microbiota.

Protective Effects of Interferon-tau Against Lipopolysaccharide-Induced Embryo Implantation Failure in Pregnant Mice

Interferon-tau (IFN-τ), a novel type I interferon, is produced by trophoblast cells in ruminants. Previous studies have confirmed that IFN-τ could induce immunological tolerance in humans and other species. However, there are few reports on whether IFN-τ has a protective effect on embryo implantation failure caused by excessive inflammation at the maternal-fetal interface. In our study, a mouse model of lipopolysaccharide (LPS)-induced implantation failure was successfully established, and we investigated the protective effects of IFN-τ. First, we showed that IFN-τ increased the number of implanted embryos in LPS-treated pregnant mice. Subsequently, quantitative real-time polymerase chain reaction (qPCR) and ELISA results showed that several inflammatory cytokines [IL-1β and tumor necrosis factor-alpha (TNF-α)] whose expression was upregulated by LPS were reversed by IFN-τ treatment. Furthermore, we performed Western blotting and found that IFN-τ restrained the LPS-induced phosphorylation of IκBα and NF-κB p65. Moreover, qPCR and immunohistochemistry analyses showed that IFN-τ decreased the LPS-induced expression of mouse major histocompatibility complex (MHC) class I genes (H-2K and H-2D) in LPS-treated pregnant mice. Taken together, these results suggest that IFN-τ has a protective effect in LPS-induced implantation failure by downregulating MHC class I genes expression and inhibiting the production of inflammatory cytokines.

Chlamydia trachomatis-induced cell-mediated and humoral immune response in women with unexplained infertility

PROBLEM

What is the role of past Chlamydia trachomatis infection in unexplained infertility?

METHOD OF STUDY

This is a prospective study of the impact of past C. trachomatis infection on pregnancy rates in 96 women with unexplained infertility. Both humoral and cell-mediated immune responses (CMI) against C. trachomatis were studied. Serum C. trachomatis IgG antibodies were analyzed using major outer membrane protein (MOMP) peptide-based ELISA. CMI was studied by lymphocyte proliferation (LP) assay in vitro. Data on given fertility treatment, time to pregnancy, and pregnancy outcome were collected.

RESULTS

Altogether, 11.5% of the 96 women had C. trachomatis IgG antibodies. LP response to C. trachomatis was positive in 62.9% women. The overall pregnancy rate or live birth rate did not differ by the presence of antichlamydial antibodies or CMI against C. trachomatis. Time to spontaneous pregnancy was longer among C. trachomatis sero-positive women than among sero-negative women (2.9 years vs 2.0 years, P = .03).

CONCLUSION

Past chlamydial infection does not play a major role in unexplained infertility. Women with unexplained infertility and positive immune response to C. trachomatis do not have reduced pregnancy rates, but time to spontaneous pregnancy is longer among C. trachomatis IgG sero-positive women than among sero-negative women.

Immunological Tolerance, Pregnancy, and Preeclampsia: The Roles of Semen Microbes and the Father

Although it is widely considered, in many cases, to involve two separable stages (poor placentation followed by oxidative stress/inflammation), the precise originating causes of preeclampsia (PE) remain elusive. We have previously brought together some of the considerable evidence that a (dormant) microbial component is commonly a significant part of its etiology. However, apart from recognizing, consistent with this view, that the many inflammatory markers of PE are also increased in infection, we had little to say about immunity, whether innate or adaptive. In addition, we focused on the gut, oral and female urinary tract microbiomes as the main sources of the infection. We here marshall further evidence for an infectious component in PE, focusing on the immunological tolerance characteristic of pregnancy, and the well-established fact that increased exposure to the father's semen assists this immunological tolerance. As well as these benefits, however, semen is not sterile, microbial tolerance mechanisms may exist, and we also review the evidence that semen may be responsible for inoculating the developing conceptus (and maybe the placenta) with microbes, not all of which are benign. It is suggested that when they are not, this may be a significant cause of PE. A variety of epidemiological and other evidence is entirely consistent with this, not least correlations between semen infection, infertility and PE. Our view also leads to a series of other, testable predictions. Overall, we argue for a significant paternal role in the development of PE through microbial infection of the mother via insemination.

A role for the endometrial microbiome in dysfunctional menstrual bleeding

This study aimed to characterise the microbial community within the endometrial cavity and endocervix in women with menorrhagia or dysmenorrhea. Paired endocervical and endometrial biopsy samples were collected from women undergoing operative hysteroscopy and/or laparoscopy. Samples were cohorted based on pathology, indications for surgery, and histological dating of the endometrium. Samples were interrogated for the presence of microbial DNA using a two-step next generation sequencing technology approach to exploit the V5-V8 regions of the 16S rRNA gene. Pyrosequencing revealed that the endocervix and endometrium share a minor microbial community, but that each site harbours a separate and distinct microbial population (p = 0.024). This was also the case for women with menorrhagia and dysmenorrhea (p = 0.017). Lactobacillus spp. were the most abundant microbial taxa present in 50% of the cohorts, and across all endocervical groups. Members of the genera Prevotella, Fusobacterium and Jonquetella were the most abundant taxa identified in samples collected from nulliparous women. It can be concluded that the female upper genital tract is not sterile. Microbial community profiling revealed differences in the endometrial microbial community profiles for: (1) the endocervix compared to the endometrium, and (2), women with menorrhagia versus dysmenorrhea. The distinct microbial community profiles in these women may offer insight into the pathology and clinical management of dysfunctional menstrual bleeding.

Damage-Associated molecular pattern markers HMGB1 and cell-Free fetal telomere fragments in oxidative-Stressed amnion epithelial cell-Derived exosomes

Term labor in humans is associated with increased oxidative stress (OS) -induced senescence and damages to amnion epithelial cells (AECs). Senescent fetal cells release alarmin high-mobility group box 1 (HMGB1) and cell-free fetal telomere fragments (cffTF) which can be carried by exosomes to other uterine tissues to produce parturition-associated inflammatory changes. This study characterized AEC-derived exosomes under normal and OS conditions and their packaging of HMGB1 and cffTF. Primary AECs were treated with either standard media or oxidative stress-induced media (exposure to cigarette smoke extract for 48h). Senescence was determined, and exosomes were isolated and characterized. To colocalize HMGB1 and cffTF in amnion exosomes, immunofluorescent staining and in situ hybridization were performed, followed by confocal microscopy. Next generation sequencing (NGS) determined exosomal cffTF and other cell-free amnion cell DNA specificity. Regardless of condition, primary AECs produce exosomes with a classic size, shape, and markers. OS and senescence caused the translocation of HMGB1 and cffTF from AECs' nuclei to cytoplasm compared to untreated cells, which was inhibited by antioxidant N-acetyl cysteine (NAC). Linescans confirmed colocalization of HMGB1 and cffTF in exosomes were higher in the cytoplasm after CSE treatment compared to untreated AECs. NGS determined that besides cffTF, AEC exosomes also carry genomic and mitochondrial DNA, regardless of growth conditions. Sterile inflammatory markers HMGB1 and cffTF from senescent fetal cells are packaged inside exosomes. We postulate that this exosomal cargo can act as a fetal signal at term and can cause labor-associated changes in neighboring tissues.

Chronic endometritis modifies decidualization in human endometrial stromal cells

BACKGROUND

Chronic endometritis (CE) is a continuous inflammation of uterine endometrium, and it is usually symptomless. As CE has been thought not to affect the reproductive status and general health of affected women, its significance has not been explored. However, recent studies have shown that CE is related with repeated implantation failures after in vitro fertilization-embryo transfer, unexplained infertility, and recurrent miscarriages. As decidua differentiates to support the implantation process and maintains the pregnancy, we hypothesized that CE may influence the process of decidualization.

METHODS

Seventeen patients were employed in the experiment involving culture of endometrial stromal cells (ESCs). After obtaining endometrial samples, ESCs were harvested and cultured for 13 days. The concentrations in culture media and the protein expressions in ESCs of prolactin (PRL) and insulin-like growth factor binding protein-1 (IGFBP-1), two well known decidualization markers used in a large number of in vitro models, were analyzed by ELISA and Western blotting, respectively, and the cell numbers were also counted. The mRNA levels of PRL and IGFBP-1 were tested by quantitative real time polymerase chain reaction (RT-PCR). Since sex hormone induce proliferation and differentiation to decidua via binding to the sex hormone receptors (ERα, ERβ, PRA, and PRB), their expression was assessed in another 17 patients' paraffin-embedded endometrial tissue specimens by immunohistochemistry and semi-quantified by H-score.

RESULTS

Increased cell numbers and reduced secretion of PRL and IGFBP-1 were detected by ELISA in the ESCs of CE patients after culture for 13 days compared with non-CE patients. The decreased protein expression of IGFBP-1 in ESCs of CE patients was detected by Western blotting. The decreased expression of PRL mRNA and IGFBP-1 mRNA were detected by RT-PCR. Increased expressions of ERα, ERβ, PRA, and PRB were observed in the stromal cells of CE patients in comparison to non-CE patients, whereas increased expressions of ERα and ERβ were detected in the glandular cells of CE.

CONCLUSION

Our data suggests that CE modifies decidualization of human ESC through untuning the function of sex steroid hormone receptor.

Association between Maternal Dietary Inflammatory Index (DII) and abortion in Iranian women and validation of DII with serum concentration of inflammatory factors: case-control study

Previous studies have shown that some dietary components may be implicated in the etiology of spontaneous abortion. However, the possible relationship between diet-related inflammation and the risk of abortion has not yet been investigated. We examined the ability of the literature-derived Dietary Inflammatory Index (DII) to predict the abortion incidence in women suffering from recurrent abortion in a case-control study conducted from April 2010 to March 2011. This included 67 incident cases and 68 controls (frequency matched to cases by age) who attended infertility and miscarriage specialized centers in Tehran, Iran. The DII was computed based on dietary intake assessed using a validated and reproducible 168 item food-frequency questionnaire. Logistic regression models were used to estimate multivariable ORs adjusted for age, education, occupation, and body mass index. Subjects with higher DII scores (i.e., a more pro-inflammatory diet) had higher odds of abortion, with the DII being used as a continuous variable (OR_continuous = 2.12, 95% CI: 1.02-4.43). When analysis was carried out with DII expressed as a dichotomous variable, women in the pro-inflammatory diet group (DII > 1.24) were at 2.12 times higher odds of having abortion compared with women in the referent group (DII ≤ 1.24) (ORDII_{>1.24/≤1.24} = 2.12; 95% CI: 1.02-4.43). In the same study, for every 1-unit increase in DII, there was a corresponding increase in interleukin-6 by 0.15 pg/mL, 95% CI (<0.01, 0.28). In conclusion, subjects who consumed a more pro-inflammatory diet were at increased odds of abortion compared with those who consumed a more anti-inflammatory diet.

Anti-inflammatory Effects of the Natural Compounds Cortex Phellodendri and Humulus japonicus on Pelvic Inflammatory Disease in Mice

Pelvic inflammatory disease (PID) is an inflammatory and/or infectious disorder of the upper female genital tract, including the uterus, fallopian tubes, and adjacent pelvic structures, that may spread upward to the peritoneum. Currently available treatment options have presented to produce adverse effects of various degrees, such as increased antimicrobial resistance and a limited effective duration of hormones. In the study, the Cortex Phellodendri (CP) and Humulus japonicus (HJ) among natural compounds that are believed to present biological activities with fewer side effects were tested in a PID animal model. The results suggested that the administration CP and HJ reduced clinical signs, inflammatory cytokine expression as well as secretion in uterine tissue, and neutrophil infiltration into the tissue.

Chronic endometritis and infertility

Chronic endometritis (CE) is a condition involving the breakdown of the peaceful co-existence between microorganisms and the host immune system in the endometrium. A majority of CE cases produce no noticeable signs or mild symptoms, and the prevalence rate of CE has been found to be approximately 10%. Gynecologists and pathologists often do not focus much clinical attention on CE due to the time-consuming microscopic examinations necessary to diagnose CE, its mild clinical manifestations, and the benign nature of the disease. However, the relationship between CE and infertility-related conditions such as repeated implantation failure and recurrent miscarriage has recently emerged as an area of inquiry. In this study, we reviewed the literature on the pathophysiology of CE and how it may be associated with infertility, as well as the literature regarding the diagnosis and treatment of CE. In addition, we discuss the value of hysteroscopic procedures in the diagnosis and treatment of CE.

Evidence that the endometrial microbiota has an effect on implantation success or failure

BACKGROUND

Bacterial cells in the human body account for 1-3% of total body weight and are at least equal in number to human cells. Recent research has focused on understanding how the different bacterial communities in the body (eg, gut, respiratory, skin, and vaginal microbiomes) predispose to health and disease. The microbiota of the reproductive tract has been inferred from the vaginal bacterial communities, and the uterus has been classically considered a sterile cavity. However, while the vaginal microbiota has been investigated in depth, there is a paucity of consistent data regarding the existence of an endometrial microbiota and its possible impact in reproductive function.

OBJECTIVE

This study sought to test the existence of an endometrial microbiota that differs from that in the vagina, assess its hormonal regulation, and analyze the impact of the endometrial microbial community on reproductive outcome in infertile patients undergoing in vitro fertilization.

STUDY DESIGN

To identify the existence of an endometrial microbiota, paired samples of endometrial fluid and vaginal aspirates were obtained simultaneously from 13 fertile women in prereceptive and receptive phases within the same menstrual cycle (total samples analyzed n = 52). To investigate the hormonal regulation of the endometrial microbiota during the acquisition of endometrial receptivity, endometrial fluid was collected at prereceptive and receptive phases within the same cycle from 22 fertile women (n = 44). Finally, the reproductive impact of an altered endometrial microbiota in endometrial fluid was assessed by implantation, ongoing pregnancy, and live birth rates in 35 infertile patients undergoing in vitro fertilization (total samples n = 41) with a receptive endometrium diagnosed using the endometrial receptivity array. Genomic DNA was obtained either from endometrial fluid or vaginal aspirate and sequenced by 454 pyrosequencing of the V3-V5 region of the 16S ribosomal RNA (rRNA) gene; the resulting sequences were taxonomically assigned using QIIME. Data analysis was performed using R packages. The χ² test, Student t test, and analysis of variance were used for statistical analyses.

RESULTS

When bacterial communities from paired endometrial fluid and vaginal aspirate samples within the same subjects were interrogated, different bacterial communities were detected between the uterine cavity and the vagina of some subjects. Based on its composition, the microbiota in the endometrial fluid, comprising up to 191 operational taxonomic units, was defined as a Lactobacillus-dominated microbiota (>90% Lactobacillus spp.) or a non-Lactobacillus-dominated microbiota (<90% Lactobacillus spp. with >10% of other bacteria). Although the endometrial microbiota was not hormonally regulated during the acquisition of endometrial receptivity, the presence of a non-Lactobacillus-dominated microbiota in a receptive endometrium was associated with significant decreases in implantation [60.7% vs 23.1% (P = .02)], pregnancy [70.6% vs 33.3% (P = .03)], ongoing pregnancy [58.8% vs 13.3% (P = .02)], and live birth [58.8% vs 6.7% (P = .002)] rates.

CONCLUSION

Our results demonstrate the existence of an endometrial microbiota that is highly stable during the acquisition of endometrial receptivity. However, pathological modification of its profile is associated with poor reproductive outcomes for in vitro fertilization patients. This finding adds a novel microbiological dimension to the reproductive process.

Transcriptomic Insights into the Response of Placenta and Decidua Basalis to the CpG Oligodeoxynucleotide Stimulation in Non-Obese Diabetic Mice and Wild-Type Controls

Intrauterine infection is one of the most frequent causes of miscarriage. CpG oligodeoxynucleotide (CpG ODN) can mimic intrauterine infection. CpG ODN-induced embryo-resorption was observed consistently in the NK-cell deficient non-obese diabetic (NOD) mice but not in the wild-type (WT) mice. To elucidate the molecular mechanisms of differential pregnancy outcomes, differentially expressed genes (DEGs) in the placenta and decidua basalis was revealed by RNA-Seq with CpG ODN or control ODN treatment. Common DEGs in the WT and NOD mice were enriched in antimicrobial/antibacterial humoral responses that may be activated as a primary response to bacterial infection. The susceptibility to CpG ODN-induced embryo-resorption in the NOD mice might mainly be attributed to M1 macrophage polarization and the immunodeficient status, such as the down-regulation in antigen processing and presentation, allograft rejection, and natural killer cell mediated cytotoxicity. In contrast, the WT mice with normal immune systems could activate multiple immune responses and be resistant to CpG ODN-induced embryo-resorption, such as M2 macrophage differentiation and activation regulated by complement component C1q and peroxisome proliferation-activated receptor (PPAR) signaling pathways. Collectively, this study suggests that the immunodeficient status of NOD mice and the macrophage polarization regulated by C1q and PPAR signaling might be the basis for differential pregnancy outcomes between the NOD and WT mice.

Association between prior appendectomy and/or tonsillectomy in women and subsequent pregnancy rate: a cohort study

OBJECTIVE

To study pregnancy rates after appendectomy and/or tonsillectomy.

DESIGN

Population-based cohort study using the United Kingdom (U.K.) primary health care-based Clinical Practice Research Datalink (CPRD).

SETTING

Not applicable.

PATIENT(S)

Female patients who underwent appendectomy, tonsillectomy, or both from 1987 to 2012 and appropriate comparators.

INTERVENTION(S)

Timed follow-up until first pregnancy after surgery. The association between prior surgery and subsequent pregnancy was determined with the use of Cox regression models.

MAIN OUTCOME MEASURE(S)

Pregnancy rate and time to first pregnancy after surgery.

RESULT(S)

The analyses included 54,675 appendectomy-only patients, 112,607 tonsillectomy-only patients, 10,340 patients who had both appendectomy and tonsillectomy, and 355,244 comparators matched for exact age and practice from the rest of female patients in the database. There were 29,732 (54.4%), 60,078 (53.4%), and 6,169 (59.7%) pregnancies in the appendectomy-only, tonsillectomy-only, and both appendectomy tonsillectomy cohorts, respectively versus 155,079 (43.7%) in the comparator cohort during a mean follow-up of 14.7 ± 9.7 years. Adjusted hazard ratios (HRs) for subsequent birth rates were 1.34 (95% confidence interval [CI] 1.32-1.35), 1.49 (95% CI 1.48-1.51), and 1.43 (95% CI 1.39-1.47), respectively. Time to pregnancy was shortest after both appendectomy and tonsillectomy followed by appendectomy only and then tonsillectomy only compared with the rest of the population.

CONCLUSION(S)

Appendectomy and/or tonsillectomy was associated with increased subsequent pregnancy rates and shorter time to pregnancy. The effect of the surgical procedures on the pregnancy outcome was cumulative.

Interferon-Gamma and Fas Are Involved in Porphyromonas gingivalis-Induced Apoptosis of Human Extravillous Trophoblast-Derived HTR8/SVneo Cells via Extracellular Signal-Regulated Kinase 1/2 Pathway

BACKGROUND

A number of studies recently revealed a link between periodontal disease and preterm birth (PTB). PTB can be induced by dental infection with Porphyromonas gingivalis (Pg), a periodontopathic bacterium. This study aims to investigate responses of human extravillous trophoblast-derived HTR8/SVneo cells to Pg infection.

METHODS

Cell apoptosis, cell viability, protein expression, and cytokine production in HTR8 cells were measured via: 1) flow cytometry, 2) CCK-8 assay, 3) western blot, and 4) enzyme-linked immunosorbent assay methods, respectively.

RESULTS

Pg decreased cell viability and increased cell apoptosis, active caspase-3 and Fas expression, and interferon-gamma (IFN-γ) secretion in HTR8 cells. Extracellular signal-regulated kinase (ERK) 1/2 inhibitor U0126 and FasL neutralizing antibody NOK1 that blocks FasL/Fas interaction both significantly suppressed Pg-induced apoptosis. U0126 also inhibited IFN-γ secretion and Fas expression close to control levels. Moreover, treatment with recombinant IFN-γ also significantly decreased number of viable HTR8 cells and increased Fas expression, suggesting IFN-γ may play an important role in Pg-induced apoptosis of HTR8 cells, at least partially through regulation of Fas expression.

CONCLUSIONS

To the best of the authors' knowledge, this is the first study to demonstrate Pg induces IFN-γ secretion, Fas expression, and apoptosis in human extravillous trophoblast-derived HTR8/SVneo cells in an ERK1/2-dependent manner, and IFN-γ (explored by recombinant IFN-γ) and Fas are involved in Pg-induced apoptosis. The finding that Pg infection abnormally regulates inflammation and apoptosis of human trophoblasts may give new insights into the possible link of PTB with maternal periodontal disease and periodontal pathogens.

CpG Oligodeoxynucleotides Downregulate Placental Adiponectin and Increase Embryo Loss in Non-Obese Diabetic Mice

PROBLEM

CpG oligodeoxynucleotides (ODNs) can induce immunological changes in non-obese diabetic (NOD) mice and increase embryo loss, but little is known about the mechanism. This study aimed to determine the role of adiponectin in CpG ODN-induced pregnancy failure.

METHOD OF STUDY

Oligodeoxynucleotide 1826 was intraperitoneally injected to NOD mice, and ODN 2216, ODN 2006, and ODN 2395 were used to stimulate human trophoblast cell lines to investigate adiponectin expression patterns and its possible effects on trophoblast function.

RESULTS

CpG ODNs downregulated adiponectin via the cJun N-terminal kinase signaling pathway and led to increased embryo loss (from 6.9 to 33.3%). ODN 2006 impaired human trophoblast cell migration, which was successfully rescued by adiponectin treatment.

CONCLUSION

CpG ODNs decreased placental adiponectin expression in NOD mice and impaired human trophoblast function and was associated with increased embryo loss. Adiponectin may therefore play an important protective role in the prevention of bacteria-induced pregnancy failure.

Macrophage depletion and TNF-α inhibition prevent resorption in CBA/J × DBA/2 model of CpG-induced abortion

OBJECTIVE

To elucidate the mechanism by which embryo-resorption was enhanced by pathogenic CpG ODN motif in abortion-prone CBA/J × DBA/2 model and to develop a counter strategy for normal pregnancy outcome.

METHODS

This is an animal model-based study. Abortion-prone model is established by CBA/J × DBA/2. An infection was mimicked by CpG ODN injection.

RESULTS

Embryo-resorption was readily induced by CpG ODN in low doses of CpG ODN (∼25 μg/dam) when intraperitoneally (IP) injected on gestational day(gd) 6.5 in male DBA/2 mated CBA/J female mice. A more modest decline in Progesterone(P4), but not Estrogen(E2) was observed after exposure to CpG ODN in the model. P4 supplement fail to improve pregnancy outcomes, even at pharmocology dose. CpG ODN-induced fetal resorption is prevented by the treatment of anti-F4/80 or by that of anti-TNFα.In the implantation sites, the treatment of anti-F4/80 inhibits the increase both of F4/80(+) macrophage proportion and TNF-αexpression level which are induced by CpG ODN. The anti-TNFαtreatment also recovers CpG ODN-induced reduction of CD4(+)Foxp3(+) T cells.

CONCLUSION

Circulating P4 is not responsible for the process by which CpG ODN-induced embryonic resorption in an abortion-prone mice. Macrophage depletion and TNF-α inhibition are really noteworthy for CpG ODN-induced pregnancy disruption.

Acute chorioamnionitis and funisitis: definition, pathologic features, and clinical significance

Acute inflammatory lesions of the placenta consist of diffuse infiltration of neutrophils at different sites in the organ. These lesions include acute chorioamnionitis, funisitis, and chorionic vasculitis and represent a host response (maternal or fetal) to a chemotactic gradient in the amniotic cavity. While acute chorioamnionitis is evidence of a maternal host response, funisitis and chorionic vasculitis represent fetal inflammatory responses. Intraamniotic infection generally has been considered to be the cause of acute chorioamnionitis and funisitis; however, recent evidence indicates that "sterile" intraamniotic inflammation, which occurs in the absence of demonstrable microorganisms induced by "danger signals," is frequently associated with these lesions. In the context of intraamniotic infection, chemokines (such as interleukin-8 and granulocyte chemotactic protein) establish a gradient that favors the migration of neutrophils from the maternal or fetal circulation into the chorioamniotic membranes or umbilical cord, respectively. Danger signals that are released during the course of cellular stress or cell death can also induce the release of neutrophil chemokines. The prevalence of chorioamnionitis is a function of gestational age at birth, and present in 3-5% of term placentas and in 94% of placentas delivered at 21-24 weeks of gestation. The frequency is higher in patients with spontaneous labor, preterm labor, clinical chorioamnionitis (preterm or term), or ruptured membranes. Funisitis and chorionic vasculitis are the hallmarks of the fetal inflammatory response syndrome, a condition characterized by an elevation in the fetal plasma concentration of interleukin-6, and associated with the impending onset of preterm labor, a higher rate of neonatal morbidity (after adjustment for gestational age), and multiorgan fetal involvement. This syndrome is the counterpart of the systemic inflammatory response syndrome in adults: a risk factor for short- and long-term complications (ie, sterile inflammation in fetuses, neonatal sepsis, bronchopulmonary dysplasia, periventricular leukomalacia, and cerebral palsy). This article reviews the definition, pathogenesis, grading and staging, and clinical significance of the most common lesions in placental disease. Illustrations of the lesions and diagrams of the mechanisms of disease are provided.

Trophoblast-microbiome interaction: a new paradigm on immune regulation

The immunologic paradigm of pregnancy led to the conceptualization of pregnancy as an organ transplant that requires, for its success, suppression of the maternal immune system. Growing scientific evidence suggests that in many ways the placenta functions as a tumor rather than a transplant and the immune regulation of the maternal-fetal interface is the result of the coordinated interaction between all its cellular components, including bacteria. Examining the role of microbiota in reproduction is in its infancy, but there is growing literature that supports its relevance. We discuss a potential normal function of bacteria in the establishment of immune tolerance and compelling evidence that a viral infection might be the underlying cause of perturbation of homeostasis. There is compelling evidence that many infectious diseases of human beings are caused by >1 microorganism and are defined as polymicrobial infections. We propose that pregnancy complications, such as preterm birth, are the result of polymicrobial infections. We examine the potential cellular and molecular mechanisms by which a viral infection of the placenta might disrupt the normal interaction between the cellular component of the implantation site and bacteria. As we better understand the normal homeostasis among the maternal immune system, placenta, and commensal, we will be able to elucidate pathogenic conditions and design better approaches to treat pregnancy complications associated with infection.

Anakinra use during pregnancy in patients with cryopyrin-associated periodic syndromes (CAPS)

Objective: To describe the pregnancy course and outcome, and use of anakinra, a recombinant selective IL-1 receptor blocker, during pregnancy in patients with cryopyrin-associated periodic syndromes (CAPS), including familial cold auto-inflammatory syndrome (FCAS), Muckle-Wells syndrome (MWS) and neonatal onset multi-system inflammatory disease (NOMID). Methods: Women currently enrolled in natural history protocols (NCT00059748, and/or NCT00069329 under IND) who have been pregnant were included. Subjects underwent a structured, standardized interview with regards to maternal health, pregnancy and fetal outcomes. Medical records were reviewed. Results: Nine women (four with FCAS, one with MWS and four with NOMID) reported one to four pregnancies, each resulting in a total of fifteen FCAS, three MWS, and six NOMID pregnancies. Six births from FCAS mothers and three births from NOMID mothers occurred while patients were receiving anakinra. If a woman became pregnant while taking anakinra, the pre-pregnancy anakinra dose was continued. Anakinra dose was increased during one twin pregnancy. No preterm births or serious complications of pregnancy were observed. One fetus of the twin pregnancy had renal agenesis and suffered fetal demise. Genetic testing showed the deceased twin carried the same NLRP3 c.785T>C, p.V262A mutation as the mother. The other twin is healthy and mutation negative. Conclusions: Anakinra was continued during pregnancy in women with CAPS and provided significant, persistent CAPS symptom relief while continuing to prevent the long-term sequelae of CAPS. Anakinra was well tolerated. Although a causal relation between anakinra and renal agenesis seems unlikely, further safety data are needed.

Chronic endometritis due to common bacteria is prevalent in women with recurrent miscarriage as confirmed by improved pregnancy outcome after antibiotic treatment

Recurrent miscarriage (RM) is defined as 3 or more miscarriages before 20 weeks' pregnancy. In recent years, interest has been focused on chronic endometritis (CE), a subtle inflammation thought to be associated with RM. We aimed to evaluate the relationships between CE and RM. The records of 360 women with unexplained RM were retrospectively analyzed. Data from hysteroscopy, endometrial histology, endometrial culture, and polymerase chain reaction for chlamydia, performed before and after antibiotic treatment for CE, were analyzed. The occurrence of successful pregnancies within 1 year after treatment was also evaluated. Results showed that 208 (57.8%) women with RM showed CE at hysteroscopy; 190 (91.3%), positive at hysteroscopy, were also positive at histology, and 142 (68.3%) had positive cultures. Common bacteria were found in 110 (77.5%) patients. Mycoplasma and Ureaplasma were found in 36 (25.3%) patients and Chlamydia in 18 patients (12.7%). In 102 (71%) women, antibiogram-based antibiotic treatment normalized hysteroscopy, histology, and cultures (group 1); while in 40 (28.2%) patients, CE was still present at hysteroscopy (group 2). In 16 of the 66 patients positive at hysteroscopy, but not at cultures, the hysteroscopy becomes normal (group 3) after a Centers for Disease Control and Prevention-based therapy; while in 50 women, CE was still present (group 4). One year after treatment, group 1 showed a significantly higher number of pregnancies (78.4%) compared to group 2 (17.5%; P < .001) and group 4 (15.3%; P = .005). The CE is frequent in women with RM. Antibiotic treatment seems to be associated with an improved reproductive outcome.

Female asthma has a negative effect on fertility: what is the connection?

Reproductive changes such as impaired fertility and adverse pregnancy outcomes have been related to female asthma. We recently found that time to pregnancy is prolonged in asthmatic females especially in women with moderate to severe asthma and in those above 30 years of age. Despite their reproductive difficulties the asthmatics ultimately conceived just as many biological children as healthy throughout their reproductive lives. This knowledge therefore raises questions about how asthma affects fertility pathophysiologically. The purpose of this review is to describe the existing knowledge in this field and suggest hypotheses of causal relationships, which may form the basis for future studies in this field. The aim is, in particular, in the literature to examine whether there is any evidence to suggest that the systemic inflammation that characterizes asthma, can affect fertility. The issue is potentially clinically important for asthmatic, infertile individuals and society because treatment of the general systemic inflammation associated with the asthmatic disease combined with hormone stimulation might be the optimal target for an effective infertility therapy, possibly decreasing the need for in vitro fertilization.

Recurrent miscarriages, innate immunity, and autoimmune reaction to chlamydial 60-kDa heat shock protein--is there an association?

OBJECTIVE

To evaluate a potential association of immunity to the Chlamydia trachomatis 60kDa heat shock protein (ChlamHSP60) and recurrent miscarriages.

DESIGN

Prospective study.

SETTING

Outpatient miscarriage clinic of a university-based hospital.

PATIENT(S)

120 asymptomatic women with a history of recurrent miscarriages.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Determination of serum immunoglobulin G (IgG) antibodies (Ab) to ChlamHSP60 and human HSP60 and, in parallel, mannose-binding lectin (MBL) and the total hemolytic complement (CH50); medical history and clinical examination, including multiple relevant laboratory determinants.

RESULT(S)

ChlamHSP60 Ab were detected in 24 (20%) of 120 patients. Antibodies to human HSP60 were found in 19 (15.8%) of 120 patients, and more frequently in individuals who tested positive for ChlamHSP60. ChlamHSP60 were statistically significantly associated with antichlamydial IgG Ab. However, antibodies to ChlamHSP60 were not related to medical history, the number of abortions, or the time frame of fetal loss. ChlamHSP60 antibodies were not associated with the relevant variables of the coagulation cascade, a panel of autoimmune parameters including thyroid autoimmunity, deficiencies of the complement system (low MBL), or with antibodies to common infectious diseases. No statistically significant differences were was found when comparing the prevalence of ChlamHSP60 Ab in the study group with recurrent miscarriages and 90 controls (women attending for an annual pelvic examination).

CONCLUSION(S)

Immunity to ChlamHSP60 does not play a major role in the etiology of recurrent miscarriages.

The hysteroscopy and histological diagnosis and treatment value of chronic endometritis in recurrent implantation failure patients

PURPOSE

To study the consistency of hysteroscopy findings and histological chronic endometritis (CE) in recurrent implantation failure (RIF) cases, and to compare their values in indicating antibiotic treatment.

METHODS

Sixty RIF cases (January 2009-January 2010) and 202 consecutive RIF cases (May 2010-April 2012) in Peking University Third Hospital reproductive medical center were studied. 60 RIF patients' endometrial samples redid section and CD38/CD138 immunohistochemical stain for CE screening. In 202 RIF cases, the presence of hyperemia, mucosal edema, and micropolyps under hysteroscopy were considered CE diagnostic parameters. Antibiotic was offered to part of the patients. The patients' clinical outcomes were analyzed by statistical methods.

RESULTS

In 202 RIF cases, the hysteroscopy CE rate was 66.3 %, while histological CE rate was 43.6 %. The sensitivity and specificity of hysteroscopy were 35.2 and 67.5 %. In histological CE patients, 68 cases underwent regular antibiotic treatment and 20 did not. Two groups had similar clinical pregnancy rates (35.3 vs. 30.0 %), embryo implantation rates (18.9 vs. 20.4 %) and ongoing pregnancy rates (29.4 vs. 25.0 %). In hysteroscopy CE patients, the implantation rate (18.6 vs. 4.9 %) and ongoing pregnancy rate (29.3 vs. 7.4 %) significantly increased (P < 0.05) with antibiotic treatment, and higher intrauterine pregnancy rate in treatment group (29.3 vs. 11.1 %). In reviewing the chosen 60 RIF cases, the histological CE rates were similar in both pregnancy and non-pregnancy group after subsequent embryo transfer.

CONCLUSIONS

CE occurs frequently in RIF patients; hysteroscopy has more diagnostic and treatment value for them.

Obesity and the Endometrium: Adipocyte-Secreted Proinflammatory TNF α Cytokine Enhances the Proliferation of Human Endometrial Glandular Cells

Obesity, a state of chronic inflammation, is associated with poor fertility and low implantation rates and is a well-documented risk factor for endometrial cancer. Adipokines, such as tumor necrosis factor alpha, play an important role in initiation of endometrial cancer. The aim of this study is to evaluate in vitro effects of human adipocyte cells (SW872) on growth of endometrial glandular epithelial cells (EGE). Methods. We measured cell proliferation and expression of cell-growth proteins—proliferating cell nuclear antigen, cyclin D1, cyclin-dependent kinase-1, and apoptotic markers (BCL-2 and BAK) in human EGE cells cocultured with SW872 cells. EGE cells were also evaluated in SW872-conditioned media neutralized with anti-TNFα antibody. Results. A significant increase in EGE cell proliferation was observed in both SW872-conditioned media and in coculture (P < 0.05). We observed an upregulation of proliferation markers PCNA, cyclin D1, CDK-1, and BCL-2 and decrease in BAK (P < 0.05). Neutralization of SW872-conditioned media using anti-TNFα antibodies reversed EGE cell proliferation as indicated by BCL-2 expression. Conclusions. Adipocytes have potent proliferative paracrine effect on EGE cells which may be, in part, mediated via TNFα. Further understanding of the role of obesity in endometrial carcinogenesis should lead to better preventative and therapeutic strategies.

Successful implantation after reducing matrix metalloproteinase activity in the uterine cavity

BACKGROUND

Recently, the concept of recurrent implantation failure (RIF) in assisted reproductive technology has been enlarged. Chronic uterine inflammation is a known cause of implantation failure and is associated with high matrix metalloproteinase (MMP) activity in uterine cavity flushing. MMP activity of women with RIF has been reported to be higher than that of fertile women. In the present retrospective study we evaluated the efficacy of treatment for high MMP activity in the uterine cavity of patients with RIF.

METHODS

Of the 597 patients recruited to the study, 360 patients underwent MMP measurements and 237 patients did not (control group). All patients had failed to become pregnant, despite at least two transfers of good-quality embryos. Gelatinase MMP-2 and MMP-9 activity in uterine flushing fluid was detected by enzymology (MMP test). All samples were classified into two groups (positive or negative) based on the intensity of the bands on the enzyme zymogram, which represents the degree of MMP activity. Patients who tested positive on the initial test were treated for 2 weeks with a quinolone antibiotic and a corticosteroid, and subsequently underwent a second MMP test. Negative results on the second MMP tests after treatment and subsequent rates of pregnancy and miscarriage were used to evaluate the efficacy of treatment. Data were analyzed by the Mann-Whitney U-test and the chi-square test.

RESULTS

Of the patients who underwent the MMP test, 15.6% had positive results (high MMP activity). After treatment, 89.3% of patients had negative results on the second MMP test. These patients had a significantly better pregnancy rate (42.0%) than the control group (26.6%), as well as a lower miscarriage rate (28.5% vs 36.5%, respectively).

CONCLUSIONS

A 2-week course of antibiotics and corticosteroids effectively improves the uterine environment underlying RIF by reducing MMP activity.

Differential effects of the CpG-Toll-like receptor 9 axis on pregnancy outcome in nonobese diabetic mice and wild-type controls

OBJECTIVE

To elucidate the relationship between CpG-induced activation of innate immunity and pregnancy outcome.

DESIGN

An animal model-based study.

SETTING

Academic.

ANIMAL(S)

Pregnant nonobese diabetic (NOD) mice were compared with nonimmunodeficient mice.

INTERVENTION(S)

We mimic toll-like receptor 9 (TLR9) activation using CpG ODN administration in pregnant wild-type (WT) and natural killer (NK) cell-deficient NOD mice.

MAIN OUTCOME MEASURE(S)

Evaluation of fetal resorption and preterm birth in pregnant mice; flow-cytometric analysis and ELISA detection.

RESULT(S)

CpG-induced fetal resorption or preterm birth was observed steadily only in NOD mice but not in WT mice. Concurrently, CpG treatment triggered amplification of uterine macrophages and neutrophils. Moreover, CpG induced a substantial increase of serum mouse keratinocyte-derived cytokine (mKC) and tumor necrosis factor-α (TNF-α) that were produced by uterine CD11b(+)F4/80(+) cells but not by NK or CD11b(+)Gr-1(+) cells. In addition, depletion of F4/80(+) cells abrogated a CpG-induced increase in TNF-α production and improved pregnancy outcomes in NOD mice treated with CpG.

CONCLUSION(S)

These results provide evidence that CpG-driven innate immune activation may lead to activation and amplification of macrophages followed by their migration to fetomaternal microenvironment, up-regulated TNF-α production, and consequent adverse pregnancy outcomes.

The Use of Total Cervical Occlusion along with McDonald Cerclage in Patients with Recurrent Miscarriage or Preterm Deliveries

OBJECTIVES

To study the fetal outcome with the use of McDonald cerclage and total cervical occlusion in women with recurrent mid-trimester miscarriages or preterm deliveries, as well as complications of total cervical occlusion in the women.

METHODS

Prospective descriptive observational study on patients with two or more mid-trimester miscarriages, deliveries before 36 weeks, or patients who have experienced failure of transvaginal cerclage.

RESULTS

Twenty-six women were studied. Of these, 92% delivered at term. Two women delivered at 33 and 35 weeks, respectively. There was one neonatal death. Take home baby rate was 96.2%. There was no serious maternal morbidity among the patients.

CONCLUSION

The addition of external cervical OS occlusion to McDonald cerclage could improve fetal outcome in women with recurrent mid-trimester miscarriages and preterm deliveries.

The effects of endometritis on the establishment of pregnancy in cattle

Endometritis is common in post partum dairy cows and is associated with impaired reproductive performance reflected in reduced first service conception, reduced hazard of pregnancy over the breeding period and increased risk of reproductive culling. The observed effects may be mediated directly by bacterial products, such as lipopolysaccharide (LPS, endotoxin), or indirectly by inflammatory mediators, such as cytokines, eicosanoids, nitric oxide and oxidative stress affecting sperm, ovarian, uterine and embryonic function. An inflammatory milieu in the uterus has been associated with changes in sperm motility and function as well as increased sperm phagocytosis. Zygotes resulting from fertilisation of oocytes with sperm subjected to oxidative stress are less likely to develop to the blastocyst stage. In addition, LPS and tumour necrosis factor-α (TNFα) impair follicular steroidogenesis, growth and ovulation. Oocytes exposed to LPS or prostaglandin (PG) F2α during maturation are less likely to develop to blastocyst stage after fertilisation. Embryos exposed to inflammatory mediators during development have fewer trophoectoderm cells. Nitric oxide impairs development of preimplantation embryos and TNFα increases blastomere apoptosis. Endometritis in women has been associated with higher rates of implantation failure. Extragenital inflammation (e.g. mastitis) is also associated with an increased rate of embryonic loss in cattle. These observations make it clear that direct and indirect effects of endometritis, and inflammation in general, can interrupt successful reproduction at several crucial stages.

Microbiological findings in endometrial specimen: our experience

PURPOSE

Collection of an endometrial specimen for investigating infectious agents in the endometrial cavity is an invasive technique that is at times difficult and painful. In order to avoid the need for endometrial sampling in the cases of suspected or evident endometrial pathology, the aim of this study is to investigate the reliability of cervical cultures for detecting infectious agents present at the endometrial level, comparing the results between cervical cultures and endometrial cultures in women with clinical signs of endometrial inflammation.

METHODS

In a prospective diagnostic study, in the period from January 2009 to October 2010, we enrolled 404 women referred to the Department of Obstetrics and Gynecology for diagnostic hysteroscopy. All the patients underwent cervical and endometrial sampling. Cultures for common bacteria, Neisseria gonorrhoeae, yeast, and Ureaplasma urealyticum were performed.

RESULTS

The most frequent infectious agents detected at the endometrial level were common bacteria, which accounted for 69% of all cases. In particular, streptococci were found in 27% of cases, and bacteria from intestinal flora (Enterococcus faecalis and Escherichia coli) was recovered in 31% of cases. U. urealyticum was detected in 10% and Mycoplasma in only one patient (0.2% of cases). No cases of N. gonorrhoeae were found.

CONCLUSIONS

Cervical culture has a low concordance with endometrial culture. In fact in only 33% of cases was the microorganism found in the cervix the same as that found in the endometrium. These results infer that an endometrial culture is a useful investigative tool for determining the microorganisms in endometrial pathology.

On the pitfalls of adjusting for gestational age at birth

Preterm delivery is a powerful predictor of newborn morbidity and mortality. Such problems are due to not only immaturity but also the pathologic factors (such as infection) that cause early delivery. The understanding of these underlying pathologic factors is incomplete at best. To the extent that unmeasured pathologies triggering preterm delivery also directly harm the fetus, they will confound the association of early delivery with neonatal outcomes. This, in turn, complicates studies of newborn outcomes more generally. When investigators analyze the association of risk factors with neonatal outcomes, adjustment for gestational age as a mediating variable will lead to bias. In the language of directed acyclic graphs, gestational age is a collider. The theoretical basis for colliders has been well described, and gestational age has recently been acknowledged as a possible collider. However, the impact of this problem, as well as its implications for perinatal research, has not been fully appreciated. The authors discuss the evidence for confounding and present simulations to explore how much bias is produced by adjustments for gestational age when estimating direct effects. Under plausible conditions, frank reversal of exposure-outcome associations can occur. When the purpose is causal inference, there are few settings in which adjustment for gestational age can be justified.

The impact of chronic endometritis on reproductive outcome

OBJECTIVE

To assess the prevalence of chronic endometritis and the impact on the fertility of asymptomatic patients indicated for in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) treatment.

DESIGN

In the context of a randomized controlled trial, a hysteroscopy-guided endometrial biopsy was obtained and histologically examined. The live birth rate (including spontaneous pregnancies) after initiation of IVF/ICSI treatment of patients diagnosed with chronic endometritis was compared with the live birth rate of a randomly selected matched control group of patients without endometritis.

SETTING

Two tertiary infertility care units.

PATIENT(S)

A total of 678 asymptomatic infertile women with a normal transvaginal ultrasound (TVS) who underwent diagnostic hysteroscopy before a first IVF/ICSI treatment cycle.

INTERVENTION(S)

Hysteroscopy guided endometrial biopsy.

MAIN OUTCOME MEASURE(S)

The prevalence of chronic endometritis and the live birth rate (including spontaneous pregnancies) within 3 years after initiation of the randomized controlled trial.

RESULT(S)

The prevalence of chronic endometritis in the 606 patients with an adequate biopsy was 2.8%. The cumulative live birth rate (including spontaneous pregnancies) did not significantly differ between patients with or without endometritis: 76% versus 54%. Also, the clinical pregnancy rate per embryo transfer was not significantly different (hazard ratio 1.456, 95% confidence interval 0.770-2.750).

CONCLUSION(S)

Chronic endometritis can be rarely diagnosed in a population of asymptomatic infertile patients with a normal TVS before a first IVF/ICSI treatment. Moreover, the reproductive outcome after initiation of IVF/ICSI was not found to be negatively affected by chronic endometritis. In conclusion, the clinical implication of chronic endometritis seems minimal.

Tumor necrosis factor-α activates estrogen signaling pathways in endometrial epithelial cells via estrogen receptor α

The pro-inflammatory cytokine TNF-α and the female hormone estrogen have been implicated in the pathophysiology of two common gynecological diseases, endometriosis and endometrial adenocarcinoma. Here we describe a novel capacity of TNF-α to activate ER signaling in endometrial epithelial cells. TNF-α induced luciferase expression in the absence and presence of estradiol and also augmented expression of the estrogen-regulated genes c-fos, GREB1, and progesterone receptor. Furthermore, TNF-α mediated ER transcriptional activity is dependent on the Extracellular Regulated Kinase (ERK) 1/2 pathway. Co-treatment with a pure ER antagonist resulted in an inhibition of this TNF-α-induced ERE luciferase activity and gene expression, demonstrating that this cytokine signals through ERs. Additional investigations confirmed that TNF-α acts specifically via ERα. Taken together, these data provide a rationale for the potential use of inhibitors of TNF-α and estrogen production/activity in combination for the treatment of endometrial pathologies.

The value of hysteroscopy in diagnosis of chronic endometritis in patients with unexplained recurrent spontaneous abortion

OBJECTIVES

We performed this study in order to investigate the role of chronic endometritis (CE) in unexplained recurrent spontaneous abortion (RSA) and to determine the correlation between hysteroscopic and histologic findings of CE in patients with unexplained RSA. We also tried to find out the relation between CE and primary vs. secondary RSA.

STUDY DESIGN

One hundred and forty-two consecutive patients with unexplained RSA and 154 fertile women were enrolled in this study. All the patients and controls underwent hysteroscopy and, at the same time, endometrial biopsy. CE was suspected when hysteroscopy revealed signs of focal or diffuse endometrial hyperemia or endometrial endopolyps (less than 1mm in size). Histopathologic diagnosis of CE was based on superficial stromal edema, increased stromal density, and pleomorphic stromal inflammatory infiltrate dominated by lymphocytes and plasma cells. Results were compared between cases and controls as well as those with primary (n=61) and secondary (n=81) RSA.

RESULTS

Patients with RSA had a significantly higher incidence of CE both hysteroscopically (67.6% vs. 27.3%; p<0.0001) and pathologically (42.9% vs. 18.2%; p<0.0001). The sensitivity, specificity, positive predictive value and negative predictive value of hysteroscopy in the diagnosis of CE were found to be 98.4%, 56.23%, 63.5% and 97.82% respectively. Patients with secondary RSA had a higher prevalence of CE both pathologically (83.9% vs. 45.9%; p<0.0001) and hysteroscopically (58.1% vs. 24.6%; p<0.0001).

CONCLUSION

CE is associated with unexplained RSA. Hysteroscopy, with high sensitivity and acceptable specificity, is suitable for the diagnosis of CE in those with unexplained RSA. CE should be taken into consideration in those with secondary unexplained RSA.

Cytokine and progesterone receptor interplay in the regulation of MUC1 gene expression

Mucin 1 (MUC1), a transmembrane mucin expressed at the apical surface of uterine epithelia, is a barrier to microbial infection and enzymatic attack. MUC1 loss at implantation sites appears to be required to permit embryo attachment and implantation in most species. MUC1 expression is regulated by progesterone (P) and proinflammatory cytokines, including TNFα and interferon γ (IFNγ). TNFα and IFNγ are highly expressed in uterine tissues under conditions where MUC1 expression is also high and activate MUC1 expression via their downstream transcription factors, nuclear factor (NF) κB and signal transducers and activators of transcription. P receptor (PR) regulates MUC1 gene expression in a PR isoform-specific fashion. Here we demonstrate that interactions among PR isoforms and cytokine-activated transcription factors cooperatively regulate MUC1 expression in a human uterine epithelial cell line, HES. Low doses of IFNγ and TNFα synergistically stimulate MUC1 promoter activity, enhance PRB stimulation of MUC1 promoter activity and cooperate with PRA to stimulate MUC1 promoter activity. Cooperative stimulation of MUC1 promoter activity requires the DNA-binding domain of the PR isoforms. MUC1 mRNA and protein expression is increased by cytokine and P treatment in HES cells stably expressing PRB. Using chromatin immunoprecipitation assays, we demonstrate efficient recruitment of NFκB, p300, SRC3 (steroid receptor coactivator 3), and PR to the MUC1 promoter. Collectively, our studies indicate a dynamic interplay among cytokine-activated transcription factors, PR isoforms and transcriptional coregulators in modulating MUC1 expression. This interplay may have important consequences in both normal and pathological contexts, e.g. implantation failure and recurrent miscarriages.

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.