Physiology of Upward Transport in the Human Female Genital Tract

3Dimensional sonography for the diagnosis of congenital uterine anomalies in women with eccentric pregnancy implantation: a novel approach

PURPOSE

The eccentric implantation of pregnancies in the upper lateral aspect of the uterine cavity is poorly defined clinically. The aim of the current study was to investigate whether differentiating between uterine anomalies that can lead to cavitary distortion has implications for the management of these pregnancies.

METHODS

Eight cases of first-trimester eccentric pregnancy implantation within the endometrial cavity (study group) were retrospectively identified. For each woman in the study group, 10 women identified as having a first-trimester concentric pregnancy implantation during the first-trimester US examination were retrieved from our database (control group). After delivery or pregnancy demise, the presence of uterine anomalies was assessed by a 3D-US examination in all patients.

RESULTS

In the study group patients, an increased incidence of uterine anomalies (50.0% vs. 8.8%, p = 0.007) was found, compared to the controls. In the study group, the eccentric location persisted in half of the pregnancies (n = 4; 50%), whereas the other half migrated to a more centric location within the endometrial cavity (n = 4; 50%). The follow-up examination showed that all the early pregnancy demises occurred in cases where the pregnancy persisted at the eccentric location. Uterine malformations were also detected in all these cases.

CONCLUSION

The data point to a significantly higher incidence of uterine anomalies in patients diagnosed with eccentric pregnancy implantation within the endometrial cavity. These results advocate for the value of differentiating between eccentric pregnancies in non-anomalous versus anomalous uteri.

Highly specific vaginal microbiome signature for gynecological cancers

To investigate the vaginal microbiota signature of patients with gynecologic cancer and evaluate its diagnostic biomarker potential. We incorporated vaginal 16S rRNA-seq data from 529 women and utilized VSEARCH to analyze the raw data. α-Diversity was evaluated utilizing the Chao1, Shannon, and Simpson indices, and β-diversity was evaluated through principal component analysis using Bray-Curtis distances. Linear discriminant analysis effect size (LEfSe) was utilized to determine species differences between groups. A bacterial co-abundance network was constructed utilizing Spearman correlation analysis. A random forest model of gynecologic tumor risk based on genus was constructed and validated to test its diagnostic efficacy. In gynecologic cancer patients, vaginal α-diversity was significantly greater than in controls, and vaginal β-diversity was significantly separated from that of controls; there was no correlation between these characteristics and menopause status among the subject women. Women diagnosed with gynecological cancer exhibited a reduction in the abundance of vaginal Firmicutes and Lactobacillus, while an increase was observed in the proportions of Bacteroidetes, Proteobacteria, Prevotella, Streptococcus, and Anaerococcus. A random forest model constructed based on 56 genus achieved high accuracy (area under the curve = 84.96%) in gynecological cancer risk prediction. Furthermore, there were discrepancies observed in the community complexity of co-abundance networks between gynecologic cancer patients and the control group. Our study provides evidence that women with gynecologic cancer have a unique vaginal flora structure and microorganisms may be involved in the gynecologic carcinogenesis process. A gynecological cancer risk prediction model based on characteristic genera has good diagnostic value.

Incidence of histologic chorioamnionitis in a rural community hospital

BACKGROUND

Histological chorioamnionitis (HCA) is a pathological condition defined as an acute inflammation of the amniochorionic membranes which has been linked to a wide range of adverse neonatal events.

AIM

The purpose of this study is to identify the incidence of HCA in the rural population and evaluate whether there are significant differences in these incidences within the different clinical parameters of delivery method, gravidity, gestational age, previous cesarean section, reason for cesarean section and body mass index (BMI).

METHODS

A retrospective chart review was conducted on 462 consecutive deliveries that occurred in a rural hospital during a four-year period. Data collected was analyzed using independent sample T-tests, chi-squared tests, and descriptive statistics, with a p-value of < 0.05.

RESULTS

Overall incidence of HCA was 15.9% (73/459), with a term incidence of 16.2% (68/421) and preterm incidence of 13.2% (5/38). The incidence of HCA was significantly higher in vaginal deliveries (18.8%; n = 54/288) than C-section deliveries (11.1%; n = 19/171) (p = 0.03). Incidence of clinical chorioamnionitis was 0.43% (2/462), with 2.74% (2/73) of HCA manifesting clinically.

CONCLUSIONS

Evaluation of the incidence of HCA and associated clinical parameters in this study showed a marked decrease in the incidence of HCA when compared to other studies. Strategies to reduce the incidence of HCA include reducing the length of labor via active labor management. We hypothesize that these findings are due to the consistent use of active labor management and our rural study population, but further investigation is required to confirm this.

The role of the endometrial microbiome in embryo implantation and recurrent implantation failure

There is a suggested pathophysiology associated with endometrial microbiota in cases where repeated implantation failure of high-quality embryos is observed. However, there is a suspected association between endometrial microbiota and the pathogenesis of implantation failure. However, there is still a lack of agreement on the fundamental composition of the physiological microbiome within the uterine cavity. This is primarily due to various limitations in the studies conducted, including small sample sizes and variations in experimental designs. As a result, the impact of bacterial communities in the endometrium on human reproduction is still a subject of debate. In this discourse, we undertake a comprehensive examination of the existing body of research pertaining to the uterine microbiota and its intricate interplay with the process of embryo implantation.

Clinical chorioamnionitis at term: definition, pathogenesis, microbiology, diagnosis, and treatment

Clinical chorioamnionitis, the most common infection-related diagnosis in labor and delivery units, is an antecedent of puerperal infection and neonatal sepsis. The condition is suspected when intrapartum fever is associated with two other maternal and fetal signs of local or systemic inflammation (eg, maternal tachycardia, uterine tenderness, maternal leukocytosis, malodorous vaginal discharge or amniotic fluid, and fetal tachycardia). Clinical chorioamnionitis is a syndrome caused by intraamniotic infection, sterile intraamniotic inflammation (inflammation without bacteria), or systemic maternal inflammation induced by epidural analgesia. In cases of uncertainty, a definitive diagnosis can be made by analyzing amniotic fluid with methods to detect bacteria (Gram stain, culture, or microbial nucleic acid) and inflammation (white blood cell count, glucose concentration, interleukin-6, interleukin-8, matrix metalloproteinase-8). The most common microorganisms are Ureaplasma species, and polymicrobial infections occur in 70% of cases. The fetal attack rate is low, and the rate of positive neonatal blood cultures ranges between 0.2% and 4%. Intrapartum antibiotic administration is the standard treatment to reduce neonatal sepsis. Treatment with ampicillin and gentamicin have been recommended by professional societies, although other antibiotic regimens, eg, cephalosporins, have been used. Given the importance of Ureaplasma species as a cause of intraamniotic infection, consideration needs to be given to the administration of antimicrobial agents effective against these microorganisms such as azithromycin or clarithromycin. We have used the combination of ceftriaxone, clarithromycin, and metronidazole, which has been shown to eradicate intraamniotic infection with microbiologic studies. Routine testing of neonates born to affected mothers for genital mycoplasmas could improve the detection of neonatal sepsis. Clinical chorioamnionitis is associated with decreased uterine activity, failure to progress in labor, and postpartum hemorrhage; however, clinical chorioamnionitis by itself is not an indication for cesarean delivery. Oxytocin is often administered for labor augmentation, and it is prudent to have uterotonic agents at hand to manage postpartum hemorrhage. Infants born to mothers with clinical chorioamnionitis near term are at risk for early-onset neonatal sepsis and for long-term disability such as cerebral palsy. A frontier is the noninvasive assessment of amniotic fluid to diagnose intraamniotic inflammation with a transcervical amniotic fluid collector and a rapid bedside test for IL-8 for patients with ruptured membranes. This approach promises to improve diagnostic accuracy and to provide a basis for antimicrobial administration.

A Landscape View of the Female Genital Tract Microbiome in Healthy Controls and Women With Reproductive Health Conditions Associated With Ectopic Pregnancy

Disruption of the female genital microbiome is associated with several pregnancy complications, including miscarriage, preterm onset of labour, and tubal pregnancy. Ectopic pregnancy is a known cause of maternal morbidity and mortality, but early diagnosis and treatment of ectopic pregnancy remain a challenge. Despite growing established associations between genital microbiome and female reproductive health, few studies have specifically focused on its link with ectopic pregnancy. Therefore, the current review aims to provide a comprehensive account of the female genital microbiome in healthy and fertile women compared to those in ectopic pregnancy and its associated risk factors. The microbial diversity from various sites of the female genital tract was explored for a reliable proxy of female reproductive health in sequencing-based ectopic pregnancy research. Our report confirmed the predominance of Lactobacillus in the vagina and the cervix among healthy women. The relative abundance decreased in the vaginal and cervical microbiome in the disease state. In contrast, there were inconsistent findings on the uterine microbiome across studies. Additionally, we explore a spectrum of opportunities to enhance our understanding of the female genital tract microbiome and reproductive conditions. In conclusion, this study identifies gaps within the field and emphasises the need for visionary solutions in metagenomic tools for the early detection of ectopic pregnancy and other gynaecological diseases.

Why Does Your Uterus Become Malignant? The Impact of the Microbiome on Endometrial Carcinogenesis

The aim of this review was to describe the uterine microbiome composition that has been analyzed so far and describe potential pathways in the carcinogenesis of the endometrium. The microbiome in the uterine environment is involved in apoptosis and proliferation during the menstruation cycle, pregnancy maintenance, and immune system support. However, bacteria in the uterus could stimulate inflammation, which when chronic results in malignancy. An altered gut microbiota initiates an inflammatory response through microorganism-associated molecular patterns, which leads to intensified steroidogenesis in the ovaries and cancers. Moreover, intestinal bacteria secreting the enzyme β-glucuronidase may increase the level of circulating estrogen and, as a result, be influential in gynecological cancers. Both the uterine and the gut microbiota play a pivotal role in immune modulation, which is why there is a demand for further investigation from both the diagnostic and the therapeutic perspectives.

Systematic review of the association between talc and female reproductive tract cancers

Talc is a hydrous magnesium sheet silicate used in cosmetic powders, ceramics, paints, rubber, and many other products. We conducted a systematic review of the potential carcinogenicity of genitally applied talc in humans. Our systematic review methods adhere to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and incorporated aspects from the US Institute of Medicine (IOM, now the National Academy of Medicine) and several US EPA frameworks for systematic reviews, evaluating and integrating the epidemiological, animal, and mechanistic literature on talc and cancer. We conducted a comprehensive literature search. Detailed data abstraction and study quality evaluation, adapting the Toxic Substances Control Act (TSCA) framework, were central to our analysis. The literature search and selection process identified 40 primary studies that assessed exposure to talc and female reproductive cancer risks in humans (n = 36) and animals (n = 4). The results of our evaluation emphasize the importance of considering biological plausibility and study quality in systematic review. Integrating all streams of evidence according to the IOM framework yielded classifications of suggestive evidence of no association between perineal application of talcum powders and risk of ovarian cancer at human-relevant exposure levels. We also concluded that there is suggestive evidence of no association between genital talc application and endometrial cancer, and insufficient evidence to determine whether a causal association exists between genital talc application and cervical cancer based on a smaller but largely null body of literature.

How Do Microorganisms Influence the Development of Endometriosis? Participation of Genital, Intestinal and Oral Microbiota in Metabolic Regulation and Immunopathogenesis of Endometriosis

Microorganisms inhabiting the human body play an extremely key role in its proper functioning, as well as in the development of the immune system, which, by maintaining the immune balance, allows you to enjoy health. Dysbiosis of the intestinal microbiota, or in the oral cavity or reproductive tract, understood as a change in the number and diversity of all microorganisms inhabiting them, may correlate with the development of many diseases, including endometriosis, as researchers have emphasized. Endometriosis is an inflammatory, estrogen-dependent gynecological condition defined by the growth of endometrial cells outside the uterine cavity. Deregulation of immune homeostasis resulting from microbiological disorders may generate chronic inflammation, thus creating an environment conducive to the increased adhesion and angiogenesis involved in the development of endometriosis. In addition, research in recent years has implicated bacterial contamination and immune activation, reduced gastrointestinal function by cytokines, altered estrogen metabolism and signaling, and abnormal progenitor and stem cell homeostasis, in the pathogenesis of endometriosis. The aim of this review was to present the influence of intestinal, oral and genital microbiota dysbiosis in the metabolic regulation and immunopathogenesis of endometriosis.

Vaginal and tumor microbiomes in gynecological cancer (Review)

Cervical, ovarian and endometrial cancer are the three most common types of gynecologic cancer. As a hub, the vagina connects the site of gynecological cancer with the external environment. Lactobacilli participate in the formation of a healthy vaginal microenvironment as the first line of defense against pathogen invasion; a dysbiotic vaginal microenvironment loses its original protective function and is associated with the onset, metastasis, poor efficacy and poor prognosis of gynecological cancer. The early diagnosis of cancer is the key to improve the survival time of patients with cancer. The screening of Porphyromonas, Sneathia and Atopobium vaginae, and other microbial markers, can assist the diagnosis of gynecological cancer, and screen out the high-risk population as early as possible. With the in-depth study of the microbes in tumor tissues, reasearchers have analyzed the immunological associations of microorganisms in tumor tissues. Due to the structural-functional interconnection between the organ of gynecological tumorigenesis and the vagina, the present study aims to review the relationship between vaginal and tumor microorganisms and gynecological cancer in terms of occurrence, screening, treatment and prognosis.

The Role of Microbiota in the Immunopathogenesis of Endometrial Cancer

The female reproductive tract hosts a specific microbiome, which plays a crucial role in sustaining equilibrium and good health. In the majority of reproductive women, the microbiota (all bacteria, viruses, fungi, and other single-celled organisms within the human body) of the vaginal and cervical microenvironment are dominated by Lactobacillus species, which benefit the host through symbiotic relationships, in comparison to the uterus, fallopian tubes, and ovaries, which may contain a low-biomass microbiome with a diverse mixture of microorganisms. Although disruption to the balance of the microbiota develops, the altered immune and metabolic signaling may cause an impact on diseases such as cancer. These pathophysiological modifications in the gut–uterus axis may spark gynecological cancers. New information displays that gynecological and gastrointestinal tract dysbiosis (disruption of the microbiota homeostasis) can play an active role in the advancement and metastasis of gynecological neoplasms, such as cervical, endometrial, and ovarian cancers. Understanding the relationship between microbiota and endometrial cancer is critical for prognosis, diagnosis, prevention, and the development of innovative treatments. Identifying a specific microbiome may become an effective method for characterization of the specific microbiota involved in endometrial carcinogenesis. The aim of this study was to summarize the current state of knowledge that describes the correlation of microbiota with endometrial cancer with regard to the formation of immunological pathologies.

The effects of female-male friendships on male postcopulatory levels of oxytocin and vasopressin, and sperm parameters in Macacaarctoides

Male and female stump-tailed macaques (Macaca arctoides) form close relationships akin to human friendships. Oxytocin and vasopressin modulate these and other social relationships and reproductive behavior and physiology in various mammal species. Besides the behavioral effects of oxytocin, this hormone plays an essential role in the ejaculatory process, favoring sperm transport upward the female reproductive tract. Therefore, we investigated the influence of friendships on postcopulatory serum levels of oxytocin and vasopressin in the stump-tailed macaque (Macaca arctoides). In addition, we searched for a correlation between this kind of social relationship and sperm transport in the vagina during the periovulatory and luteal phases. Six female and six male adult macaques having different friendship indices served as experimental animals. Allocated in 57 mating pairs combinations, these animals were allowed to copulate once in the luteal and periovulatory phases. Blood samples were collected from each animal finishing copulation to measure oxytocin and vasopressin. Afterward, we profoundly sedated the females and collected three semen samples from the vagina every 10 min to perform spermatobioscopies. Males' post-copulation oxytocin values increased along with the friendship index, while vasopressin behaves oppositely. Sperm concentration and immotile and motile sperm decreased from one sample to another as male-female closeness increased. Finally, in the periovulatory phase, only in the first vaginal sample, sperm velocities significantly increased with friendship indices. Our results showed that in stump-tailed macaques, heterosexual friendships promote higher postcopulatory oxytocin concentrations and better physiological conditions to males, which probably enhance reproductive success.

Mode Switch of Ca2 + Oscillation-Mediated Uterine Peristalsis and Associated Embryo Implantation Impairments in Mouse Adenomyosis

Adenomyosis is a debilitating gynecological disease of the uterus with no medicinal cure. The tissue injury and repair hypothesis for adenomyosis suggests that uterine hyperperistalsis or dysperistalsis plays a pivotal role in establishing adenomyotic lesions. However, specific impairments in uterine peristalsis and the underlying cellular signals for these changes in adenomyosis remain elusive. Here, we report a precision-cut uterine slice preparation that preserves in vivo uterine architecture and generates peristalsis similar to that seen in the whole uterus. We found that uterine peristalsis in neonatal mice at day 14 and adult mice at day 55 presents as bursts with multiple peaks induced by intracellular Ca²⁺ oscillations. Using a mouse model of adenomyosis induced by tamoxifen, a selective estrogen receptor modulator, we discovered that uterine peristalsis and Ca²⁺ oscillations from adenomyotic uteri on days 14 and 55 become spikes (single peaks) with smaller amplitudes. The peak frequency of Ca²⁺ oscillations or peristalsis does not show a difference between control and adenomyotic mice. However, both the estimated force generated by uterine peristalsis and the total Ca²⁺ raised by Ca²⁺ oscillations are smaller in uteri from adenomyotic mice. Uteri from adenomyotic mice on day 14, but not on day 55, exhibit hyperresponsiveness to oxytocin. Embryo implantations are decreased in adenomyotic adult mice. Our results reveal a mode switch from bursts to spikes (rather than an increased peak frequency) of uterine Ca²⁺ oscillations and peristalsis and concurrent hyperresponsiveness to oxytocin in the neonatal stage are two characteristics of adenomyosis. These characteristics may contribute to embryo implantation impairments and decreased fertility in adenomyosis.

The role of gut and genital microbiota and the estrobolome in endometriosis, infertility and chronic pelvic pain

BACKGROUND

Endometriosis is a chronic, burdensome condition that is historically understudied. Consequently, there is a lack of understanding of the etiology of the disease and its associated symptoms, including infertility and chronic pelvic pain (CPP). Endometriosis development is influenced by estrogen metabolism and inflammation, which are modulated by several factors including the microbiome and the estrobolome (the collection of genes encoding estrogen-metabolizing enzymes in the gut microbiome). Therefore, there is increasing interest in understanding the role of microbiota in endometriosis etiology.

OBJECTIVE AND RATIONALE

To date, there is no cure for endometriosis and treatment options often are ineffective. This manuscript will review the potential relationship between the microbiome and endometriosis, infertility and CPP and highlight the available data on the microbiome in relation to endometriosis and its related symptoms. The overarching goal of this manuscript is to inform future microbiome research that will lead to a deeper understanding of the etiology of the disease and possible diagnostic modalities and treatments. The potential impact of the microbiome on estrogen regulation modulated by the estrobolome, as well as inflammation and other endometriosis-promoting mechanisms within the genital tract, will be reviewed. The methodological limitations of microbiome-related studies will be critically assessed to provide improved guidelines for future microbiome and clinical studies.

SEARCH METHODS

PubMed databases were searched using the following keywords: endometriosis AND microbiome, infertility AND microbiome, pelvic pain AND microbiome, IVF (in-vitro fertilization) AND microbiome, endometriosis AND infertility. Clinical and preclinical animal trials that were eligible for review, and related to microbiome and endometriosis, infertility or CPP were included. All available manuscripts were published in 2002-2021.

OUTCOMES

In total, 28 clinical and 6 animal studies were included in the review. In both human and animal studies, bacteria were enriched in endometriosis groups, although there was no clear consensus on specific microbiota compositions that were associated with endometriosis, and no studies included infertility or CPP with endometriosis. However, bacterial vaginosis-associated bacteria and Lactobacillus depletion in the cervicovaginal microbiome were associated with endometriosis and infertility in the majority (23/28) of studies. Interpretation of endometrial studies is limited owing to a variety of methodological factors, discussed in this review. In addition, metadata outlining antibiotic usage, age, race/ethnicity, menopausal status and timing of sample collection in relation to diagnosis of endometriosis was not consistently reported. Animal studies (6/6) support a bidirectional relationship between the gut microbiota and endometriosis onset and progression.

WIDER IMPLICATIONS

There is evidence that a dysbiotic gut or genital microbiota is associated with multiple gynecologic conditions, with mounting data supporting an association between the microbiome and endometriosis and infertility. These microbiomes likely play a role in the gut-brain axis, which further supports a putative association with the spectrum of symptoms associated with endometriosis, including infertility and CPP. Collectively, this review highlights the demand for more rigorous and transparent methodology and controls, consistency across the field, and inclusion of key demographic and clinical characteristics of disease and comparison participants. Rigorous study designs will allow for a better understanding of the potential role of the microbiome in endometriosis etiology and the relationship to other disorders of the female reproductive tract.

CHRONIC ENDOMETRITIS IN PATIENTS WITH REPEATED IMPLANTATION FAILURES:EPIDEMIOLOGY, ETIOLOGY, PATHOGENESIS AND OVERCOMING INFERTILITY

Recent evidence indicates that the endometrium plays a much more important role in successful implantation and clinical pregnancy than many other recognized factors. Chronic endometritis (CE) is associated with negative reproductive outcomes, including repeated implantation failures. Streptococcus spp., Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae, Staphylococcus spp., Corynebacterium and Mycoplasma / Ureaplasmaspp are currently considered the main pathogens of CE. This disease disrupts the architectonics of the endometrium at different levels: first of all, CE promotes changes in the population of immunocompetent cells and, therefore, contributes to the disruption of the local immune response in the endometrium at the time of implantation. Antibiotic treatment for CE improves implantation rates and decreases abortion rates, although there are no well-designed prospective studies to support this conclusion. Considering the insufficient effectiveness of antibiotic therapy for CE, especially in cases of resistance of pathogens, or in the case of viral chronic endometritis, it is necessary to develop schemes with additional use of drugs that affect other etiopathogenetic pathways of development and maintenance of CE. An example of such a treatment can be cytokine therapy, which requires further study regarding the efficacy and safety in CE therapy.

Sperm migration, selection, survival, and fertilizing ability in the mammalian oviduct†

In vitro fertilization (IVF) gives rise to embryos in a number of mammalian species and is currently widely used for assisted reproduction in humans and for genetic purposes in cattle. However, the rate of polyspermy is generally higher in vitro than in vivo and IVF remains ineffective in some domestic species like pigs and horses, highlighting the importance of the female reproductive tract for gamete quality and fertilization. In this review, the way the female environment modulates sperm selective migration, survival, and acquisition of fertilizing ability in the oviduct is being considered under six aspects: (1) the utero-tubal junction that selects a sperm sub-population entering the oviduct; (2) the presence of sperm binding sites on luminal epithelial cells in the oviduct, which prolong sperm viability and plays a role in limiting polyspermic fertilization; (3) the contractions of the oviduct, which promote sperm migration toward the site of fertilization in the ampulla; (4) the regions of the oviduct, which play different roles in regulating sperm physiology and interactions with oviduct epithelial cells; (5) the time of ovulation, and (6) the steroid hormonal environment which regulates sperm release from the luminal epithelial cells and facilitates capacitation in a finely orchestrated manner.

Recent advances in critical nodes of embryo engineering technology

The normal development and maturation of oocytes and sperm, the formation of fertilized ova, the implantation of early embryos, and the growth and development of foetuses are the biological basis of mammalian reproduction. Therefore, research on oocytes has always occupied a very important position in the life sciences and reproductive medicine fields. Various embryo engineering technologies for oocytes, early embryo formation and subsequent developmental stages and different target sites, such as gene editing, intracytoplasmic sperm injection (ICSI), preimplantation genetic diagnosis (PGD), and somatic cell nuclear transfer (SCNT) technologies, have all been established and widely used in industrialization. However, as research continues to deepen and target species become more advanced, embryo engineering technology has also been developing in a more complex and sophisticated direction. At the same time, the success rate also shows a declining trend, resulting in an extension of the research and development cycle and rising costs. By studying the existing embryo engineering technology process, we discovered three critical nodes that have the greatest impact on the development of oocytes and early embryos, namely, oocyte micromanipulation, oocyte electrical activation/reconstructed embryo electrofusion, and the in vitro culture of early embryos. This article mainly demonstrates the efforts made by researchers in the relevant technologies of these three critical nodes from an engineering perspective, analyses the shortcomings of the current technology, and proposes a plan and prospects for the development of embryo engineering technology in the future.

Labor dystocia and risk of histological chorioamnionitis and funisitis: a study from a single tertiary referral center

Background

Intrauterine inflammation affects short- and long-term neonatal outcomes. Histological chorioamnionitis and funisitis are acute inflammatory responses in the fetal membranes and umbilical cord, respectively. Although labor dystocia includes a potential risk of intrauterine inflammation, the risk of histological chorioamnionitis and funisitis of labor dystocia has not been evaluated yet. This study aimed to examine the association between labor dystocia and risk of histological chorioamnionitis and funisitis.

Methods

In this retrospective cohort study, the cases who underwent histopathological examinations of the placenta and umbilical cord at Fukushima Medical University Hospital, Japan, between 2015 and 2020, were included. From the dataset, the pathological findings of the patients with labor dystocia and spontaneous preterm birth were reviewed. Based on the location of leukocytes, the inflammation in the placenta (histological chorioamnionitis) and umbilical cord (funisitis) was staged as 0–3. Multiple logistic regression analysis was performed to evaluate the risk of histological chorioamnionitis, histological chorioamnionitis stage ≥2, funisitis, and funisitis stage ≥2.

Result

Of 317 women who met the study criteria, 83 and 144 women had labor dystocia and spontaneous preterm birth, respectively, and 90 women were included as controls. Labor dystocia was a risk factor for histological chorioamnionitis (adjusted odds ratio, 6.3; 95% confidential interval, 1.9–20.5), histological chorioamnionitis stage ≥2 (adjusted odds ratio, 6.0; 95% confidence interval, 1.7–21.8), funisitis (adjusted odds ratio, 15.4; 95% confidence interval, 2.3–101.3), and funisitis stage ≥2 (adjusted odds ratio, 18.5; 95% confidence interval, 2.5–134.0). Spontaneous preterm birth was also a risk factor for histological chorioamnionitis (adjusted odds ratio, 3.7; 95% confidence interval, 1.7–7.8), histological chorioamnionitis stage ≥2 (adjusted odds ratio, 3.0; 95% confidence interval, 1.2–7.9), and funisitis (adjusted odds ratio, 6.6; 95% confidence interval, 1.4–30.6). However, the adjusted odds ratio was smaller in spontaneous preterm births than in labor dystocia.

Conclusion

Labor dystocia is a risk factor for severe histological chorioamnionitis and funisitis. Further studies are required to evaluate the effects of histological chorioamnionitis and funisitis on long-term neonatal outcomes.

Clinical chorioamnionitis at term X: microbiology, clinical signs, placental pathology, and neonatal bacteremia - implications for clinical care

OBJECTIVES

Clinical chorioamnionitis at term is considered the most common infection-related diagnosis in labor and delivery units worldwide. The syndrome affects 5-12% of all term pregnancies and is a leading cause of maternal morbidity and mortality as well as neonatal death and sepsis. The objectives of this study were to determine the (1) amniotic fluid microbiology using cultivation and molecular microbiologic techniques; (2) diagnostic accuracy of the clinical criteria used to identify patients with intra-amniotic infection; (3) relationship between acute inflammatory lesions of the placenta (maternal and fetal inflammatory responses) and amniotic fluid microbiology and inflammatory markers; and (4) frequency of neonatal bacteremia.

METHODS

This retrospective cross-sectional study included 43 women with the diagnosis of clinical chorioamnionitis at term. The presence of microorganisms in the amniotic cavity was determined through the analysis of amniotic fluid samples by cultivation for aerobes, anaerobes, and genital mycoplasmas. A broad-range polymerase chain reaction coupled with electrospray ionization mass spectrometry was also used to detect bacteria, select viruses, and fungi. Intra-amniotic inflammation was defined as an elevated amniotic fluid interleukin-6 (IL-6) concentration ≥2.6 ng/mL.

RESULTS

(1) Intra-amniotic infection (defined as the combination of microorganisms detected in amniotic fluid and an elevated IL-6 concentration) was present in 63% (27/43) of cases; (2) the most common microorganisms found in the amniotic fluid samples were Ureaplasma species, followed by Gardnerella vaginalis; (3) sterile intra-amniotic inflammation (elevated IL-6 in amniotic fluid but without detectable microorganisms) was present in 5% (2/43) of cases; (4) 26% of patients with the diagnosis of clinical chorioamnionitis had no evidence of intra-amniotic infection or intra-amniotic inflammation; (5) intra-amniotic infection was more common when the membranes were ruptured than when they were intact (78% [21/27] vs. 38% [6/16]; p=0.01); (6) the traditional criteria for the diagnosis of clinical chorioamnionitis had poor diagnostic performance in identifying proven intra-amniotic infection (overall accuracy, 40-58%); (7) neonatal bacteremia was diagnosed in 4.9% (2/41) of cases; and (8) a fetal inflammatory response defined as the presence of severe acute funisitis was observed in 33% (9/27) of cases.

CONCLUSIONS

Clinical chorioamnionitis at term, a syndrome that can result from intra-amniotic infection, was diagnosed in approximately 63% of cases and sterile intra-amniotic inflammation in 5% of cases. However, a substantial number of patients had no evidence of intra-amniotic infection or intra-amniotic inflammation. Evidence of the fetal inflammatory response syndrome was frequently present, but microorganisms were detected in only 4.9% of cases based on cultures of aerobic and anaerobic bacteria in neonatal blood.

Biomechanics of Early Life in the Female Reproductive Tract

Early human life that starts at the onset of fertilization and ends with implantation of the embryo in the uterine wall is the foundation for a successful pregnancy. The different stages during this period require biomechanical mechanisms, which are mostly unknown due to difficulties to conduct in vivo studies in humans.

Microbial Colonization From the Fetus to Early Childhood-A Comprehensive Review

The development of the neonatal gastrointestinal tract microbiota remains a poorly understood process. The interplay between neonatal (gestational age, genetic background), maternal (mode of delivery, nutritional status) and environmental factors (antibiotic exposure, available nutrition) are thought to influence microbial colonization, however, the exact mechanisms are unclear. Derangements in this process likely contribute to various gastrointestinal diseases including necrotizing enterocolitis and inflammatory bowel disease. As such, enhanced understanding of microbiota development may hold the key to significantly reduce the burden of gastrointestinal disease in the pediatric population. The most debatable topics during microbial seeding and possible future treatment approaches will be highlighted in this review.

Uterine microbiome-low biomass and high expectations†

The existence of different bacterial communities throughout the female reproductive tract has challenged the traditional view of human fetal development as a sterile event. There is still no consensus on what physiological microbiota exists in the upper reproductive tract of the vast majority of women who are not in periods of infection or pregnancy, and the role of bacteria that colonize the upper reproductive tract in uterine diseases or pregnancy outcomes is not well established. Despite published studies and advances in uterine microbiome sequencing, some study aspects-such as study design, sampling method, DNA extraction, sequencing methods, downstream analysis, and assignment of taxa-have not yet been improved and standardized. It is time to further investigate the uterine microbiome to increase our understanding of the female reproductive tract and to develop more personalized reproductive therapies, highlighting the potential importance of using microbiological assessment in infertile patients.

New Opportunities for Endometrial Health by Modifying Uterine Microbial Composition: Present or Future?

Current knowledge suggests that the uterus harbours its own microbiota, where the microbes could influence the uterine functions in health and disease; however, the core uterine microbial composition and the host-microbial relationships remain to be fully elucidated. Different studies are indicating, based on next-generation sequencing techniques, that microbial dysbiosis could be associated with several gynaecological disorders, such as endometriosis, chronic endometritis, dysfunctional menstrual bleeding, endometrial cancer, and infertility. Treatments using antibiotics and probiotics and/or prebiotics for endometrial microbial dysbiosis are being applied. Nevertheless there is no unified protocol for assessing the endometrial dysbiosis and no optimal treatment protocol for the established dysbiosis. With this review we outline the microbes (mostly bacteria) identified in the endometrial microbiome studies, the current treatments offered for bacterial dysbiosis in the clinical setting, and the future possibilities such as pro- and prebiotics and microbial transplants for modifying uterine microbial composition.

Microbial burden and inflammasome activation in amniotic fluid of patients with preterm prelabor rupture of membranes

Background Intra-amniotic inflammation, which is associated with adverse pregnancy outcomes, can occur in the presence or absence of detectable microorganisms, and involves activation of the inflammasome. Intra-amniotic inflammasome activation has been reported in clinical chorioamnionitis at term and preterm labor with intact membranes, but it has not yet been investigated in women with preterm prelabor rupture of membranes (preterm PROM) in the presence/absence of detectable microorganisms. The aim of this study was to determine whether, among women with preterm PROM, there is an association between detectable microorganisms in amniotic fluid and intra-amniotic inflammation, and whether intra-amniotic inflammasome activation correlates with microbial burden. Methods Amniotic fluids from 59 cases of preterm PROM were examined for the presence/absence of microorganisms through culture and 16S ribosomal RNA (rRNA) gene quantitative real-time polymerase chain reaction (qPCR), and concentrations of interleukin-6 (IL-6) and ASC [apoptosis-associated spec-like protein containing a caspase recruitment domain (CARD)], an indicator of inflammasome activation, were determined. Results qPCR identified more microbe-positive amniotic fluids than culture. Greater than 50% of patients with a negative culture and high IL-6 concentration in amniotic fluid yielded a positive qPCR signal. ASC concentrations were greatest in patients with high qPCR signals and elevated IL-6 concentrations in amniotic fluid (i.e. intra-amniotic infection). ASC concentrations tended to increase in patients without detectable microorganisms but yet with elevated IL-6 concentrations (i.e. sterile intra-amniotic inflammation) compared to those without intra-amniotic inflammation. Conclusion qPCR is a valuable complement to microbiological culture for the detection of microorganisms in the amniotic cavity in women with preterm PROM, and microbial burden is associated with the severity of intra-amniotic inflammatory response, including inflammasome activation.

Vaginal dysbiosis associated-bacteria Megasphaera elsdenii and Prevotella timonensis induce immune activation via dendritic cells

Dysbiosis of the vaginal microbiome as a result of overgrowth of anaerobic bacteria leads to bacterial vaginosis (BV) which is associated with increased inflammation in the genital mucosa. Moreover, BV increases susceptibility to sexual transmitted infections (STIs) and is associated with adverse pregnancy outcomes. It remains unclear how specific vaginal aerobic and anaerobic bacteria affect health and disease. We selected different vaginal bacteria ranging from true commensals to species associated with dysbiosis and investigated their effects on activation of dendritic cells (DCs). Commensal Lactobacilli crispatus did not induce DC maturation nor led to production of pro-inflammatory cytokines. In contrast, BV-associated bacteria Megasphaera elsdenii and Prevotella timonensis induced DC maturation and increased levels of pro-inflammatory cytokines. Notably, DCs stimulated with Prevotella timonensis suppressed Th2 responses and induced Th1 skewing, typically associated with preterm birth. In contrast, Lactobacillus crispatus and Megasphaera elsdenii did not affect Th cell polarization. These results strongly indicate that the interaction of vaginal bacteria with mucosal DCs determines mucosal inflammation and we have identified the anaerobic bacterium Prevotella timonensis as a strong inducer of inflammatory responses. Specifically targeting these inflammation-inducing bacteria might be a therapeutic strategy to prevent BV and associated risks in STI susceptibility and preterm birth.

The differential distribution of bacteria between cancerous and noncancerous ovarian tissues in situ

Background

With the improvement of bacterial detection, the theory of the sterile female upper reproductive tract has been frequently challenged in recent years. However, thus far, no researchers have used ovaries as study targets.

Methods

Six women who were diagnosed with ovarian cancer were included in the cancer group, and ten women who were diagnosed with a noncancerous ovarian condition (including three patients with uterine myoma and seven patients with uterine adenomyosis) were included in the control group. Immunohistochemistry staining using an antibacterial lipopolysaccharide (LPS) antibody was used to confirm the presence of bacteria in the ovarian tissues. In addition, 16S rRNA sequencing was used to compare the differences in the bacteria between ovarian cancer tissues and noncancerous ovarian tissues. BugBase and Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) were used to predict the functional composition of the bacteria.

Results

Bacterial LPS was present in ovarian cancer tissue and noncancerous ovarian tissue, which implied the presence of bacteria in ovarian tissue. When compared to the noncancerous ovarian bacteria at the phylum level, the cancerous ovarian bacteria were composed of increased Aquificae and Planctomycetes and decreased Crenarchaeota. When predicting metagenomes, gene functions associated with the potentially pathogenic and the oxidative stress-tolerant phenotype were enriched in the ovaries of the cancer group. Forty-six significantly different KEGG pathways existed in the ovarian bacteria of the cancer group compared to that of the control group.

Conclusions

Different bacteria compositions were present in cancerous and noncancerous ovarian tissues.

Trial registration

Chines Clinical Trail Registry, CHiCTR1800020018, Registered 11 September 2018, http://www.chictr.org.cn/

Peculiarities of Uterine Cavity Biocenosis in Patients with Different Types of Endometrial Hyperproliferative Pathology

The peculiarities of the microbiocenosis of the uterine cavity in 184 patients of reproductive age with different types of endometrial hyperproliferative processes were studied: Group 1, n=60, non-atypical endometrial hyperplasia (NAEH); Group 2, n=62, endometrial polyps (EPs); Group 3, n=62, NAEH + EPs. Correlation analysis of the degree of association between different biological media (uterus and genital tract) was carried out. Contamination of the uterine cavity by bacterial flora was diagnosed in all groups of patients examined. Anaerobic flora was about 30% while bacteria of the genus Bacteroides were the most common. Among aerobic organisms, representatives of the Enterobacteriaceae family and coccal flora are noted. The widest was the spectrum of isolated microorganisms in patients of group 2 (with endometrial polyps). A strong positive correlation was established between indices of genital tract contamination and the uterine cavity by coccal flora, Escherichia coli, and anaerobic organisms. The findings suggest dysbiotic changes and the presence of a chronic inflammatory focus in the endometrium, which pathogenetically substantiates the application of anti-inflammatory therapy in such patients.

Bacterial Colonization of the Female Upper Genital Tract

Bacteria colonize most of the human body, and the female genital tract is not an exception. While the existence of a vaginal microbiota has been well established, the upper genital tract has been considered a sterile environment, with a general assumption that bacterial presence is associated with adverse clinical manifestation. However, recent metagenomic studies identified specific patterns of microbiota colonizing the uterus, fallopian tubes, ovaries, and placenta. These results need confirmation and further investigations since the data are only scarce. Bacterial colonization of these sites appears different from the vaginal one, despite evidence that vaginal bacteria could ascend to the upper genital tract through the cervix. Are these bacteria only commensal or do they play a role in the physiology of the female upper genital tract? Which are the genera that may have a negative and a positive impact on the female reproductive function? The aim of this review is to critically present all available data on upper genital tract microbiota and discuss its role in human reproduction, ranging from the technical aspects of these types of analyses to the description of specific bacterial genera. Although still very limited, research focusing on genital colonization of bacteria other than the vaginal milieu might bring novel insights into physiopathology of human reproduction.

Does the endometrial cavity have a molecular microbial signature?

Recent molecular studies concluded that the endometrium has a resident microbiota dominated by Lactobacillus spp. and is therefore similar to that of the vagina. These findings were largely derived from endometrial samples obtained through a transcervical catheter and thus prone to contamination. Herein, we investigated the molecular microbial profiles of mid-endometrial samples obtained through hysterectomy and compared them with those of the cervix, vagina, rectum, oral cavity, and controls for background DNA contamination. Microbial profiles were examined through 16S rRNA gene qPCR and sequencing. Universal bacterial qPCR of total 16S rDNA revealed a bacterial load exceeding that of background DNA controls in the endometrium of 60% (15/25) of the study subjects. Bacterial profiles of the endometrium differed from those of the oral cavity, rectum, vagina, and background DNA controls, but not of the cervix. The bacterial profiles of the endometrium and cervix were dominated by Acinetobacter, Pseudomonas, Cloacibacterium, and Comamonadaceae. Both 16S rRNA gene sequencing and Lactobacillus species-specific (L. iners & L crispatus) qPCR showed that Lactobacillus was rare in the endometrium. In conclusion, if there is a microbiota in the middle endometrium, it is not dominated by Lactobacillus as was previously concluded, yet further investigation using culture and microscopy is necessary.

Intrauterine Microbiota: Missing, or the Missing Link?

The intrauterine environment provides a key interface between the mother and the developing fetus during pregnancy, and is a target for investigating mechanisms of fetal programming. Studies have demonstrated an association between prenatal stress and neurodevelopmental disorders. The role of the intrauterine environment in mediating this effect is still being elucidated. In this review, we discuss emerging preclinical and clinical evidence suggesting the existence of microbial communities in utero. We also outline possible mechanisms of bacterial translocation to the intrauterine environment and immune responses to the presence of microbes or microbial components. Lastly, we overview the effects of intrauterine inflammation on neurodevelopment. We hypothesize that maternal gestational stress leads to disruptions in the maternal oral, gut, and vaginal microbiome that may lead to the translocation of bacteria to the intrauterine environment, eliciting an inflammatory response and resulting in deficits in neurodevelopment.

Molecular detection of microbial colonization in cervical mucus of women with and without endometriosis

PROBLEM

Intrauterine microbial colonization and its association with the pathogenesis of endometriosis via an innate immune cascade have been reported. As a potential source of microbial transmission, information on microbial colonization in cervical mucus is unknown. We investigated pattern of microbiota in the cervical mucus collected from women with and without endometriosis using next-generation sequencing (NGS) technology.

METHOD OF STUDY

Cervical mucus samples were collected from women with (n = 30) and without (n = 39) endometriosis. The communities of microbiota in cervical mucus in the endometriosis group and the control group were examined by Gram staining and NGS targeting the V5-V6 region of 16S ribosomal RNA gene. Copy number of some target bacteria was detected by real-time PCR.

RESULTS

We confirmed visual presence of bacteria in cervical mucus by Gram staining. NGS analysis showed that distribution of microbiota was similar in cervical mucus of women with and without endometriosis regardless of the phases of the menstrual cycle. In addition to predominant Lactobacilli spp., the populations of Corynebacterium, Enterobacteriaceae, Flavobacterium, Pseudomonas, and Streptococcus were increased in the endometriosis group. Of them, Enterobacteriaceae and Streptococcus were identified as the more significant candidates in the endometriosis group than in controls by real-time PCR (P < 0.05 for each).

CONCLUSION

Our NGS analysis of cervical mucus indicated that among a variable microbiota, two candidates (Enterobacteriaceae and Streptococcus) were more frequently detected in women with endometriosis. Further investigation is needed to elucidate a mechanistic link of these bacteria in the pathophysiology of endometriosis.

Microorganisms in the healthy upper reproductive tract: from denial to beneficial assignments for reproductive biology

Contrary to the traditional assumption of a sterile uterus, the number of studies characterizing microbial entities in the healthy upper reproductive tract (endometrial cavity, including follicular fluid and placenta) have been on the increase. Substantial data has been accumulated correlating microbial composition with fertility outcome. In this context, the presence of certain taxa was associated to an improved reproductive success. A summarization for the evidence of these molecular mechanisms through which bacteria may affect developmental processes during pregnancy is presented and discussed with special focus placed upon the immunological aspects.

Improvement of embryonic development and clinical outcomes of germinal vesicle stage oocytes using a microvibration culture system

In vitro maturation (IVM) has evolved as a clinical treatment option in assisted reproductive technology. However, the poor developmental potential of germinal vesicle (GV)-stage oocytes is still suboptimal. This study's objective was to evaluate the effect of a microvibration culture system (MVC) during IVM and/or in vitro culture (IVC) on the clinical outcomes and the embryonic development potential of human GV-stage oocytes collected from human chorionic gonadotropin (HCG)-primed IVM and fertilization-embryo transfer (IVM/F-ET) cycles of patients with polycystic ovaries (PCO). A total of 206 HCG-primed IVM/F-ET cycles were divided into four groups according to the microvibration and static culture system applied during IVM and/or IVC: Group SS (static system during both IVM and IVC); Group SV (static system during IVM alternated with microvibration system during IVC); Group VS (microvibration system during IVM alternated with static system during IVC), and Group VV (microvibration system during both IVM and IVC). The results indicate that the rates of in vitro MII oocytes per cycle, fertilization, and cleavage were not significantly different between the groups. The rate of good-quality embryos in Group SV tended to be higher than the rate in Groups SS and VS, but there was no significant difference between Group SS and Group SV. Clinical pregnancy, implantation, and live birth rates of Groups SV and VS were slightly higher than those of Group SS. However, the rate of good-quality embryos with at least six cells on day 4, the clinical pregnancy, implantation, and live births in Group VV were significantly higher than those in Group SS. These results indicate that, compared with the static culture system, the MVC system applied for both IVM and IVC seems to improve the clinical outcomes and the quality of embryos of GV oocytes derived from HCG-primed IVM/F-ET cycles in PCO patients. Abbreviations: PCO: polycystic ovaries; HCG: human chorionic gonadotropin; GV: germinal vesicle; MII: metaphase II; IVM: in vitro maturation; IVF: in vitro fertilization; IVC: in vitro culture: MVC: microvibration culture; SC: static culture; ICSI: intracytoplasmic sperm injection; IVM/F-ET: IVM and fertilization-embryo transfer; AMH: anti-Mullerian hormone; OHSS: ovarian hyperstimulation syndrome.

Review: Chronic endometritis and its effect on reproduction

AIM

Chronic endometritis (CE) is a disease of continuous and subtle inflammation characterized by the infiltration of plasma cells in the endometrial stromal area. Although the clinical significance of CE has been thought in clinical practice for a long time because it is either asymptomatic or presents with subtle symptoms, recent studies have shown the potential adverse effects of CE on fertility. In the present review, we focus on the concept, diagnosis, etiology, pathophysiology, diagnosis, impact on reproduction and treatment for it to understand CE.

METHODS

The published articles were reviewed.

RESULTS

The prevalence of CE has been found to be 2.8-56.8% in infertile women, 14-67.5% in women with recurrent implantation failure (RIF), and 9.3-67.6% in women with recurrent pregnancy loss. Microorganisms are thought to be a main cause of CE, since antibiotic treatment has been reported to be an effective therapy for CE. Common bacteria are frequently detected in the uterine cavity of CE patients by microbial culture. In CE endometrium, the prevalence of immune cells and decidualization has been reported to be modified, and these modifications are thought to adversely affect fertility. The gold standard for the diagnosis of CE is the histological detection of plasma cells in the stromal area of the endometrium in endometrial specimens, although universally accepted criteria for the diagnosis of CE have not been determined. The treatment currently thought to be most effective for the recovery of fertility in CE is administration of oral antibiotics. Patients whose CE has been cured have been reported to have a higher ongoing pregnancy rate, clinical pregnancy rate, and implantation rate compared with patients with persistent CE.

CONCLUSION

CE greatly affects implantation and impairs fertility. Antibiotic administration is an effective therapeutic option. Pregnancy rate in in vitro fertilization is improved when CE is cured by antibiotic.

In vitro decidualisation of human endometrial stromal cells is enhanced by seminal fluid extracellular vesicles

Extracellular vesicles are highly abundant in seminal fluids and have a known role enhancing sperm function. Clinical pregnancy rates after IVF treatment are improved after female exposure to seminal fluid. Seminal fluid extracellular vesicles (SF-EVs) are candidate enhancers, however, whether SF-EVs interact with cells from the endometrium and modulate the implantation processes is unknown. Here, we investigated whether SF-EVs interact with endometrial stromal cells (ESCs) and enhance decidualisation, a requisite for implantation. SF-EVs, isolated from human seminal fluid (n = 11) by ultracentrifugation, were characterised by nanoparticle tracking analysis and Western blotting, and purified using size exclusion chromatography. Non-decidualised and decidualised primary ESCs (n = 5) were then treated with SF-EVs. Binding of bio-maleimide-labelled SF-EVs was detected by flow cytometry and fluorescence microscopy. Prolactin and IGFBP-1 protein levels in culture media were also analysed after single and multiple SF-EV exposure. SF-EVs size ranged from 50 to 300 nm, and they expressed exosomal markers (ALIX, SYNTENIN-1, CD9 and CD81). SF-EVs bound to non-decidualised and decidualised ESCs at similar levels. ESCs prolactin secretion was increased after single (p = 0.0044) and multiple (p = 0.0021) SF-EV exposure. No differences were found in IGFBP-1 protein levels. In conclusion, SF-EVs enhance in vitro ESC decidualisation and increase secretion of prolactin, an essential hormone in implantation. This elucidates a novel role of SF-EVs on endometrial receptivity. Abbreviations: ECACC: European Collection of Authenticated Cell Cultures; ESCs: endometrial stromal cells; EVs: extracellular vesicles; FCS: foetal calf serum; HRP: horse-radish peroxidase; IFNγ: interferon-gamma; IGF: insulin-like growth factor; IGFBP-1: insulin-like growth factor binding protein 1; IVF: in vitro fertilisation; MVB: multivesicular bodies; NTA: nanoparticle tracking analysis; PRLR^−/−: homozygous prolactin receptor knockout; RT: room temperature; SF-EVs: seminal fluid extracellular vesicles; STR: short tandem repeat; TGFβ: transforming growth factor β; uNK: uterine natural killer

How uterine microbiota might be responsible for a receptive, fertile endometrium

BACKGROUND

Fertility depends on a receptive state of the endometrium, influenced by hormonal and anatomical adaptations, as well as the immune system. Local and systemic immunity is greatly influenced by microbiota. Recent discoveries of 16S rRNA in the endometrium and the ability to detect low-biomass microbiota fueled the notion that the uterus may be indeed a non-sterile compartment. To date, the concept of the 'sterile womb' focuses on in utero effects of microbiota on offspring and neonatal immunity. However, little awareness has been raised regarding the importance of uterine microbiota for endometrial physiology in reproductive health; manifested in fertility and placentation.

OBJECTIVE AND RATIONALE

Commensal colonization of the uterus has been widely discussed in the literature. The objective of this review is to outline the possible importance of this uterine colonization for a healthy, fertile uterus. We present the available evidence regarding uterine microbiota, focusing on recent findings based on 16S rRNA, and depict the possible importance of uterine colonization for a receptive endometrium. We highlight a possible role of uterine microbiota for host immunity and tissue adaptation, as well as conferring protection against pathogens. Based on knowledge of the interaction of the mucosal immune cells of the gut with the local microbiome, we want to investigate the potential implications of commensal colonization for uterine health.

SEARCH METHODS

PubMed and Google Scholar were searched for articles in English indexed from 1 January 2008 to 1 March 2018 for '16S rRNA', 'uterus' and related search terms to assess available evidence on uterine microbiome analysis. A manual search of the references within the resulting articles was performed. To investigate possible functional contributions of uterine microbiota to health, studies on microbiota of other body sites were additionally assessed.

OUTCOMES

Challenging the view of a sterile uterus is in its infancy and, to date, no conclusions on a 'core uterine microbiome' can be drawn. Nevertheless, evidence for certain microbiota and/or associated compounds in the uterus accumulates. The presence of microbiota or their constituent molecules, such as polysaccharide A of the Bacteroides fragilis capsule, go together with healthy physiological function. Lessons learned from the gut microbiome suggest that the microbiota of the uterus may potentially modulate immune cell subsets needed for implantation and have implications for tissue morphology. Microbiota can also be crucial in protection against uterine infections by defending their niche and competing with pathogens. Our review highlights the need for well-designed studies on a 'baseline' microbial state of the uterus representing the optimal starting point for implantation and subsequent placenta formation.

WIDER IMPLICATIONS

The complex interplay of processes and cells involved in healthy pregnancy is still poorly understood. The correct receptive endometrial state, including the local immune environment, is crucial not only for fertility but also placenta formation since initiation of placentation highly depends on interaction with immune cells. Implantation failure, recurrent pregnancy loss, and other pathologies of endometrium and placenta, such as pre-eclampsia, represent an increasing societal burden. More robust studies are needed to investigate uterine colonization. Based on current data, future research needs to include the uterine microbiome as a relevant factor in order to understand the players needed for healthy pregnancy.

Risk of intra-amniotic infection/inflammation and respiratory distress syndrome according to the birth order in twin preterm neonates

Objective: Prior studies have suggested that nonpresenting twins are more likely to develop respiratory distress syndrome (RDS) than presenting twins. While the underlying mechanism is not known, exposure to intra-amniotic infection/inflammation (IAI) has been associated with a reduced risk of RDS in singleton gestations. In the current study, we compared the risk of RDS in preterm twin neonates according to birth order with adjustment for the presence or absence of IAI.Methods: The study population consisted of consecutive twin neonates who delivered ≤35 weeks and underwent amniocentesis within 7 days of delivery. The frequency of RDS and IAI was compared between presenting and nonpresenting twin pairs. Amniotic fluid (AF) was cultured for aerobic/anaerobic bacteria and genital mycoplasma. IAI was defined as a positive AF culture or an AF white cell count ≥19/mm³.Results: A total of 120 twin pairs were enrolled. Compared with presenting twins, nonpresenting twins had a lower risk of IAI (36 vs. 26%, respectively, p < .05), but a higher risk of RDS (18 vs. 25%, respectively, p < .05). In multivariate analysis, only IAI remained significantly associated with RDS (OR 0.18, 95% CI 0.05-0.65), whereas birth order was not.Conclusions: In preterm twin neonates, the increased risk of RDS in nonpresenting twins is likely due to lower exposure to IAI and not birth order.

Poly (I:C) and LPS induce distinct immune responses by ovarian stromal fibroblasts

Despite its anatomical location, the ovary is a site of pathogen exposure in the human female reproductive tract (FRT). However, the role of ovarian stromal fibroblasts in immune protection is unclear. We generated a population of ovarian stromal fibroblasts derived from normal human ovaries that expressed the pattern recognition receptors TLR3, TLR4, RIG-I, & MDA5. Poly (I:C) and LPS, respective mimics of viral and bacterial infections, selectively upregulated antiviral gene expression and secretion of chemokines and antimicrobials. Poly (I:C) exclusively stimulated the expression of interferon (IFN) β, IFNλ1, and the IFN-stimulated gene OAS2. Poly (I:C) also significantly increased secretion of elafin, CCL20, and RANTES, but had no effect on SDF-1α. In contrast, LPS had no effect on IFN or ISG expression but significantly increased secretion of RANTES and SDF-1α. Secretions from poly (I:C)-treated fibroblasts had both greater anti-HIV activity and induced higher levels of CD4 + T cell chemotaxis than those from LPS-treated cells. Our studies demonstrate a potential key role for ovarian fibroblasts in innate immune protection against incoming pathogens in the normal ovary.

Hysteroscopic evaluation of tubal peristaltic dysfunction in unexplained infertility

It has been realised that rhythmic peristalsis of the ostia and tubes can be observed during hysteroscopy. The aim of this study was to examine the presence of tubal peristaltic dysfunction in unexplained infertility (UI). Hysteroscopy was performed in 35 women with UI and in 37 healthy fertile women. Bilateral tubal peristalses were assessed hysteroscopically by the observation of methylene blue injection and its transport to the Fallopian tubes. Tubal patency was evaluated with laparoscopic chromopertubation. Two women in control group (6.67%) and eight women in UI group (30.77%) had no tubal peristalsis, at least one tube with normal tubal patency. The difference was statistically significant (p = .019). Tubal peristaltic dysfunction may be a hidden cause of subfertility in women with bilateral patent Fallopian tubes. There is a definite need for larger trials to identify tubal peristaltic dysfunction as a cause of UI. Impact statement What is already known on this subject? Unexplained infertility has no identified pathophysiologic basis. It has been realised that rhythmic peristalsis of the ostia and tubes can be observed during hysteroscopy. What do the results of this study add? Tubal peristaltic dysfunction was detected in two tubes (3.70%) in a control group and nine tubes (19.57%) in women with unexplained infertility, when the tubes were patent. The difference was statistically significant (p = .012). What are the implications of these findings for clinical practice and/or further research? In cases of bilateral patent Fallopian tubes such as in unexplained infertility, tubal peristaltic dysfunction may be a hidden additional cause of subfertility.

Uterine Microbiota: Residents, Tourists, or Invaders?

Uterine microbiota have been reported under various conditions and populations; however, it is uncertain the level to which these bacteria are residents that maintain homeostasis, tourists that are readily eliminated or invaders that contribute to human disease. This review provides a historical timeline and summarizes the current status of this topic with the aim of promoting research priorities and discussion on this controversial topic. Discrepancies exist in current reports of uterine microbiota and are critically reviewed and examined. Established and putative routes of bacterial seeding of the human uterus and interactions with distal mucosal sites are discussed. Based upon the current literature, we highlight the need for additional robust clinical and translational studies in this area. In addition, we discuss the necessity for investigating host–microbiota interactions and the physiologic and functional impact of these microbiota on the local endometrial microenvironment as these mechanisms may influence poor reproductive, obstetric, and gynecologic health outcomes and sequelae.

Biomechanics of the human uterus

The appropriate biomechanical function of the uterus is required for the execution of human reproduction. These functions range from aiding the transport of the embryo to the implantation site, to remodeling its tissue walls to host the placenta, to protecting the fetus during gestation, to contracting forcefully for a safe parturition and postpartum, to remodeling back to its nonpregnant condition to renew the cycle of menstruation. To serve these remarkably diverse functions, the uterus is optimally geared with evolving and contractile muscle and tissue layers that are cued by chemical, hormonal, electrical, and mechanical signals. The relationship between these highly active biological signaling mechanisms and uterine biomechanical function is not completely understood for normal reproductive processes and pathological conditions such as adenomyosis, endometriosis, infertility and preterm labor. Animal studies have illuminated the rich structural function of the uterus, particularly in pregnancy. In humans, medical imaging techniques in ultrasound and magnetic resonance have been combined with computational engineering techniques to characterize the uterus in vivo, and advanced experimental techniques have explored uterine function using ex vivo tissue samples. The collective evidence presented in this review gives an overall perspective on uterine biomechanics related to both its nonpregnant and pregnant function, highlighting open research topics in the field. Additionally, uterine disease and infertility are discussed in the context of tissue injury and repair processes and the role of computational modeling in uncovering etiologies of disease. WIREs Syst Biol Med 2017, 9:e1388. doi: 10.1002/wsbm.1388 For further resources related to this article, please visit the WIREs website.

Endocrinology of human female sexuality, mating, and reproductive behavior

Hormones orchestrate and coordinate human female sexual development, sexuality, and reproduction in relation to three types of phenotypic changes: life history transitions such as puberty and childbirth, responses to contextual factors such as caloric intake and stress, and cyclical patterns such as the ovulatory cycle. Here, we review the endocrinology underlying women's reproductive phenotypes, including sexual orientation and gender identity, mate preferences, competition for mates, sex drive, and maternal behavior. We highlight distinctive aspects of women's sexuality such as the possession of sexual ornaments, relatively cryptic fertile windows, extended sexual behavior across the ovulatory cycle, and a period of midlife reproductive senescence-and we focus on how hormonal mechanisms were shaped by selection to produce adaptive outcomes. We conclude with suggestions for future research to elucidate how hormonal mechanisms subserve women's reproductive phenotypes.

Measuring sperm backflow following female orgasm: a new method

BACKGROUND

Human female orgasm is a vexed question in the field while there is credible evidence of cryptic female choice that has many hallmarks of orgasm in other species. Our initial goal was to produce a proof of concept for allowing females to study an aspect of infertility in a home setting, specifically by aligning the study of human infertility and increased fertility with the study of other mammalian fertility. In the latter case - the realm of oxytocin-mediated sperm retention mechanisms seems to be at work in terms of ultimate function (differential sperm retention) while the proximate function (rapid transport or cervical tenting) remains unresolved.

METHOD

A repeated measures design using an easily taught technique in a natural setting was used. Participants were a small (n=6), non-representative sample of females. The introduction of a sperm-simulant combined with an orgasm-producing technique using a vibrator/home massager and other easily supplied materials.

RESULTS

The sperm flowback (simulated) was measured using a technique that can be used in a home setting. There was a significant difference in simulant retention between the orgasm (M=4.08, SD=0.17) and non-orgasm (M=3.30, SD=0.22) conditions; t (5)=7.02, p=0.001. Cohen's d=3.97, effect size r=0.89. This indicates a medium to small effect size.

CONCLUSIONS

This method could allow females to test an aspect of sexual response that has been linked to lowered fertility in a home setting with minimal training. It needs to be replicated with a larger sample size.

Comparison of static culture, micro-vibration culture, and micro-vibration culture with co-culture in poor ovarian responders

Objective

This study was conducted to compare the effects of static culture, dynamic culture, and the combination of dynamic culture with specialized surfaces involving co-culture on human embryonic development. Embryos cultured using conventional static culture (SC) techniques served as a control group. We compared dynamic culture using micro-vibration culture (MVC) and micro-vibration with co-culture (MCoC), in which autologous cumulus cells were used as a specialized surface.

Methods

We conducted a chart review of patients who were treated between January 2011 and November 2014 in order to compare embryonic development rates and pregnancy rates among the groups. Zygotes were cultured in micro-droplets, and embryos were subsequently selected for transfer. Some surplus embryos were cryopreserved, and the others were cultured for blastocyst development. A micro-vibrator was set at the frequency of 42 Hz for duration of 5 seconds per 60 minutes to facilitate embryo development.

Results

No significant differences among the groups were present in patient's characteristics. However, the clinical pregnancy rates were significantly higher in the MVC group and the MCoC group than in the SC group. No significant differences were found in the blastocyst development rate between the SC group and the MVC group, but the blastocyst development rate in the MCoC group was significantly higher than in the SC and MVC groups.

Conclusion

The clinical pregnancy rate was significantly increased by the application of micro-vibration to the embryonic cultures of poor responders. The blastocyst development rate was significantly increased by the application of MCoC to surplus embryos.

Funisitis is more common in cervical insufficiency than in preterm labor and preterm premature rupture of membranes

OBJECTIVE

To compare the frequency of histologic chorioamnionitis and funisitis among women experiencing preterm labor, preterm premature rupture of membranes (PROM) and cervical insufficiency.

METHODS

This retrospective cohort study included singleton pregnant women who delivered at ≤36 weeks of gestation. The patients with preterm birth were subdivided into preterm labor (n=117), preterm PROM (n=153), and cervical insufficiency (n=20). All placentas were examined for pathology, according to the criteria of Salafia with minor modification. Frequencies of histologic chorioamnionitis and funisitis were evaluated according to the causes of preterm birth.

RESULTS

1) Histologic chorioamnionitis was diagnosed in 48.7% (57/117) of cases with preterm labor, 47.4% (73/153) with preterm PROM, and 75.0% (15/20) with cervical insufficiency. Funisitis was detected in 11.1% (13/117) of cases with preterm labor, 15.7% (24/153) with preterm PROM, and 40.0% (8/20) with cervical insufficiency. 2) Frequency of histologic chorioamnionitis was higher in cases with cervical insufficiency compared to preterm PROM. Frequency of funisitis was higher in cases with cervical insufficiency compared to both preterm labor and preterm PROM (P<0.05). The difference in frequency of funisitis remained significant after adjustment for gestational age at delivery and cervical dilatation at diagnosis. 3) Frequency of grade 2 funisitis was higher in cases with cervical insufficiency (35.0%, 7/20) compared to both preterm labor (6.8%, 8/117) and preterm PROM (9.8%, 15/153) (P=0.001). And the difference remained significant after adjustment for gestational age at delivery and cervical dilatation at diagnosis.

CONCLUSION

The highest frequency of funisitis was observed in cervical insufficiency among cases with spontaneous preterm birth.