Predictive potential of various plasma inflammation-, angiogenesis-, and extracellular matrix remodeling-associated mediators for intra-amniotic inflammation and/or microbial invasion of the amniotic cavity in preterm labor.

PURPOSE: To determine whether various inflammatory-, angiogenic/anti-angiogenic-, and extracellular matrix remodeling-associated proteins in plasma, alone or in combination with conventional blood-based markers, can predict intra-amniotic inflammation and/or microbial invasion of the amniotic cavity (IAI/MIAC) in women with spontaneous preterm labor (PTL). METHODS: A total of 193 singleton pregnant women with PTL (23-33 weeks) were included in this retrospective cohort study. Plasma samples were obtained at the time of amniocentesis. Amniotic fluid (AF) was cultured for microorganism detection and consequent MIAC diagnosis. IL-6 levels were determined in AF and used to identify IAI (AF IL-6 ≥ 2.6 ng/mL). Endostatin, haptoglobin, IGFBP-2/3, LBP, M-CSF, MMP-2/8, pentraxin 3, PlGF, S100A8/A9, and VEGFR-1 levels were assayed in plasma samples by ELISA. CRP levels and neutrophil-to-lymphocyte ratio (NLR) were measured. RESULTS: Plasma LBP, MMP-8, and S100A8/A9 levels, CRP levels, and NLR were significantly higher, and plasma IGFBP-2 and MMP-2 levels were significantly lower in women with IAI/MIAC than in those without this condition, whereas no baseline variables differed significantly between the two groups. Using a stepwise regression analysis, a noninvasive prediction model for IAI/MIAC was developed, which included plasma LBP, MMP-2, and MMP-8 levels (area under the curve [AUC], 0.785). The AUC for this prediction model was significantly or borderline greater than that of any single factor included in the model. CONCLUSIONS: IGFBP-2, LBP, MMP-2, MMP-8, and S100A8/A9 may represent valuable plasma biomarkers for predicting IAI/MIAC in women with PTL. Combination of LBP, MMP-2, and MMP-8 expression data can significantly improve the predictive potential for IAI/MIAC.

Vaginal microbiota in women with spontaneous preterm labor versus those with term labor in Kenya: a case control study.

BACKGROUND: Preterm birth is a global problem with about 12% of births in sub-Saharan Africa occurring before 37 weeks of gestation. Several studies have explored a potential association between vaginal microbiota and preterm birth, and some have found an association while others have not. We performed a study designed to determine whether there is an association with vaginal microbiota and/or placental microbiota and preterm birth in an African setting. METHODS: Women presenting to the study hospital in labor with a gestational age of 26 to 36 weeks plus six days were prospectively enrolled in a study of the microbiota in preterm labor along with controls matched for age and parity. A vaginal sample was collected at the time of presentation to the hospital in active labor. In addition, a placental sample was collected when available. Libraries were constructed using PCR primers to amplify the V6/V7/V8 variable regions of the 16S rRNA gene, followed by sequencing with an Illumina MiSeq machine and analysis using QIIME2 2022.2. RESULTS: Forty-nine women presenting with preterm labor and their controls were enrolled in the study of which 23 matched case-control pairs had sufficient sequence data for comparison. Lactobacillus was identified in all subjects, ranging in abundance from < 1% to > 99%, with Lactobacillus iners and Lactobacillus crispatus the most common species. Over half of the vaginal samples contained Gardnerella and/or Prevotella; both species were associated with preterm birth in previous studies. However, we found no significant difference in composition between mothers with preterm and those with full-term deliveries, with both groups showing roughly equal representation of different Lactobacillus species and dysbiosis-associated genera. Placental samples generally had poor DNA recovery, with a mix of probable sequencing artifacts, contamination, and bacteria acquired during passage through the birth canal. However, several placental samples showed strong evidence for the presence of Streptococcus species, which are known to infect the placenta. CONCLUSIONS: The current study showed no association of preterm birth with composition of the vaginal community. It does provide important information on the range of sequence types in African women and supports other data suggesting that women of African ancestry have an increased frequency of non-Lactobacillus types, but without evidence of associated adverse outcomes.

¿Son útiles los antimicrobianos en pacientes con trabajo de parto prematuro, espontáneo, membranas intactas e infección bacteriana ascendente? Una revisión narrativa / Are antibiotics useful in patients with preterm and spontaneous labor, intact membranes and ascendant bacterial infection? A narrative review

El parto prematuro (PP) es la principal causa de morbilidad/mortalidad perinatal y frecuentemente es espontáneo, con membranas intactas (MI). La infección intrauterina es su causa más común en un hospital público de Chile. Existe evidencia que la infección bacteriana ascendente desde la vagina es responsable de la infección/inflamación intraamniótica, del PP y de los resultados adversos maternos y perinatales. Esta revisión narrativa incluye ensayos controlados aleatorizados (ECAs), publicados en PubMed, Cochrane, Embase, Scielo, Science Direct, Wiley Online Library, sobre los mecanismos que intervienen en el ascenso de la infección vaginal, los factores infecciosos que participan en el resultado adverso materno-perinatal y la eficacia de los antimicrobianos en estos casos. Estos trabajos no recomiendan usar antimicrobianos profilácticos porque producen daño a corto y largo plazo en los hijos. Pero este resultado tiene sesgo porque no se evaluó la presencia de infección/inflamación subclínica, lo que disminuye el grado de recomendación. También existen ECAs, que erradican la infección/inflamación intraamniótica, reducen la morbilidad/mortalidad neonatal, pero son trabajos aislados, obtenidos de subanálisis, con bajo nivel de evidencia. Se requieren revisiones sistemáticas y metaanális de ECAs con estudio de infección/inflamación subclínica para evaluar si son útiles los antimicrobianos en el PP espontáneo con MI.

Preterm labor (PL) is the leading cause of perinatal morbidity/ mortality and is frequently spontaneous with intact membranes (IM). Intrauterine infection is its most common cause in a public hospital in Chile. There is evidence that ascending bacterial infection from the vagina is responsible for intraamniotic infection/inflammation, PL, and adverse maternal and perinatal outcomes. This narrative review includes randomized controlled trials (RCTs), published in PubMed, Cochrane, Embase, Scielo, Science Direct, Wiley Online Library on the mechanisms involved in the rise of vaginal infection, the infectious factors involved in adverse maternal-perinatal outcomes, and the efficacy of antibiotics in these cases. They do not recommend the use of prophylactic antibiotics because they cause short and long-term damage to children. But this result is biased because the presence of subclinical infection/inflammation was not evaluated, which lowers the degree of recommendation. There are also RCTs that eradicate intra-amniotic infection/inflammation, reduce neonatal morbidity/ mortality, but they are isolated studies, obtained from subanalyses, with a low level of evidence. Systematic reviews and meta-analyses of RCTs with subclinical infection/inflammation study are required to assess whether antibiotics are useful in spontaneous PL with IM.

Differential impact of abnormal vaginal colonization on perinatal outcome and association with early-onset neonatal sepsis: preterm labor vs. preterm premature rupture of membrane.

OBJECTIVE: The purpose of this study was to check whether the impact of abnormal vaginal colonization on perinatal outcomes would be different in patients with preterm labor (PTL) and premature membrane rupture (PPROM). We also sought to determine the concordance rate of microorganisms isolated from the maternal vagina and neonatal blood in cases of early-onset neonatal sepsis (EONS) in PTL and PPROM. METHODS: This retrospective study included 996 singleton pregnancies who were admitted to the high risk care unit of our institution due to PTL (n = 519) or PPROM (n = 477) and underwent vaginal culture examination at admission between January 2005 and April 2019. Abnormal vaginal colonization was defined upon isolation of aerobic microorganisms. The maternal baseline characteristics, delivery, and neonatal outcomes were compared according to the presence or absence of abnormal vaginal flora, both in PTL and PPROM. RESULTS: The rate of abnormal vaginal colonization in PTL and PPROM was 17.0 and 21.4%, respectively. Both in PTL and PPROM, the gestational age at admission was lower in the abnormal vaginal colonization group (PTL, 27.2 ± 3.5 vs. 28.2 ± 3.5 weeks, p = .024; PPROM, 26.1 ± 5.3 vs. 27.5 ± 4.5 weeks, p = .007). Multivariable analysis demonstrated that the group with abnormal bacteria in PPROM but not in PTL had a significantly higher rate of EONS than the group without abnormal bacteria after adjustment for confounders including gestational age at admission (PPROM, odds ratio, OR [95% confidence interval, CI]: 4.172 [1.426-12.206]; PTL, OR [95% CI]: 0.661 [0.079-5.505]). Concordance analysis showed that the maternal vaginal bacteria colonization by Escherichia coli (5.9 vs. 0.5%, p = .033) and Staphylococcus aureus (14.3 vs. 0.2%, p = .032) in PPROM was significantly correlated with the microorganisms from the neonatal blood culture EONS cases. In PTL, no specific microorganisms showed concordance between maternal vaginal bacteria and microorganisms causing EONS. CONCLUSION: Our data showed that maternal vaginal colonization in PPROM, but not in PTL, is an independent risk factor for EONS.

Intra-amniotic infection and sterile intra-amniotic inflammation in women with preterm labor with intact membranes are associated with a higher rate of Ureaplasma species DNA presence in the cervical fluid.

OBJECTIVE: To determine the prevalence of Ureaplasma spp. DNA and its load in the cervical fluid in women with preterm labor with intact membranes (PTL) complicated by intra-amniotic infection (the presence of both microbial invasion of the amniotic cavity and intra-amniotic inflammation) or sterile intra-amniotic inflammation (the presence of intra-amniotic inflammation alone). METHODS: Overall, 115 women with singleton pregnancies complicated by PTL between gestational ages of 22 + 0 and 34 + 6 weeks were included in this study. Paired amniotic and cervical fluid samples were collected at the time of admission via transabdominal amniocentesis using a Dacron polyester swab. Microbial invasion of the amniotic cavity was diagnosed based on a combination of culture and molecular biology methods. Intra-amniotic inflammation was determined based on the concentration of interleukin-6 in the amniotic fluid. Bacterial and Ureaplasma spp. DNA loads were assessed in the cervical fluid using PCR. RESULTS: Intra-amniotic infection and sterile inflammation were identified in 14% (16/115) and 25% (29/115) of the women, respectively. Ureaplasma spp. DNA in the cervical fluid was identified in 51% (59/115) of women. The presence of Ureaplasma spp. DNA in the cervical fluid was higher in women with intra-amniotic infection (75% (12/16)) and sterile intra-amniotic inflammation (76% (22/29)) than in women without intra-amniotic inflammation (36% (25/70); p = .0002). Concurrent presence of Ureaplasma spp. and Mycoplasma hominis DNA was higher in women with intra-amniotic infection (42% (5/12)) than women with sterile intra-amniotic inflammation (7% (2/29)) and women without intra-amniotic inflammation (7% (5/70); p = .001). There were no differences in the load of Ureaplasma spp. DNA in the cervical fluid among women with intra-amniotic infection, sterile intra-amniotic inflammation, and those without intra-amniotic inflammation (median values; infection: 1.2 × 104 copies DNA/mL; sterile: 5.0 × 105 copies DNA/mL; without: 8.4 × 104 copies DNA/mL; p = .18). CONCLUSIONS: In PTL , both forms of intra-amniotic inflammation were associated with a higher prevalence of Ureaplasma spp. DNA in the cervical fluid. The presence of intra-amniotic infection was related to a higher rate of concurrent Ureaplasma spp. and M. hominis DNA in the cervical fluid.

Whole-genome sequencing-based phylogeny, antibiotic resistance, and invasive phenotype of Escherichia coli strains colonizing the cervix of women in preterm labor.

BACKGROUND: Escherichia coli is a major neonatal pathogen and the leading cause of early-onset sepsis in preterm newborns. Maternal E. coli strains are transmitted to the newborn causing invasive neonatal disease. However, there is a lack of data regarding the phenotypic and genotypic characterization of E. coli strains colonizing pregnant women during labor. METHODS: This prospective study performed at the University of Oklahoma Medical Center (OUHSC) from March 2014 to December 2015, aimed to investigate the colonization rate, and the phylogeny, antibiotic resistance traits, and invasive properties of E. coli strains colonizing the cervix of fifty pregnant women diagnosed with preterm labor (PTL). Molecular analyses including bacterial whole-genome sequencing (WGS), were performed to examine phylogenetic relationships among the colonizing strains and compare them with WGS data of representative invasive neonatal E. coli isolates. Phenotypic and genotypic antibiotic resistance traits were investigated. The bacteria's ability to invade epithelial cells in vitro was determined. RESULTS: We recruited fifty women in PTL. Cervical samples yielded E. coli in 12 % (n=6). The mean gestational age was 32.5 (SD±3.19) weeks. None delivered an infant with E. coli disease. Phenotypic and genotypic antibiotic resistance testing did not overall demonstrate extensive drug resistance traits among the cervical E. coli isolates, however, one isolate was multi-drug resistant. The isolates belonged to five different phylogroups, and WGS analyses assigned each to individual multi-locus sequence types. Single nucleotide polymorphism-based comparisons of cervical E. coli strains with six representative neonatal E. coli bacteremia isolates demonstrated that only half of the cervical E. coli isolates were phylogenetically related to these neonatal invasive strains. Moreover, WGS comparisons showed that each cervical E. coli isolate had distinct genomic regions that were not shared with neonatal E. coli isolates. Cervical and neonatal E. coli isolates that were most closely related at the phylogenetic level had similar invasion capacity into intestinal epithelial cells. In contrast, phylogenetically dissimilar cervical E. coli strains were the least invasive among all isolates. CONCLUSIONS: This pilot study showed that a minority of women in PTL were colonized in the cervix with E. coli, and colonizing strains were not phylogenetically uniformly representative of E. coli strains that commonly cause invasive disease in newborns. Larger studies are needed to determine the molecular characteristics of E. coli strains colonizing pregnant women associated with an increased risk of neonatal septicemia.

The Role of Innate Immune System in the Human Amniotic Membrane and Human Amniotic Fluid in Protection Against Intra-Amniotic Infections and Inflammation.

Intra-amniotic infection and inflammation (IAI) affect fetal development and are highly associated with preterm labor and premature rupture of membranes, which often lead to adverse neonatal outcomes. Human amniotic membrane (hAM), the inner part of the amnio-chorionic membrane, protects the embryo/fetus from environmental dangers, including microbial infection. However, weakened amnio-chorionic membrane may be breached or pathogens may enter through a different route, leading to IAI. The hAM and human amniotic fluid (hAF) respond by activation of all components of the innate immune system. This includes changes in 1) hAM structure, 2) presence of immune cells, 3) pattern recognition receptors, 4) cytokines, 5) antimicrobial peptides, 6) lipid derivatives, and 7) complement system. Herein we provide a comprehensive and integrative review of the current understanding of the innate immune response in the hAM and hAF, which will aid in design of novel studies that may lead to breakthroughs in how we perceive the IAI.

Vaginal microbiome as a tool for prediction of chorioamnionitis in preterm labor: a pilot study.

Intra-amniotic infection (IAI) is a major cause of preterm birth with a poor perinatal prognosis. We aimed to determine whether analyzing vaginal microbiota can evaluate the risk of chorioamnionitis (CAM) in preterm labor cases. Vaginal discharge samples were collected from 83 pregnant women admitted for preterm labor. Based on Blanc's classification, the participants were divided into CAM (stage ≥ II; n = 46) and non-CAM (stage ≤ I; n = 37) groups. The 16S rDNA amplicons (V1-V2) from vaginal samples were sequenced and analyzed. Using a random forest algorithm, the bacterial species associated with CAM were identified, and a predictive CAM (PCAM) scoring method was developed. The α diversity was significantly higher in the CAM than in the non-CAM group (P < 0.001). The area under the curve was 0.849 (95% confidence interval 0.765-0.934) using the PCAM score. Among patients at < 35 weeks of gestation, the PCAM group (n = 22) had a significantly shorter extended gestational period than the non-PCAM group (n = 25; P = 0.022). Multivariate analysis revealed a significant difference in the frequency of developmental disorders in 3-year-old infants (PCAM, 28%, non-PCAM, 4%; P = 0.022). Analyzing vaginal microbiota can evaluate the risk of IAI. Future studies should establish appropriate interventions for IAI high-risk patients to improve perinatal prognosis.

Detection of Vaginal Metabolite Changes in Premature Rupture of Membrane Patients in Third Trimester Pregnancy: a Prospective Cohort Study.

Premature rupture of membranes (PROM) is usually associated with pregnant and neonatal complications. Most of the PROM cases are caused by ascending asymptomatic genital infection. In China, PROM (15.3%) is more common than spontaneous preterm labor (7.3%) and leads to more adverse pregnancy outcomes. Here, we designed a prospective cohort study to measure the metabolomics changes in vaginal swab samples and explored their potential contribution to PROM. A total of 260 differentially expressed metabolites were identified and further analyzed. In the PROM group, N-acetyl-D-galactosamine and sucrose were downregulated (P = 0.0025, P = 0.0195, respectively), both of which are the upstream metabolites of the glycolysis pathway. Furthermore, estriol 3-sulfate 16-glucuronide (P = 0.0154) and 2-methoxy-17beta-estradiol 3-glucosiduronic acid (P = 0.004), two final metabolites in steroid hormone biosynthesis, were both downregulated in the PROM group. Finally, we found two catechin metabolites (epigallocatechin-7-glucuronide, P = 0.0009; 4'-methyl-epigallocatechin-7-glucuronide, P = 0.01) as well as DL-citrulline (P = 0.0393) were also significantly downregulated in the PROM group compared with the healthy control (HC) group, which are related to important antioxidant and anti-inflammatory activities in the human body. Altogether, metabolite changes in glycolysis, steroid hormone biosynthesis, and antioxidant/anti-inflammatory pathways may contribute to (or be a consequence of) vaginal dysbiosis and PROM. Metabolite pathway analysis is a new and promising approach to further investigate the mechanism of PROM and help prevent its unfavorable pregnant outcomes at a functional level. Trial registration number: ChiCTR2000034721.

Relationship between histologic chorioamnionitis and genital tract cultures in pre term labour.

The objective was to determine the relationship of histological chorioamnionitis (HCA) with genital tract cultures in preterm birth. Among two hundred women recruited for the study, 100 were taken as cases with gestational age between ≥28 and <37 weeks and 100 women with gestational age >37 weeks were taken as controls. Vaginal swabs were taken for culture sensitivity and vaginal smears were made for performing whiff test and heat dry gram stained smear was examined for growth of microorganisms. Histopathologic examination of the placenta was done after delivery. 49 cases and 26 controls had evidence of histological chorioamnionitis. A significant difference was observed in relation to the presence of E. coli, presence of clue cells, positive whiff test and occurrence of bacterial vaginosis in subjects with and without histological chorioamnionitis. Thus, we conclude that the presence of histological chorioamnionitis is closely related to the presence of pathogenic microorganisms in the cervicovaginal region.IMPACT STATEMENTWhat is already known on the subject? Histologic chorioamnionitis has been regarded to reflect amniotic fluid infection and there are studies showing an association between histologic chorioamnionitis, amniotic fluid, and subchorionic plate cultures. Nevertheless, studies of the correlation of the cervical swab cultures with intrauterine infection in preterm birth remain inconclusive.What do the results of this study add? Histologic chorioamnionitis is closely related to the presence of pathogenic microorganisms in the cervicovaginal region.What are the implications of these findings for clinical practice and/or further research? High vaginal swab cultures and gram staining of vaginal smear is useful in detecting antenatal patients who are at a higher risk for preterm labour. After detection, early intervention may be done to avoid preterm deliveries in these high-risk pregnancies.

Intestinal Dysbiosis As a Possible Predictor of Very Early Preterm Labor in Pregnant Women With Metabolic Syndrome.

The work assessed the state of the intestinal microbiocenosis in 52 puerperae at the in whom the pregnancy developed against the background of the metabolic syndrome. The diagnosis of metabolic syndrome was determined according to the criteria approved by the World Health Organization for pregnant women. The state of intestinal microbiocenosis was assessed by a bacteriological examination of feces immediately after delivery. The content of the main representatives of the obligate microflora (bifidobacteria, lactobacilli, native intestinal bacilli, fecal streptococci) and facultative (conditionally pathogenic) microorganisms (representatives of the genus Prоteus, Klebsiella, pathogenic strains of E. coli, Staphylococcus epidermidis, Enterobacter, Citrobacter, Clostridium difficile, Candida fungi) was determined. Cultures were made on appropriate growth media. At the time of birth, all patients of group I showed signs of intestinal microbiocenosis disorder. At the same time, 13 (54.2%) puerperae were diagnosed signs of dysbiosis of II degree, 9 (37.5%) with signs of III degree, which were generally characterized by a significant decrease in the content of the main representatives of obligate microflora (Bifidobacterium, Lactobacillus, Escherichia coli, Fecal streptococci) with simultaneous high contamination of Candida albicans and Clostridium difficile. So, it can be considered as a possible predictor of very early preterm birth in women with MS. In pregnant women with MS, but who gave timely birth (group II), dysbiotic disorders were detected to a lesser extent. Thus, in 13 (46.4%) patients, initial signs of intestinal dysbiosis (first degree) were detected in 4 (14.3%) patients (second degree). In 11 (39.3%) puerperae of group II, microbial indices indicated normal eubiotic ratios.

Lactobacillus crispatus dominant vaginal microbita in pregnancy.

OBJECTIVE: To summarize current knowledge regarding Lactobacillus crispatus-dominated vaginal microbiota in pregnancy, as well as an association between the presence of Lactobacillus crispatus-dominated vaginal microbiota and pregnancy complications. DESIGN: Review. SETTING: Department of Obstetrics and Gynecology, University Hospital Hradec Kralove. MATERIAL AND METHODOLOGY: In this review, the results from literature available about the presence of L. crispatus-dominated microbiota in pregnancy are summarized. RESULTS: Pregnant women with Lactobacillus crispatus-dominated vaginal microbiota is very common in pregnancy and it is associated with a lower risk of preterm delivery. CONCLUSION: Lactobacillus crispatus-dominated vaginal microbiota represents an optimal vaginal microbiota in pregnancy.

Cervicovaginal Fluid Protein Microarray for Detection of Microbial Invasion of the Amniotic Cavity in Preterm Labor.

We aimed to identify cervicovaginal fluid (CVF) biomarkers that can detect microbial invasion of the amniotic cavity (MIAC) in women with preterm labor (PTL) with an antibody microarray and to develop the best combined model for detection of MIAC using these biomarkers in combination with conventional clinical variables. This retrospective cohort study included 168 singleton pregnant women with PTL (23-34 weeks) who underwent amniocentesis. AF was cultured, and CVF samples were obtained at the time of amniocentesis. An antibody microarray was used to analyze the CVF proteome (n = 40). The validation of four candidate biomarkers of interest was performed by enzyme-linked immunosorbent assay (ELISA) in the final cohort (n = 168). For comparison with candidate markers, CVF IL-6 concentration was also measured. Twenty-seven molecules studied exhibited intergroup differences. Validation by ELISA confirmed significantly higher levels of CVF DKK3, M-CSF, and TIMP-1, but not of IGFBP-2, independent of gestational age, in CVF of women with MIAC. The area under the curve (AUC) of DKK3, M-CSF, and TIMP-1 from CVF was not significantly different from the AUC of IL-6 from CVF for detecting MIAC in women with PTL. By using a stepwise regression analysis, a combined detection model was developed, which included the CVF M-CSF, TIMP-1, and gestational age at sampling (AUC = 0.823). An antibody microarray identified useful biomarkers (DKK3, M-CSF, and TIMP-1) in CVF for detection of MIAC, and a combined model including these biomarkers and gestational age can accurately detect MIAC in women with PTL.

Compartmentalized profiling of amniotic fluid cytokines in women with preterm labor.

OBJECTIVE: Amniotic fluid cytokines have been implicated in the mechanisms of preterm labor and birth. Cytokines can be packaged within or on the surface of extracellular vesicles. The main aim of this study was to test whether the protein abundance internal to and on the surface of extracellular vesicles changes in the presence of sterile intra-amniotic inflammation and proven intra-amniotic infection in women with preterm labor as compared to the women with preterm labor without either intra-amniotic inflammation or proven intra-amniotic infection. STUDY DESIGN: Women who had an episode of preterm labor and underwent an amniocentesis for the diagnosis of intra-amniotic infection or intra-amniotic inflammation were classified into three groups: 1) preterm labor without either intra-amniotic inflammation or proven intra-amniotic infection, 2) preterm labor with sterile intra-amniotic inflammation, and 3) preterm labor with intra-amniotic infection. The concentrations of 38 proteins were determined on the extracellular vesicle surface, within the vesicles, and in the soluble fraction of amniotic fluid. RESULTS: 1) Intra-amniotic inflammation, regardless of detected microbes, was associated with an increased abundance of amniotic fluid cytokines on the extracellular vesicle surface, within vesicles, and in the soluble fraction. These changes were most prominent in women with proven intra-amniotic infection. 2) Cytokine changes on the surface of extracellular vesicles were correlated with those determined in the soluble fraction; yet the magnitude of the increase was significantly different between these compartments. 3) The performance of prediction models of early preterm delivery based on measurements on the extracellular vesicle surface was equivalent to those based on the soluble fraction. CONCLUSIONS: Differential packaging of amniotic fluid cytokines in extracellular vesicles during preterm labor with sterile intra-amniotic inflammation or proven intra-amniotic infection is reported herein for the first time. The current study provides insights into the biology of the intra-amniotic fluid ad may aid in the development of biomarkers for obstetrical disease.

Defining microbial biomarkers for risk of preterm labor.

Preterm birth remains the main contributor to early childhood mortality. The vaginal environment, including microbiota composition, might contribute to the risk of preterm delivery. Alterations in the vaginal microbial community structure might represent a risk factor for preterm birth. Here, we aimed to (a) investigate the association between preterm birth and the vaginal microbial community and (b) identify microbial biomarkers for risk of preterm birth. Microbial DNA was isolated from vaginal swabs in a cohort of 69 women enrolled at hospital admission for their delivery. Microbiota was analyzed by high-throughput 16S rRNA sequencing. While no differences in microbial diversity measures appeared associated with the spontaneous preterm and full-term outcomes, the microbial composition was distinct for these groups. Differential abundance analysis showed Lactobacillus species to be associated with full-term birth whereas an unknown Prevotella species was more abundant in the spontaneous preterm group. Although we studied a very miscegenated population from Brazil, our findings were similar to evidence pointed by other studies in different countries. The role of Lactobacillus species as a protector in the vaginal microbiome is demonstrated to be also a protector of spontaneous preterm outcome whereas the presence of pathogenic species, such as Prevotella spp., is endorsed as a factor of risk for spontaneous preterm delivery.

Characterization of vaginal microbiota in women with preterm labor with intra-amniotic inflammation.

This study aims to investigate the relation between vaginal microbiota and exposition to intra-amniotic inflammation (IAI). We conducted a prospective cohort study in women with preterm labor <34 weeks who had undergone amniocentesis to rule out IAI. Vaginal samples were collected after amniocentesis. Women with IAI included those with positive amniotic fluid (AF) for a microorganism identified by specific culture media and Sanger sequencing 16S ribosomal RNA gene and/or high AF interleukin (IL)-6 levels. Vaginal microbiota was characterized by 16S ribosomal RNA gene amplicon sequencing. Specific quantitative PCR targeted to Lactobacillus spp. was also performed. Regression models were used to evaluate associations between vaginal microbiota and exposition to IAI. Concerning our results, 64 women were included. We observed an inverse association between AF IL-6 levels and load of Lactobacillus spp. Depletion in Lactobacillus spp. load was significantly associated with an early gestational age at delivery and a short latency to delivery. Microbial-diversity was found to be a risk factor for the subsequent occurrence of clinical chorioamnionitis. To the contrary, higher Lactobacillus spp. load had a protective role. In conclusion, the study identifies reduced bacterial load of Lactobacillus spp. in women exposed to IAI and found microbial-diversity and Lactobacillus spp. depletion to be associated with a worse perinatal outcome.

Cytokine profiles of umbilical cord blood mononuclear cells upon in vitro stimulation with lipopolysaccharides of different vaginal gram-negative bacteria.

Inflammatory immune responses induced by lipopolysaccharides (LPS) of gram-negative bacteria play an important role in the pathogenesis of preterm labor and delivery, and in neonatal disorders. To better characterize LPS-induced inflammatory response, we determined the cytokine profile of umbilical cord blood mononuclear cells (UBMC) stimulated with LPS of seven vaginal gram-negative bacteria commonly found in pregnant women with preterm labor and preterm rupture of membrane. UBMC from ten newborns of healthy volunteer mothers were stimulated with purified LPS of Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Proteus mirabilis, Acinetobacter calcoaceticus, Citrobacter freundii, and Pseudomonas aeruginosa. UBMC supernatants were tested for the presence of secreted pro-inflammatory cytokines (IL-6, IL-1ß, TNF), anti-inflammatory cytokine (IL-10), TH1-type cytokines (IL-12, IFN-γ), and chemokines (IL-8, MIP-1α, MIP-1ß, MCP-1) by Luminex technology. The ten cytokines were differentially induced by the LPS variants. LPS of E. coli and E. aerogenes showed the strongest stimulatory activity and P. aeruginosa the lowest. Interestingly, the ability of UBMC to respond to LPS varied greatly among donors, suggesting a strong individual heterogeneity in LPS-triggered inflammatory response.

Chlamydia trachomatis screening in preterm labor: A systematic review and meta-analysis.

OBJECTIVE: Spontaneous preterm labor (PTL) is responsible for approximately half of all preterm births with intrauterine infection being an important risk factor for PTL. Chlamydia trachomatis infections have been associated with preterm prelabor rupture of membranes (P-PROM) and preterm birth, but its impact on PTL has not previously been specified. The aim of this study was to evaluate the overall prevalence of Chlamydia trachomatis infections in pregnant women with threatened PTL compared to those not in threatened PTL. STUDY DESIGN: A literature search was performed in electronic databases using combinations of: "Chlamydia", "vaginal cervical infection" and "preterm labor." Cohort and case-controlled studies examining threatened PTL and Chlamydia trachomatis infection demonstrated by culture or NAAT methods at time of diagnosis of threatened labor. The Meta-analyses of Observational Studies in Epidemiology (MOOSE) guidelines for reporting of observational studies for systematic reviews was used. Bias was assessed with the Methodological Index for Non-Randomized Studies (MINORS) score. Meta-analysis was performed using a random effects model. RESULTS: Four studies were identified. A total of 591 women were included, 309 in the threatened PTL, and 282 controls not in threatened PTL. Women presenting in PTL had an increased risk of screening positive for Chlamydia trachomatis compared to the control group (27/308 (9%) vs 3/282 (1%); OR 7.74, 95% CI 2.64-22.71). CONCLUSIONS: The incidence of Chlamydia trachomatis in women with threatened PTL is approximately 9%, and significantly increased compared to asymptomatic controls. Women with threatened PTL should be considered for screening for Chlamydia trachomatis.

Vaginal microbiome profiles of pregnant women in Korea using a 16S metagenomics approach.

PROBLEM: The stability and dominance of Lactobacillus spp. in vaginal fluid are important for reproductive health. However, the characterization of the vaginal microbiota of women with preterm labor (PTL) or preterm premature rupture of membranes (P-PROM), and its association with preterm birth (PTB) are poorly understood. METHOD OF STUDY: We collected vaginal fluid from women at risk of PTB (n = 58) in five university hospitals in Korea. We performed a hierarchical clustering analysis and classification according to the Lactobacillus spp. and Lactobacillus abundance using Illumina MiSeq sequencing of 16S rRNA gene amplicons. RESULTS: Women at risk for PTB caused by P-PROM had greater bacterial richness and diversity at the time of admission than those with PTL (P < 0.05). However, they were not significantly different between term and preterm samples. In the classification by Lactobacillus spp., the community commonly dominated by Bacteroides and Lactobacillus crispatus was found for the first time in pregnant women in Korea, and all women with this community delivered preterm. Intriguingly, women with an abundance of Weissella in a Bacteroides-dominant community delivered at term. Moreover, in the classification by Lactobacillus proportion, the abundances of Weissella and Rickettsiales were associated with term deliveries, but the abundances of Bacteroides and Escherichia-Shigella were associated with PTBs (P < 0.05). CONCLUSION: This result suggests that Lactobacillus abundance-based classification of vaginal fluid may reveal the microbiome associated with PTB. Further studies are needed to investigate the mechanism underlying the link between the microbiome and PTB.

Lactobacillus iners-dominated vaginal microbiota in pregnancy.

OBJECTIVE: To summarize current knowledge regarding Lactobacillus iners-dominated vaginal microbiota in pregnancy, as well as an association between the presence of Lactobacillus iners and pregnancy complications Type of study: Review. SETTING: Department of Obstetrics and Gynecology, University Hospital Hradec Kralove, Charles University, Faculty of Medicine in Hradec Kralove. METHODS AND RESULTS: In this review, the results from literature available about the presence of L. iners-dominated microbiota in pregnancy and the association between the presence of L. iners-dominated microbiota and abortion, spontaneous preterm delivery with intact membranes, and preterm prelabor rupture of membranes are summarized. CONCLUSION: L. iners-dominated vaginal microbiota appears to be associated with an increased risk of the development of specific pregnancies pathologies.