scholarly journals Influence of Maternal Microbiome and Inflammatory Response in Preterm Birth: Recent Aspects of the Prevention of Preterm Birth

2021 ◽  
Vol 13 (1) ◽  
pp. 1-13
Author(s):  
Hee Young Cho ◽  
Sung Shin Shim ◽  
Hee Jin Park ◽  
Dong Hyun Cha

Preterm birth (PTB) is a global health issue and one of the most challenging problems affecting 12.9 million births worldwide. PTB is a multi-etiological disease and remains incompletely understood. The major cause of PTB is infection or inflammation and disruption of the vaginal microbiome, which affects the maternal immunologic response leading to PTB. The vaginal microbiome composition changes by a shift in the community are typically dominated by Lactobacillus during pregnancy. There are complex interactions between the maternal microbiome in pregnancy and the development of PTB, therefore, researchers have struggled to connect the maternal microbiome with the dysregulation of the maternal immune response in cases of PTB. The host microbiome affects alterations of the microorganisms with external stimuli such as disease, nutrition, immunity, and behavior. In this review, we discuss the complex association between the maternal microbiome and the risk of PTB and also focus on recent aspects of the prevention of PTB.

2020 ◽  
Vol 42 (4) ◽  
pp. 487-499 ◽  
Author(s):  
Erna Bayar ◽  
Phillip R. Bennett ◽  
Denise Chan ◽  
Lynne Sykes ◽  
David A. MacIntyre

Abstract Preterm birth is a global health concern and continues to contribute to substantial neonatal morbidity and mortality despite advances in obstetric and neonatal care. The underlying aetiology is multi-factorial and remains incompletely understood. In this review, the complex interplay between the vaginal microbiome in pregnancy and its association with preterm birth is discussed in depth. Advances in the study of bacteriology and an improved understanding of the human microbiome have seen an improved awareness of the vaginal microbiota in both health and in disease.


mBio ◽  
2019 ◽  
Vol 10 (5) ◽  
Author(s):  
Steven S. Witkin ◽  
Antonio F. Moron ◽  
Benjamin J. Ridenhour ◽  
Evelyn Minis ◽  
Alan Hatanaka ◽  
...  

ABSTRACT In many impoverished regions of the world, it may not be possible to assess two major risk factors for preterm birth: a short cervical length and the depletion of vaginal lactobacilli. We determined whether measuring specific compounds in vaginal fluid might be a simple, noninvasive, and cost-effective way to predict the bacteria that dominate the vaginal microbiome and indicate the presence of a shortened cervix (<25 mm). Vaginal fluid samples were prospectively collected from mid-trimester pregnant women, and the concentrations of d- and l-lactic acid, tissue inhibitor of matrix metalloproteinases TIMP-1 and TIMP-2, matrix metalloproteinases MMP-2 and MMP-8, the 70-kDa heat shock protein, a2 isoform of vacuolar ATPase, and sequestrome-1 were quantified by an enzyme-linked immunosorbent assay (ELISA). The compositions of vaginal microbiomes were assessed by analysis of the V1-V3 regions of 16S rRNA genes, while cervical length was determined by transvaginal ultrasonography. The vaginal microbiomes could be clustered into five community state types (CSTs), four of which were dominated by a single Lactobacillus species. The dominance of Lactobacillus crispatus or Lactobacillus jensenii in the vaginal microbiome predicted the level of d-lactic acid present. Several of the biomarkers, especially TIMP-1, in combination with the subject’s age and race, were significantly associated with cervical length. Using piecewise structural equation modeling, we established a causal network that links CST to cervical length via biomarkers. We concluded that measuring levels of TIMP-1 and d-lactic acid in vaginal secretions might be a straightforward way to assess the risk for preterm birth due to a short cervix and microbiome composition. IMPORTANCE Premature birth and its complications are the largest contributors to infant death in the United States and globally. A short cervical length and the depletion of Lactobacillus species are known risk factors for preterm birth. However, in many resource-poor areas of the world, the technology to test for their occurrence is unavailable, and pregnant women with these risk factors are neither identified nor treated. In this study, we used path analysis to gain an unprecedented understanding of interactions between vaginal microbiome composition, the concentrations of various compounds in vaginal secretions, and cervical length. We identified low-cost point-of-care measures that might be used to identify pregnant women at risk for preterm birth. The use of these measures coupled with appropriate preventative or treatment strategies could reduce the incidence of preterm births in poor areas of the world that lack access to more sophisticated diagnostic methods.


mSphere ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Nkechi Martina Odogwu ◽  
Jun Chen ◽  
Chinedum Amara Onebunne ◽  
Patricio Jeraldo ◽  
Lu Yang ◽  
...  

ABSTRACT Preterm birth (PTB) is the largest contributor to infant death in sub-Saharan Africa and globally. With a global estimate of 773,600, Nigeria has the third highest rate of PTB worldwide. There have been a number of microbiome profiling studies to identify vaginal microbiomes suggestive of preterm and healthy birth outcome. However, studies on the pregnancy vaginal microbiome in Africa are sparse with none performed in Nigeria. Moreover, few studies have considered the concurrent impact of steroid hormones and the vaginal microbiome on pregnancy outcome. We assessed two key determinants of pregnancy progression to gain a deeper understanding of the interactions between vaginal microbiome composition, steroid hormone concentrations, and pregnancy outcome. Vaginal swabs and blood samples were prospectively collected from healthy midtrimester pregnant women. Vaginal microbiome compositions were assessed by analysis of the V3-V5 region of 16S rRNA genes, and potential functional metabolic traits of identified vaginal microbiomes were imputed by PICRUSt (phylogenetic investigation of communities by reconstruction of unobserved states) analysis, while plasma estradiol (E2) and progesterone (P1) levels were quantified by the competitive enzyme-linked immunosorbent assay (ELISA). PTB vaginal samples were characterized by increased microbial richness, high diversity, and depletion of lactobacilli compared to term delivery samples. Women who delivered preterm were characterized by an Atopobium vaginae-dominated vagitype. High relative abundance of Atopobium vaginae at the midtrimester was highly predictive of PTB (area under the receiving operator characteristics [AUROC] of 0.983). There was a marked overlap in the range of plasma E2 and P1 values between term and PTB groups. IMPORTANCE Giving birth too soon accounts for half of all newborn deaths worldwide. Clinical symptoms alone are not sufficient to identify women at risk of giving birth too early, as such a pragmatic approach to reducing the incidence of preterm birth entails developing early strategies for intervention before it materializes. In view of the role played by the vaginal microbiome and maternal steroid hormones in determining obstetric outcome, we assessed the vaginal microbiome composition and steroid hormone during pregnancy and examined their relationship in predicting preterm birth risk in Nigerian women. This study highlights a potential early-driver microbial marker for prediction of preterm birth risk and supports the notion that vaginal microbiome composition varies across populations. A knowledge of relevant preterm birth microbial markers specific to populations would enhance the development of personalized therapeutic interventions toward restoring a microbiome that optimizes reproductive health fitness, therefore reducing the incidence of preterm birth.


2021 ◽  
Vol 10 (4) ◽  
pp. 667
Author(s):  
Kjerstine Breintoft ◽  
Regitze Pinnerup ◽  
Tine Brink Henriksen ◽  
Dorte Rytter ◽  
Niels Uldbjerg ◽  
...  

Background: This systematic review and meta-analysis summarizes the evidence for the association between endometriosis and adverse pregnancy outcome, including gestational hypertension, pre-eclampsia, low birth weight, and small for gestational age, preterm birth, placenta previa, placental abruption, cesarean section, stillbirth, postpartum hemorrhage, spontaneous hemoperitoneum in pregnancy, and spontaneous bowel perforation in pregnancy. Methods: We performed the literature review in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), by searches in PubMed and EMBASE, until 1 November 2020 (PROSPERO ID CRD42020213999). We included peer-reviewed observational cohort studies and case-control studies and scored them according to the Newcastle–Ottawa Scale, to assess the risk of bias and confounding. Results: 39 studies were included. Women with endometriosis had an increased risk of gestational hypertension, pre-eclampsia, preterm birth, placenta previa, placental abruption, cesarean section, and stillbirth, compared to women without endometriosis. These results remained unchanged in sub-analyses, including studies on spontaneous pregnancies only. Spontaneous hemoperitoneum in pregnancy and bowel perforation seemed to be associated with endometriosis; however, the studies were few and did not meet the inclusion criteria. Conclusions: The literature shows that endometriosis is associated with an increased risk of gestational hypertension, pre-eclampsia, preterm birth, placenta previa, placental abruption, cesarean section, and stillbirth.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexandra Brunner ◽  
Márta Medvecz ◽  
Nóra Makra ◽  
Miklós Sárdy ◽  
Kinga Komka ◽  
...  

AbstractHuman beta defensins (hBDs) may play an important role in the progression of lichen sclerosus (LS), due to their ability to induce excessive stimulation of extracellular matrix synthesis and fibroblast activation. The genetic ability of the individual to produce defensins, the presence of microbes influencing defensin production, and the sensitivity of microbes to defensins together regulate the formation of an ever-changing balance between defensin levels and microbiome composition. We investigated the potential differences in postmenopausal vaginal microbiome composition and vaginal hBD levels in LS patients compared to non-LS controls. LS patients exhibited significantly lower levels of hBD1 (p = 0.0003), and significantly higher levels of hBD2 (p = 0.0359) and hBD3 (p = 0.0002), compared to the control group. The microbiome of the LS patients was dominated by possibly harmful bacteria including Lactobacillus iners, Streptococcus anginosus or Gardnerella vaginalis known to initiate direct or indirect damage by increasing defensin level production. Our observations highlight that correcting the composition of the microbiome may be applicable in supplementary LS therapy by targeting the restoration of the beneficial flora that does not increase hBD2-3 production.


2016 ◽  
Vol 73 (1) ◽  
pp. 94-104 ◽  
Author(s):  
Elsa Goerig ◽  
Theodore Castro-Santos ◽  
Normand Émile Bergeron

Culverts can restrict access to habitat for stream-dwelling fishes. We used passive integrated transponder telemetry to quantify passage performance of >1000 wild brook trout (Salvelinus fontinalis) attempting to pass 13 culverts in Quebec under a range of hydraulic and environmental conditions. Several variables influenced passage success, including complex interactions between physiology and behavior, hydraulics, and structural characteristics. The probability of successful passage was greater through corrugated metal culverts than through smooth ones, particularly among smaller fish. Trout were also more likely to pass at warmer temperatures, but this effect diminished above 15 °C. Passage was impeded at higher flows, through culverts with steep slopes, and those with deep downstream pools. This study provides insight on factors influencing brook trout capacity to pass culverts as well as a model to estimate passage success under various conditions, with an improved resolution and accuracy over existing approaches. It also presents methods that could be used to investigate passage success of other species, with implications for connectivity of the riverscape.


2016 ◽  
Vol 9s1 ◽  
pp. CMWH.S34684 ◽  
Author(s):  
Nichelle Satterfield ◽  
Edward R. Newton ◽  
Linda E. May

Author(s):  
A. V. Karaulov ◽  
M. S. Afanasiev ◽  
Yu. V. Nesvizhsky ◽  
S. S. Afanasiev ◽  
E. A. Voropaeva ◽  
...  

Introduction. Chronic and latent infections are often activated during pregnancy.Aim - to asses the pathogenetic role of microbial pathogens in urogenital tract infection (UTI) in pregnant women.Materials and methods. 89 pregnant women underwent general clinical examination, examination of smears from urethra, vagina, cervical canal; bacteriological analysis of vaginal contents; enzyme-linked immunosorbent assay, polymerase chain reaction and determination of specific antibodies for verification of herpes simplex virus (HSV) type I and II, cytomegalovirus (CMV), Epstein-Barr (EBV) and UTI pathogens in pregnant women in blood and mucosal scrapes.Results. Prevalence of Herpesviridae was revealed (90-100% -EBV, HSV type I and II, CMV); in 41% of cases - bacterial pathogens, in 57% of cases - Mycoplasma, Ureaplasma.Discussion. In preterm birth and pregnancy termination mycoplasma and ureaplasma were more often revealed, and in pregnancy termination - association of HSV type I and II in comparison with urgent birth; in the last equally often - HSV type I and association of HSV type I and II; in urgent birth (infection) more often - HSV type I, than association of HSV type I and II; in preterm birth more often - HSV type I, than the association of HSV types I and II, and less often than combination of HSV type I and association of HSV types I and II in pregnancy termination; in the last, the association of HSV types I and II is more common than HSV type I. Increase of TLRs genes expression levels depends on HSV type I less than from association of HSV types I and II, less than from combination of HSV type I and association of HSV types I and II (it determines the clinical manifestations of genital herpes).Conclusion. Microbial pathogens determine the character of pregnancy course, and HSV types I and II- are the triggers of the infectious process, prognosing its course.


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