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Biology of Reproduction Nov 2008The amnion plays an important role during pregnancy and parturition. Though referred to as a single structure, this fetal tissue is regionally divided into placental...
The amnion plays an important role during pregnancy and parturition. Though referred to as a single structure, this fetal tissue is regionally divided into placental amnion, reflected amnion, and umbilical amnion. Histological differences between placental amnion and reflected amnion led us to hypothesize that the amnion is biologically heterogeneous. The gene expression profiles of placental amnion and reflected amnion were compared in patients at term with no labor (TNL; n = 10) and in labor (TIL; n = 10). Real-time quantitative RT-PCR revealed a higher expression of IL1B mRNA in reflected amnion than in placental amnion in TNL cases but not in TIL cases. Extended screening using microarrays showed differential expression of 17 genes in labor, regardless of the region. Interestingly, 839 genes were differentially expressed between placental amnion and reflected amnion. Pathway analysis identified 19 signaling pathways, such as mitogen-activated protein kinase and transforming growth factor beta pathways, associated with region. Lipopolysaccharide (LPS) treatment of the amnion explants showed more robust activation of mitogen-activated protein kinase 3/1 (extracellular signal-regulated kinase 1/2) in placental amnion of TNL but not in TIL cases. Placental amnion from TNL and TIL cases showed a significant difference in the amplitude of IL1B mRNA induction by LPS. We report that the anatomical region has a substantial impact on the transcriptional program and the biological properties of the amnion. Labor-associated switching to a proinflammatory signature is a feature particular to placental amnion. The novel observations herein strongly suggest that the seemingly homogeneous amnion is biologically heterogeneous and compartmentalized, with implications for the physiology of pregnancy and parturition.
Topics: Amnion; Female; Gene Expression Profiling; Humans; Interleukin-1beta; Lipopolysaccharides; Meconium; Oligonucleotide Array Sequence Analysis; Parturition; Placenta; Pregnancy; RNA, Messenger
PubMed: 18685129
DOI: 10.1095/biolreprod.108.069260 -
Developmental Dynamics : An Official... May 2016Despite being a short-lived, extraembryonic tissue, the amnioserosa plays critical roles in the major morphogenetic events of Drosophila embryogenesis. These roles... (Review)
Review
Despite being a short-lived, extraembryonic tissue, the amnioserosa plays critical roles in the major morphogenetic events of Drosophila embryogenesis. These roles involve both cellular mechanics and biochemical signaling. Its best-known role is in dorsal closure-well studied by both developmental biologists and biophysicists-but the amnioserosa is also important during earlier developmental stages. Here, we provide an overview of amnioserosa specification and its role in several key developmental stages: germ band extension, germ band retraction, and dorsal closure. We also compare embryonic development in Drosophila and its relative Megaselia to highlight how the amnioserosa and its roles have evolved. Placed in context, the amnioserosa provides a fascinating example of how signaling, mechanics, and morphogen patterns govern cell-type specification and subsequent morphogenetic changes in cell shape, orientation, and movement. Developmental Dynamics 245:558-568, 2016. © 2016 Wiley Periodicals, Inc.
Topics: Amnion; Animals; Body Patterning; Drosophila; Embryo, Nonmammalian; Embryonic Development; Morphogenesis; Serous Membrane
PubMed: 26878336
DOI: 10.1002/dvdy.24395 -
The Journal of Maternal-fetal &... Dec 2023Histologic chorioamnionitis (HCA) is most often caused by ascending bacterial infection originating from the cervicovaginal tract. (Observational Study)
Observational Study
BACKGROUND
Histologic chorioamnionitis (HCA) is most often caused by ascending bacterial infection originating from the cervicovaginal tract.
OBJECTIVES
To investigate whether HCA with a fetal inflammatory response (FIR) has a worse clinical outcome than HCA alone. Further, if FIR or a positive maternal microbiologic culture obtained prior to birth were related to adverse neonatal outcomes in a cohort of extremely preterm (EP) neonates.
METHODS
Prospective observational cohort study recruiting EP singleton pregnancies (gestational age at birth ≤28 weeks) with confirmed HCA. FIR was defined by fetal neutrophils in the chorionic vessels and/or umbilical vessels. Positive culture was defined as growth of potentially pathogenic bacteria in a sample from the cervicovaginal tract prior to birth, or if a cervicovaginal culture was lacking, a culture result from the placenta was used. Logistic regression was used to estimate odds ratios and 95% confidence intervals for the associations between FIR, a positive culture result and adverse outcomes, defined as bronchopulmonary dysplasia (BPD), brain pathology assessed by magnetic resonance imaging, retinopathy of prematurity, necrotizing enterocolitis, early-onset neonatal sepsis, and perinatal death. A composite outcome variable included one or more adverse outcomes.
RESULTS
We included 71 cases with HCA, of which 51 (72%) had FIR. Maternal age, rate of clinical chorioamnionitis (CCA), preterm pre-labor rupture of membranes (PPROM), the number of women receiving antenatal steroids and antibiotics, and the rate of positive maternal cultures of potentially pathogenic bacteria were all significantly higher in the HCA with FIR. Neonates in the FIR group had significantly higher levels of blood leukocytes compared to those without. FIR was associated with a longer interval from PPROM to delivery (log-rank test: = .022). Microbiological sampling had been performed in 63 (89%) cases, of which 60 (95%) were cervicovaginal samples. No associations were found between a positive culture and adverse neonatal outcomes, in contrast to FIR, that was significantly associated to BPD and brain pathology.
CONCLUSIONS
In a cohort of EP pregnancies with confirmed HCA, the presence of FIR was associated with advanced maternal age, CCA, PPROM, antenatal steroids and antibiotics, and a positive maternal culture of potentially pathogenic bacteria. However, the presence of FIR, and not a positive culture, was associated with adverse neonatal outcomes.
Topics: Infant, Newborn; Female; Infant; Pregnancy; Humans; Chorioamnionitis; Infant, Extremely Premature; Prospective Studies; Premature Birth; Fetal Membranes, Premature Rupture; Gestational Age; Infant, Newborn, Diseases; Bronchopulmonary Dysplasia
PubMed: 37031964
DOI: 10.1080/14767058.2023.2196599 -
American Journal of Obstetrics and... Jan 2023Spontaneous preterm birth accounts for most preterm births and leads to significant morbidity in the newborn and childhood period. This subtype of preterm birth...
BACKGROUND
Spontaneous preterm birth accounts for most preterm births and leads to significant morbidity in the newborn and childhood period. This subtype of preterm birth represents an increasing proportion of all preterm births when compared with medically indicated preterm birth, yet it is understudied in omics analyses. The placenta is a key regulator of fetal and newborn health, and the placental transcriptome can provide insight into pathologic changes that lead to spontaneous preterm birth.
OBJECTIVE
This analysis aimed to identify genes for which placental expression was associated with spontaneous preterm birth (including early preterm and late preterm birth).
STUDY DESIGN
The ECHO PATHWAYS consortium extracted RNA from placental samples collected from the Conditions Affecting Neurocognitive Development and Learning in Early Childhood and the Global Alliance to Prevent Prematurity and Stillbirth studies. Placental transcriptomic data were obtained by RNA sequencing. Linear models were fit to estimate differences in placental gene expression between term birth and spontaneous preterm birth (including gestational age subgroups defined by the American College of Obstetricians and Gynecologists). Models were adjusted for numerous confounding variables, including labor status, cohort, and RNA sequencing batch. This analysis excluded patients with induced labor, chorioamnionitis, multifetal gestations, or medical indications for preterm birth. Our combined cohort contained gene expression data for 14,023 genes in 48 preterm and 540 term samples. Genes and pathways were considered statistically significantly different at false discovery rate-adjusted P value of <.05.
RESULTS
In total, we identified 1728 genes for which placental expression was associated with spontaneous preterm birth with more differences in expression in early preterm samples than late preterm samples when compared with full-term samples. Of those, 9 genes were significantly decreased in both early and late spontaneous preterm birth, and the strongest associations involved placental expression of IL1B, ALPL, and CRLF1. In early and late preterm samples, we observed decreased expression of genes involved in immune signaling, signal transduction, and endocrine function.
CONCLUSION
This study provides a comprehensive assessment of the differences in the placental transcriptome associated with spontaneous preterm birth with robust adjustment for confounding. Results of this study are in alignment with the known etiology of spontaneous preterm birth, because we identified multiple genes and pathways for which the placental and chorioamniotic membrane expression was previously associated with prematurity, including IL1B. We identified decreased expression in key signaling pathways that are essential for placental growth and function, which may be related to the etiology of spontaneous preterm birth. We identified increased expression of genes within metabolic pathways associated exclusively with early preterm birth. These signaling and metabolic pathways may provide clinically targetable pathways and biomarkers. The findings presented here can be used to understand underlying pathologic changes in premature placentas, which can inform and improve clinical obstetrics practice.
Topics: Child, Preschool; Infant, Newborn; Pregnancy; Female; Humans; Premature Birth; Placenta; Transcriptome; Infant, Premature; Chorioamnionitis
PubMed: 35868418
DOI: 10.1016/j.ajog.2022.07.015 -
BMC Pregnancy and Childbirth Sep 2023Prelabour rupture of membranes at term affects approximately 10% of women during pregnancy, and it is often associated with a higher risk of infection than when the...
INTRODUCTION
Prelabour rupture of membranes at term affects approximately 10% of women during pregnancy, and it is often associated with a higher risk of infection than when the membranes are intact. In an attempt to control the risk of infection, two main approaches have been used most widely in clinical practice: induction of labour (IOL) soon after the rupture of membranes, also called active management (AM), and watchful waiting for the spontaneous onset of labour, also called expectant management (EM). In addition, previous studies have demonstrated that vaginal examinations increase the risk of chorioamnionitis. However, the effect of vaginal examinations in the context of prelabour rupture of membranes have not been researched to the same extent.
METHODS
This systematic review analyses and critiques the latest research on the management of term prelabour rupture of membranes, including the effect of vaginal examinations during labour, with a focus on the outcomes of both normal birth, and chorioamnionitis. Due to its complexity, three research questions were identified using the PICO diagram, and subsequently, the results from these searches were combined. The systematic review aimed to identify randomised controlled trials (RCTs) and observational studies that compared active vs expectant management, included number of vaginal examinations and had chorioamnionitis and/or normal birth as outcomes. The following databases were used: MEDLINE, EMBASE, Maternity and Infant care, LILACS, CINAHL and the Cochrane Central Register of Controlled trials. Quality was assessed using a tool developed especifically for this study that included questions from CASP and the Cochrane risk of bias tool. Due to the high degree of heterogeneity meta-analysis was not deemed appropriate. Therefore, simple narrative analysis was carried out.
RESULTS
Thirty-two studies met the inclusion criteria, of which 27 were RCTs and 5 observational studies. The overall quality of the studies wasn't high, 15 out of the 32 studies were deemed to be low quality and only 17 out of 32 studies were deemed to be of intermediate quality. The systematic review revealed that the management of term prelabour rupture of membranes continues to be controversial. Previous research has compared active management (Induction of labour shortly after the rupture of membrane) against expectant management (watchful waiting for the spontaneous onset of labour). Although previous studies have demonstrated that vaginal examinations increase the risk of chorioamnionitis, no prospective studies have included an intervention to reduce the number of vaginal examinations.
CONCLUSION
A RCT assessing the consequences of active management and expectant management as well as the effect of vaginal examinations during labour for term prelabour rupture of membranes is necessary.
Topics: Female; Pregnancy; Infant; Child; Humans; Chorioamnionitis; Delivery, Obstetric; Labor, Obstetric; Databases, Factual; Infant Care
PubMed: 37684576
DOI: 10.1186/s12884-023-05878-x -
Deutsches Arzteblatt International Apr 2011Amniotic membrane transplantation (AMT) has a long tradition in ophthalmic surgery and has become very popular recently because of newly developed methods of tissue... (Review)
Review
BACKGROUND
Amniotic membrane transplantation (AMT) has a long tradition in ophthalmic surgery and has become very popular recently because of newly developed methods of tissue preservation.
METHODS
We selectively review the literature on recent developments, mechanisms of action, and established indications of AMT in the treatment of various diseases of the ocular surface. We searched the PubMed database for articles that appeared from 1994 to 2009 with the key words "amniotic membrane," "cornea," and/or "conjunctiva."
RESULTS
Amniotic membrane (AM) can function in the eye as a basement membrane substitute or as a temporary graft. It has anti-inflammatory and anti-scarring effects and contains growth factors that promote epithelial wound healing on the surface of the eye. AMT has been found to be a good alternative for corneal and conjunctival reconstruction in many clinical situations, including acute burns, persistent epithelial defects of the cornea, and diseases that cause conjunctival scarring. Nonetheless, there have been no more than a few randomized and controlled trials of AMT to date. Other studies have shown that AM can serve as a culture substrate to expand epithelial progenitor cells for use in ocular surface reconstruction.
CONCLUSION
AMT is an established technique in the treatment of various diseases of the external eye. In the last few years, AMT has brought about major advances in the reconstructive surgery of the ocular surface.
Topics: Amnion; Cryopreservation; Eye Diseases; Humans; Organ Preservation; Treatment Outcome
PubMed: 21547164
DOI: 10.3238/arztebl.2011.0243 -
Nature Sep 2019Early human embryonic development involves extensive lineage diversification, cell-fate specification and tissue patterning. Despite its basic and clinical importance,...
Early human embryonic development involves extensive lineage diversification, cell-fate specification and tissue patterning. Despite its basic and clinical importance, early human embryonic development remains relatively unexplained owing to interspecies divergence and limited accessibility to human embryo samples. Here we report that human pluripotent stem cells (hPSCs) in a microfluidic device recapitulate, in a highly controllable and scalable fashion, landmarks of the development of the epiblast and amniotic ectoderm parts of the conceptus, including lumenogenesis of the epiblast and the resultant pro-amniotic cavity, formation of a bipolar embryonic sac, and specification of primordial germ cells and primitive streak cells. We further show that amniotic ectoderm-like cells function as a signalling centre to trigger the onset of gastrulation-like events in hPSCs. Given its controllability and scalability, the microfluidic model provides a powerful experimental system to advance knowledge of human embryology and reproduction. This model could assist in the rational design of differentiation protocols of hPSCs for disease modelling and cell therapy, and in high-throughput drug and toxicity screens to prevent pregnancy failure and birth defects.
Topics: Amnion; Cell Differentiation; Embryo, Mammalian; Female; Germ Layers; Humans; Models, Biological; Pluripotent Stem Cells; Pregnancy; Primitive Streak
PubMed: 31511693
DOI: 10.1038/s41586-019-1535-2 -
Clinical Microbiology Reviews Jan 2017The human Ureaplasma species are the most frequently isolated microorganisms from the amniotic fluid and placentae of women who deliver preterm and are also associated... (Review)
Review
The human Ureaplasma species are the most frequently isolated microorganisms from the amniotic fluid and placentae of women who deliver preterm and are also associated with spontaneous abortions or miscarriages, neonatal respiratory diseases, and chorioamnionitis. Despite the fact that these microorganisms have been habitually found within placentae of pregnancies with chorioamnionitis, the role of Ureaplasma species as a causative agent has not been satisfactorily explained. There is also controversy surrounding their role in disease, particularly as not all women infected with Ureaplasma spp. develop chorioamnionitis. In this review, we provide evidence that Ureaplasma spp. are associated with diseases of pregnancy and discuss recent findings which demonstrate that Ureaplasma spp. are associated with chorioamnionitis, regardless of gestational age at the time of delivery. Here, we also discuss the proposed major virulence factors of Ureaplasma spp., with a focus on the multiple-banded antigen (MBA), which may facilitate modulation/alteration of the host immune response and potentially explain why only subpopulations of infected women experience adverse pregnancy outcomes. The information presented within this review confirms that Ureaplasma spp. are not simply "innocent bystanders" in disease and highlights that these microorganisms are an often underestimated pathogen of pregnancy.
Topics: Chorioamnionitis; Female; Humans; Infant, Newborn; Obstetric Labor, Premature; Pregnancy; Ureaplasma; Ureaplasma Infections; Virulence Factors
PubMed: 27974410
DOI: 10.1128/CMR.00091-16 -
The Journal of Maternal-fetal &... Apr 2021Dysregulated maternal systemic inflammatory response is a commonly accepted component in the pathogenesis of preeclampsia. Chronic inflammation then occurs characterized...
BACKGROUND
Dysregulated maternal systemic inflammatory response is a commonly accepted component in the pathogenesis of preeclampsia. Chronic inflammation then occurs characterized by oxidative stress, proinflammatory cytokine production, and abnormal T-cell function. Infection results in similar physiologic changes.
OBJECTIVE
The objective of this study was to examine the association between the diagnosis of preeclampsia and the development of chorioamnionitis, postpartum fever, endometritis and wound infection. We hypothesize that the heightened chronic inflammatory state of preeclampsia increases the risk for maternal peripartum infection.
STUDY DESIGN
This was a retrospective cohort study from the Consortium on Safe Labor (CSL). In the present analysis, we included all women from the CSL database and compared their characteristics and pregnancy outcomes between those with and without a diagnosis of preeclampsia prior to labor. Women presenting with preterm prelabor rupture of membranes or were diagnosed with preeclampsia during labor or postpartum were excluded. The primary outcome was a composite of maternal peripartum infections including intrapartum chorioamnionitis, postpartum fever, endometritis, and wound infection. This outcome was compared between women with and without a diagnosis of preeclampsia prior to labor using univariable and multivariable analyses.
RESULTS
A total of 227,052 women were eligible for the analysis, of these 14,268 (6.3%) were diagnosed with preeclampsia. In univariable analysis, the rate of composite maternal peripartum infection was higher among women with preeclampsia (4.2 versus 3.8%, = .026). When looking at each individual component, that rates of wound infection (1.0 versus 0.5%, < .001) and postpartum fever (8.2 versus 4.4%, < .001) were higher among women with diagnosis of preeclampsia, whereas the rate of intrapartum chorioamnionitis was lower among women with preeclampsia (1.3 versus 1.7% = .004). Endometritis rates did not differ between the two groups. In multivariable logistic regression, adjusted for confounding variables, including maternal race, insurance status, prepregnancy BMI, maternal age, number of fetuses, number of vaginal exams, intrauterine pressure catheter and fetal scalp electrode placement, mode of delivery, group B streptococcus positivity, maternal education level, induction of labor, prelabor rupture of membranes, tobacco use, presence of diabetes (pregestational and gestational), gestational age at delivery, and chronic hypertension, the association between preeclampsia and composite maternal peripartum infection did not persist. In fact, after controlling for these influences, women with preeclampsia showed lower rates of intrapartum chorioamnionitis (aOR 0.83, 95% CI 0.70-0.99). The rest of the individual component of the primary composite outcome, postpartum fever, endometritis, and wound infection, were not associated with the diagnosis of preeclampsia.
CONCLUSIONS
In this large cohort of women diagnosed with preeclampsia prior to labor, the rate of intrapartum chorioamnionitis was decreased and the rate of postpartum infectious morbidity was not higher compared to women without a diagnosis of preeclampsia.
Topics: Chorioamnionitis; Endometritis; Female; Humans; Infant, Newborn; Morbidity; Peripartum Period; Pre-Eclampsia; Pregnancy; Retrospective Studies
PubMed: 31167579
DOI: 10.1080/14767058.2019.1628944 -
Acta Biomaterialia Jan 2015Characterizing the mechanical response of the human amnion is essential to understand and to eventually prevent premature rupture of fetal membranes. In this study, a...
Characterizing the mechanical response of the human amnion is essential to understand and to eventually prevent premature rupture of fetal membranes. In this study, a large set of macroscopic and microscopic mechanical tests have been carried out on fresh unfixed amnion to gain insight into the time-dependent material response and the underlying mechanisms. Creep and relaxation responses of amnion were characterized in macroscopic uniaxial tension, biaxial tension and inflation configurations. For the first time, these experiments were complemented by microstructural information from nonlinear laser scanning microscopy performed during in situ uniaxial relaxation tests. The amnion showed large tension reduction during relaxation and small inelastic strain accumulation in creep. The short-term relaxation response was related to a concomitant in-plane and out-of-plane contraction, and was dependent on the testing configuration. The microscopic investigation revealed a large volume reduction at the beginning, but no change of volume was measured long-term during relaxation. Tension-strain curves normalized with respect to the maximum strain were highly repeatable in all configurations and allowed the quantification of corresponding characteristic parameters. The present data indicate that dissipative behavior of human amnion is related to two mechanisms: (i) volume reduction due to water outflow (up to ∼20 s) and (ii) long-term dissipative behavior without macroscopic deformation and no systematic global reorientation of collagen fibers.
Topics: Amnion; Computer Simulation; Elastic Modulus; Humans; In Vitro Techniques; Models, Biological; Stress, Mechanical; Tensile Strength; Viscosity
PubMed: 25240983
DOI: 10.1016/j.actbio.2014.09.012