Analysis of cell-cell junctions in human amnion and chorionic plate affected by chorioamnionitis.

Chorioamnionitis is an acute inflammatory reaction associated with the premature rupture of the fetal membranes. It is caused mainly by invasion of bacteria from the vaginal tract that can penetrate the intact membranes and invade the amnion cavity and the decidua. Tight junctions (TJs) and adherent junctions (AJs) are intercellular junctions crucial for epithelia adhesion and permeability regulation in a wide variety of tissues and organs. Our aim is to investigate if TJ and AJ molecules are involved in human chorioamnionitis. We studied the protein expression (by immunohistochemistry and western blotting) and the mRNA levels (by RT-PCR) of some junction proteins such as Zonula Occludens-1 (ZO-1), occludin, VE-cadherin and ß-catenin in fetal membranes from women with chorioamnionitis compared to those membranes derived from idiopathic pregnancies. Western blotting and immunohistochemical data established that occludin expression was decreased in amnion with chorioamnionitis compared to amnion from idiopathic pregnancies. Samples tested for ZO-1, VE-cadherin and ß-catenin (proteins and mRNAs) showed no differences between idiopathic and pathological membranes. One of the most relevant results is the decrease of occludin in membranes with chorioamnionitis. Since we have previously demonstrated that some cytokines, particularly elevated in the chorioamnionitis, cause the disruption of TJs in placental villi, we suggest that the decrease of occludin in amnion may be the first change that leads to the rupture of the amniotic membrane in this pathology.

Corticotropin releasing hormone and Urocortin 2 activate inflammatory pathways in cultured trophoblast cell lines.

OBJECTIVE: Embryo implantation and parturition are recognized as inflammatory events involving endocrine and immune system. NF-kB and MAPK are two transcription factor families involved in inflammation. A possible role of neuroendocrine mechanism in early pregnancy and delivery was proposed for the neuropeptides related to corticotropin releasing hormones (CRH), named Urocortins (Ucns). Experimental and clinical studies support a role for CRH, Ucn, Ucn2 and Ucn3 in the endocrine/immune modulation of inflammation in human trophoblast; however the intracellular mechanisms are not yet recognized. The aim of the present study was to evaluate which of these neuropeptides modulate NF-kB or MAPKs pathways. STUDY DESIGN: In Jeg-3 placental cell line the effect of CRH, Ucn, Ucn2 or Ucn3 on NF-kB and MAPKs pathways were evaluated using Western blot analysis. RESULTS: CRH induced the phosphorylation of MAPK subunits; Ucn2 was able to induce the phosphorylation of both NF-kB and MAPK subunits. Ucn and Ucn3 had no effects on these pathways. CONCLUSIONS: These data provide novel information on inflammatory process in trophoblast cells: Ucn2 is a potent pro-inflammatory neuropeptide via NF-kB and MAPK pathways and CRH via MAPK, and CRH and Ucn2 network participates in the inflammatory mechanisms of pregnancy and parturition.

Term histologic chorioamnionitis: a heterogeneous condition.

A histologic response of histologic chorioamnionitis (HCA) is defined as an intrauterine inflammatory condition characterized by acute granulocyte infiltration into the fetal-maternal or the fetal tissues. Prevalence of HCA is inversely correlated with gestational age, occurring in 50% of preterm birth and in up to 20% of deliveries at term. Regardless of these standard definitions, understanding HCA is challenging as it reflects a heterogeneous condition. A histologic response of HCA from term placentas often does not correspond to a clinical presentation; in this context, the present review aims to analyze main characteristics of this condition, in particular focusing on mechanisms and birth outcomes.

Urocortin 2 role in placental and myometrial inflammatory mechanisms at parturition.

The purpose of the study was to investigate urocortin (Ucn)2 involvement in placental and myometrial inflammatory pathways associated with parturition by evaluating: 1) Ucn2 and its receptor, CRH-receptor type 2 (CRH-R2), expression in laboring/nonlaboring human gestational tissues and in mouse utero-placental tissues approaching delivery; and 2) Ucn2 effect on myometrial contractility and on the expression of inflammatory mediators (prostaglandin F2α receptor and cytokines) and regulation of Ucn2 by TNF-α in cultured myometrial cell line. Placenta (n = 16), fetal membranes (n = 16), and myometrium (n = 22) were obtained from healthy pregnant women delivering at term by vaginal/elective caesarean delivery and from timed-pregnant mice on days 16-19. Expression of Ucn2/CRH-R2 in human/mouse tissues and inflammatory mediators in myometrial cell lines were measured by RT-PCR or ELISA, mouse Ucn2/CRH-R2 protein localization by immunohistochemistry. Ucn2 but not CRH-R2 was up-regulated (P < .05) in all human tissues in labor (compared with before labor) and increased significantly (P < .01) in mouse placenta approaching delivery. Ucn2 was up-regulated by TNF-α via nuclear factor-κB (NF-kB) in myometrium cell lines (P < .05 or P < .01 on the basis of treatment doses) and increased proinflammatory mediators and prostaglandin F (PGF2α) receptor expression (P < .05) via CRH-R2, without a direct effect on contractility. Placental and myometrial Ucn2 may play a role in the endocrine-inflammatory processes of parturition, representing a potential target for treating inflammation-induced obstetric complications.

Neuroendocrinology of pregnancy and parturition.

During pregnancy, the maternal brain drives a series of adaptive mechanisms that are fundamental for allowing fetal growth and development, protecting both mother and fetus from adverse programming and timing of parturition. This neuroendocrine concept is even more complex as fetal brain and placenta also participate as regulators of maternal-placental-fetal physiology. The placenta is now seen as a neuroendocrine organ, acting as a source of several neuroactive factors that may exert their biologic effects either locally or by entering maternal and fetal circulation, thus acting in an autocrine, paracrine, and endocrine manner. A variety of hypothalamic neurohormones (GnRH, GHRH, somatostatin, CRH, oxytocin) are expressed in the placenta. When stress occurs during pregnancy, the maternal, fetal, and placental hypothalamic-pituitary-adrenal (HPA) axes are activated to stimulate a series of responses contributing to maintain physiologic conditions while at the same time avoiding the adverse effects of stress on the mother and offspring. However, when stress is excessive, a number of obstetric complications may occur, such as preterm birth, pre-eclampsia and intrauterine growth restriction, related to an impairment of the placental adaptive response.

Histologic chorioamnionitis: different histologic features at different gestational ages.

OBJECTIVE: The aim of this study was to investigate the rate of the different histological chorioamnionitis (HCA) grade in relation to the gestational age in term and preterm delivery. METHODS: Three hundred and ninety-two women with singleton pregnancy with spontaneous onset of labor either prematurely or at term, with histologic diagnosis of HCA, were enrolled. Placentas were classified as: deciduitis and/or histologic chorioamnionitis within the membranes (HCA1); amnionitis or inflammation of the chorionic plate without funisitis (HCA2); and histologic chorioamnionitis with funisitis (HCA3). Microbiological culture was performed on both placental and fetal membrane samples. RESULTS: HCA1 was more frequent in women delivering at term than in preterm (p < 0.001). HCA2 was more represented in women delivering between 32 and 36 weeks (p < 0.001) and HCA3 occurred more frequently in those delivering within 32 weeks (p < 0.001). The positive bacterial culture was higher (p = 0.008) in presence of HCA3 in comparison with HCA1 and HCA2. CONCLUSIONS: This study showed a significantly different distribution of HCA grades in relation to gestational age at delivery. HCA may represent the expression of different subtending etiologies and may also reflect specific immune competence of gestational tissues at different gestational ages, strengthening as pregnancy advances.

Understanding spontaneous preterm birth: from underlying mechanisms to predictive and preventive interventions.

Preterm birth is defined as birth before 37 weeks' gestational age. With an incidence of 7% to 11%, it is one of the major causes of perinatal mortality and morbidity. Preterm birth is considered a clinical syndrome, which arises from different pathological processes that activate prematurely one or more components of the mechanisms leading to parturition. The premature activation of labor may be caused by multiple pathological conditions; in particular a deregulation of the immune system and an exaggeration of inflammatory processes represent common central mechanisms. The complex pathogenesis, the main risk factors and the different therapeutic options will be described in the present review. Since its incidence is still increasing in the last decades, the goal is to improve the primary and secondary prevention.

Weight gain regardless of pre-pregnancy BMI and influence of fetal gender in response to labor induction in postdate pregnancy.

OBJECTIVE: To evaluate whether maternal weight and body mass index (BMI) and their increase throughout pregnancy are associated with the response to labor induction in postdate pregnancies. METHODS: A total of 376 nulliparous women carrying singleton postdate pregnancies with unfavorable cervix were enrolled. We considered as primary outcome vaginal delivery within 24 h after induction, and outcomes were divided into responders (n = 258) and non-responders (n = 107) to the induction of labor to perform the statistical analyses. RESULTS: In the total population of study, women who successfully delivered within 24 h differed significantly from the remaining patients in terms of maternal weight gain (p = 0.009) and BMI increase (p = 0.02) during pregnancy. In addition, males were significantly more (p = 0.005) than females among newborns of women not responding to induction of labor. In the multivariate analysis, maternal weight gain and fetal sex significantly influenced the induction response. The occurrence of a failed induction of labor was more likely in patients presenting a greater maternal weight gain (cut-off 12 kg) and male fetus. CONCLUSION: Weight gain over 12 kg regardless of pre-pregnancy weight and male fetal gender are two novel potential risk factors for the prediction of failure to induction of labor in postdate pregnancy.

Histologic chorioamnionitis at term: implications for the progress of labor and neonatal wellbeing.

OBJECTIVE: The aim of the present study was to evaluate: i) the rate of histologic chorioamnionitis in relation to the onset of labor and mode of delivery; ii) influence of clinical parameters on the risk of histologic chorioamnionitis in laboring women; iii) neonatal outcome in relation to histologic chorioamnionitis. METHODS: A cohort study was conducted on 395 healthy women at term, with singleton uneventful pregnancy, of which 195 with spontaneous onset of labor and 200 with elective cesarean section. All placentas, collected after delivery, were examined for the diagnosis of histologic chorioamnionitis. Mode of delivery, presence of bacterial infection of placenta and membranes, maternal clinical parameters and neonatal outcome were recorded. RESULTS: The rate of histologic chorioamnionitis in women with spontaneous onset of labor was significantly higher than in those experiencing elective cesarean section (28.7% vs. 11.5%). Nulliparity and the duration of labor were independent variables associated with acute histologic chorioamnionitis. The presence of histologic chorioamnionitis did not affect neonatal outcome. CONCLUSIONS: The present study showed a highest rate of histological chorionamniositis in women delivering after spontaneous onset of term labor, although the mode of delivery either vaginally or by emergency cesarean section was not influenced by the presence of this pathological condition.

Fetal gender effects on induction of labor in postdate pregnancies.

OBJECTIVE: To determine delivery outcome in women undergoing induction of labor for postdate pregnancy in relation to fetal gender. STUDY DESIGN: A total of 365 nulliparous and 127 multiparous women carrying singleton postdate pregnancies with unfavorable cervix were enrolled. Clinical characteristics and delivery outcome were analyzed in relation to fetal gender. RESULTS: Women carrying male fetuses showed higher rate of caesarean section than those carrying females, in both nulliparous and multiparous women. Moreover, women carrying male fetuses presented more frequently with (i) interval between induction of labor and delivery >24 hours (P < .0002); (ii) augmentation of labor after cervical ripening (P < .0391); (iii) meconium-stained liquor (P< .0126); and (iv) higher neonatal weight (P < .0011) than those carrying females. CONCLUSION: Male fetuses are more likely to be associated with higher rates of cesarean section. In maternal fetal medicine, gender differences may add prognostic information on the delivery outcome in women induced for postdate pregnancy.

The obstetric syndromes: clinical relevance of placental hormones.

Preterm delivery, preeclampsia and intrauterine growth restriction are the major diseases of pregnancy. A key role in their pathogenesis is played by the placenta, which is the source of hormones and other important regulatory molecules providing the metabolic and endocrine homeostasis of the fetal-placental unit. Since obstetric syndromes are characterized by important maternal and neonatal morbidity and mortality worldwide, numerous efforts have been made over the years to prevent and treat them. Due to their complex pathogenesis, however, the therapy is poor and not very effective. Therefore, great emphasis is currently given to the prevention of these diseases through the identification of biochemical and biophysical markers, among which placental factors play a crucial role. The increasing knowledge of the role of placental molecules can indeed lead to the development of new therapeutic and diagnostic tools.

Activin A and its regulatory molecules in placenta and fetal membranes of women with preterm premature rupture of the membranes associated with acute chorioamnionitis.

UNLABELLED: LABELED PROBLEM: To investigate regulation of activin A and related molecules in placenta/fetal membranes from preterm premature rupture of membranes (pPROM) associated with acute chorioamnionitis (ACA). METHOD OF STUDY: Tissues were obtained from women with spontaneous preterm deliveries (PTD), pPROM without ACA, pPROM with ACA. Activin A, follistatin, and nodal and cripto mRNA were measured by RT-PCR. RESULTS: Activin A mRNA was up-regulated in tissues from pPROM, in presence or absence of HCA, respect to PTD and in pPROM with ACA respect to pPROM without ACA. Follistatin mRNA expression did not differ between the groups. In placenta, nodal mRNA showed the same trend of activin A, while cripto was down-regulated in pPROM with ACA than other groups. Nodal and cripto were not expressed by fetal membranes. CONCLUSION: The study shows the involvement of activin A pathway in pPROM with ACA. Further studies will focus on its role in placental immune functions.

The identification of high risk pregnancy: a new challenge in obstetrics.

Preterm delivery (PTD) and pre-eclampsia (PE) represent the main "obstetric syndromes," caused by multiple conditions, and characterized by complex pathogenesis. Nonetheless, recent evidences attest that deregulation of the immune system and exaggeration of inflammatory processes, taking place in the feto-placental unit, represent common central mechanisms occurring in both diseases. Tertiary prevention represents the only intervention to prevent PTD, but its incidence is still increasing. Advances in secondary prevention, focusing on risk factors and possible markers, are necessary.

A novel antiinflammatory role for the short-chain fatty acids in human labor.

Human parturition is an inflammatory process that can be activated prematurely by pathological stimuli. This study investigated the expression of G protein-coupled receptors GPR43 and GPR41 receptors in human uteroplacental tissues and the role of short-chain fatty acids (SCFA) in modulating inflammatory pathways in fetal membranes. Expression of GPR43 and GPR41 was investigated in uteroplacental tissues collected from women delivering at term or preterm after ethical approval and patient informed consent. The effect of SCFA on expression of inflammatory genes was assessed in amnion explants after culture with a mimetic of infection (lipopolysaccharide, LPS). Sodium propionate effect on LPS-induced neutrophil chemotaxis was evaluated by transwell assay. GPR43 and GPR41 mRNA expression was higher in myometrium and fetal membranes collected from women after the onset of labor. GPR43 protein expression localized to immune cells and vascular endothelium in the myometrium and epithelium of fetal membranes. Treatment with LPS significantly increased mRNA expression of GPR43 and inflammatory genes. Cotreatment with LPS and sodium propionate decreased LPS-induced expression of inflammatory genes including IL-6, IL-8, cyclooxygenase-2, IL-1α, intercellular adhesion molecule-1, and platelet endothelial cell adhesion molecule-1 but not IL-1ß or lymphocyte function-associated antigen-1. Sodium propionate reduced LPS-induced neutrophil chemotaxis and protein secretion of the neutrophil chemoattractant IL-8. Finally, fetal membrane expression of GPR43 was significantly higher in women delivering preterm with evidence of infection. GPR43-SCFA interactions may represent novel pathways that regulate inflammatory processes involved in human labor. Suppression of inflammatory pathways by SCFA may be therapeutically beneficial for pregnant women at risk of pathogen-induced preterm delivery.

Biomarkers of spontaneous preterm birth: an overview of the literature in the last four decades.

BACKGROUND: Understanding spontaneous preterm birth ([PTB] < 37 weeks) is difficult due to heterogeneities associated with multitudes of risk factors and pathophysiological pathways. Several biomarkers are routinely used clinically for predicting preterm labor; however, these factors are either nonspecific or detected too late. OBJECTIVE: Systematic review of literature on PTB biomarkers in the last 40 years to map out the existing knowledge and gaps in understanding PTB biomarkers. SEARCH STRATEGIES: Five electronic databases were searched for human studies on PTB biomarkers published in any language between 1965 and 2008. SELECTION CRITERIA: The phenotype of interest for final data extraction was exclusively spontaneous PTB with no rupture of membranes. Data extraction included (a) general characteristics of the study (clinical setting, period, and study design), (b) study/participant characteristics (inclusion and exclusion criteria, race/ethnicity, number of participants, gestational age at sampling, (c) characteristics of the biomarker (type, rationale for its selection, type of biological sample, and assay used, and (d) concentration of biomarkers in cases and controls. DATA COLLECTION AND ANALYSIS: The search yielded 7255 citations and data were extracted from 217 articles which met our inclusion and exclusion criteria. MAIN RESULTS: A total of 116 different biomarkers were reported and these were assayed 578 times in the 217 included studies. Over two thirds of the 217 studies were performed on North American or European populations. No reliable biomarkers emerged as a risk predictor of PTB. CONCLUSIONS: Identifying similar studies on biomarkers for the prediction of PTB was a very challenging task due heterogeneities in study design, sampling issues (types, timing and processing), assay methods, and analyses. Major areas of concern identified in this review include poor phenotype definition, nonideal study designs and poor rationale for biomarker selection and assays and population stratification issues.

High levels of maternal serum IL-17 and activin A in pregnant women affected by systemic lupus erythematosus.

PROBLEM: To evaluate changes of serum IL-17, activin A, follistatin, and other cytokines during pregnancy in women with systemic lupus erythematosus (SLE). METHOD OF STUDY: A group of patients with SLE and controls were longitudinally studied, collecting a blood sample before and during three trimesters of pregnancy. Serum activin A, follistatin, IL-17, IL-6, IL-10, and TNF-α concentrations were evaluated by specific ELISA. RESULTS: Before pregnancy, while serum IL-17, IL-6, IL-10, and TNF-α resulted significantly higher in women with SLE (P<0.001), activin A and follistatin were not changed. Serum IL-17 concentrations were higher in SLE than in controls with no changes during pregnancy. IL-6 increased in both groups, resulting higher in SLE than in controls only in the first trimester (P<0.05). IL-10 concentration in SLE increased during pregnancy resulting significantly higher than in controls (P<0.01). TNF-α levels were higher in SLE than in controls in third trimester (P<0.01). Serum activin A levels in SLE were significantly higher than in controls (P<0.001) at third trimester. CONCLUSION: Women with SLE show increased secretions of activin A, IL-17, IL-6, IL-10, and TNF-α during gestation, with a different trend for the various cytokines. These data suggest that patients with SLE have a hyper-reactive immune system, probably receiving a placental contribution.

Biochemical and biophysical predictors of the response to the induction of labor in nulliparous postterm pregnancy.

OBJECTIVE: The objective of the study was to evaluate the clinical, sonographic, and hormonal variables that influence the success of labor induction in nulliparous postterm pregnancies. STUDY DESIGN: Fifty nulliparous women with a single postterm pregnancy receiving a slow-release prostaglandin estradiol pessary were prospectively enrolled, and clinical characteristics were analyzed in relation to success of induction of labor. Clinical, sonographic, and hormonal variables were analyzed by univariate statistical analysis and multivariate logistic regression for the prediction of successful induction. RESULTS: The group of patients delivering within 24 hours differed significantly from the remaining patients by higher Bishop scores, body mass indices, estradiol serum concentrations, estriol to estradiol ratios, and shorter cervices. The combination of cervical length and estriol to estradiol ratio achieved a sensitivity of 100% (95% confidence interval, 71.3-100%) and a specificity of 94.1% (95% confidence interval, 80.3-99.1%). CONCLUSION: Cervical length and the estriol to estradiol ratio represent good predictive indicators of the response to the induction of labor in postterm pregnancies.

Inflammatory and infectious risk factors are associated with the response to tocolysis in patients with preterm labor.

OBJECTIVE: Inflammation/infection is the most frequent conditions leading to preterm delivery (PTD). A few studies have assessed the clinical efficacy of long-term tocolysis with ritodrine hydrochloride. In this study, the relationship among inflammatory/infective risk factors of PTD, the response to long-term tocolysis, and timing of delivery were evaluated in women with preterm labor. METHODS: On the basis of different responses to long-term tocolysis, defined as ≥ 7 days tocolysis, the cohort were classified as: (i) patients delivering at term (Group A) and (ii) patients delivering preterm (group B). Group B was subclassified as: (i) delivery before 48 h (group B1); (ii) delivery between 48 h and 7 days (Group B2), and (iii) delivery after 7 days (Group B3). Group B is divided in early preterm (<32 weeks) (Group B early) and late PTD (32-36 weeks) (Group B late). RESULTS: Group A delivered at term and Group B preterm. Group B showed significantly higher (p < 0.0001) rate of CRP, bacterial vaginosis, and chorioamnionitis at placental histological examination than Group A. The same parameters were statistically higher (p < 0.0001) in group B1 than in B3. CRP, chorioamnionitis at placental histological examination was statistically higher (p < 0.0001) in Group B early than in Group B late. CONCLUSIONS: This retrospective study suggested that in women affected by preterm labor, the long-term tocolysis with intravenous ritodrine is able to prolong gestation beyond 7 days, in absence of inflammatory/infective risk factors of PTD.

Levels of antibodies against protein C and protein S in pregnancy and in preeclampsia.

OBJECTIVES: The clinical relevance of antibodies anti-protein C and anti-protein S in pregnancy remains controversial. We evaluate whether, in the absence of thrombophilic diseases, maternal plasma levels of antibodies (IgM and IgG) change during pregnancy and in preeclampsia (PE), with and without superimposed fetal growth restriction (FGR). METHODS: A retrospective cohort of 50 women with PE (n = 30) and PE + FGR (n = 20) and 70 controls [first trimester (n = 20); second trimester (n = 20); third trimester (n = 30)] were enrolled in the study. RESULTS: In healthy pregnant women, plasma levels of anti-protein C antibodies decreased from first to third trimester and were below the range of positivity. IgM anti-protein-C and anti-protein-S were significantly higher (P < 0.001) in both PE (23.88 +/- 10.65 MoM and 43.90 +/- 20.45 MoM, respectively) and PE + FGR group (15.95 +/- 12.62 MoM and 36.02 +/- 27.43 MoM, respectively) than in control group (2.23 +/- 3.23 MoM and 1.68 +/- 4.075 MoM, respectively), in the presence of unchanged levels of IgG isotype. CONCLUSIONS: In this study, we first found that the production of anti-protein C and anti-protein S antibodies decreases throughout healthy pregnancies, while they circulate in high levels in women with PE and PE/FGR.