Sequelae of chorioamnionitis

Association between acetaminophen metabolites and CYP2E1 DNA methylation level in neonate cord blood in the Boston Birth Cohort

BACKGROUND

Acetaminophen is a commonly used medication by pregnant women and is known to cross the placenta. However, little is known about the biological mechanisms that regulate acetaminophen in the developing offspring. Cytochrome 2E1 (CYP2E1) is the primary enzyme responsible for the conversion of acetaminophen to its toxic metabolite. Ex vivo studies have shown that the CYP2E1 gene expression in human fetal liver and placenta is largely controlled by DNA methylation (DNAm) at CpG sites located in the gene body of CYP2E1 at the 5' end. To date, no population studies have examined the association between acetaminophen metabolite and fetal DNAm of CYP2E1 at birth.

METHODS

We utilized data from the Boston Birth Cohort (BBC) which represents an urban, low-income, racially and ethnically diverse population in Boston, Massachusetts. Acetaminophen metabolites were measured in the cord plasma of newborns enrolled in BBC between 2003 and 2013 using liquid chromatography-tandem mass spectrometry. DNAm at 28 CpG sites of CYP2E1 was measured by Illumina Infinium MethylationEPIC BeadChip. We used linear regression to identify differentially methylated CpG sites and the "DiffVar" method to identify differences in methylation variation associated with the detection of acetaminophen, adjusting for cell heterogeneity and batch effects. The false discovery rate (FDR) was calculated to account for multiple comparisons.

RESULTS

Among the 570 newborns included in this study, 96 (17%) had detectable acetaminophen in cord plasma. We identified 7 differentially methylated CpGs (FDR < 0.05) associated with the detection of acetaminophen and additional 4 CpGs showing a difference in the variation of methylation (FDR < 0.05). These CpGs were all located in the gene body of CYP2E1 at the 5' end and had a 3-6% lower average methylation level among participants with detectable acetaminophen compared to participants without. The CpG sites we identified overlap with previously identified DNase hypersensitivity and open chromatin regions in the ENCODE project, suggesting potential regulatory functions.

CONCLUSIONS

In a US birth cohort, we found detection of cord biomarkers of acetaminophen was associated with DNAm level of CYP2E1 in cord blood. Our findings suggest that DNA methylation of CYP2E1 may be an important regulator of acetaminophen levels in newborns.

Tdap vaccination during pregnancy and risk of chorioamnionitis and related infant outcomes

INTRODUCTION

An increased risk of chorioamnionitis in people receiving tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine during pregnancy has been reported. The importance of this association is unclear as additional study has not demonstrated increased adverse infant outcomes associated with Tdap vaccination in pregnancy.

METHODS

We conducted a retrospective observational cohort study of pregnant people ages 15-49 years with singleton pregnancies ending in live birth who were members of 8 Vaccine Safety Datalink (VSD) sites during October 2016-September 2018. We used a time-dependent covariate Cox model with stabilized inverse probability weights applied to evaluate associations between Tdap vaccination during pregnancy and chorioamnionitis and preterm birth outcomes. We used Poisson regression with robust variance with stabilized inverse probability weights applied to evaluate the association of Tdap vaccination with adverse infant outcomes. We performed medical record reviews on a random sample of patients with ICD-10-CM-diagnosed chorioamnionitis to determine positive predictive values (PPV) of coded chorioamnionitisfor "probable clinical chorioamnionitis," "possible clinical chorioamnionitis," or "histologic chorioamnionitis."

RESULTS

We included 118,211 pregnant people; 103,258 (87%) received Tdap vaccine during pregnancy; 8098 (7%) were diagnosed with chorioamnionitis. The adjusted hazard ratio for chorioamnionitis in the Tdap vaccine-exposed group compared to unexposed was 0.96 (95% CI 0.90-1.03). There was no association between Tdap vaccine and preterm birth or adverse infant outcomes associated with chorioamnionitis. Chart reviews were performed for 528 pregnant people with chorioamnionitis. The PPV for clinical (probable or possible clinical chorioamnionitis) was 48% and 59% for histologic chorioamnionitis. The PPV for the combined outcome of clinical or histologic chorioamnionitis was 81%.

CONCLUSIONS AND RELEVANCE

Tdap vaccine exposure during pregnancy was not associated with chorioamnionitis, preterm birth, or adverse infant outcomes. ICD-10 codes for chorioamnionitis lack specificity for clinical chorioamnionitis and should be a recognized limitation when interpreting results.

Is chorioamnionitis associated with hearing impairment in preterm infants? A systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

It has been reported that chorioamnionitis (CA) could increase the risk of hearing impairment in premature infants, but results are inconsistent. A meta-analysis was performed to systematically evaluate the relationship between CA and hearing impairment in premature infants.

MATERIAL AND METHODS

Search in PubMed, Embase, Cochrane Library from their inception to May 2020. We concluded all cohort and case-control studies which explored the associations between CA and hearing impairment in preterm infants. Pregnant women with other infections besides CA were excluded. PRISMA guidelines were followed. Fixed-and random-effects models were used, depending on heterogeneity. And we performed to calculate odds ratio (ORs), and 95% CIs using fixed-effects models.

RESULTS

Seven studies involving 4134 premature infants were included. There was non-significant association between CA and hearing impairment (adjusted OR 1.43, 95% CI 0.99 to 2.04, P = 0.05; heterogeneity: I² = 13%, P = 0.33).

CONCLUSION

This article concludes that CA is not a risk factor for hearing impairment in premature infants, but most of the current studies are retrospective studies with low intensity and lack of high-quality articles to discuss it.

Comparison between Cervical Ureaplasma spp. Colonization and the Intensity of Inflammatory Mediators in the Amniotic Fluid Retrieved during Cesarean Delivery in Preterm Birth

We investigated whether cervical Ureaplasma spp. colonization affects the intensity of inflammatory mediators in amniotic fluid retrieved during cesarean delivery in singleton preterm birth. One hundred fifty-three cases in singleton preterm birth with 24-34 weeks' gestation were enrolled. The intensities of seven inflammatory mediators (interleukin (IL)-1β, IL-6, IL-8, IL-10, tumor necrosis factor-α, and matrix metalloproteins (MMP)-8, MMP-9) of amniotic fluid were measured. We tested cervical swab specimens using real-time polymerase chain reaction assays to detect Ureaplasma spp. colonization. Histologic chorioamnionitis (HCA) was diagnosed when acute inflammation was observed in any of the placental tissues. Mean gestational age at delivery and birth weight were 30.9 ± 2.4 weeks and 1567 ± 524 g, respectively. Cervical Ureaplasma spp. colonization was detected 78 cases. The incidence of HCA was 32.3% (43/133). Although the intensities of all inflammatory mediators were significantly different according to presence or absence of HCA, there were no significant differences according to cervical Ureaplasma spp. colonization. In all 43 cases with HCA and 90 cases without HCA, there were no significant differences between cervical Ureaplasma spp. colonization and the intensity of inflammatory mediators. Cervical Ureaplasma spp. colonization did not affect the intensity of inflammatory mediators in the amniotic fluid retrieved during cesarean delivery.

Targeted drug delivery for maternal and perinatal health: Challenges and opportunities

Pre-existing conditions at reproductive age, and complications arising during pregnancy can be detrimental to maternal and fetal health. Current therapies to combat obstetric disorders are limited due to the inherent complexity of pregnancy, and can have harmful effects on developing fetus. Emerging research shows intricate signaling between the cells from mother and fetus at maternal-fetal interface, providing unique opportunities for interventions specifically targeted to the mother, fetus, or placenta. Advancements in nanotechnology, stem-cell biology and gene therapy have resulted in target-specific treatments with promising results in pre-clinical maternal and fetal disorder models. Comprehensive understanding of the effect of physicochemical properties of delivery systems on their uptake, retention and accumulation across placenta will help in the better diagnosis and treatment of perinatal disorders. This review describes the factors leading to obstetric complications along with their effect on pregnancy outcomes, and discusses key targeted therapeutic strategies for addressing conditions related to maternal and fetal health.

Feasibility and accuracy of cord blood sampling for admission laboratory investigations: A pilot trial

AIM

Phlebotomy losses greatly contribute to anaemia following preterm birth. Therefore, the possibility of drawing initial tests from the placenta seems attractive. There is a lack of literature regarding the feasibility and accuracy of pathology tests taken from umbilical arterial and venous (UAB/UVB) compared to blood collected from the newborn.

METHODS

UAB and UVB complete blood pictures were compared with the initial neonatal blood test. The relationship between UAB, UVB and neonatal complete blood picture values was determined by Spearman's Rho correlation with absolute values compared by Kruskal-Wallis. P < 0.05 was considered significant.

RESULTS

Neonatal haemoglobin, white cell count, immature/total ratio and platelets were significantly correlated to the corresponding values in the UAB and UVB (all P < 0.001). While UAB and UVB haemoglobin and white cell count were similar, both were significantly lower than the neonatal values (P < 0.001 and P = 0.014, respectively). No difference was seen for immature/total ratio and platelet concentrations. UVB blood culture (BC) was feasible (90%), even with delayed cord clamping, and the UVB BC volume was significantly higher (P < 0.001), with a low rate of BC contamination (1.5%).

CONCLUSIONS

Our findings support the feasibility and accuracy of umbilical blood in place of blood collected from the newborn. This reduces the phlebotomy losses and allows higher blood volume collection which may increase the sensitivity of BC collection.

Screening of Chorioamnionitis Using Volatile Organic Compound Detection in Exhaled Breath: A Pre-clinical Proof of Concept Study

Chorioamnionitis is a major risk factor for preterm birth and an independent risk factor for postnatal morbidity for which currently successful therapies are lacking. Emerging evidence indicates that the timing and duration of intra-amniotic infections are crucial determinants for the stage of developmental injury at birth. Insight into the dynamical changes of organ injury after the onset of chorioamnionitis revealed novel therapeutic windows of opportunity. Importantly, successful development and implementation of therapies in clinical care is currently impeded by a lack of diagnostic tools for early (prenatal) detection and surveillance of intra-amniotic infections. In the current study we questioned whether an intra-amniotic infection could be accurately diagnosed by a specific volatile organic compound (VOC) profile in exhaled breath of pregnant sheep. For this purpose pregnant Texel ewes were inoculated intra-amniotically with Ureaplasma parvum and serial collections of exhaled breath were performed for 6 days. Ureaplasma parvum infection induced a distinct VOC-signature in expired breath of pregnant sheep that was significantly different between day 0 and 1 vs. day 5 and 6. Based on a profile of only 15 discriminatory volatiles, animals could correctly be classified as either infected (day 5 and 6) or not (day 0 and 1) with a sensitivity of 83% and a specificity of 71% and an area under the curve of 0.93. Chemical identification of these distinct VOCs revealed the presence of a lipid peroxidation marker nonanal and various hydrocarbons including n-undecane and n-dodecane. These data indicate that intra-amniotic infections can be detected by VOC analyses of exhaled breath and might provide insight into temporal dynamics of intra-amniotic infection and its underlying pathways. In particular, several of these volatiles are associated with enhanced oxidative stress and undecane and dodecane have been reported as predictive biomarker of spontaneous preterm birth in humans. Applying VOC analysis for the early detection of intra-amniotic infections will lead to appropriate surveillance of these high-risk pregnancies, thereby facilitating appropriate clinical course of action including early treatment of preventative measures for pre-maturity-associated morbidities.

A Neonatal Murine Escherichia coli Sepsis Model Demonstrates That Adjunctive Pentoxifylline Enhances the Ratio of Anti- vs. Pro-inflammatory Cytokines in Blood and Organ Tissues

Introduction: Neonatal sepsis triggers an inflammatory response that contributes to mortality and multiple organ injury. Pentoxifylline (PTX), a phosphodiesterase inhibitor which suppresses pro-inflammatory cytokines, is a candidate adjunctive therapy for newborn sepsis. We hypothesized that administration of PTX in addition to antibiotics decreases live bacteria-induced pro-inflammatory and/or enhances anti-inflammatory cytokine production in septic neonatal mice without augmenting bacterial growth.

Methods: Newborn C57BL/6J mice (< 24 h old) were injected intravenously with 10⁵ colony forming units (CFUs)/g weight of a bioluminescent derivative of the encapsulated clinical isolate Escherichia coli O18:K1. Adequacy of intravenous injections was validated using in vivo bioluminescence imaging and Evans blue. Pups were treated with gentamicin (GENT), PTX, (GENT + PTX) or saline at 0, 1.5, or 4 h after sepsis initiation, and euthanized after an additional 4 h. CFUs and cytokines were measured from blood and homogenized organ tissues.

Results: GENT alone inhibited bacterial growth, IL-1β, and IL-6 production in blood and organs. Addition of PTX to GENT profoundly inhibited E. coli-induced TNF and enhanced IL-10 in blood of newborn mice at all timepoints, whereas it primarily upregulated IL-10 production in peripheral organs (lung, spleen, brain). PTX, whether alone or adjunctive to GENT, did not increase microbial colony counts in blood and organs.

Conclusion: Addition of PTX to antibiotics in murine neonatal E. coli sepsis promoted an anti-inflammatory milieu through inhibition of plasma TNF and enhancement of IL-10 production in plasma and organs without increasing bacterial growth, supporting its utility as a potential adjunctive agent for newborn sepsis.

Pathological staging of chorioamnionitis contributes to complications in preterm infants

Objective

To investigate the effect of pathological staging of chorioamnionitis (CA) on complications in preterm infants;

Methods

A single-center, retrospective study was conducted to choose singleton preterm infants (gestational age < 37 weeks) from the Department of Obstetrics and Gynecology in our hospital from December 2016 to December 2017. The basic data and placental pathological results were retrospectively collected. According to the placental pathological results of whether inflammation infiltrating amnion, CA 0/I phase was classified into non-amnionitis group, CA II/III phase was classified into amnionitis group, the incidence of common complications in preterm infants was compared. Further, logistic regression was used to analyze the effects of amnionitis on complications after being adjusted to gestational age, birth weight and thrombocytopenia.

Results

A total of 221 preterm infants were enrolled, including 186 cases in non-amnionitis group and 35 cases in amnionitis group. The gestational age of amnionitis group (32.00 ± 2.71 weeks) was significantly lower than non-amnionitis group (34.14 ± 2.06 weeks), birth weight (1.93 ± 0.64 kg) was significantly lower than that of non-amnionitis group (2.26 ± 0.58 kg), and the hospital stay in amnionitis group was significantly longer (25.71 ± 19.23 days), all of the difference above was statistically significant(P < 0.05). The incidence of intraventricular hemorrhage (IVH) in amnionitis group (37.14%) was significantly higher than that in non-amnionitis group (13.98%) (P = 0.002), and the risk of IVH was significantly increased by amnionitis (OR = 3.636, 95%CI: 1.632–8.102); after correction of gestational age, birth weight and thrombocytopenia, the risk of IVH was still significantly increased (OR = 2.471, P = 0.046, 95% CI: 1.015–6.015). And the late-onset IVH was more common (P = 0.009).

Conclusion

Amnionitis leads to a significant reduction in gestational age and birth weight in preterm infants, and it is an independent risk factor for IVH.

Early- and Late-Respiratory Outcome in Very Low Birth Weight with or without Intrauterine Inflammation

• IUI is a risk factor for spontaneous preterm birth and contributes to prematurity-associated mortality and morbidity.• HCA greatly affected Apgar's score and lung management of VLBWI at birth and later on with increased incidence of BPD.• HCA + FUN did not significantly impact on respiratory outcome.

OBJECTIVE

Intrauterine inflammation or infection (IUI) is a risk factor for spontaneous preterm birth and contributes to prematurity-associated mortality and morbidity. IUI can include inflammation, as well as infections of varying degrees of severity and duration. Histological chorioamnionitis (HCA) remains the "gold standard" for the diagnosis but clinical, microbiological, and biochemical criteria are often used to define chorioamnionitis. The impact of intrauterine inflammation on respiratory outcome, in infants with very low birth weight, is still unclear and previous data are conflicting showing increase, decrease, or no risk of respiratory complications.

STUDY DESIGN

This is a retrospective study aimed to investigate the role of IUI on neonatal respiratory outcome. Histological criteria (HCA alone and HCA + funisitis [FUN]) and "intrauterine inflammation or infection or both" "Triple I" definition were used; different management in delivery room, in the first 7 days of life (early outcome) and incidence of mild, moderate, and severe bronchopulmonary dysplasia (BPD; late outcome) were considered.

RESULTS

A total of 162 infants with very low birth weight (VLBW) with placenta histology were enrolled. Suspected TRIPLE or fever alone was present in 7.4%, and confirmed TRIPLE or HCA in 29.6% of cases (HCA alone 19.1% vs. HCA + FUN 10.5%). Preterm premature rupture of membrane (p-PROM) was strongly associated with HCA (66.6% in HCA group) and HCA was present in 80% neonates born between 22 and 24 weeks of gestational age (GA). HCA group (GA, 26 weeks; birth weight [BW], 880 g) showed lower Apgar's score, higher intubation rate, and need of ventilation in delivery room, surfactant, duration of noninvasive ventilation (NIV), severe patent ductus arteriosus (PDA), and incidence of BPD compared with no-HCA (GA, 30 weeks; BW, 1,210 g). Length of hospital stay and mortality were higher in HCA group (p = 0.01) and an increasing trend was present for HCA + FUN compared with HCA alone.

CONCLUSION

HCA greatly affected Apgar's score and lung management of VLBW infants (VLBWI) at birth and later on with increased incidence of BPD, thus impacting length of stay and quality of life, while HCA + FUN did not significantly impact on respiratory outcome. Further studies are needed to clarify the role of HCA and FUN in VLBW neonates.

Small for gestational age very preterm infants present a higher risk of developing bronchopulmonary dysplasia

INTRODUCTION

Several studies assessed the influence of a low birth weight on bronchopulmonary dysplasia (BPD), but not all could find a significant association. Our aim was to assess the association between low birth weight and BPD in preterm infants, prospectively recruited at 11 level III Portuguese neonatal centers.

METHODS

Obstetrical and neonatal data on mothers and preterm infants with gestational ages between 24 and 30 weeks, born during 2015 and 2016 after a surveilled pregnancy, were analyzed. Neonates were considered small for gestational age (SGA) when their birthweight was below the 10th centile of Fenton's growth chats and BPD was defined as the dependency for oxygen therapy until 36 weeks of corrected age. Statistical analysis was performed using IBM SPSS® statistics 23 and a p-value <0.05 was considered statistically significant.

RESULTS

Out of 614, a total of 494 preterm infants delivered from 410 women were enrolled in the study; 40 (8.0%) infants with SGA criteria. SGA were more often associated with a single pregnancy, had greater use of antenatal corticosteroids, increased prevalence of gestational hypertensive disorders, C-section, rupture of membranes below 18 hours, rate of intubation in the delivery room, use of surfactant treatment, oxygen therapy, mechanical ventilation need, BPD, cystic periventricular leukomalacia, nosocomial sepsis and pneumonia; had lower prevalence of chorioamnionitis, and lower Apgar scores. The multivariate analysis by logistic regression, adjusted for BPD risk factors revealed a significant association between SGA and BPD: OR = 5.2 [CI: 1.46-18.58]; p = 0.01.

CONCLUSION

The results of this study increase the scientific evidence that SGA is an independent risk factor for BPD.

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

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

Very preterm infant outcomes according to timing of birth

INTRODUCTION

Extremely preterm infants are a population of high risk for morbidity and mortality. NICU's staffing is often lower during nights, weekends and holidays than weekdays, and this fact may contribute to higher morbidities and mortality. Our aim was to analyze the neonatal morbidity and mortality of very preterm infants delivered at our center and admitted to the NICU during the night period, weekends and holidays compared to that registered on weekday admissions.

METHODS

A retrospective study was conducted at our level III NICU, including data on mother, pregnancy, delivery, and neonatal outcomes of preterm infants with a gestational age below 30 weeks, admitted between January 1st 2005 and December 31st 2017. Statistical analysis was performed using IBM SPSS® Statistics 23.

RESULTS

220 infants were included in the study; median gestational age 27 weeks (min = 23; max = 29); median birth weight of 922 g (min = 360; max1555); 95 (43.2%) infants were delivered during weekdays and 125 (56.8%) were delivered during weeknights, weekends and holidays. There were no differences on mother's age, pregnancy complications, Apgar scores, birth weights, gestational ages and gender between the two groups. C-sections (p = 0.006), and small for gestational age infants (p = 0.010) were more prevalent in week day births. Chorioamnionitis with chorionic vasculitis (p = 0.028) and cystic periventricular leukomalacia (p = 0.032) were more prevalent in those delivered during the night period, weekends and holidays. In the multivariate analysis, cystic periventricular leukomalacia was not associated to a deliver during weeknights, weekends and holidays (OR = 0.580; 95% CI: 0.19-1.71, p = 0.324).

CONCLUSION

We did not find any increased morbidity and mortality associated with a birth during nights, weekends and holidays compared to that registered on weekday admissions.

Is chorioamnionitis associated with neurodevelopmental outcomes in preterm infants? A systematic review and meta-analysis following PRISMA

BACKGROUND

The relationships between chorioamnionitis (CA) and neurodevelopmental outcomes in preterm infants remain controversial. The meta-analysis aims to evaluate the associations between CA and neurodevelopmental deficits in preterm infants.

METHODS

All studies exploring the associations between CA and neurodevelopmental deficits in preterm infants were retrieved from the following databases: PubMed, Embase, OVID, EBSCO, ProQuest, CDSR, and CENTRAL. The NOS was used to evaluate the quality of the studies, RevMan was adopted to analyze the data.

RESULTS

Twelve studies involving 4267 preterm infants were included. The ORs across studies was 0.95 (P = .77, I = 51%) for cognitive deficits, 1.09 (P = .44, I = 10%) for psychomotor deficits, 1.21 (P = .08, I = 25%) for language deficits, 2.34 (P = .02, I = 0%) for performance intelligence quotient impairment and 2.81 (P = .03, I = 0%) for verbal intelligence quotient impairment. Subgroup analyses based on the severity of cognitive deficits indicated that CA might be correlated with severe cognitive deficits (P = .01, I = 0%) but not with mild cognitive deficits (P = .40, I = 19%). In terms of the CA category, clinical CA may be related to overall psychomotor deficits (P = .01, I = 25%) and overall language deficits (P < .00001, I = 23%) other than histological CA.

CONCLUSION

In preterm infants, CA might be a risk factor for performance and verbal intelligence quotient impairment and severe cognitive deficits, and clinical CA might be a risk factor for overall psychomotor and language deficits.

Maternal inflammation exacerbates neonatal hyperoxia-induced kidney injury in rat offspring

BACKGROUND

Preclinical studies have demonstrated that maternal inflammation or neonatal hyperoxia adversely affects kidney maturation. This study explored whether prenatal lipopolysaccharide (LPS) exposure can augment neonatal hyperoxia-induced kidney injury.

METHODS

Pregnant Sprague-Dawley rats received intraperitoneal injections of LPS (0.5 mg/kg) in normal saline (NS) or NS on 20 and 21 days of gestation. The pups were reared in room air (RA) or 2 weeks of 85% O₂, creating the four study groups, NS + RA, NS + O₂, LPS + RA, and LPS + O₂. Kidneys were taken for oxidase stress and histological analyses.

RESULTS

The rats exposed to maternal LPS or neonatal hyperoxia exhibited significantly higher kidney injury score, lower glomerular number, higher toll-like receptor 4 (TLR4), myeloperoxidase (MPO), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) expressions, and higher MPO activity compared with the rats exposed to maternal NS and neonatal RA. The rats exposed to both maternal LPS and neonatal hyperoxia exhibited significantly lower glomerular number, higher kidney injury score, TLR4, MPO, and 8-OHdG expressions compared with the rats exposed to maternal LPS or neonatal hyperoxia.

CONCLUSION

Maternal inflammation exacerbates neonatal hyperoxia-induced kidney injury and the underlying mechanism may be related to activation of TLR4 and increased oxidative stress.

High level antibodies to TORCH in the IVIG preparation from Taiwanese

BACKGROUND

Congenital TORCH (toxoplasmosis, other viruses [varicella-zoster virus, VZV, etc.], rubella, cytomegalovirus [CMV], Herpes simplex virus [HSV]) infections are major causes of prenatal, perinatal, and postnatal morbidity and mortality. Although treatment or prevention strategies are available for these pathogens, all drugs may not be safe during the pregnancy. The aim of this study is to measure the antibodies (Abs) concentration in the intravenous immunoglobulin (IVIG) preparation to evaluate the therapeutic potential for TORCH infection.

METHODS

We tested the only one commercial IVIG preparation from Taiwanese for the presence of Abs against Toxoplasma gondii, VZV, Epstein-Barr virus (EBV), measles, mumps, rubella, CMV, HSV type 1 (HSV-1), and HSV type 2 (HSV-2) by using enzyme-linked immunosorbent assay or chemiluminescent microparticle immunoassay.

RESULTS

In our study, the median level (range) of anti-CMV immunoglobulin G (IgG) is > 250 (All > 250) (arbitrary unit, AU)/mL, anti-EBV > 200 (All > 200) (relative unit, RU)/mL, anti-HSV > 200 (152.75 to >200) RU/mL, anti-VZV > 5000 (All > 5000) IU/L, anti-measles > 5000 (All > 5000) IU/L, anti-mumps > 200 (156.5 to > 200) RU/mL, anti-rubella 209.8 IU/mL (192.7 to 238.5), and anti-Toxoplasma is 14.05 (12.3 to 16) IU/mL. There was not any immunoglobulin M (IgM) against HSV, VZV, mumps, measles, rubella, CMV, EBV, and Toxoplasma in the "Taiwan Blood Services Foundation" IVIG preparations.

CONCLUSION

There was high activity against T. gondii, VZV, EBV, measles, mumps, rubella, CMV, HSV-1, and HSV-2 in all IVIG batches. Further investigation is warranted to confirm the efficacy of IVIG from Taiwanese for congenital TORCH infections.

Placental inflammation, lifestyle, maternal and early child sensitisation to allergens - the assessment of lifestyle and allergic disease during infancy birth cohort

AIM

To investigate (i) whether maternal sensitisation to allergens, and lifestyle can influence the risk of acute and chronic inflammation of the placenta, in the forms of chorioamnionitis and villitis, respectively, and (ii) whether these placental inflammations are associated with the outcome of sensitisation for the child during preschool age.

METHODS

Placentas from term uncomplicated pregnancies (n = 275) in the assessment of lifestyle and allergic disease during infancy study were analysed for the presence of acute chorioamnionitis and chronic villitis. Stepwise logistic regression was performed to estimate the relative risk of placental inflammation in relation to maternal allergic sensitisation and lifestyle, and the association between placental inflammation and sensitisation of the child up to five years of age.

RESULTS

Parity and delivery at home were independently associated with chorioamnionitis, home delivery only with the low grade. Maternal allergic sensitisation was associated with increased risk of villitis in the bivariable model, however, not in the multivariable model. No significant associations were detected between placental inflammation and the outcome of sensitisation to allergens at five years of age.

CONCLUSION

Our data do not support the hypothesis that the increased risk for sensitisation of a child when the mother is allergic is mediated via placental inflammation.

Clinical chorioamnionitis at term IX: in vivo evidence of intra-amniotic inflammasome activation

Background The inflammasome has been implicated in the mechanisms that lead to spontaneous labor at term. However, whether the inflammasome is activated in the amniotic cavity of women with clinical chorioamnionitis at term is unknown. Herein, by measuring extracellular ASC [apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain (CARD)], we investigated whether there is in vivo inflammasome activation in amniotic fluid of patients with clinical chorioamnionitis at term with sterile intra-amniotic inflammation and in those with intra-amniotic infection. Methods This was a retrospective cross-sectional study that included amniotic fluid samples collected from 76 women who delivered after spontaneous term labor with diagnosed clinical chorioamnionitis. Intra-amniotic inflammation was defined as an elevated amniotic fluid interleukin (IL)-6 concentration ≥2.6 ng/mL, and intra-amniotic infection was diagnosed by the presence of microbial invasion of the amniotic cavity (MIAC) accompanied by intra-amniotic inflammation. Patients were classified into the following groups: (1) women without intra-amniotic inflammation or infection (n=16); (2) women with MIAC but without intra-amniotic inflammation (n=5); (3) women with sterile intra-amniotic inflammation (n=15); and (4) women with intra-amniotic infection (n=40). As a readout of in vivo inflammasome activation, extracellular ASC was measured in amniotic fluid by enzyme-linked immunosorbent assay. Acute inflammatory responses in the amniotic fluid and placenta were also evaluated. Results In clinical chorioamnionitis at term: (1) amniotic fluid concentrations of ASC (extracellular ASC is indicative of in vivo inflammasome activation) and IL-6 were greater in women with intra-amniotic infection than in those without intra-amniotic inflammation, regardless of the presence of MIAC; (2) amniotic fluid concentrations of ASC and IL-6 were also higher in women with sterile intra-amniotic inflammation than in those without intra-amniotic inflammation, regardless of the presence of MIAC; (3) amniotic fluid concentrations of IL-6, but not ASC, were more elevated in women with intra-amniotic infection than in those with sterile intra-amniotic inflammation; (4) a positive and significant correlation was observed between amniotic fluid concentrations of ASC and IL-6; (5) no differences were observed in amniotic fluid ASC and IL-6 concentrations between women with and without MIAC in the absence of intra-amniotic inflammation; (6) women with intra-amniotic infection had elevated white blood cell counts and reduced glucose levels in amniotic fluid compared to the other three study groups; and (7) women with intra-amniotic infection presented higher frequencies of acute maternal and fetal inflammatory responses in the placenta than those with sterile intra-amniotic inflammation. Conclusion The intra-amniotic inflammatory response, either induced by alarmins or microbes, is characterized by the activation of the inflammasome - as evidenced by elevated amniotic fluid concentrations of extracellular ASC - in women with clinical chorioamnionitis at term. These findings provide insight into the intra-amniotic inflammatory response in women with clinical chorioamnionitis at term.

Preeclampsia predicts higher incidence of bronchopulmonary dysplasia

INTRODUCTION

It is not known whether very preterm infants born to preeclamptic women have worse outcomes than those delivered preterm for other causes.

OBJECTIVE

We assessed the association between preeclampsia (PE) and the neonatal morbidity and mortality of very preterm infants.

METHODS

Over 2015 and 2016, 11 collaborating Portuguese level III NICUs prospectively enrolled a cohort of mothers with or without PE who delivered liveborn premature infants between 24 and 30 completed weeks of gestation. Data on neonatal morbidities were collected and their association to PE was assessed.

RESULTS

The final cohort consisted of 410 mothers who delivered 494 preterm infants. Infants from PE mothers weighed less than those of non-PE mothers (819 ± 207 g vs. 989 ± 256 g, p < 0.0001). Incidences of respiratory distress syndrome, patent ductus arteriosus, early and nosocomial sepsis, necrotizing enterocolitis, pneumonia, meningitis, retinopathy of prematurity, intraventricular hemorrhage, periventricular infarction, periventricular leukomalacia, and mortality did not differ significantly between infants of PE or non-PE mothers. Incidence of bronchopulmonary dysplasia (BPD-defined as oxygen dependency at 36 weeks) was higher in PE infants compared with non-PE infants by both univariate and multivariate logistic regression (p = 0.007).

CONCLUSION

We conclude that, when controlling for gestational age, maternal PE results in higher incidence of only BPD among preterm Portuguese infants.

Pentoxifylline, dexamethasone and azithromycin demonstrate distinct age-dependent and synergistic inhibition of TLR- and inflammasome-mediated cytokine production in human newborn and adult blood in vitro

Introduction

Neonatal inflammation, mediated in part through Toll-like receptor (TLR) and inflammasome signaling, contributes to adverse outcomes including organ injury. Pentoxifylline (PTX), a phosphodiesterase inhibitor which potently suppresses cytokine production in newborn cord blood, is a candidate neonatal anti-inflammatory agent. We hypothesized that combinations of PTX with other anti-inflammatory agents, the steroid dexamethasone (DEX) or the macrolide azithromycin (AZI), may exert broader, more profound and/or synergistic anti-inflammatory activity towards neonatal TLR- and inflammasome-mediated cytokine production.

Methods

Whole newborn and adult blood was treated with PTX (50–200 μM), DEX (10⁻¹⁰–10⁻⁷ M), or AZI (2.5–20 μM), alone or combined, and cultured with lipopolysaccharide (LPS) (TLR4 agonist), R848 (TLR7/8 agonist) or LPS/adenosine triphosphate (ATP) (inflammasome induction). Supernatant and intracellular cytokines, signaling molecules and mRNA were measured by multiplex assay, flow cytometry and real-time PCR. Drug interactions were assessed based on Loewe's additivity.

Results

PTX, DEX and AZI inhibited TLR- and/or inflammasome-mediated cytokine production in newborn and adult blood, whether added before, simultaneously or after TLR stimulation. PTX preferentially inhibited pro-inflammatory cytokines especially TNF. DEX inhibited IL-10 in newborn, and TNF, IL-1β, IL-6 and interferon-α in newborn and adult blood. AZI inhibited R848-induced TNF, IL-1β, IL-6 and IL-10, and LPS-induced IL-1β and IL-10. (PTX+DEX) synergistically decreased LPS- and LPS/ATP-induced TNF, IL-1β, and IL-6, and R848-induced IL-1β and interferon-α, while (PTX+AZI) synergistically decreased induction of TNF, IL-1β, and IL-6. Synergistic inhibition of TNF production by (PTX+DEX) was especially pronounced in newborn vs. adult blood and was accompanied by reduction of TNF mRNA and enhancement of IL10 mRNA.

Conclusions

Age, agent, and specific drug-drug combinations exert distinct anti-inflammatory effects towards TLR- and/or inflammasome-mediated cytokine production in human newborn blood in vitro. Synergistic combinations of PTX, DEX and AZI may offer benefit for prevention and/or treatment of neonatal inflammatory conditions while potentially limiting drug exposure and toxicity.

Histologic chorioamnionitis in preterm infants: correlation with brain magnetic resonance imaging at term equivalent age

BACKGROUND

To explore the associations between histologic chorioamnionitis with brain injury, maturation and size on magnetic resonance imaging (MRI) of preterm infants at term equivalent age.

METHODS

Preterm infants (23-36 weeks' gestational age) were recruited into two longitudinal cohort studies. Presence or absence of chorioamnionitis was obtained from placental histology and clinical data were recorded. MRI at term-equivalent age was assessed for brain injury (intraventricular haemorrhage, cysts, signal abnormalities), maturation (degree of myelination, gyral maturation) and size of cerebral structures (metrics and brain segmentation). Histologic chorioamnionitis was assessed as a predictor of MRI variables using linear and logistic regression, with adjustment for confounding perinatal variables.

RESULTS

Two hundred and twelve infants were included in this study, 47 (22%) of whom had histologic chorioamnionitis. Histologic chorioamnionitis was associated with higher odds of intraventricular haemorrhage (odds ratio [OR] (95% confidence interval [CI]) = 7.4 (2.4, 23.1)), less mature gyral maturation (OR (95% CI) = 2.0 (1.0, 3.8)) and larger brain volume (mean difference in cubic centimeter (95% CI) of 14.1 (1.9, 26.2)); but all relationships disappeared following adjustment for perinatal variables.

CONCLUSION

Histologic chorioamnionitis was not independently associated with IVH, less mature gyral maturation or brain volume at term-equivalent age in preterm infants.

Chorioamnionitis, IL-17A, and fetal origins of neurologic disease

The Centers for Disease Control and Prevention estimate that 1 in 323 infants have cerebral palsy. Highly correlated to intrauterine infection and inflammation, the incidence of cerebral palsy has remained constant over the last few decades despite significant advances in neonatal intensive care including improved ventilator techniques, surfactant therapy, maternal steroid administration, and use of intrapartum empiric antimicrobials. Recent advances in our understanding of immune responses to infection and inflammation have identified the cytokine IL-17A as a crucial component of early proinflammatory mediators that cause brain injury associated with neurologic impairment. Remarkably, maternal inflammatory responses to in utero inflammation and infection can also lead to potentially debilitating neurologic conditions in the offspring, which often become clinically apparent during childhood and/or early adulthood. This review details the role of IL-17A in fetal and maternal proinflammatory responses that lead to fetal brain injury and neurologic sequelae, including cerebral palsy. Recent findings regarding the role of maternal inflammatory responses in the development of childhood and adult neurologic conditions, such as autism, schizophrenia, and multiple sclerosis, will also be highlighted.

Clinical chorioamnionitis at term VIII: a rapid MMP-8 test for the identification of intra-amniotic inflammation

OBJECTIVE

Clinical chorioamnionitis is the most common infection/inflammatory process diagnosed in labor and delivery units worldwide. The condition is a syndrome that can be caused by (1) intra-amniotic infection, (2) intra-amniotic inflammation without demonstrable microorganisms (i.e. sterile intra-amniotic inflammation), and (3) maternal systemic inflammation that is not associated with intra-amniotic inflammation. The presence of intra-amniotic inflammation is a risk factor for adverse maternal and neonatal outcomes in a broad range of obstetrical syndromes that includes clinical chorioamnionitis at term. Although the diagnosis of intra-amniotic infection has relied on culture results, such information is not immediately available for patient management. Therefore, the diagnosis of intra-amniotic inflammation could be helpful as a proxy for intra-amniotic infection, while results of microbiologic studies are pending. A rapid test is now available for the diagnosis of intra-amniotic inflammation, based on the determination of neutrophil collagenase or matrix metalloproteinase-8 (MMP-8). The objectives of this study were (1) to evaluate the diagnostic indices of a rapid MMP-8 test for the identification of intra-amniotic inflammation/infection in patients with the diagnosis of clinical chorioamnionitis at term, and (2) to compare the diagnostic performance of a rapid MMP-8 test to that of a conventional enzyme-linked immunosorbent assay (ELISA) interleukin (IL)-6 test for patients with clinical chorioamnionitis at term.

MATERIALS AND METHODS

A retrospective cohort study was conducted. A transabdominal amniocentesis was performed in patients with clinical chorioamnionitis at term (n=44). Amniotic fluid was analyzed using cultivation techniques (for aerobic and anaerobic bacteria as well as genital Mycoplasmas) and broad-range polymerase chain reaction (PCR) coupled with electrospray ionization mass spectrometry (PCR/ESI-MS). Amniotic fluid IL-6 concentrations were determined by ELISA, and rapid MMP-8 results were determined by Yoon's MMP-8 Check®. Intra-amniotic inflammation was defined as an elevated amniotic fluid IL-6 concentration ≥2.6 ng/mL, and intra-amniotic infection was diagnosed by the presence of microorganisms in the amniotic fluid accompanied by intra-amniotic inflammation. The diagnostic indices of Yoon's MMP-8 Check® for the identification of intra-amniotic inflammation were calculated. In order to objectively compare Yoon's MMP-8 Check® with the ELISA IL-6 test for the identification of intra-amniotic inflammation, we used an amniotic fluid white blood cell (WBC) count ≥50 cells/mm3 to define intra-amniotic inflammation.

RESULTS

(1) A positive rapid MMP-8 test had a sensitivity of 82.4% (28/34), specificity of 90% (9/10), positive predictive value of 96.6% (28/29), negative predictive value of 60% (9/15), positive likelihood ratio 8.2 (95% CI 1.3-53.2), and negative likelihood ratio 0.2 (95% CI 0.1-0.4) for the identification of intra-amniotic inflammation (prevalence 77.3%); (2) a positive rapid MMP-8 test had a sensitivity of 91.7% (22/24), specificity of 65% (13/20), positive predictive value of 75.9% (22/29), negative predictive value of 86.7% (13/15), positive likelihood ratio of 2.6 (95% CI 1.4-4.8), and negative likelihood ratio of 0.1 (95% CI 0.03-0.5) for the identification of intra-amniotic infection; (3) the rapid MMP-8 test had a significantly higher specificity than the ELISA IL-6 test in the identification of intra-amniotic inflammation as determined by an amniotic fluid WBC count ≥50 cells/mm3. The sensitivity and accuracy of the rapid MMP-8 test were comparable to those of the ELISA IL-6 test; and (4) importantly, the rapid MMP-8 test had 100% sensitivity and 100% negative predictive value in the identification of neonates affected with fetal inflammatory response syndrome (FIRS).

CONCLUSION

The rapid diagnosis of intra-amniotic inflammation is possible by analysis of amniotic fluid using a point-of-care test for MMP-8. Patients with a positive test are at risk of delivering a neonate affected with systemic inflammation, a risk factor for adverse neonatal outcome.

Inflammation-induced preterm lung maturation: lessons from animal experimentation

Intrauterine inflammation, or chorioamnionitis, is a major contributor to preterm birth. Prematurity per se is associated with considerable morbidity and mortality resulting from lung immaturity but exposure to chorioamnionitis reduces the risk of neonatal respiratory distress syndrome (RDS) in preterm infants. Animal experiments have identified that an increase in pulmonary surfactant production by the preterm lungs likely underlies this decreased risk of RDS in infants exposed to chorioamnionitis. Further animal experimentation has shown that infectious or inflammatory agents in amniotic fluid exert their effects on lung development by direct effects within the developing respiratory tract, and probably not by systemic pathways. Differences in the effects of intrauterine inflammation and glucocorticoids demonstrate that canonical glucocorticoid-mediated lung maturation is not responsible for inflammation-induced changes in lung development. Animal experimentation is identifying alternative lung maturational pathways, and transgenic animals and cell culture techniques will allow identification of novel mechanisms of lung maturation that may lead to new treatments for the prevention of RDS.

Maternal Tdap vaccination and risk of infant morbidity

INTRODUCTION

An increased risk of diagnosed chorioamnionitis in women vaccinated with Tdap during pregnancy was previously detected at two Vaccine Safety Datalink (VSD) sites. The clinical significance of this finding related to infant outcomes remains uncertain.

METHODS

Retrospective cohort study of singleton live births born to women who were continuously insured from 6months prior to their last menstrual period through 6weeks postpartum, with ≥1 outpatient visit during pregnancy from January 1, 2010 to November 15, 2013 at seven integrated United States health care systems part of the VSD. We re-evaluated the association between maternal Tdap and chorioamnionitis and evaluated whether specific infant morbidities differ among infants born to mothers who did and did not receive Tdap during pregnancy. We focused on 2 Tdap exposure windows: the recommended 27-36weeks gestation or anytime during pregnancy. We identified inpatient diagnostic codes for transient tachypnea of the newborn (TTN), neonatal sepsis, neonatal pneumonia, respiratory distress syndrome (RDS), and newborn convulsions associated with an infant's first hospitalization. A generalized linear model with Poisson distribution and log-link was used to estimate propensity score adjusted rate ratios (ARR) with 95% confidence intervals (CI).

RESULTS

The analyses included 197,564 pregnancies. Chorioamnionitis was recorded in 6.4% of women who received Tdap vaccination any time during pregnancy and 5.2% of women who did not (ARR [95% CI]: 1.23 [1.17, 1.28]). Compared with unvaccinated women, there were no significant increased risks (ARR [95% CI]) for TTN (1.04 [0.98, 1.11]), neonatal sepsis (1.06 [0.91, 1.23]), neonatal pneumonia (0.94 [0.72, 1.22]), RDS (0.91 [0.66, 1.26]), or newborn convulsions (1.16 [0.87, 1.53]) in infants born to Tdap-vaccinated women.

CONCLUSIONS AND RELEVANCE

Despite an observed association between maternal Tdap vaccination and maternal chorioamnionitis, we did not find increased risk for clinically significant infant outcomes associated with maternal chorioamnionitis.

Maternal Chorioamnionitis and Postneonatal Respiratory Tract Infection in Ex-Preterm Infants

OBJECTIVE

To assess whether exposure to histologically confirmed chorioamnionitis (ie, histologic chorioamnionitis [HCA]) is associated with altered risk of infection-related hospitalization (IRH) during the first 24 months of life in very preterm infants.

STUDY DESIGN

This single-center retrospective cohort study analyzed data on 1218 infants born at <30 weeks gestational age (GA). Semiquantitative placental histology, obstetric, and neonatal data were extracted from hospital databases and linked with discharge diagnoses on rehospitalization until age 24 months from statewide statutory data. The associations between HCA and overall and clinical categories of IRH were analyzed by Cox proportional hazards regression with left-truncated failure times.

RESULTS

Mean GA was 27 weeks, and HCA was present in 577 placentas (47.4%). Among the 1088 infants surviving until the birth-related discharge, 684 (62.9%) of had at least 1 IRH by age 24 months, of whom 287 included a diagnosis of acute lower respiratory tract infection (ALRTI). Following adjustment for sex, birth weight z-score, GA, early-onset sepsis, late-onset sepsis, previous antibiotic use, age at birth-related discharge, and chronic lung disease, HCA was associated with a 32% increased risk of hospitalization with ALRTI (HR, 1.32; 95% CI, 1.02-1.70; P = .033). There was no association with infection overall or with other infection categories.

CONCLUSIONS

HCA is associated with a significantly increased risk of hospitalization with ALRTI that is independent of known risk factors, including chronic lung disease.

Immunophenotyping and activation status of maternal peripheral blood leukocytes during pregnancy and labour, both term and preterm

The onset of labour in rodents and in humans is associated with physiological inflammation which is manifested by infiltration of activated maternal peripheral leukocytes (mPLs) into uterine tissues. Here, we used flow cytometry to immunophenotype mPLs throughout gestation and labour, both term and preterm. Peripheral blood was collected from non-pregnant women and pregnant women in the 1st, 2nd and 3rd trimesters. Samples were also collected from women in active labour at term (TL) or preterm (PTL) and compared with women term not-in-labour (TNIL) and preterm not-in-labour (PTNIL). Different leukocyte populations were identified by surface markers such as CD45, CD14, CD15, CD3, CD4, CD8, CD19 and CD56. Their activation status was measured by the expression levels of CD11b, CD44, CD55, CD181 and CD192 proteins. Of all circulating CD45+ leukocytes, we detected significant increases in CD15+ granulocytes (i) in pregnant women versus non-pregnant; (ii) in TL women versus TNIL and versus pregnant women in the 1st/2nd/3rd trimester; (iii) in PTL women versus PTNIL. TL was characterized by (iv) increased expressions of CD11b, CD55 and CD192 on granulocytes; (v) increased mean fluorescent intensity (MFI) of CD55 and CD192 on monocytes; (vi) increased CD44 MFI on CD3+ lymphocytes as compared to late gestation. In summary, we have identified sub-populations of mPLs that are specifically activated in association with gestation (granulocytes) or with the onset of labour (granulocytes, monocytes and lymphocytes). Additionally, beta regression analysis created a set of reference values to rank this association between immune markers of pregnancy and to identify activation status with potential prognostic and diagnostic capability.

Activation of the IL-1β/CXCL1/MMP-10 axis in chorioamnionitis induced by inactivated Group B Streptococcus

Infection or inflammation during pregnancy is known to lead to maternal immune activation triggering a fetal inflammatory response syndrome associated with deleterious effects, such as brain injury and neurodevelopmental disabilities. Group B Streptococcus (GBS) - one of the most common bacterium colonizing pregnant women - can be responsible for chorioamnionitis. Given that interleukin (IL)-1β has a major role in anti-GBS host defense, we hypothesized that IL-1β-driven innate immune response is implicated in GBS-induced chorioamnionitis. Using a rat model of GBS-induced chorioamnionitis, this study showed that inflammatory response to this pathogen was associated with maternal and placental IL-1β hyper expression. Following placental chemokine (C-X-C motif) ligand 1 (CXCL1) production, polymorphonuclear leukocytes (PMN) placental infiltration started at 24 h post-GBS exposure, and MMP-10 was released within these placentas. At 72 h, PMN infiltration extended to membranes and to membranes' arteries. This was associated with IL-1β release within the fetus blood at 72 h. Such a GBS-associated inflammatory cascade might be deleterious for fetal organs. These results pave the way toward targeted placento-protective anti-inflammatory strategies against GBS-induced chorioamnionitis.

Revisiting the diagnostic criteria of clinical chorioamnionitis in preterm birth

OBJECTIVE

To re-evaluate the utility of the conventional criteria for clinical chorioamnionitis in the prediction of early-onset neonatal sepsis (EONS) in preterm birth.

DESIGN

Retrospective cohort study.

SETTING

Seoul, Republic of Korea.

SAMPLE

A total of 1468 singleton births between 24 and 34 weeks due to preterm labour (n = 713) or preterm prelabour rupture of membranes (n = 755).

METHOD

We evaluated three diagnostic categories of clinical chorioamnionitis: Criteria 1, conventional criteria; Criteria 2, combination of any three conventional parameters without prerequisite fever; Criteria 3, Criteria 1 plus positive maternal C-reactive protein and neutrophil left-shift into minor criteria. EONS included proven or suspected sepsis within 7 days following birth. Neonatal morbidity and mortality of EONS were also reviewed.

MAIN OUTCOME MEASURES

Diagnostic performance of three combinations.

RESULTS

The prevalence of EONS was 13.8%. Among 203 cases of EONS, maternal manifestation of clinical chorioamnionitis by criteria 1 was evident in only one out of seven, indicating 15.3% sensitivity for EONS prediction. However, with application of criteria 2, sensitivity significantly increased to 34.0%, while compromising specificity from 92.3% to 78.7%. Criteria 3 showed similar diagnostic performance compared with criteria 1 (sensitivity 16.7%, specificity 91.6%). Overall, neonatal mortality and neonatal composite morbidity in EONS were 14.9% and 67.8%, respectively, and there was no difference in neonatal morbidity and mortality between neonates whose mothers showed fever as a sign of clinical chorioamnionitis and those whose mothers did not.

CONCLUSION

The renouncement of fever as a prerequisite for the criteria of clinical chorioamnionitis could increase sensitivity for the identification of EONS, a serious outcome of preterm birth.

TWEETABLE ABSTRACT

The renouncement of fever as an essential can increase sensitivity for prediction of neonatal sepsis.

Funisitis is associated with adverse neonatal outcome in low-risk unselected deliveries at or near term

This study aimed to determine the incidence and clinical outcomes for varying patterns of placental histological inflammation (consistent with fetal or maternal inflammatory response) in an unselected population of >1000 women with a singleton pregnancy resulting in live birth delivering at or near term. One thousand one hundred nineteen cases were studied in a blind, prospective, unselected study with placentas categorized into five histological subgroups reflecting underlying maternal or fetal inflammatory response. Clinical outcomes studied included interventional delivery, an Apgar score <7 at 1 min, neonatal acidosis (pH < 7.2) and admission to neonatal special care. One hundred eighty-eight placentas (17 %) showed histological evidence of acute inflammation: 64 with funisitis (with or without other inflammation; 6 %); 16 with extensive acute inflammation across the chorionic plate, free membranes and subchorionic fibrin (1 %); 28 with acute inflammation restricted to the chorionic plate (2 %); 12 with acute inflammation restricted to the free membranes (1 %) and 68 with acute inflammation restricted to the subchorionic fibrin (6 %). Features of extensive acute inflammation were significantly associated with increased rate of interventional delivery (assisted vaginal delivery or emergency caesarean section; P < 0.01). The presence of funisitis was significantly associated with interventional delivery and other adverse outcomes including an Apgar score <7 at 1 min, clinical evidence of sepsis and admission to the neonatal intensive care unit (P < 0.05 for all). The data represent a quantitative rather than purely qualitative analysis of the contribution of histological lesions related to inflammation on short-term adverse neonatal outcomes and interventional delivery. Funisitis and extensive inflammation are associated with adverse clinical outcomes, but the precise mechanism underlying these remains to be elucidated.

Clinical chorioamnionitis at term IV: the maternal plasma cytokine profile

INTRODUCTION

Fever is a major criterion for clinical chorioamnionitis; yet, many patients with intrapartum fever do not have demonstrable intra-amniotic infection. Some cytokines, such as interleukin (IL)-1, IL-6, interferon-gamma (IFN-γ), and tumor necrosis factor alpha (TNF-α), can induce a fever. The objective of this study was to determine whether maternal plasma concentrations of cytokines could be of value in the identification of patients with the diagnosis of clinical chorioamnionitis at term who have microbial-associated intra-amniotic inflammation.

METHODS

A retrospective cross-sectional study was conducted, including patients with clinical chorioamnionitis at term (n=41; cases) and women in spontaneous labor at term without clinical chorioamnionitis (n=77; controls). Women with clinical chorioamnionitis were classified into three groups according to the results of amniotic fluid culture, broad-range polymerase chain reaction coupled with electrospray ionization mass spectrometry (PCR/ESI-MS), and amniotic fluid IL-6 concentration: 1) no intra-amniotic inflammation; 2) intra-amniotic inflammation without detectable microorganisms; or 3) microbial-associated intra-amniotic inflammation. The maternal plasma concentrations of 29 cytokines were determined with sensitive and specific V-PLEX immunoassays. Nonparametric statistical methods were used for analysis, adjusting for a false discovery rate of 5%.

RESULTS

1) The maternal plasma concentrations of pyrogenic cytokines (IL-1β, IL-2, IL-6, IFN-γ, and TNF-α) were significantly higher in patients with clinical chorioamnionitis at term than in those with spontaneous term labor without clinical chorioamnionitis; 2) the maternal plasma concentrations of cytokines were not significantly different among the three subgroups of patients with clinical chorioamnionitis (intra-amniotic inflammation with and without detectable bacteria and those without intra-amniotic inflammation); and 3) among women with the diagnosis of clinical chorioamnionitis, but without evidence of intra-amniotic inflammation, the maternal plasma concentrations of pyrogenic cytokines were significantly higher than in patients with spontaneous labor at term. These observations suggest that a fever can be mediated by increased circulating concentrations of these cytokines, despite the absence of a local intra-amniotic inflammatory response.

CONCLUSIONS

1) The maternal plasma concentrations of pyrogenic cytokines (e.g. IL-1β, IL-2, IL-6, IFN-γ, and TNF-α) are higher in patients with intra-partum fever and the diagnosis of clinical chorioamnionitis at term than in those in spontaneous labor at term without a fever; and 2) maternal plasma cytokine concentrations have limited value in the identification of patients with bacteria in the amniotic cavity. Accurate assessment of the presence of intra-amniotic infection requires amniotic fluid analysis.

Clinical chorioamnionitis at term V: umbilical cord plasma cytokine profile in the context of a systemic maternal inflammatory response

OBJECTIVE

Microbial invasion of the fetus due to intra-amniotic infection can lead to a systemic inflammatory response characterized by elevated concentrations of cytokines in the umbilical cord plasma/serum. Clinical chorioamnionitis represents the maternal syndrome often associated with intra-amniotic infection, although other causes of this syndrome have been recently described. The objective of this study was to characterize the umbilical cord plasma cytokine profile in neonates born to mothers with clinical chorioamnionitis at term, according to the presence or absence of bacteria and/or intra-amniotic inflammation.

MATERIALS AND METHODS

A cross-sectional study was conducted, including patients with clinical chorioamnionitis at term (n=38; cases) and those with spontaneous term labor without clinical chorioamnionitis (n=77; controls). Women with clinical chorioamnionitis were classified according to the results of amniotic fluid culture, broad-range polymerase chain reaction coupled with electrospray ionization mass spectrometry (PCR/ESI-MS) and amniotic fluid interleukin (IL)-6 concentration into three groups: 1) no intra-amniotic inflammation; 2) intra-amniotic inflammation without detectable microorganisms; or 3) microbial-associated intra-amniotic inflammation. A fetal inflammatory response syndrome (FIRS) was defined as an umbilical cord plasma IL-6 concentration >11 pg/mL. The umbilical cord plasma concentrations of 29 cytokines were determined with sensitive and specific V-PLEX immunoassays. Nonparametric statistical methods were used for analysis, adjusting for a false discovery rate of 5%.

RESULTS

1) Neonates born to mothers with clinical chorioamnionitis at term (considered in toto) had significantly higher median umbilical cord plasma concentrations of IL-6, IL-12p70, IL-16, IL-13, IL-4, IL-10 and IL-8, but significantly lower interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF)-α concentrations than neonates born to mothers with spontaneous term labor without clinical chorioamnionitis; 2) neonates born to mothers with clinical chorioamnionitis at term but without intra-amniotic inflammation had higher concentrations of IL-6, IL-12p70, IL-13, IL-4, IL-5, and IL-8, but lower IFN-γ, than neonates not exposed to clinical chorioamnionitis, suggesting that maternal fever in the absence of intra-amniotic inflammation leads to a change in the fetal cytokine network; 3) there were significant, positive correlations between maternal and umbilical cord plasma IL-6 and IL-8 concentrations (IL-6: Spearman correlation=0.53; P<0.001; IL-8: Spearman correlation=0.42; P<0.001), consistent with placental transfer of cytokines; 4) an elevated fetal plasma IL-6 (>11 pg/mL), the diagnostic criterion for FIRS, was present in 21% of cases (8/38), and all these neonates were born to mothers with proven intra-amniotic infection; and 5) FIRS was associated with a high concentration of umbilical cord plasma IL-8, IL-10 and monocyte chemoattractant protein (MCP)-1.

CONCLUSIONS

Neonates born to mothers with clinical chorioamnionitis at term had higher concentrations of umbilical cord plasma cytokines than those born to mothers without clinical chorioamnionitis. Even neonates exposed to clinical chorioamnionitis but not to intra-amniotic inflammation had elevated concentrations of multiple cytokines, suggesting that intrapartum fever alters the fetal immune response.

White matter injury and the inflammatory response following neonatal cardiac surgery

White matter injury (WMI) is a known complication following neonatal heart surgery in term infants. In preterm infants, WMI has been associated with the degree of systemic inflammation. It is not known whether inflammation is an important mechanism of WMI as documented by magnetic resonance imaging (MRI) following neonatal heart surgery with cardiopulmonary bypass. Term neonates with congenital heart disease were enrolled in a prospective study with postoperative MRI. White matter injury was recorded by the number of T1 hyperintense foci with >5 foci consistent with significant WMI. Eleven candidate cytokine markers (INF-gamma, TNF-alpha, IL-1 beta, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, and IL-13) were assayed preoperatively and daily for 5 days following surgery. Multiple clinical factors were recorded and correlated with WMI. Ninety-two subjects were enrolled in the study. The median age at surgery was 5 days (interquartile range 4-7 days). Compared with the presurgery level, there were statistically significant increases (p < 0.005) for 8 out of 11 inflammatory markers. In all, 64 postoperative MRIs were performed. No significant correlation was detected between WMI and clinical variables or inflammatory markers assessed immediately postoperative and on postoperative days 1 and 3, with exception of IL-1 beta on postoperative day 1. WMI correlates poorly with the systemic inflammatory response after congenital heart surgery and a number of herein measured clinical factors. WMI following neonatal heart surgery is a complex, still incompletely understood phenomenon that warrants continued investigation.

Clinical chorioamnionitis at term I: microbiology of the amniotic cavity using cultivation and molecular techniques

INTRODUCTION

The objectives of this study were: 1) to determine the amniotic fluid (AF) microbiology of patients with the diagnosis of clinical chorioamnionitis at term using both cultivation and molecular techniques; and 2) to examine the relationship between intra-amniotic inflammation with and without microorganisms and placental lesions consistent with acute AF infection.

METHODS

The AF samples obtained by transabdominal amniocentesis from 46 women with clinical signs of chorioamnionitis at term were analyzed using cultivation techniques (for aerobic and anerobic bacteria as well as genital mycoplasmas) and broad-range polymerase chain reaction (PCR) coupled with electrospray ionization mass spectrometry (PCR/ESI-MS). The frequency of microbial invasion of the amniotic cavity (MIAC), intra-amniotic inflammation [defined as an AF interleukin 6 (IL-6) concentration ≥2.6 ng/mL], and placental lesions consistent with acute AF infection (acute histologic chorioamnionitis and/or acute funisitis) were examined according to the results of AF cultivation and PCR/ESI-MS as well as AF IL-6 concentrations.

RESULTS

1) Culture identified bacteria in AF from 46% (21/46) of the participants, whereas PCR/ESI-MS was positive for microorganisms in 59% (27/46) – combining these two tests, microorganisms were detected in 61% (28/46) of patients with clinical chorioamnionitis at term. Eight patients had discordant test results; one had a positive culture and negative PCR/ESI-MS result, whereas seven patients had positive PCR/ESI-MS results and negative cultures. 2) Ureaplasma urealyticum (n=8) and Gardnerella vaginalis (n=10) were the microorganisms most frequently identified by cultivation and PCR/ESI-MS, respectively. 3) When combining the results of AF culture, PCR/ESI-MS and AF IL-6 concentrations, 15% (7/46) of patients did not have intra-amniotic inflammation or infection, 6.5% (3/46) had only MIAC, 54% (25/46) had microbial-associated intra-amniotic inflammation, and 24% (11/46) had intra-amniotic inflammation without detectable microorganisms. 4) Placental lesions consistent with acute AF infection were significantly more frequent in patients with microbial-associated intra-amniotic inflammation than in those without intra-amniotic inflammation [70.8% (17/24) vs. 28.6% (2/7); P=0.04].

CONCLUSION

Microorganisms in the AF were identified in 61% of patients with clinical chorioamnionitis at term; 54% had microbial-associated intra-amniotic inflammation, whereas 24% had intra-amniotic inflammation without detectable microorganisms.

Morbidity and mortality among very-low-birth-weight infants born to mothers with clinical chorioamnionitis

BACKGROUND

Controversy exists about the relationship between maternal inflammation and the development of different morbidities and mortality in the newborn. We aimed to establish the incidence of clinical chorioamnionitis in our Neonatal Intensive Care Unit and its relation to morbidity and mortality among very-low-birth-weight infants.

METHODS

This was an observational study of a cohort of very-low-birth-weight neonates admitted to our Neonatal Intensive Care Unit, between January 2008 and December 2012. Demographic characteristics and outcomes were analyzed and a comparison between exposed and non-exposed infants was carried out.

RESULTS

During the study period, 451 very-low-birth-weight infants were admitted to our Neonatal Intensive Care Unit, and 31 (6.87%) were exposed to maternal clinical chorioamnionitis. The incidence was higher at lower gestational ages: 13.2% (23-26 weeks), 8.1% (27-30 weeks), and 2.6% (31-34 weeks) (p = 0.022). After correcting by gestational age and birth weight, early-onset neonatal sepsis (adjusted relative risk = 6.13; 95% confidence interval = 1.67-22.58; p = 0.006) and periventricular leukomalacia (adjusted relative risk = 24.62; 95% confidence interval = 1.87-324.28; p = 0.015) were significantly associated with maternal clinical chorioamnionitis. There were no differences in mortality or in survival without major morbidity.

CONCLUSION

Clinical chorioamnionitis confers an increased risk of early-onset neonatal sepsis and periventricular leukomalacia to exposed very-low-birth-weight infants.

Inhibition of infection-mediated preterm birth by administration of broad spectrum chemokine inhibitor in mice

Preterm birth (PTB) is the single most important cause of perinatal and infant mortality worldwide. Maternal infection can result in PTB. We investigated the ability of a Broad Spectrum Chemokine Inhibitor (BSCI) to prevent infection-induced PTB in mice. PTB was initiated in pregnant mice by intraperitoneal injection of lipopolysaccharide (LPS; 50 μg). Half the mice received BSCI (10 mg/kg) 24 hrs prior to and immediately before LPS administration. The impact of LPS alone or LPS plus BSCI was assessed on (i) injection-to-delivery interval, foetal survival rate, placental and neonates' weight; (ii) amniotic fluid and maternal plasma cytokine levels (by Luminex assay); foetal and maternal tissue cytokine gene expression levels (by Real-Time RT-PCR); (iii) immune cells infiltration into the uterine tissue (by stereological immunohistochemistry). Pre-treatment with BSCI (i) decreased LPS-induced PTB (64% versus 100%, P < 0.05); (ii) significantly attenuated cytokine/chemokine expression in maternal tissues (plasma, liver, myometrium, decidua); (iii) significantly decreased neutrophil infiltration in the mouse myometrium. BSCI-treated mice in which PTB was delayed till term had live foetuses with normal placental and foetal weight. BSCI represents a promising new class of therapeutics for PTB. In a mouse model of preterm labour, BCSI suppresses systemic inflammation in maternal tissues which resulted in the reduced incidence of LPS-mediated PTB. These data provide support for efforts to target inflammatory responses as a means of preventing PTB.

Chorioamnionitis in the pathogenesis of brain injury in preterm infants

Chorioamnionitis (or placental infection) is suspected to be a risk factor for brain injury in premature infants. The suggested association between chorioamnionitis and cystic periventricular leukomalacia and cerebral palsy is uncertain because of the variability of study designs and definitions of chorioamnionitis. Improvements in neonatal intensive care may have attenuated the impact of chorioamnionitis on brain health outcomes. Large multicenter studies using rigorous definitions of chorioamnionitis on placental pathologies and quantitative magnetic resonance techniques may offer the optimal way to clarify the complex role of chorioamnionitis in modifying brain health and long-term outcomes.

Outcomes of very-low-birth-weight infants exposed to maternal clinical chorioamnionitis: a multicentre study

BACKGROUND

Chorioamnionitis is a recognized risk factor of preterm delivery; however, controversy still persists concerning the relationship between maternal inflammation and neonatal morbidity and mortality.

OBJECTIVE

To determine the incidence of clinical chorioamnionitis and its relationship to morbidity and mortality among very-low-birth-weight (VLBW) infants.

METHODS

This was a retrospective analysis of prospectively collected data of VLBW neonates ≤ 32 weeks' gestational age (GA) admitted to collaborating units in the Spanish SEN1500 Network between January 2008 and December 2011. Clinical chorioamnionitis was defined by obstetricians based on clinical findings, and neonatal outcomes were compared between exposed and non-exposed infants by multivariate logistic regression analysis.

RESULTS

During the study period, 11,464 VLBW newborns were admitted to our units and 10,026 were ≤ 32 weeks' GA. Among them, 8,330 (83.1%) had complete data and were included. Of these, 1,480 (17.8%) were exposed to maternal clinical chorioamnionitis. The incidence was higher at lower GA and, after adjusting for confounding factors, exposed infants had higher risks of early-onset neonatal sepsis (EONS) (10.0 vs. 2.8%; aOR 3.102; 95% CI 2.306-4.173; p < 0.001) and necrotizing enterocolitis (NEC) (11.2 vs. 7.7%; aOR 1.300; 95% CI 1.021-1.655; p < 0.033), but lower risks of patent ductus arteriosus (PDA) (43.2 vs. 34.9%; aOR 0.831; 95% CI 0.711-0.971; p < 0.02) and late-onset bacterial sepsis (LONS) (36.6 vs. 32.5%; aOR 0.849; 95% CI 0.729-0.989; p < 0.035). There were no differences in mortality between the groups.

CONCLUSIONS

The incidence of maternal clinical chorioamnionitis is inversely related to GA at delivery, and in VLBW infants ≤ 32 weeks' GA it is associated with higher risks of EONS and NEC, but lower risks of PDA and LONS. We did not found differences in survival.

Management of prelabour rupture of membranes (PROM) at term

Over a 20-month period we identified several cases of neonatal pneumonia associated with prelabour rupture of membranes (PROM) at term. PROM complicates 8%-10% of all pregnancies, yet 60% of cases occur at term. Ascending infection is a contributing factor and the incidence of chorioamnionitis in these patients is relatively high, especially with prolonged membrane rupture. The signs and symptoms NICE recommends patients look out for are not always present as the majority of infections are subclinical, yet associated maternal and neonatal morbidity of chorioamnionitis is potentially devastating. A survey of maternity units in the West Midlands reveals significant variance in management of these cases. Given the lack of consensus and clear evidence on optimal management of PROM at term, we believe early detection of developing infections could be enhanced by using a combination of investigations (at presentation, 12 and 24 h), as well as current advice to self-monitor temperature and vaginal loss.

Preterm prelabour rupture of membranes: effect of latency on neonatal and maternal outcomes

OBJECTIVES

To compare risks of infection and prematurity-related outcomes according to latency periods among women with preterm prelabour rupture of membranes (PPROM).

METHODS

Women with PPROM occurring between 24+0 and 36+6 weeks of gestation were identified from a provincial population-based perinatal database in Nova Scotia. The primary outcomes included composite variables for serious maternal and neonatal infectious morbidity and neonatal prematurity-related morbidity. Logistic regression was used to quantify the relationship between latency period (< 24 hours, 24 hours to < 48 hours, 48 hours to < 7 days, and ≥ 7 days) and maternal and neonatal outcomes. Separate analyses were conducted for gestational age groups 24+0 to 33+6 weeks and 34+0 to 36+6 weeks.

RESULTS

There were 4329 women included in the cohort. The composite variables representing serious maternal or neonatal infectious morbidity were not significantly associated with latency for either gestational age group. For PPROM occurring at gestational ages of 24+0 to 33+6 weeks, the odds of neonatal prematurity-related morbidity were significantly decreased at the latency periods of 48 hours or more compared with < 24 hours latency. For PPROM at 34+0 to 36+6 weeks of gestation, the odds of prematurity-related morbidity at 48 hours to < 7 days latency was decreased compared with latencies < 24 hours (OR 0.4; 95% CI 0.2 to 0.8).

CONCLUSION

Postponing delivery following PPROM may contribute to less prematurity-related morbidity, even close to term, without putting mother or neonate at substantial risk for serious infectious morbidity. Generalization of these findings to other obstetric populations should be informed by the underlying risk of infection.

Mechanisms of acute respiratory distress syndrome in children and adults: a review and suggestions for future research

OBJECTIVES

To provide a current overview of the epidemiology and pathophysiology of acute respiratory distress syndrome in adults and children, and to identify research questions that will address the differences between adults and children with acute respiratory distress syndrome.

DATA SOURCES

Narrative literature review and author-generated data.

DATA SELECTION

The epidemiology of acute respiratory distress syndrome in adults and children, lung morphogenesis, and postnatal lung growth and development are reviewed. The pathophysiology of acute respiratory distress syndrome is divided into eight categories: alveolar fluid transport, surfactant, innate immunity, apoptosis, coagulation, direct alveolar epithelial injury by bacterial products, ventilator-associated lung injury, and repair.

DATA EXTRACTION AND SYNTHESIS

Epidemiologic data suggest significant differences in the prevalence and mortality of acute respiratory distress syndrome between children and adults. Postnatal lung development continues through attainment of adult height, and there is overlap between the regulation of postnatal lung development and inflammatory, apoptotic, alveolar fluid clearance, and repair mechanisms. Therefore, there is a different biological baseline network of gene and protein expression in children as compared with adults.

CONCLUSIONS

There are significant obstacles to performing research on children with acute respiratory distress syndrome. However, epidemiologic, clinical, and animal studies suggest age-dependent differences in the pathophysiology of acute respiratory distress syndrome. In order to reduce the prevalence and improve the outcome of patients with acute respiratory distress syndrome, translational studies of inflammatory, apoptotic, alveolar fluid clearance, and repair mechanisms are needed. Understanding the differences in pathophysiologic mechanisms in acute respiratory distress syndrome between children and adults should facilitate identification of novel therapeutic interventions to prevent or modulate lung injury and improve lung repair.

Thrown off balance: the effect of antenatal inflammation on the developing lung and immune system

In recent years, translational research with various animal models has been helpful to answer basic questions about the effect of antenatal inflammation on maturation and development of the fetal lung and immune system. The fetal lung and immune systems are very plastic and their development can be conditioned and influenced by both endogenous and/or exogenous factors. Antenatal inflammation can induce pulmonary inflammation, leading to lung injury and remodeling in the fetal lung. Exposure to antenatal inflammation can induce interleukin-1α production, which enhances surfactant protein and lipid synthesis thereby promoting lung maturation. Interleukin-1α is therefore a candidate for the link between lung inflammation and lung maturation, preventing respiratory distress syndrome in preterm infants. Antenatal inflammation can, however, cause structural changes in the fetal lung and affect the expression of growth factors, such as transforming growth factor-beta, connective tissue growth factor, fibroblast growth factor-10, or bone morphogenetic protein-4, which are essential for branching morphogenesis. These alterations cause alveolar and microvascular simplification resembling the histology of bronchopulmonary dysplasia. Antenatal inflammation may also affect neonatal outcome by modulating the responsiveness of the immune system. Lipopolysaccharide-tolerance (endotoxin hyporesponsiveness/immunoparalysis), induced by exposure to inflammation in utero, may prevent fetal lung damage, but increases susceptibility to postnatal infections. Moreover, prenatal exposure to inflammation appears to be a predisposition for the development of adverse neonatal outcomes, like bronchopulmonary dysplasia, if the preterm infant is exposed to a second postnatal hit, such as mechanical ventilation oxygen exposure, infections, or steroids.

The immune consequences of preterm birth

Preterm birth occurs in 11% of live births globally and accounts for 35% of all newborn deaths. Preterm newborns have immature immune systems, with reduced innate and adaptive immunity; their immune systems may be further compromised by various factors associated with preterm birth. The immune systems of preterm infants have a smaller pool of monocytes and neutrophils, impaired ability of these cells to kill pathogens, and lower production of cytokines which limits T cell activation and reduces the ability to fight bacteria and detect viruses in cells, compared to term infants. Intrauterine inflammation is a major contributor to preterm birth, and causes premature immune activation and cytokine production. This can induce immune tolerance leading to reduced newborn immune function. Intrauterine inflammation is associated with an increased risk of early-onset sepsis and likely has long-term adverse immune consequences. Requisite medical interventions further impact on immune development and function. Antenatal corticosteroid treatment to prevent newborn respiratory disease is routine but may be immunosuppressive, and has been associated with febrile responses, reductions in lymphocyte proliferation and cytokine production, and increased risk of infection. Invasive medical procedures result in an increased risk of late-onset sepsis. Respiratory support can cause chronic inflammatory lung disease associated with increased risk of long-term morbidity. Colonization of the infant by microorganisms at birth is a significant contributor to the establishment of the microbiome. Caesarean section affects infant colonization, potentially contributing to lifelong immune function and well-being. Several factors associated with preterm birth alter immune function. A better understanding of perinatal modification of the preterm immune system will allow for the refinement of care to minimize lifelong adverse immune consequences.

The consequences of chorioamnionitis: preterm birth and effects on development

Preterm birth is a major cause of perinatal mortality and long-term morbidity. Chorioamnionitis is a common cause of preterm birth. Clinical chorioamnionitis, characterised by maternal fever, leukocytosis, tachycardia, uterine tenderness, and preterm rupture of membranes, is less common than subclinical/histologic chorioamnionitis, which is asymptomatic and defined by inflammation of the chorion, amnion, and placenta. Chorioamnionitis is often associated with a fetal inflammatory response. The fetal inflammatory response syndrome (FIRS) is defined by increased systemic inflammatory cytokine concentrations, funisitis, and fetal vasculitis. Clinical and epidemiological studies have demonstrated that FIRS leads to poor cardiorespiratory, neurological, and renal outcomes. These observations are further supported by experimental studies that have improved our understanding of the mechanisms responsible for these outcomes. This paper outlines clinical and experimental studies that have improved our current understanding of the mechanisms responsible for chorioamnionitis-induced preterm birth and explores the cellular and physiological mechanisms underlying poor cardiorespiratory, neural, retinal, and renal outcomes observed in preterm infants exposed to chorioamnionitis.

Effects of intrauterine infection or inflammation on fetal lung development

1. Intrauterine infection or inflammation is common in cases of preterm birth. Preterm infants are at risk of acute respiratory distress as a result of lung immaturity; evidence of exposure to infection and/or inflammation before birth is associated with a reduced risk of neonatal respiratory distress syndrome (RDS). Experimentally induced intrauterine inflammation or infection in sheep causes a precocious increase in pulmonary surfactant in the preterm lungs that improves preterm lung function, consistent with the reduced risk of RDS in human infants exposed to infection and/or inflammation before birth. 2. The effects of intrauterine inflammation on fetal lung development appear to result from direct action of proinflammatory stimuli within the lungs rather than by systemic signals, such as the classical glucocorticoid-mediated lung maturation pathway. However, paracrine and/or autocrine production and/or metabolism of glucocorticoids in fetal lung tissue may occur as a result of inflammation-induced changes in the expression of 11β-hydroxysteroid dehydrogenase (types 1 and 2). 3. Likely candidates that mediate inflammation-induced surfactant production by the preterm lung include prostaglandin E₂ and/or other arachidonic acid metabolites. Intrauterine inflammation induces the expression of enzymes responsible for prostaglandin production in fetal lung tissue. Inhibition of prostaglandin production prevents, at least in part, the effects of inflammation on fetal lungs. 4. Our experiments are identifying mechanisms of surfactant production by the preterm lungs that may be exploited as novel therapies for preventing respiratory distress in preterm infants. Elucidation of the effects of inflammation on the fetal lungs and other organs will allow more refined approaches to the care of preterm infants exposed to inflammation in utero.

Intraamniotic lipopolysaccharide exposure changes cell populations and structure of the ovine fetal thymus

RATIONALE

Chorioamnionitis induces preterm delivery and acute involution of the fetal thymus which is associated with postnatal inflammatory disorders. We studied the immune response, cell composition, and architecture of the fetal thymus following intraamniotic lipopolysaccharide (LPS) exposure.

METHODS

Time-mated ewes received an intraamniotic injection of LPS 5, 12, or 24 hours or 2, 4, 8, or 15 days before delivery at 125 days gestational age (term = 150 days).

RESULTS

The LPS exposure resulted in decreased blood lymphocytes within 5 hours and decreased thymic corticomedullary ratio within 24 hours. Thymic interleukin 6 (IL6) and IL17 messenger RNA (mRNA) increased 5-fold 24 hours post-LPS exposure. Increased toll-like receptor 4 (TLR4) mRNA and nuclear factor κB positive cells at 24 hours after LPS delivery demonstrated acute thymic activation. Both TLR4 and IL1 mRNA increased by 5-fold and the number of Foxp3-positive cells (Foxp3+ cells) decreased 15 days after exposure.

CONCLUSION

Intraamniotic LPS exposure caused a proinflammatory response, involution, and a persistent depletion of thymic Foxp3+ cells indicating disturbance of the fetal immune homeostasis.

Clinical chorioamnionitis is characterized by changes in the expression of the alarmin HMGB1 and one of its receptors, sRAGE

OBJECTIVE

High mobility group box-1 (HMGB1) protein is an alarmin, a normal cell constituent, which is released into the extracellular environment upon cellular stress/damage and capable of activating inflammation and tissue repair. The receptor for advanced glycation end products (RAGE) can bind HMGB1. RAGE, in turn, can induce the production of pro-inflammatory cytokines; this may be modulated by the soluble truncated forms of RAGE, including soluble RAGE (sRAGE) and endogenous secretory RAGE (esRAGE). The objectives of this study were to determine whether: 1) clinical chorioamnionitis at term is associated with changes in amniotic fluid concentrations of HMGB1, sRAGE and esRAGE; and 2) the amniotic fluid concentration of HMGB1 changes with labor or as a function of gestational age.

METHODS

Amniotic fluid samples were collected from the following groups: 1) mid-trimester (n = 45); 2) term with (n = 48) and without labor (n = 22) without intra-amniotic infection; and 3) term with clinical chorioamnionitis (n = 46). Amniotic fluid concentrations of HMGB1, sRAGE and esRAGE concentrations were determined by ELISA.

RESULTS

1) the median amniotic fluid HMGB1 concentration was higher in patients at term with clinical chorioamnionitis than in those without this condition (clinical chorioamnionitis: median 3.8 ng/mL vs. term in labor: median 1.8 ng/mL, p = 0.007; and vs. term not in labor: median 1.1 ng/mL, p = 0.003); 2) in contrast, patients with clinical chorioamnionitis had a lower median sRAGE concentration than those without this condition (clinical chorioamnionitis: median 9.3 ng/mL vs. term in labor: median 18.6 ng/mL, p = 0.001; and vs. term not in labor median: 28.4 ng/mL, p < 0.001); 3) amniotic fluid concentrations of esRAGE did not significantly change in patients with clinical chorioamnionitis at term (clinical chorioamnionitis: median 5.4 ng/mL vs. term in labor: median 6.1 ng/mL, p = 0.9; and vs. term not in labor: median 9.5 ng/mL, p = 0.06); and 4) there was no significant difference in the median AF HMGB1 concentration between women at term in labor and those not in labor (p = 0.4) and between women in the mid-trimester and those at term not in labor (mid-trimester: median 1.5 ng/mL; p = 0.2).

CONCLUSION

An increase in the amniotic fluid HMGB1 concentration and a decrease in sRAGE were observed in clinical chorioamnionitis at term. This finding provides evidence that an alarmin, HMGB1, and one of its receptors, sRAGE, are engaged in the process of clinical chorioamnionitis at term. These changes are quite different from those observed in cases of intra-amniotic infection/inflammation in preterm gestations.

Perinatal outcome and placental histological characteristics: a single-center study

OBJECTIVE

Placental pathology assists in characterizing the antenatal environment and may provide information about the baby's subsequent development. We aim to assess whether histological patterns of placenta are associated with an increased risk of perinatal diseases and to evaluate how different patterns of placental dysfunction can affect the neurodevelopmental outcome.

METHODS

We analyzed the histopathological characteristics of 105 singleton placentas from infants born between 23 and 31 weeks of gestation and we assessed pair-wise correlations with perinatal diseases. Estimated relative risks were calculated from odds ratios.

RESULTS

Histological chorioamnionitis (CA group) was detected on 51 of 100 placentas tested. Lesions of uteroplacental circulation (abruption, infarction or thrombosis, perivillous fibrin deposition, syncytial knots; vasculopathy group) were detected on 29. 25 normal placentas served as controls. The incidence of bronchopulmonary dysplasia (BPD) and patent ductus arteriosus (PDA) was higher in CA than in control group. The risk of developing retinopathy of prematurity (ROP), intraventricular hemorrhage (IVH) and PDA was higher in CA than in vasculopathy group.

CONCLUSIONS

At low gestational age CA, rather than placental lesions of vasculopathy, negatively impacts perinatal outcome. Clinical significance of histologic vasculopathy remains questionable. Other pathophysiological mechanisms than those associated with placental changes may occur following dysfunction of uteroplacental circulation.

Incidence of and risk factors for neonatal respiratory depression and encephalopathy in rural Sarlahi, Nepal

OBJECTIVES

To characterize the incidence of, risk factors for, and neonatal morbidity and mortality associated with respiratory depression at birth and neonatal encephalopathy (NE) among term infants in a developing country.

METHODS

Data were collected prospectively in 2002-2006 during a community-based trial that enrolled 23 662 newborns in rural Nepal and evaluated the impact of umbilical-cord and skin cleansing on neonatal morbidity and mortality rates. Respiratory depression at birth and NE were defined on the basis of symptoms from maternal reports and study-worker observations during home visits.

RESULTS

Respiratory depression at birth was reported for 19.7% of live births, and 79% of cases involved term infants without congenital anomalies. Among newborns with probable intrapartum-related respiratory depression (N = 3465), 112 (3%) died before their first home visit (presumed severe NE), and 178 (5%) eventually developed symptoms of NE. Overall, 629 term infants developed NE (28.1 cases per 1000 live births); 2% of cases were associated with congenital anomalies, 25% with infections, and 28% with a potential intrapartum event. The incidence of intrapartum-related NE was 13.0 cases per 1000 live births; the neonatal case fatality rate was 46%. Infants with NE more frequently experienced birth complications and were male, of multiple gestation, or born to nulliparous mothers.

CONCLUSIONS

In Sarlahi, the incidence of neonatal respiratory depression and NE, associated neonatal case fatality, and morbidity prevalence are high. Action is required to increase coverage of skilled obstetric/neonatal care in this setting and to evaluate long-term impairments.