The consequences of chorioamnionitis: preterm birth and effects on development

High-Throughput 3D-Printed Model of the Feto-Maternal Interface for the Discovery and Development of Preterm Birth Therapies

Spontaneous preterm birth (PTB) affects around 11% of births, posing significant risks to neonatal health due to the inflammation at the fetal-maternal interface (FMi). This inflammation disrupts immune tolerance during pregnancy, often leading to PTB. While organ-on-a-chip (OOC) devices effectively mimic the physiology, pathophysiology, and responses of FMi, their relatively low throughput limits their utility in high-throughput testing applications. To overcome this, we developed a three-dimensional (3D)-printed model that fits in a well of a 96-well plate and can be mass-produced while also accurately replicating FMi, enabling efficient screening of drugs targeting FMi inflammation. Our model features two cell culture chambers (maternal and fetal cells) interlinked via an array of microfluidic channels. It was thoroughly validated, ensuring cell viability, metabolic activity, and cell-specific markers. The maternal chamber was exposed to lipopolysaccharides (LPS) to induce an inflammatory state, and proinflammatory cytokines in the culture supernatant were quantified. Furthermore, the efficacy of anti-inflammatory inhibitors in mitigating LPS-induced inflammation was investigated. Results demonstrated that our model supports robust cell growth, maintains viability, and accurately mimics PTB-associated inflammation. This high-throughput 3D-printed model offers a versatile platform for drug screening, promising advancements in drug discovery and PTB prevention.

Maternal obesity alters fetal neuroinflammation in a murine model of preterm birth

BACKGROUND

Preterm birth from intrauterine infection is a leading cause of neonatal neurologic morbidity. Likewise, maternal obesity is associated with intra-amniotic infection and inflammation. Whether maternal obesity is a risk factor for fetal brain injury that occurs with premature birth remains unknown. This study hypothesized that maternal obesity intensifies fetal neuroinflammation in the setting of premature delivery.

OBJECTIVE

This study aimed to examine the influence of maternal obesity on perinatal neuroinflammatory responses that arise with preterm birth using a murine model.

STUDY DESIGN

Dams with obesity were generated via a high-fat diet that was maintained throughout pregnancy. In parallel, dams without obesity (normal) received a control diet. All dams were paired with males on normal diet. Pregnant dams were randomized to receive an intrauterine administration of bacterial endotoxin (lipopolysaccharide) or the vehicle (phosphate-buffered saline) on embryo day 15.5 of what is typically a 19- to 21-day gestation. Fetal brains were harvested 6 hours after intrauterine administrations, and the expressions of key inflammatory cytokines (Il1b, Il6, and Tnf) and panels of metabolic, immune, and inflammatory genes were analyzed.

RESULTS

With the phosphate-buffered saline, there was no difference in gene expression related to maternal obesity. There were substantial differences in Il6 and immune/inflammatory expression profiles in fetal brains from dams with obesity vs normal dams that received lipopolysaccharide. Few differences were observed among the metabolic genes examined under these conditions. The gene expression pattern associated with maternal obesity correlated with pathways related to white matter injury.

CONCLUSION

The expression of neuroinflammatory markers instigated by bacterial endotoxin via intrauterine lipopolysaccharide was greater in embryo brains obtained from dams with obesity. Expression profiles suggest that in combination with intrauterine inflammation, maternal obesity may increase the risk of fetal white matter injury. Further investigation is warranted to understand the relationship between maternal health and neurologic outcomes associated with prematurity.

Clinical utility of gastric fluid cytokine levels in preterm infants for predicting histological chorioamnionitis

BACKGROUND

The risk of various complications, such as neonatal death, early onset sepsis, and chronic lung disease, is increased in infants born to mothers with chorioamnionitis (CAM). However, predicting the diagnosis of histological CAM (hCAM) in the early postnatal period is challenging for clinicians due to pathological considerations. Therefore, an early diagnostic tool for hCAM is needed. Gastric fluid at birth is considered a suitable biomarker for predicting the intrauterine environment because most of its components are from amniotic fluid, and the sampling technique is less invasive. This study aimed to evaluate the clinical utility of cytokines in the gastric fluid of preterm infants at birth as predictors of hCAM.

METHODS

We retrieved gastric fluid and serum from 21 preterm infants with a gestational age of ≤ 32 weeks within 1 h after birth and used cytometric bead array to measure the concentrations of interleukin (IL)-2, IL-4, IL-6, IL-10, tumor necrosis factor-alpha, and interferon-gamma. We compared the cytokine concentrations in the gastric fluid and serum of the preterm infants born to mothers with or without hCAM.

RESULTS

The gastric fluid, serum IL-6, and serum IL-10 concentrations were significantly higher in the hCAM group than that in the non-hCAM group. The best cutoff values for predicting hCAM was > 2,855 pg/mL and > 315 pg/mL for IL-6 in the gastric fluid and serum, respectively. Receiver operating characteristic curves showed that gastric fluid IL-6 concentrations correlated more strongly with the presence of hCAM than serum IL-6 concentrations.

CONCLUSION

IL-6 in the gastric fluid at birth may be a more promising biomarker for predicting the presence of hCAM than that in serum. IL-6 concentration analysis in the gastric fluid at birth might help to diagnose hCAM immediately after birth and improve the prognosis of preterm infants.

The synergistic effects of mechanical ventilation and intrauterine inflammation on cerebral inflammation in preterm fetal sheep

Background

Intrauterine inflammation and the requirement for mechanical ventilation independently increase the risk of perinatal brain injury and adverse neurodevelopmental outcomes. We aimed to investigate the effects of mechanical ventilation for 24 h, with and without prior exposure to intrauterine inflammation, on markers of brain inflammation and injury in the preterm sheep brain.

Methods

Chronically instrumented fetal sheep at ~115 days of gestation were randomly allocated to receive a single intratracheal dose of 1 mg lipopolysaccharide (LPS) or isovolumetric saline, then further randomly allocated 1 h after to receive mechanical ventilation with room air or no mechanical ventilation (unventilated control + saline [UVC, n = 7]; in utero mechanical ventilation + saline [VENT, n = 8], unventilated control + intratracheal LPS [UVC + LPS, n = 7]; in utero ventilation + intratracheal LPS [VENT + LPS, n = 7]). Serial fetal blood and plasma samples were collected throughout the experimental protocol for assessment of blood biochemistry and plasma interleukin (IL)-6 levels. After 24 h of mechanical ventilation, fetal brains were collected for RT-qPCR and immunohistochemical analyses.

Results

LPS exposure increased numbers of microglia and upregulated pro-inflammatory related genes within the cortical gray matter (GM) and subcortical white matter (SCWM) (pLPS  < 0.05). Mechanical ventilation alone increased astrocytic cell density in the periventricular white matter (PVWM) (pVENT  = 0.03) but had no effect on pro-inflammatory gene expression. The combination of ventilation and LPS increased plasma IL-6 levels (p < 0.02 vs. UVC and VENT groups), and exacerbated expression of pro-inflammatory-related genes (IL1β, TLR4, PTGS2, CXCL10) and microglial density (p < 0.05 vs. VENT).

Conclusion

This study demonstrates that 24 h of mechanical ventilation after exposure to intrauterine inflammation increased markers of systemic and brain inflammation and led to the upregulation of pro-inflammatory genes in the white matter. We conclude that 24 h of mechanical ventilation following intrauterine inflammation may precondition the preterm brain toward being more susceptible to inflammation-induced injury.

Progesterone inactivation in decidual stromal cells: A mechanism for inflammation-induced parturition

The process of human parturition involves inflammation at the interface where fetal chorion trophoblast cells interact with maternal decidual stromal (DS) cells and maternal immune cells in the decidua (endometrium of pregnancy). This study tested the hypothesis that inflammation at the chorion-decidua interface (CDI) induces labor by negating the capacity for progesterone (P4) to block labor and that this is mediated by inactivation of P4 in DS cells by aldo-keto reductase family 1 member C1 (AKR1C1). In human, Rhesus macaque, and mouse CDI, AKR1C1 expression increased in association with term and preterm labor. In a human DS cell line and in explant cultures of term human fetal membranes containing the CDI, the prolabor inflammatory cytokine, interleukin-1ß (IL-1ß), and media conditioned by LPS-stimulated macrophages increased AKR1C1 expression and coordinately reduced nuclear P4 levels and P4 responsiveness. Loss of P4 responsiveness was overcome by inhibition of AKR1C1 activity, inhibition of AKR1C1 expression, and bypassing AKR1C1 activity with a P4 analog that is not metabolized by AKR1C1. Increased P4 activity in response to AKR1C1 inhibition was prevented by the P4 receptor antagonist RU486. Pharmacologic inhibition of AKR1C1 activity prevented parturition in a mouse model of inflammation-induced preterm parturition. The data suggest that inflammatory stimuli at the CDI drive labor by inducing AKR1C1-mediated P4 inactivation in DS cells and that inhibiting and/or bypassing of AKR1C1-mediated P4 inactivation is a plausible therapeutic strategy to mitigate the risk of inflammation-associated preterm birth.

Perinatal compromise affects development, form, and function of the hippocampus part one; clinical studies

The hippocampus is a neuron-rich specialised brain structure that plays a central role in the regulation of emotions, learning and memory, cognition, spatial navigation, and motivational processes. In human fetal development, hippocampal neurogenesis is principally complete by mid-gestation, with subsequent maturation comprising dendritogenesis and synaptogenesis in the third trimester of pregnancy and infancy. Dendritogenesis and synaptogenesis underpin connectivity. Hippocampal development is exquisitely sensitive to perturbations during pregnancy and at birth. Clinical investigations demonstrate that preterm birth, fetal growth restriction (FGR), and acute hypoxic-ischaemic encephalopathy (HIE) are common perinatal complications that alter hippocampal development. In turn, deficits in hippocampal development and structure mediate a range of neurodevelopmental disorders, including cognitive and learning problems, autism, and Attention-Deficit/Hyperactivity Disorder (ADHD). In this review, we summarise the developmental profile of the hippocampus during fetal and neonatal life and examine the hippocampal deficits observed following common human pregnancy complications. IMPACT: The review provides a comprehensive summary of the developmental profile of the hippocampus in normal fetal and neonatal life. We address a significant knowledge gap in paediatric research by providing a comprehensive summary of the relationship between pregnancy complications and subsequent hippocampal damage, shedding new light on this critical aspect of early neurodevelopment.

Perinatal compromise affects development, form, and function of the hippocampus part two; preclinical studies

The hippocampus is a vital brain structure deep in the medial temporal lobe that mediates a range of functions encompassing emotional regulation, learning, memory, and cognition. Hippocampal development is exquisitely sensitive to perturbations and adverse conditions during pregnancy and at birth, including preterm birth, fetal growth restriction (FGR), acute hypoxic-ischaemic encephalopathy (HIE), and intrauterine inflammation. Disruptions to hippocampal development due to these conditions can have long-lasting functional impacts. Here, we discuss a range of preclinical models of prematurity and FGR and conditions that induce hypoxia and inflammation, which have been critical in elucidating the underlying mechanisms and cellular and subcellular structures implicated in hippocampal dysfunction. Finally, we discuss potential therapeutic targets to reduce the burden of these perinatal insults on the developing hippocampus. IMPACT: The review explores the preclinical literature examining the association between pregnancy and birth complications, and hippocampal form and function. The developmental processes and cellular mechanisms that are disrupted within the hippocampus following perinatal compromise are described, and potential therapeutic targets are discussed.

Intrauterine inflammation and postnatal intravenous dopamine alter the neurovascular unit in preterm newborn lambs

BACKGROUND

Intrauterine inflammation is considered a major cause of brain injury in preterm infants, leading to long-term neurodevelopmental deficits. A potential contributor to this brain injury is dysregulation of neurovascular coupling. We have shown that intrauterine inflammation induced by intra-amniotic lipopolysaccharide (LPS) in preterm lambs, and postnatal dopamine administration, disrupts neurovascular coupling and the functional cerebral haemodynamic responses, potentially leading to impaired brain development. In this study, we aimed to characterise the structural changes of the neurovascular unit following intrauterine LPS exposure and postnatal dopamine administration in the brain of preterm lambs using cellular and molecular analyses.

METHODS

At 119-120 days of gestation (term = 147 days), LPS was administered into the amniotic sac in pregnant ewes. At 126-7 days of gestation, the LPS-exposed lambs were delivered, ventilated and given either a continuous intravenous infusion of dopamine at 10 µg/kg/min or isovolumetric vehicle solution for 90 min (LPS, n = 6; LPSDA, n = 6). Control preterm lambs not exposed to LPS were also administered vehicle or dopamine (CTL, n = 9; CTLDA, n = 7). Post-mortem brain tissue was collected 3-4 h after birth for immunohistochemistry and RT-qPCR analysis of components of the neurovascular unit.

RESULTS

LPS exposure increased vascular leakage in the presence of increased vascular density and remodelling with increased astrocyte "end feet" vessel coverage, together with downregulated mRNA levels of the tight junction proteins Claudin-1 and Occludin. Dopamine administration decreased vessel density and size, decreased endothelial glucose transporter, reduced neuronal dendritic coverage, increased cell proliferation within vessel walls, and increased pericyte vascular coverage particularly within the cortical and deep grey matter. Dopamine also downregulated VEGFA and Occludin tight junction mRNA, and upregulated dopamine receptor DRD1 and oxidative protein (NOX1, SOD3) mRNA levels. Dopamine administration following LPS exposure did not exacerbate any effects induced by LPS.

CONCLUSION

LPS exposure and dopamine administration independently alters the neurovascular unit in the preterm brain. Alterations to the neurovascular unit may predispose the developing brain to further injury.

Palmitate and group B Streptococcus synergistically and differentially induce IL-1β from human gestational membranes

Introduction

Rupture of the gestational membranes often precedes major pregnancy complications, including preterm labor and preterm birth. One major cause of inflammation in the gestational membranes, chorioamnionitis (CAM) is often a result of bacterial infection. The commensal bacterium Streptococcus agalactiae, or Group B Streptococcus (GBS) is a leading infectious cause of CAM. Obesity is on the rise worldwide and roughly 1 in 4 pregnancy complications is related to obesity, and individuals with obesity are also more likely to be colonized by GBS. The gestational membranes are comprised of several distinct cell layers which are, from outermost to innermost: maternally-derived decidual stromal cells (DSCs), fetal cytotrophoblasts (CTBs), fetal mesenchymal cells, and fetal amnion epithelial cells (AECs). In addition, the gestational membranes have several immune cell populations; macrophages are the most common phagocyte. Here we characterize the effects of palmitate, the most common long-chain saturated fatty acid, on the inflammatory response of each layer of the gestational membranes when infected with GBS, using human cell lines and primary human tissue.

Results

Palmitate itself slightly but significantly augments GBS proliferation. Palmitate and GBS co-stimulation synergized to induce many inflammatory proteins and cytokines, particularly IL-1β and matrix metalloproteinase 9 from DSCs, CTBs, and macrophages, but not from AECs. Many of these findings are recapitulated when treating cells with palmitate and a TLR2 or TLR4 agonist, suggesting broad applicability of palmitate-pathogen synergy. Co-culture of macrophages with DSCs or CTBs, upon co-stimulation with GBS and palmitate, resulted in increased inflammatory responses, contrary to previous work in the absence of palmitate. In whole gestational membrane biopsies, the amnion layer appeared to dampen immune responses from the DSC and CTB layers (the choriodecidua) to GBS and palmitate co-stimulation. Addition of the monounsaturated fatty acid oleate, the most abundant monounsaturated fatty acid in circulation, dampened the proinflammatory effect of palmitate.

Discussion

These studies reveal a complex interplay between the immunological response of the distinct layers of the gestational membrane to GBS infection and that such responses can be altered by exposure to long-chain saturated fatty acids. These data provide insight into how metabolic syndromes such as obesity might contribute to an increased risk for GBS disease during pregnancy.

Evaluation of Postnatal Complications in Clinical and Histological Chorioamnionitis in Extremely Preterm Infants: A Japanese Cohort Study

OBJECTIVE

Terminating pregnancy appropriately before the intrauterine infection has progressed may have an improved prognosis for preterm infants. We evaluate how the combination of histological chorioamnionitis (hCAM) and clinical chorioamnionitis (cCAM) affects the short-term prognosis of infants.

STUDY DESIGN

This retrospective multicenter cohort study based on the Neonatal Research Network of Japan included extremely preterm infants born weighing <1,500 g between 2008 and 2018. Demographic characteristics, morbidity, and mortality were compared between the cCAM(-)hCAM(+) and cCAM(+)hCAM(+) groups.

RESULTS

We included 16,304 infants. The progression to cCAM in infants with hCAM was correlated with the increase in home oxygen therapy (HOT) (adjusted odds ratio [aOR], 1.27; 95% confidence interval [CI], 1.11-1.44) and persistent pulmonary hypertension of the newborn (PPHN) (1.20, 1.04-1.38). Furthermore, increased progression of the hCAM stage in infants with cCAM correlated with an increase in bronchopulmonary dysplasia (BPD; 1.05, 1.01-1.11), HOT (1.10, 1.02-1.18), and PPHN (1.09, 1.01-1.18). However, it had a negative impact on hemodynamically significant patent ductus arteriosus (hsPDA; 0.87, 0.83-0.92) and death before discharge from the neonatal intensive care unit (NICU; 0.88, 0.81-0.96).

CONCLUSION

Progression to cCAM in infants with hCAM positively correlated with HOT and PPHN. Progression of hCAM staging in infants with cCAM further increases the prevalence of BPD and the need for HOT and PPHN while reducing the prevalence of hsPDA and death before discharge from the NICU. The effects of the progressive hCAM stage in infants with cCAM vary from positive to negative by disease.

KEY POINTS

· Retrospective multicenter cohort study based on the Neonatal Research Network of Japan.. · Clinical and histological chorioamnionitis increases the prevalence of BPD, HOT, and PPHN.. · Progression of histological chorioamnionitis in infants reduces the prevalence of hsPDA and death..

Overexpression of Connexin 40 in the Vascular Endothelial Cells of Placenta with Acute Chorioamnionitis

BACKGROUND

Connexins (Cx) 43 and 40 play a role in leukocytes recruitment in acute inflammation. They are expressed in the endothelial cells. They are also found in the placenta and involved in the placenta development. Acute chorioamnionitis is associated with an increased risk of adverse perinatal outcomes. The aim of this study was to determine the expressions of Cx43 and Cx40 in the placenta of mothers with acute chorioamnionitis, and to correlate their association with the severity of chorioamnionitis and adverse perinatal outcomes.

METHODS

This study comprised a total of 81 cases, consisting of 39 placenta samples of mothers with acute chorioamnionitis and 42 non-acute chorioamnionitis controls. Cx43 and Cx40 immunohistochemistry were performed on all cases and their expressions were evaluated on cytotrophoblasts, syncytiotrophoblasts, chorionic villi endothelial cells, stem villi endothelial cells, maternal endothelial cells and decidua of the placenta.

RESULTS

Primigravida has a significantly higher risk of developing acute chorioamnionitis (p < 0.001). Neonates of mothers with a higher stage of fetal inflammatory response was significantly associated with lung complications (p = 0.041) compared to neonates of mothers with a lower stage. The expression of Cx40 was significantly higher in fetal and maternal vascular endothelial cells in acute chorioamnionitis (p < 0.001 and p = 0.037, respectively) compared to controls. Notably, Cx43 was not expressed in most of the types of cells in the placenta, except for decidua. Both Cx43 and Cx40 expressions did not have correlation with the severity of acute chorioamnionitis and adverse perinatal outcomes.

CONCLUSION

Cx40 was overexpressed in the fetal and maternal vascular endothelial cells in the placenta of mothers with acute chorioamnionitis, and it may have a role in the development of inflammation in placenta.

Incidence of histologic chorioamnionitis in a rural community hospital

BACKGROUND

Histological chorioamnionitis (HCA) is a pathological condition defined as an acute inflammation of the amniochorionic membranes which has been linked to a wide range of adverse neonatal events.

AIM

The purpose of this study is to identify the incidence of HCA in the rural population and evaluate whether there are significant differences in these incidences within the different clinical parameters of delivery method, gravidity, gestational age, previous cesarean section, reason for cesarean section and body mass index (BMI).

METHODS

A retrospective chart review was conducted on 462 consecutive deliveries that occurred in a rural hospital during a four-year period. Data collected was analyzed using independent sample T-tests, chi-squared tests, and descriptive statistics, with a p-value of < 0.05.

RESULTS

Overall incidence of HCA was 15.9% (73/459), with a term incidence of 16.2% (68/421) and preterm incidence of 13.2% (5/38). The incidence of HCA was significantly higher in vaginal deliveries (18.8%; n = 54/288) than C-section deliveries (11.1%; n = 19/171) (p = 0.03). Incidence of clinical chorioamnionitis was 0.43% (2/462), with 2.74% (2/73) of HCA manifesting clinically.

CONCLUSIONS

Evaluation of the incidence of HCA and associated clinical parameters in this study showed a marked decrease in the incidence of HCA when compared to other studies. Strategies to reduce the incidence of HCA include reducing the length of labor via active labor management. We hypothesize that these findings are due to the consistent use of active labor management and our rural study population, but further investigation is required to confirm this.

The role of placental insufficiency in spontaneous preterm birth: A literature review

Preterm Birth (delivery before 37 weeks of gestation) is the leading cause of childhood mortality and is also associated with significant morbidity both in the neonatal period and beyond. The aetiology of spontaneous preterm birth is unclear and likely multifactorial incorporating factors such as infection/inflammation and cervical injury. Placental insufficiency is emerging as an additional contributor to spontaneous preterm delivery; however, the mechanisms by which this occurs are not fully understood. Serum biomarkers and imaging techniques have been investigated as potential predictors of placental insufficiency, however none have yet been found to have a sufficient predictive value. This review examines the evidence for the role of the placenta in preterm birth, preterm prelabour rupture of the membranes and abruption as well as highlighting areas where further research is required.

Strategies for Safeguarding High-Risk Pregnancies From Preterm Birth: A Narrative Review

Preterm birth is the delivery of a live fetus before the 37th week of gestation. Preterm birth may stem from various factors, including premature rupture of membranes, spontaneous preterm labor, or medically induced circumstances. Premature delivery can result in serious and long-lasting difficulties even for infants who survive, as it is the leading cause of death for infants under five years old. Numerous nations have implemented initiatives to detect and track pregnant women who may give birth before their due date. Numerous therapies are available to protect these at-risk groups from the devastating effects of premature delivery, given the complex nature of preterm birth risk factors. Among the preventive measures, prophylactic progesterone appears to hold significant promise, while cervical cerclage proves effective in cases of cervical insufficiency. Conversely, pessaries show no discernible beneficial effects in reducing the risk of preterm birth. Regular antenatal visits are imperative for frequent patient evaluation and screening for potential risk factors. Adopting a healthy lifestyle can influence the risk of developing preeclampsia, with regular physical activity, a fiber-rich diet, and smoking cessation serving to mitigate the risk of preterm birth. The efficacy of bed rest in preventing preterm birth remains inconclusive due to insufficient evidence. This study aims to explore various preventive strategies for averting premature birth in high-risk women.

The Association between Term Chorioamnionitis during Labor and Long-Term Infectious Morbidity of the Offspring

Background: Chorioamnionitis during labor exposes the fetus to an intrauterine state that may alter the future immune response and may expose the offspring to future susceptibility to infectious disease. We evaluated the long-term pediatric infectious morbidity of children born at term to mothers who have chorioamnionitis during labor. Methods: This was a population-based cohort analysis including only term singleton deliveries at a regional tertiary hospital between the years 1991 and 2021. Offspring to mothers with and without a diagnosis of chorioamnionitis during labor were compared. Offspring hospitalizations up to the age of 18 years involving infectious morbidity were evaluated using the Kaplan-Meier survival curve and a Cox regression model to control possible confounders. Results: A total of 331,598 deliveries were included, 988 (0.3%) of which were of mothers diagnosed with chorioamnionitis during labor. All infectious morbidity rates included in the analysis were comparable between groups. The Kaplan-Meier survival curves were similar for both groups (log-rank = 0.881) and the multivariable analysis ascertained that chorioamnionitis during labor was not a risk factor for offspring's long-term infectious morbidity (HR 0.929, 95%CI 0.818-1.054, p = 0.254). Conclusions: In our cohort, term chorioamnionitis during labor was not associated with a higher risk of pediatric hospitalization due to infections. The infectious/inflammatory state during labor did not expose nor increase the susceptibility of the term offspring to future infectious morbidity.

Prevalence of Fetal Inflammatory Response Syndrome and Villitis of Unknown Etiology in the Placenta of Saudi Women and Their Association with Baby Sex

Long-term health consequences are influenced by circumstances that occur during pregnancy. The convergence of the maternal and fetal circulations occurs in the placenta, which is the first organ to develop. Placental pathology provides an accurate diagnosis of amniotic sac inflammation, and pathological alterations in preterm placentas provide evidence for the causes of numerous perinatal pathologies, including spontaneous preterm births. This retrospective study aimed to re-examine placentas regarded as normal by the Obstetrics and Gynecology Department at our institution. Thirty-seven male and forty-seven female placentas were collected following full-term delivery, and the grading and staging of any evident inflammatory responses were evaluated and correlated with the babies' sex. Full-thickness placental samples that were considered normal and not sent to the histopathology department were obtained from the central and marginal regions of placental discs. Morphological examination of the fresh placenta was conducted, and fetal and maternal inflammatory response syndromes were assessed. In addition, placental villitis of unknown etiology (VUE) and chronic deciduitis were evaluated. Immunohistochemistry was performed to evaluate the patterns of inflammation in the placenta using anti-CD8 and anti-CD68 antibodies. The correlation between silent pathologies and clinical complications or the development of fetal inflammatory response syndrome was measured. In this study, 17 (20%) maternal and 10 (12%) fetal samples showed inflammatory responses. The frequencies of chronic deciduitis and VUE were higher among pregnant Saudi women than previously reported, probably because fetal inflammatory response syndrome goes unnoticed in Saudi Arabia. In addition, the prevalence of fetal and maternal inflammatory responses was higher in the placentas of the mothers of males than in those of females, suggesting that differences occur in the inflammatory response in the placenta depending on the sex of the newborn. Grading placental inflammation (in cases of VUE) typically predicts the degree of maternal anti-fetal cellular rejection; therefore, increasing the number of placental samples sent for microscopic inspection may be preferable because of their significance in identifying the causes of chronic disorders.

Prevalence and risk factors associated with the need for surgical intervention due to necrotizing enterocolitis in very low birth weight infants

INTRODUCTION

Necrotizing enterocolitis (NEC) is one of the most common gastrointestinal emergencies affecting very low birth weight (VLBW) infants with an incidence of 6-15 %. Early recognition is crucial. Mortality is high and variable (30-50 %). Those requiring surgical intervention have a higher mortality rate than those who receive medical treatment.

OBJECTIVES

1) To assess the prevalence of surgical NEC and associated risk factors 2) To compare outcomes based on the type of treatment required 3) To estimate the mortality associated with NEC and surgical NEC.

METHODS

A multicentre retrospective cohort study was designed (level II), including VLBW infants born between 2011 and 2020 in Centers of the Neocosur Network. A multivariate logistic regression analysis was performed to evaluate risk factors associated with the need for surgery.

RESULTS

NEC was diagnosed in 1679 (10.4 %) of 16,131 births in this period. The prevalence of surgery was 25 % (95 % CI 23-27 %). In multivariable analysis, variables associated with an increased risk of surgery requirement were birth weight <750 g (aOR 1.73-95%CI 1.2-2.5) and receiving antenatal antibiotics (aOR 1.54-95%CI 1.09-2.74). Those requiring surgery had significantly higher morbidity and mortality than the ones receiving medical treatment.

CONCLUSION

In VLBW infants with NEC, lower birth weight and antenatal antibiotics administration were independently associated with the need for surgical intervention.

Hemodynamic evaluation of extremely low birth weight infants during the first 7 days of life

BACKGROUND AND AIM

We aimed to investigate the hemodynamic status of extremely low birth weight (ELBW) infants during the transitional period under intensive management.

METHODS

This retrospective cohort study analyzed left ventricular ejection fraction (LVEF), left ventricular end-systolic wall stress (ESWS), left ventricular internal dimension in diastole (LVIDd), and mean arterial pressure (MAP) of ELBW infants during their first week of life. Small for gestational age (SGA), histological chorioamnionitis (hCAM), severe intraventricular hemorrhage (IVH), and non-survival to discharge infants were compared to their counterparts.

RESULTS

Sixty-two infants (25.7 ± 2.1 weeks, 700.7 ± 165.4 g) were analyzed. MAP gradually increased. Median LVEF was 69.8 % on day 1, decreased to 62.7 % on day 2, then increased throughout the week. ESWS was lowest at birth, rose to 28.2 g/cm2 on day 2, and decreased on day 6. There were no significant changes in LVIDd. SGA infants had higher MAP throughout, higher LVEF on day 2 and 3, but lower LVEF on day 5 to 7. LVIDd was lower in hCAM group. Severe IVH group had a more significant drop in LVEF on day 2, higher ESWS, and a higher incidence of hemodynamic significant patent ductus arteriosus (hsPDA). Non-survival had lower LVIDd.

CONCLUSIONS

MAP increased gradually. Hemodynamic instability was observed in the first two days, with decreased LVEF and increased ESWS before stabilization. We observed an alteration in hemodynamic adaptation in SGA and hCAM infants. Severe IVH group experienced early hemodynamic instability and a higher incidence of hsPDA.

The effect of leucocytosis on retinopathy of prematurity

Postnatal leukocytosis reflects the general condition of inflammatory. Infection and inflammatory reaction have been proven to affect the occurrence of ROP and other visual dysfunction. Infants with a gestational age of < 28 weeks who were less than three days of age and admitted to the hospital between September 2015 and March 2021 were included in the study. Infants with a white blood cell (WBC) count ≥ 30 × 109/L were assigned to the leucocytosis group (n = 82). Gestational age- and weight-matched infants without leucocytosis were included as a control group (n = 85). The incidence and prognosis of ROP in preterm infants were compared between the groups. Receiver operating characteristic (ROC) curves were used to analyse the correlation between the WBC count and severe ROP. Compared to the infants in the control group, those in the leucocytosis group had lower 1-min Apgar scores (p < 0.001); higher C-reactive protein (p < 0.001) and procalcitonin (p < 0.001); and higher incidences of intracranial haemorrhage (p = 0.007), leukomalacia (p = 0.045), sepsis (p = 0.006), bronchopulmonary dysplasia (p = 0.017). The maternal age was higher in the leucocytosis group (p < 0.001). After adjusting for gestational age at 45 weeks, the incidence of severe ROP (p = 0.001) and the requirement for ranibizumab injections (p = 0.004) were higher in the leucocytosis group. The cut-off WBC count was determined to be 19.1 × 109/L, with a sensitivity of 88.6%, a specificity of 77.3%, and an area under the curve of 0.941 (95% confidence interval: 0.904-0.978) for the detection of severe ROP. Leucocytosis may be associated with severe ROP in premature infants.

Hofbauer cell function in the term placenta associates with adult cardiovascular and depressive outcomes

Pathological placental inflammation increases the risk for several adult disorders, but these mediators are also expressed under homeostatic conditions, where their contribution to adult health outcomes is unknown. Here we define an inflammation-related expression signature, primarily expressed in Hofbauer cells of the term placenta and use expression quantitative trait loci to create a polygenic score (PGS) predictive of its expression. Using this PGS in the UK Biobank we conduct a phenome-wide association study, followed by Mendelian randomization and identify protective, sex-dependent effects of the placental module on cardiovascular and depressive outcomes. Genes differentially regulated by intra-amniotic infection and preterm birth are over-represented within the module. We also identify aspirin as a putative modulator of this inflammation-related signature. Our data support a model where disruption of placental Hofbauer cell function, due to preterm birth or prenatal infection, contributes to the increased risk of depression and cardiovascular disease observed in these individuals.

Validation of diagnosis codes for chorioamnionitis in medical encounter data, 2013-2018

PURPOSE

Chorioamnionitis refers to intrauterine infection/inflammation that can be diagnosed clinically or from laboratory testing. This study aimed to validate chorioamnionitis International Classification of Diseases (ICD) codes using reference standards for clinical and histologic cases.

METHODS

Department of Defense Birth and Infant Health Research program data identified a cohort of live deliveries at two United States military hospitals from 2013 to 2018. Deliveries were screened for chorioamnionitis using ICD codes from maternal delivery records; a sample of screen positive and negative deliveries was selected for chart review. Primary analyses validated deliveries using a reference standard for clinical chorioamnionitis; secondary analyses employed a reference standard that also included histologic cases, but were limited by temporal differences in availability of laboratory data. Sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values were calculated with 95% confidence intervals (CIs).

RESULTS

Overall, 1857 deliveries (465 screen positive, 1392 screen negative) were eligible for analysis and 336 met the reference standard for clinical chorioamnionitis, yielding a PPV of 0.68 (95% CI 0.63, 0.72) and sensitivity of 0.76 (95% CI 0.72, 0.81). In secondary analyses, 390 deliveries met the reference standard for clinical or histologic chorioamnionitis, resulting in an overall PPV of 0.75 (95% CI 0.71, 0.79); in 2018, when more laboratory results were available, the PPV was 0.91 (95% CI 0.84, 0.97). NPV and specificity were ≥0.97 across reference standards.

CONCLUSIONS

Chorioamnionitis ICD codes exhibited moderate correlation with clinical disease, suggesting challenges in using medical encounter data to isolate clinical cases from those only identified through laboratory testing.

Risk Scoring Systems for Preterm Birth and Their Performance: A Systematic Review

Introduction: Nowadays, the risk stratification of preterm birth (PTB) and its prediction remain a challenge. Many risk factors associated with PTB have been identified, and risk scoring systems (RSSs) have been developed to face this challenge. The objectives of this systematic review were to identify RSSs for PTB, the variables they consist of, and their performance. Materials and methods: Two databases were searched, and two authors independently performed the screening and eligibility phases. Records studying an RSS, based on specified variables, with an evaluation of the predictive value for PTB, were considered eligible. Reference lists of eligible studies and review articles were also searched. Data from the included studies were extracted. Results: A total of 56 studies were included in this review. The most frequently incorporated variables in the RSS included in this review were maternal age, weight, history of smoking, history of previous PTB, and cervical length. The performance measures varied widely among the studies, with sensitivity ranging between 4.2% and 92.0% and area under the curve (AUC) between 0.59 and 0.95. Conclusions: Despite the recent technological and scientifical evolution with a better understanding of variables related to PTB and the definition of new ultrasonographic parameters and biomarkers associated with PTB, the RSS's ability to predict PTB remains poor in most situations, thus compromising the integration of a single RSS in clinical practice. The development of new RSSs, the identification of new variables associated with PTB, and the elaboration of a large reference dataset might be a step forward to tackle the problem of PTB.

Progressive inflammation reduces high-frequency EEG activity and cortical dendritic arborisation in late gestation fetal sheep

BACKGROUND

Antenatal infection/inflammation is associated with disturbances in neuronal connectivity, impaired cortical growth and poor neurodevelopmental outcomes. The pathophysiological substrate that underpins these changes is poorly understood. We tested the hypothesis that progressive inflammation in late gestation fetal sheep would alter cortical neuronal microstructure and neural function assessed using electroencephalogram band power analysis.

METHODS

Fetal sheep (0.85 of gestation) were surgically instrumented for continuous electroencephalogram (EEG) recording and randomly assigned to repeated saline (control; n = 9) or LPS (0 h = 300 ng, 24 h = 600 ng, 48 h = 1200 ng; n = 8) infusions to induce inflammation. Sheep were euthanised 4 days after the first LPS infusion for assessment of inflammatory gene expression, histopathology and neuronal dendritic morphology in the somatosensory cortex.

RESULTS

LPS infusions increased delta power between 8 and 50 h, with reduced beta power from 18 to 96 h (P < 0.05 vs. control). Basal dendritic length, numbers of dendritic terminals, dendritic arborisation and numbers of dendritic spines were reduced in LPS-exposed fetuses (P < 0.05 vs. control) within the somatosensory cortex. Numbers of microglia and interleukin (IL)-1β immunoreactivity were increased in LPS-exposed fetuses compared with controls (P < 0.05). There were no differences in total numbers of cortical NeuN + neurons or cortical area between the groups.

CONCLUSIONS

Exposure to antenatal infection/inflammation was associated with impaired dendritic arborisation, spine number and loss of high-frequency EEG activity, despite normal numbers of neurons, that may contribute to disturbed cortical development and connectivity.

Maternal Infection and Preterm Birth: From Molecular Basis to Clinical Implications

As the leading cause of neonatal morbidity and mortality, preterm birth is recognized as a major public health concern around the world. The purpose of this review is to analyze the connection between infections and premature birth. Spontaneous preterm birth is commonly associated with intrauterine infection/inflammation. The overproduction of prostaglandins caused by the inflammation associated with an infection could lead to uterine contractions, contributing to preterm delivery. Many pathogens, particularly Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, Gardnerella vaginalis, Ureaplasma urealyticum, Mycoplasma hominis, Actinomyces, Candida spp., and Streptococcus spp. have been related with premature delivery, chorioamnionitis, and sepsis of the neonate. Further research regarding the prevention of preterm delivery is required in order to develop effective preventive methods with the aim of reducing neonatal morbidity.

The Role of the Interleukin-1 Family in Complications of Prematurity

Preterm birth is a major contributor to neonatal morbidity and mortality. Complications of prematurity such as bronchopulmonary dysplasia (BPD, affecting the lung), pulmonary hypertension associated with BPD (BPD-PH, heart), white matter injury (WMI, brain), retinopathy of prematurity (ROP, eyes), necrotizing enterocolitis (NEC, gut) and sepsis are among the major causes of long-term morbidity in infants born prematurely. Though the origins are multifactorial, inflammation and in particular the imbalance of pro- and anti-inflammatory mediators is now recognized as a key driver of the pathophysiology underlying these illnesses. Here, we review the involvement of the interleukin (IL)-1 family in perinatal inflammation and its clinical implications, with a focus on the potential of these cytokines as therapeutic targets for the development of safe and effective treatments for early life inflammatory diseases.

Postnatal corticosteroid response in neonates < 32 weeks and relation with placental pathology

Acute chorioamnionitis and maternal vascular malperfusion are associated with an increased risk of bronchopulmonary dysplasia. To prevent bronchopulmonary dysplasia, postnatal corticosteroids are given to preterm neonates. Clinical observations indicate not all neonates respond to corticosteroids, the so-called non-responders. This study aimed to investigate the association between placental pathology and short-term response to postnatal corticosteroids in neonates < 32 weeks postconceptional age at risk for bronchopulmonary dysplasia. All neonates < 32 weeks born between 2009 and 2016, receiving corticosteroids in the course of BPD, were included. The preterm neonates were divided into three groups depending on placental histology: acute chorioamnionitis, maternal vascular malperfusion, or no placental pathology. Respiratory support was assessed prior to treatment and at days 4 and 7. A responder was defined as extubation within 7 days after starting corticosteroid treatment. In total, 52% of the chorioamnionitis neonates, 67% of the maternal vascular malperfusion neonates, and 58% of neonates in the no pathology group were responders. The odds ratio for extubation was 0.53 (0.18-1.55) at day 4 and 0.66 (0.23-1.97) at day 7, in the chorioamnionitis group compared to the maternal vascular malperfusion.

CONCLUSION

Short-term response to postnatal corticosteroids did not significantly differ between premature neonates born after acute chorioamnionitis, maternal vascular malperfusion, or no placenta pathology. However, a trend of better corticosteroid response in maternal vascular malperfusion neonates was found, potentially due to differences in prenatal pulmonary development and postnatal cortisol.

WHAT IS KNOWN

• Bronchopulmonary dysplasia is related to chorioamnionitis and maternal vascular malperfusion. • Corticosteroids remain an important treatment in the course of bronchopulmonary dysplasia despite conflicting results and non-responsiveness in some preterm neonates.

WHAT IS NEW

• Non-responsiveness might be related to differences in pulmonary inflammation and systemic cortisol due to predispositions triggered by chorioamnionitis or maternal vascular malperfusion. • Neonates born after maternal vascular malperfusion seem to respond better to postnatal corticosteroid treatment.

Actualidad en corioamnionitis

La corioamnionitis se ha relacionados con desenlaces desfavorables en el período prenatal y neonatal (abortos, parto pretérmino, sepsis neonatal, entre otros), además de implicaciones a largo plazo en la infancia, tales como alteraciones en el coeficiente intelectual. Por esta razón es de vital importancia el diagnóstico histopatológico oportuno. En este artículo se revisará el abordaje histopatológico de la corioamnionitis, su estadificación e implicaciones clínicas.

The Association of Patent Ductus Arteriosus with Inflammation: A Narrative Review of the Role of Inflammatory Biomarkers and Treatment Strategy in Premature Infants

Patent ductus arteriosus (PDA) is a common cardiovascular complication that complicates clinical care in the intensive care of premature infants. Prenatal and postnatal infections and the inflammation process can contribute to PDA, and intrauterine inflammation is a known risk factor of PDA. A variety of inflammatory biomarkers have been reported to be associated with PDA. Chorioamnionitis induces the fetal inflammatory process via several cytokines that have been reported to be associated with the presence of PDA and may have a role in the vascular remodeling process or vessel dilation of the ductus. On the other hand, anti-inflammatory agents, such as antenatal steroids, decrease PDA incidence and severity in patients born to those with chorioamnionitis. Proinflammatory cytokines, which are expressed more significantly in preterm neonates and chorioamnionitis, are associated with the presence of PDA. In this review, we focus on the pathogenesis of PDA in preterm infants and the role of biomarkers associated with the perinatal inflammatory process.

Value of Placental Examination in the Diagnostic Evaluation of Stillbirth

ObjectiveThe aim was to assess the contribution of placental examination in the etiologic investigation of stillbirth. Materials and Methods: A retrospective review of stillbirths that occurred after 14 weeks gestation was conducted for a one-year period. Twin pregnancies and fetuses without placentas were excluded. According to the fetoplacental examination, stillbirths were classified into etiologic groups. Results: A total of 147 stillbirths were selected. They were associated with placental, materno-fetal, fetal and multiple causes in 89 cases (61%), 23 cases (16%), 14 cases (9%) and 13 cases (9%), respectively. Unexplained stillbirths were observed in 8 cases (5%). Placental abnormalities were identified in 132/147 cases (90%). They were consistent with vascular, inflammatory and developmental lesions in 82/132 cases (61%), 28/132 cases (21%) and 18/132 cases (13%), respectively. Conclusion: Placental lesions were the main causes of stillbirth and were predominantly of vascular type including chronic villous hypoxia-ischemia and funicular anomalies.

Predicting risk of severe neonatal outcomes in preterm infants born from mother with prelabor rupture of membranes

BACKGROUND

Perinatal complications are common burdens for neonates born from mother with pPROM. Physicians and parents sometimes need to make critical decisions about neonatal care with short- and long-term implications on infant's health and families and it is important to predict severe neonatal outcomes with high accuracy.

METHODS

The study was based on our prospective study on 1001 preterm infants born from mother with pPROM from August 1, 2017, to March 31, 2018 in three hospitals in China. Multivariable logistic regression analysis was applied to build a predicting model incorporating obstetric and neonatal characteristics available within the first day of NICU admission. We used enhanced bootstrap resampling for internal validation.

RESULTS

One thousand one-hundred pregnancies with PROM at preterm with a single fetus were included in our study. SNO was diagnosed in 180 (17.98%) neonates. On multivariate analysis of the primary cohort, independent factors for SNO were respiratory support on the first day,, surfactant on day 1, and birth weight, which were selected into the nomogram. The model displayed good discrimination with a C-index of 0.838 (95%CI, 0.802-0.874) and good calibration performance. High C-index value of 0.835 could still be reached in the internal validation and the calibration curve showed good agreement. Decision curve analysis showed if the threshold is > 15%, using our model would achieve higher net benefit than model with birthweight as the only one predictor.

CONCLUSION

Variables available on the first day in NICU including respiratory support on the first day, the use of surfactant on the first day and birthweight could be used to predict the risk of SNO in infants born from mother with pPROM with good discrimination and calibration performance.

Leveraging bioengineering to assess cellular functions and communication within human fetal membranes

The fetal membranes enclose the growing fetus and amniotic fluid. Preterm prelabor rupture of fetal membranes is a leading cause of preterm birth. Fetal membranes are composed of many different cell types, both structural and immune. These cells must coordinate functions for tensile strength and membrane integrity to contain the growing fetus and amniotic fluid. They must also balance immune responses to pathogens with maintaining maternal-fetal tolerance. Perturbation of this equilibrium can lead to preterm premature rupture of membranes without labor. In this review, we describe the formation of the fetal membranes to orient the reader, discuss some of the common forms of communication between the cell types of the fetal membranes, and delve into the methods used to tease apart this paracrine signaling within the membranes, including emerging technologies such as organ-on-chip models of membrane immunobiology.

Infections and Pregnancy: Effects on Maternal and Child Health

Pregnancy causes physiological and immunological adaptations that allow the mother and fetus to communicate with precision in order to promote a healthy pregnancy. At the same time, these adaptations may make pregnant women more susceptible to infections, resulting in a variety of pregnancy complications; those pathogens may also be vertically transmitted to the fetus, resulting in adverse pregnancy outcomes. Even though the placenta has developed a robust microbial defense to restrict vertical microbial transmission, certain microbial pathogens have evolved mechanisms to avoid the placental barrier and cause congenital diseases. Recent mechanistic studies have begun to uncover the striking role of the maternal microbiota in pregnancy outcomes. In this review, we discuss how microbial pathogens overcome the placental barrier to cause congenital diseases. A better understanding of the placental control of fetal infection should provide new insights into future translational research.

Connexins, Pannexins and Gap Junctions in Perinatal Brain Injury

Perinatal brain injury secondary to hypoxia-ischemia and/or infection/inflammation remains a major cause of disability. Therapeutic hypothermia significantly improves outcomes, but in randomized controlled trials nearly half of infants still died or survived with disability, showing that additional interventions are needed. There is growing evidence that brain injury spreads over time from injured to previously uninjured regions of the brain. At least in part, this spread is related to opening of connexin hemichannels and pannexin channels, both of which are large conductance membrane channels found in many brain cells. Opening of these membrane channels releases adenosine triphosphate (ATP), and other neuroactive molecules, into the extracellular space. ATP has an important role in normal signaling, but pathologically can trigger the assembly of the multi-protein inflammasome complex. The inflammasome complex promotes activation of inflammatory caspases, and release of inflammatory cytokines. Overall, the connexin hemichannel appears to play a primary role in propagation of injury and chronic disease, and connexin hemichannel blockade has been shown to be neuroprotective in multiple animal models. Thus, there is potential for some blockers of connexin or pannexin channels to be developed into targeted interventions that could be used in conjunction with or separate to therapeutic hypothermia.

Abnormal vaginal flora and spontaneous preterm birth in high-risk singleton pregnancies with cervical cerclage

OBJECTIVE

To investigate abnormal vaginal and suture-based bacterial flora for associations with spontaneous preterm birth in high-risk singleton pregnancies with an ultrasound-indicated or emergency cervical cerclage.

MATERIALS AND METHODS

A retrospective study of 196 singleton pregnancies with an ultrasound-indicated or emergency cerclage at the Royal Women's Hospital, Australia, from 2004 to 2018. High vaginal swabs were collected regularly between 14 and 26 weeks' gestation, including pre- and post-cerclage insertion, and sent for microscopy and culture. Cervical suture was cultured upon removal. Primary outcomes were spontaneous preterm birth <37, <34 and <30 weeks.

RESULTS

43.4% (85/196) of women delivered preterm. The acquisition and persistence of vaginal Escherichia coli following cerclage insertion were independently associated with spontaneous preterm birth <37 weeks (p = .0225, p = .0477). Escherichia coli growth from the cervical suture upon removal was associated with spontaneous preterm birth <34 weeks (p = .0458). The acquisition of vaginal mixed anaerobes post-cerclage was independently associated with spontaneous preterm birth <34 weeks (p = .0480).

CONCLUSION

For singleton pregnancies with an ultrasound-indicated or emergency cerclage, the presence of vaginal or suture-based Escherichia coli following cerclage insertion yields increased risk of cerclage failure and spontaneous preterm birth.

Preterm Birth Associates With Increased Placental Expression of MDR Transporters Irrespective of Prepregnancy BMI

CONTEXT

Preterm birth (PTB) and suboptimal prepregnancy body mass index (BMI) operate through inflammatory pathways to impair fetoplacental development. Placental efflux transporters mediate fetal protection and nutrition; however, few studies consider the effect of both PTB and BMI on fetal protection. We hypothesized that PTB would alter the expression of placental multidrug resistance (MDR) transporters and selected proinflammatory cytokines, and that maternal underweight and obesity would further impair placental phenotype.

OBJECTIVE

To determine whether placental MDR transporters P-glycoprotein (P-gp, encoded by ABCB1) and breast cancer resistance protein (BCRP/ABCG2), and proinflammatory cytokine levels are altered by PTB and maternal BMI.

METHODS

A cross-sectional study was conducted to assess the effect of PTB (with/without chorioamnionitis), or the effect of maternal prepregnancy BMI on placental MDR transporter and interleukin (IL)-6 and -8 expression in 60 preterm and 36 term pregnancies.

RESULTS

ABCB1 expression was increased in preterm compared to term placentae (P = .04). P-gp (P = .008) and BCRP (P = .01) immunolabeling was increased among all preterm compared to term placentae, with P-gp expression further increased in preterm pregnancies with chorioamnionitis (PTC, P = .007). Placental IL-6 mRNA expression was decreased in PTC compared to term placentae (P = .0005) and PTC associated with the greatest proportion of anti-inflammatory medications administered during pregnancy. Maternal BMI group did not influence placental outcomes.

CONCLUSION

PTB and infection, but not prepregnancy BMI, alter placental expression of MDR transporters and IL-6. This may have implications for fetal exposure to xenobiotics that may be present in the maternal circulation in pregnancies complicated by PTB.

Impact of Lockdown Measures during COVID-19 Pandemic on Pregnancy and Preterm Birth

OBJECTIVE

The objective of this study is to assess the effect of the lockdown measures during the coronavirus disease 2019 (COVID-19) pandemic on pregnancy outcomes of women who were not affected by severe acute respiratory syndrome coronavirus 2 infection.

STUDY DESIGN

We used data from the perinatal health program and neonatal databases to conduct a cohort analysis of pregnancy outcomes during the COVID-19 lockdown in the Calgary region, Canada. Rates of preterm birth were compared between the lockdown period (March 16 to June 15, 2020) and the corresponding pre-COVID period of 2015 to 2019. We also compared maternal and neonatal characteristics of preterm infants admitted to neonatal intensive care units (NICUs) in Calgary between the two periods.

FINDINGS

A total of 4,357 and 24,160 live births occurred in the lockdown and corresponding pre-COVID period, respectively. There were 366 (84.0 per 1,000 live births) and 2,240 (92.7 per 1,000 live births) preterm births in the lockdown and corresponding pre-COVID period, respectively (p = 0.07). Rates of very preterm and very-low-birth-weight births were lower in the lockdown period compared with the corresponding pre-COVID period (11.0 vs. 15.6 and 9.0 vs. 14.4 per 1,000 live births, p = 0.02 and p = 0.005, respectively). There was no difference in spontaneous stillbirth between the two periods (3.7 vs. 4.1 per 1,000 live birth, p = 0.71). During the lockdown period, the likelihood of multiple births was lower (risk ratio [RR] 0.73, 95% confidence interval [CI]: 0.60-0.88), while gestational hypertension and clinical chorioamnionitis increased (RR 1.24, 95%CI: 1.10-1.40; RR 1.33, 95%CI 1.10-1.61, respectively).

CONCLUSION

Observed rates of very preterm and very-low-birth-weight births decreased during the COVID-19 lockdown. Pregnant women who delivered during the lockdown period were diagnosed with gestational hypertension and chorioamnionitis more frequently than mothers in the corresponding pre-COVID period.

KEY POINTS

· Lockdown measures to reduce COVID-19 transmission were associated with a lower rate of preterm birth.. · Mental and physical wellbeing of pregnant women were significantly affected by the lockdown measures.. · A comprehensive public health plan to relieve psychosocial stress during pregnancy is required..

Molecular mechanisms of environmental toxin cadmium at the feto-maternal interface investigated using an organ-on-chip (FMi-OOC) model

Human labor is associated with feto-maternal-derived signals that coordinate to initiate delivery. Exposure to environmental chemicals can prematurely trigger labor-initiating signals at the feto-maternal interface (FMi: decidua, amniochorion), leading to spontaneous preterm birth (PTB). Testing the association between environmental chemical exposure and PTB is difficult due to many limitations in vivo or in vitro. Physiological organ-on-chips (OOCs) are potential alternatives for studying mechanisms leading to PTB. The presented study tested the effect of maternal exposure to cadmium (Cd), an environmental toxin, using the FMi-OOC that incorporates maternal decidua cells and three different fetal cells (chorion, amnion mesenchymal, and amnion epithelial cells). Cd transport through the FMi and its impact on cell cycle, cell death, and inflammation were analyzed. Cd treatment resulted in significant cell death and a pro-inflammatory environment in the maternal decidua, but had minimal effect on the fetal chorion cells, and no effect in the fetal amnion cells compared to controls. The maternal response, but lack of fetal response, indicates that Cd-mediated adverse effects originate from maternal pathophysiology rather than fetal-derived triggers of preterm labor. This study demonstrates that the FMi-OOC can indeed predict the response of FMi upon exposure to chemicals, opening the possibility for using OOC models for environmental toxin screens.

Immunometabolic Analysis of Mobiluncus mulieris and Eggerthella sp. Reveals Novel Insights Into Their Pathogenic Contributions to the Hallmarks of Bacterial Vaginosis

The cervicovaginal microbiome plays an important role in protecting women from dysbiosis and infection caused by pathogenic microorganisms. In healthy reproductive-age women the cervicovaginal microbiome is predominantly colonized by protective Lactobacillus spp. The loss of these protective bacteria leads to colonization of the cervicovaginal microenvironment by pathogenic microorganisms resulting in dysbiosis and bacterial vaginosis (BV). Mobiluncus mulieris and Eggerthella sp. are two of the many anaerobes that can contribute to BV, a condition associated with multiple adverse obstetric and gynecological outcomes. M. mulieris has been linked to high Nugent scores (relating to BV morphotypes) and preterm birth (PTB), whilst some bacterial members of the Eggerthellaceae family are highly prevalent in BV, and identified in ~85-95% of cases. The functional impact of M. mulieris and Eggerthella sp. in BV is still poorly understood. To determine the individual immunometabolic contributions of Eggerthella sp. and M. mulieris within the cervicovaginal microenvironment, we utilized our well-characterized human three-dimensional (3-D) cervical epithelial cell model in combination with multiplex immunoassays and global untargeted metabolomics approaches to identify key immune mediators and metabolites related to M. mulieris and Eggerthella sp. infections. We found that infection with M. mulieris significantly elevated multiple proinflammatory markers (IL-6, IL-8, TNF-α and MCP-1) and altered metabolites related to energy metabolism (nicotinamide and succinate) and oxidative stress (cysteinylglycine, cysteinylglycine disulfide and 2-hydroxygluatrate). Eggerthella sp. infection significantly elevated multiple sphingolipids and glycerolipids related to epithelial barrier function, and biogenic amines (putrescine and cadaverine) associated with elevated vaginal pH, vaginal amine odor and vaginal discharge. Our study elucidated that M. mulieris elevated multiple proinflammatory markers relating to PTB and STI acquisition, as well as altered energy metabolism and oxidative stress, whilst Eggerthella sp. upregulated multiple biogenic amines associated with the clinical diagnostic criteria of BV. Future studies are needed to evaluate how these bacteria interact with other BV-associated bacteria within the cervicovaginal microenvironment.

Chorioamnionitis and neonatal outcomes

Chorioamnionitis or intrauterine inflammation is a frequent cause of preterm birth. Chorioamnionitis can affect almost every organ of the developing fetus. Multiple microbes have been implicated to cause chorioamnionitis, but "sterile" inflammation appears to be more common. Eradication of microorganisms has not been shown to prevent the morbidity and mortality associated with chorioamnionitis as inflammatory mediators account for continued fetal and maternal injury. Mounting evidence now supports the concept that the ensuing neonatal immune dysfunction reflects the effects of inflammation on immune programming during critical developmental windows, leading to chronic inflammatory disorders as well as vulnerability to infection after birth. A better understanding of microbiome alterations and inflammatory dysregulation may help develop better treatment strategies for infants born to mothers with chorioamnionitis.

Risk factors and postnatal biomarkers for acute placental inflammatory lesions and intrauterine infections in preterm infants

The purpose of this study is to explore risk factors of acute placental inflammatory lesions and the potential postnatal serum biomarkers for predicting the severity of intrauterine infection in preterm infants. We performed a retrospective analysis of premature infants with or without acute placental inflammatory lesions and their mothers by chart review for clinical data and placental histopathology. The preterm infants with acute placental inflammatory lesions had a higher rate of premature rupture of membranes (PROM), a longer duration of PROM, and a higher level of serum sialic acid (SIA) than those of the non-inflammation group (all p < 0.001). According to the different inflammatory histological structures, preterm infants with funisitis had a dominant longer duration of PROM than others (p < 0.05), and their gestational age was youngest among all the infants (p < 0.05). Furthermore, they had the highest content of serum SIA above other groups. The preterm infants in the acute histological chorioamnionitis group showed a similar trend of clinical manifestation and laboratory parameters with the funisitis group. Moreover, the closer the placental lesions were to the fetus, the lower the gestational age of preterm infants was, and the higher the serum SIA content was.

CONCLUSION

We utilized a simple and precise anatomically category method of placental inflammatory histopathology for pediatricians to distinguish the extent of fetal inflammatory response for representing early-onset infectious diseases of preterm infants. SIA might be one of the potential early-stage serum biomarkers to reflect the severe intrauterine infections and could guide the postnatal anti-infection treatment.

WHAT IS KNOWN

• Acute placental inflammatory lesion contributes to preterm birth and a series of complications in preterm infants. • C-reactive protein and interleukin-6 in neonatal blood can be used as biomarkers for potential early-onset sepsis, but they are influenced by the postnatal physiological changes of preterm infants.

WHAT IS NEW

• The value of serum sialic acids of preterm infants within 1-hour afterbirth may be one of the rapid postnatal biomarkers for evaluating the severity of intra-amniotic infection. • The closer the placental lesions are to the fetus, the higher the content of serum sialic acid is.

Intrauterine inflammation exacerbates maladaptive remodeling of the immature myocardium after preterm birth in lambs

BACKGROUND

Antenatal conditions that are linked with preterm birth, such as intrauterine inflammation, can influence fetal cardiac development thereby rendering the heart more vulnerable to the effects of prematurity. We aimed to investigate the effect of intrauterine inflammation, consequent to lipopolysaccharide exposure, on postnatal cardiac growth and maturation in preterm lambs.

METHODS

Preterm lambs (~129 days gestational age) exposed antenatally to lipopolysaccharide or saline were managed according to contemporary neonatal care and studied at postnatal day 7. Age-matched fetal controls were studied at ~136 days gestational age. Cardiac tissue was sampled for molecular analyses and assessment of cardiac structure and cardiomyocyte maturation.

RESULTS

Lambs delivered preterm showed distinct ventricular differences in cardiomyocyte growth and maturation trajectories as well as remodeling of the left ventricular myocardium compared to fetal controls. Antenatal exposure to lipopolysaccharide resulted in further collagen deposition in the left ventricle and a greater presence of immune cells in the preterm heart.

CONCLUSIONS

Adverse impacts of preterm birth on cardiac structure and cardiomyocyte growth kinetics within the first week of postnatal life are exacerbated by intrauterine inflammation. The maladaptive remodeling of the cardiac structure and perturbed cardiomyocyte growth likely contribute to the increased vulnerability to cardiac dysfunction following preterm birth.

IMPACT

Preterm birth induces maladaptive cardiac remodeling and adversely impacts cardiomyocyte growth kinetics within the first week of life in sheep. These effects of prematurity on the heart are exacerbated when preterm birth is preceded by exposure to intrauterine inflammation, a common antecedent of preterm birth. Inflammatory injury to the fetal heart coupled with preterm birth consequently alters neonatal cardiac growth and maturation and thus, may potentially influence long-term cardiac function and health.

What is known about neuroplacentology in fetal growth restriction and in preterm infants: A narrative review of literature

The placenta plays a fundamental role during pregnancy for fetal growth and development. A suboptimal placental function may result in severe consequences during the infant's first years of life. In recent years, a new field known as neuroplacentology has emerged and it focuses on the role of the placenta in fetal and neonatal brain development. Because of the limited data, our aim was to provide a narrative review of the most recent knowledge about the relation between placental lesions and fetal and newborn neurological development. Papers published online from 2000 until February 2022 were taken into consideration and particular attention was given to articles in which placental lesions were related to neonatal morbidity and short-term and long-term neurological outcome. Most research regarding the role of placental lesions in neurodevelopment has been conducted on fetal growth restriction and preterm infants. Principal neurological outcomes investigated were periventricular leukomalacia, intraventricular hemorrhages, neonatal encephalopathy and autism spectrum disorder. No consequences in motor development were found. All the considered studies agree about the crucial role played by placenta in fetal and neonatal neurological development and outcome. However, the causal mechanisms remain largely unknown. Knowledge on the pathophysiological mechanisms and on placenta-related risks for neurological problems may provide clues for early interventions aiming to improve neurological outcomes, especially among pediatricians and child psychiatrists.

Detection of spontaneous preterm birth by maternal urinary volatile organic compound analysis: A prospective cohort study

Accurate prediction of preterm birth is currently challenging, resulting in unnecessary maternal hospital admittance and fetal overexposure to antenatal corticosteroids. Novel biomarkers like volatile organic compounds (VOCs) hold potential for predictive, bed-side clinical applicability. In a proof of principle study, we aimed to assess the predictive potential of urinary volatile organic compounds in the identification of pregnant women at risk for preterm birth. Urine samples of women with a high risk for preterm birth (≧24 + 0 until 36 + 6 weeks) were collected prospectively and analyzed for VOCs using gas chromatography coupled with an ion mobility spectrometer (GS-IMS). Urinary VOCs of women delivering preterm were compared with urine samples of women with suspicion of preterm birth collected at the same gestation period but delivering at term. Additionally, the results were also interpreted in combination with patient characteristics, such as physical examination at admission, microbial cultures, and placental pathology. In our cohort, we found that urinary VOCs of women admitted for imminent preterm birth were not significantly different in the overall group of women delivering preterm vs. term. However, urinary VOCs of women admitted for imminent preterm birth and delivering between 28 + 0 until 36 + 6 weeks compared to women with a high risk for preterm birth during the same gestation period and eventually delivering at term (>37 + 0 weeks) differed significantly (area under the curve: 0.70). In addition, based on the same urinary VOCs, we could identify women with a confirmed chorioamnionitis (area under the curve: 0.72) and urinary tract infection (area under the curve: 0.97). In conclusion, urinary VOCs hold potential for non-invasive, bedside prediction of preterm birth and on the spot identification of intra-uterine infection and urinary tract infections. We suggest these observations are further explored in larger populations.

Intersection of Epigenetic and Immune Alterations: Implications for Fetal Alcohol Spectrum Disorder and Mental Health

Prenatal alcohol exposure can impact virtually all body systems, resulting in a host of structural, neurocognitive, and behavioral abnormalities. Among the adverse impacts associated with prenatal alcohol exposure are alterations in immune function, including an increased incidence of infections and alterations in immune/neuroimmune parameters that last throughout the life-course. Epigenetic patterns are also highly sensitive to prenatal alcohol exposure, with widespread alcohol-related alterations to epigenetic profiles, including changes in DNA methylation, histone modifications, and miRNA expression. Importantly, epigenetic programs are crucial for immune system development, impacting key processes such as immune cell fate, differentiation, and activation. In addition to their role in development, epigenetic mechanisms are emerging as attractive candidates for the biological embedding of environmental factors on immune function and as mediators between early-life exposures and long-term health. Here, following an overview of the impact of prenatal alcohol exposure on immune function and epigenetic patterns, we discuss the potential role for epigenetic mechanisms in reprogramming of immune function and the consequences for health and development. We highlight a range of both clinical and animal studies to provide insights into the array of immune genes impacted by alcohol-related epigenetic reprogramming. Finally, we discuss potential consequences of alcohol-related reprogramming of immune/neuroimmune functions and their effects on the increased susceptibility to mental health disorders. Overall, the collective findings from animal models and clinical studies highlight a compelling relationship between the immune system and epigenetic pathways. These findings have important implications for our understanding of the biological mechanisms underlying the long-term and multisystem effects of prenatal alcohol exposure, laying the groundwork for possible novel interventions and therapeutic strategies to treat individuals prenatally exposed to alcohol.

Pathologist interobserver variability in diagnosing acute ascending intrauterine infection

The histologic diagnosis of acute ascending intrauterine infection permits a higher-efficacy identification of both subclinical infection and clinical chorioamnionitis, but procedures for placental pathology need to adopt a unified approach and work toward reproducible grading and staging systems. We conducted a retrospective chart review of 696 placental records from single and multiple deliveries between January 2011 and February 2020. Then, we compared original diagnoses with diagnoses based on Redline criteria, which is an internationally recognized system of staging and grading. Of the 696 cases available for review, 255 had complete medical records. Findings showed a strong degree of agreement (90%-100%) between original investigators' histological diagnoses of acute ascending intrauterine infection and a review by researchers using Redline criteria. Although interobserver agreement was good, more education is needed on Redline criteria to avoid missed cases (primarily Stage 1), support protocols for pathologists and obstetricians/gynecologists in determining which cases need to be investigated, and the development of reporting standards for acute ascending intrauterine infection and feedback mechanisms during follow-up.