TLR8-activating miR-146a-3p is an intermediate signal contributing to fetal membrane inflammation in response to bacterial LPS.

Preterm birth is the largest contributor to neonatal morbidity and is often associated with chorioamnionitis, defined as inflammation/infection of the fetal membranes (FMs). Chorioamnionitis is characterised by neutrophil infiltration of the FMs and is associated with elevated levels of the neutrophil chemoattractant, interleukin (IL)-8 and the proinflammatory cytokine, IL-1ß. While FMs can respond to infections through innate immune sensors, such as toll-like receptors (TLRs), the downstream mechanisms by which chorioamnionitis arises are not fully understood. A novel group of non-classical microRNAs (miR-21a, miR-29a, miR-146a-3p, Let-7b) function as endogenous danger signals by activating the ssRNA viral sensors TLR7 and TLR8. In this study, the pro-inflammatory roles of TLR7/TLR8-activating miRs were examined as mediators of FM inflammation in response to bacterial lipopolysaccharide (LPS) using an in vitro human FM explant system, an in vivo mouse model of pregnancy, and human clinical samples. Following LPS exposure, miR-146a-3p was significantly increased in both human FM explants and wild-type mouse FMs. Expression of miR-146a-3p was also significantly elevated in FMs from women with preterm birth and chorioamnionitis. FM IL-8 and inflammasome-mediated IL-1ß production in response to LPS was dependent on miR-146a-3p and TLR8 downstream of TLR4 activation. In wild-type mice, LPS exposure increased FM IL-8 and IL-1ß production and induced preterm birth. In TLR7-/-/TLR8-/- mice, LPS exposure was able to initiate but not sustain preterm birth, and FM inflammation was reduced. Together, we demonstrate a novel signalling mechanism at the maternal-fetal interface in which TLR8-activating miR-146a-3p acts as an intermediate danger signal to drive FM inflammasome-dependent and -independent mechanisms of inflammation and, thus, may play a role in chorioamnionitis and subsequent preterm birth.

Antenatal creatine supplementation reduces persistent fetal lung inflammation and oxidative stress in an ovine model of chorioamnionitis.

Chorioamnionitis is a common antecedent of preterm birth and induces inflammation and oxidative stress in the fetal lungs. Reducing inflammation and oxidative stress in the fetal lungs may improve respiratory outcomes in preterm infants. Creatine is an organic acid with known anti-inflammatory and antioxidant properties. The objective of the study was to evaluate the efficacy of direct fetal creatine supplementation to reduce inflammation and oxidative stress in fetal lungs arising from an in utero proinflammatory stimulus. Fetal lambs (n = 51) were instrumented at 90 days gestation to receive a continuous infusion of creatine monohydrate (6 mg·kg-1·h-1) or saline for 17 days. Maternal chorioamnionitis was induced with intra-amniotic lipopolysaccharide (LPS; 1 mg, O55:H6) or saline 7 days before delivery at 110 days gestation. Tissue creatine content was assessed with capillary electrophoresis, and inflammatory markers were analyzed with Luminex Magpix and immunohistochemistry. Oxidative stress was measured as the level of protein thiol oxidation. The effects of LPS and creatine were analyzed using a two-way ANOVA. Fetal creatine supplementation increased lung creatine content by 149% (PCr < 0.0001) and had no adverse effects on lung morphology. LPS-exposed groups showed increased levels of interleukin-8 in the bronchoalveolar lavage (PLPS < 0.0001) and increased levels of CD45+ leukocytes (PLPS < 0.0001) and MPO+ (PLPS < 0.0001) cells in the lung parenchyma. Creatine supplementation significantly reduced the levels of CD45+ (PCr = 0.045) and MPO+ cells (PCr = 0.012) in the lungs and reduced thiol oxidation in plasma (PCr < 0.01) and lung tissue (PCr = 0.02). In conclusion, fetal creatine supplementation reduced markers of inflammation and oxidative stress in the fetal lungs arising from chorioamnionitis.NEW & NOTEWORTHY We evaluated the effect of antenatal creatine supplementation to reduce pulmonary inflammation and oxidative stress in the fetal lamb lungs arising from lipopolysaccharide (LPS)-induced chorioamnionitis. Fetal creatine supplementation increased lung creatine content and had no adverse effects on systemic fetal physiology and overall lung architecture. Importantly, fetuses that received creatine had significantly lower levels of inflammation and oxidative stress in the lungs, suggesting an anti-inflammatory and antioxidant benefit of creatine.

Chorioamnionitis accelerates granule cell and oligodendrocyte maturation in the cerebellum of preterm nonhuman primates.

BACKGROUND: Preterm birth is often associated with chorioamnionitis and leads to increased risk of neurodevelopmental disorders, such as autism. Preterm birth can lead to cerebellar underdevelopment, but the mechanisms of disrupted cerebellar development in preterm infants are not well understood. The cerebellum is consistently affected in people with autism spectrum disorders, showing reduction of Purkinje cells, decreased cerebellar grey matter, and altered connectivity. METHODS: Preterm rhesus macaque fetuses were exposed to intra-amniotic LPS (1 mg, E. coli O55:B5) at 127 days (80%) gestation and delivered by c-section 5 days after injections. Maternal and fetal plasma were sampled for cytokine measurements. Chorio-decidua was analyzed for immune cell populations by flow cytometry. Fetal cerebellum was sampled for histology and molecular analysis by single-nuclei RNA-sequencing (snRNA-seq) on a 10× chromium platform. snRNA-seq data were analyzed for differences in cell populations, cell-type specific gene expression, and inferred cellular communications. RESULTS: We leveraged snRNA-seq of the cerebellum in a clinically relevant rhesus macaque model of chorioamnionitis and preterm birth, to show that chorioamnionitis leads to Purkinje cell loss and disrupted maturation of granule cells and oligodendrocytes in the fetal cerebellum at late gestation. Purkinje cell loss is accompanied by decreased sonic hedgehog signaling from Purkinje cells to granule cells, which show an accelerated maturation, and to oligodendrocytes, which show accelerated maturation from pre-oligodendrocytes into myelinating oligodendrocytes. CONCLUSION: These findings suggest a role of chorioamnionitis on disrupted cerebellar maturation associated with preterm birth and on the pathogenesis of neurodevelopmental disorders among preterm infants.

Clinical Chorioamnionitis and Neurodevelopment at 5 Years of Age in Children Born Preterm: The EPIPAGE-2 Cohort Study.

OBJECTIVE: To assess the association between clinical chorioamnionitis and neurodevelopmental disorders at 5 years of age in children born preterm. STUDY DESIGN: EPIPAGE 2 is a national, population-based cohort study of children born before 35 weeks of gestation in France in 2011. We included infants born alive between 240/7 and 346/7 weeks after preterm labor or preterm premature rupture of membranes. Clinical chorioamnionitis was defined as maternal fever before labor (>37.8°C) with ≥2 of the following criteria: maternal tachycardia, hyperleukocytosis, uterine contractions, purulent amniotic fluid, or fetal tachycardia. The primary outcome was a composite, including cerebral palsy, coordination disorders, cognitive disorders, sensory disorders, or behavioral disorders. We also analyzed each of these disorders separately as secondary outcomes. We performed a multivariable analysis using logistic regression models. We accounted for the nonindependence of twins and missing data by generalized estimating equation models and multiple imputations, respectively. RESULTS: Among 2927 children alive at 5 years of age, 124 (3%) were born in a context of clinical chorioamnionitis. Overall, 8.2% and 9.6% of children exposed and unexposed, respectively, to clinical chorioamnionitis had moderate-to-severe neurodevelopmental disorders. After multiple imputations and multivariable analysis, clinical chorioamnionitis was not associated with the occurrence of moderate-to-severe neurodevelopmental disorders (aOR, 0.9; 95% CI, 0.5-1.8). CONCLUSIONS: We did not find any association between clinical chorioamnionitis and neurodevelopmental disorders at 5 years of age in children born at <35 weeks of gestation after preterm labor or preterm premature rupture of membrane.

Early changes in serum interleukin-6 levels in extremely premature newborns for detecting fetal inflammation.

BACKGROUND: Fetal inflammatory response syndrome (FIRS) is defined by elevated levels of inflammatory cytokines circulating in fetal blood, which may result in preterm morbidities. Serum interleukin-6 (IL-6) level has been reported to be a good indicator of FIRS; however, changes in IL-6 levels after birth remain to be elucidated. Herein, we characterized early changes in serum IL-6 levels in extremely premature newborns (EPNs, < 28 wks gestation), and then determined the cut-off values for detecting fetal inflammation at each postnatal epoch. METHODS: In this single-center study, 49 EPNs were retrospectively studied. Serum IL-6 measurements are routinely performed at delivery, 1-3, 6-12, and 24-36 h of life. Receiver operating characteristic (ROC) curve analyses were performed for detecting the presence of funisitis, the histologic counterpart of FIRS. RESULTS: Overall, serum IL-6 levels were significantly elevated at 1-3 (298 [31-4719] pg/mL) and 6-12 (29 [2-12,635] pg/mL) hours of life, then returned to at-delivery levels at 24-36 h of life. When comparing serum IL-6 levels at each postnatal epoch, the levels at delivery, 1-3, and 6-12 h of life were significantly higher in the EPNs with funisitis. Serum IL-6 cut-off values at delivery, 1-3, 6-12, and 24-36 h of life for the presence of funisitis were 20, 572, 290, and 13 pg/mL with area under ROCs of 0.75, 0.71, 0.68, and 0.53, respectively. CONCLUSIONS: Serum IL-6 levels in EPNs significantly increase early after birth, then decrease to at-delivery levels by 24-36 h of life. Therefore, postnatal age-dependent cut-off values of serum IL-6 might be considered for detecting fetal inflammation with confirmed funisitis.

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.

Histological chorioamnionitis and pathological stages on very preterm infant outcomes.

AIMS: Histological chorioamnionitis (HCA) is a condition linked to preterm birth and neonatal infection and its relationship with various pathological stages in extremely preterm neonates, and with their associated short- and long-term consequences, remains a subject of research. This study investigated the connection between different pathological stages of HCA and both short-term complications and long-term outcomes in preterm infants born at or before 32 weeks of gestational age. METHODS: Preterm infants born at ≤ 32 weeks of gestation who underwent placental pathology evaluation and were followed-up at 18-24 months of corrected age were included. Neonates were classified based on their exposure to HCA and were further subdivided into different groups according to maternal inflammatory responses (MIR) and fetal inflammatory responses (FIR) stages. We compared short-term complications during their hospital stay between the HCA-exposed and -unexposed groups and examined the influence of HCA stages on long-term outcomes. RESULTS: The HCA group exhibited distinct characteristics such as higher rates of premature rupture of membranes > 18 h, reduced amniotic fluid, early-onset sepsis, bronchopulmonary dysplasia and intraventricular haemorrhage (IVH) grades III-IV (P < 0.05). The moderate-severe HCA group displayed lower gestational age, lower birth weight and higher incidence of IVH (grades III-IV) and preterm sepsis compared with the mild HCA group (P < 0.05). After adjusting for confounders, the MIR stages 2-3 group showed associations with cognitive impairment and cerebral palsy (P < 0.05), and the FIR stages 2-3 group also showed poor long-term outcomes and cognitive impairment (P < 0.05). CONCLUSIONS: Moderate-severe HCA was associated with increased early-onset sepsis, severe IVH and poor long-term outcomes, including cognitive impairment and cerebral palsy. Vigilant prevention strategies are warranted for severe HCA cases in order to mitigate poorer clinical outcomes.

Clinical chorioamnionitis at term: definition, pathogenesis, microbiology, diagnosis, and treatment.

Clinical chorioamnionitis, the most common infection-related diagnosis in labor and delivery units, is an antecedent of puerperal infection and neonatal sepsis. The condition is suspected when intrapartum fever is associated with two other maternal and fetal signs of local or systemic inflammation (eg, maternal tachycardia, uterine tenderness, maternal leukocytosis, malodorous vaginal discharge or amniotic fluid, and fetal tachycardia). Clinical chorioamnionitis is a syndrome caused by intraamniotic infection, sterile intraamniotic inflammation (inflammation without bacteria), or systemic maternal inflammation induced by epidural analgesia. In cases of uncertainty, a definitive diagnosis can be made by analyzing amniotic fluid with methods to detect bacteria (Gram stain, culture, or microbial nucleic acid) and inflammation (white blood cell count, glucose concentration, interleukin-6, interleukin-8, matrix metalloproteinase-8). The most common microorganisms are Ureaplasma species, and polymicrobial infections occur in 70% of cases. The fetal attack rate is low, and the rate of positive neonatal blood cultures ranges between 0.2% and 4%. Intrapartum antibiotic administration is the standard treatment to reduce neonatal sepsis. Treatment with ampicillin and gentamicin have been recommended by professional societies, although other antibiotic regimens, eg, cephalosporins, have been used. Given the importance of Ureaplasma species as a cause of intraamniotic infection, consideration needs to be given to the administration of antimicrobial agents effective against these microorganisms such as azithromycin or clarithromycin. We have used the combination of ceftriaxone, clarithromycin, and metronidazole, which has been shown to eradicate intraamniotic infection with microbiologic studies. Routine testing of neonates born to affected mothers for genital mycoplasmas could improve the detection of neonatal sepsis. Clinical chorioamnionitis is associated with decreased uterine activity, failure to progress in labor, and postpartum hemorrhage; however, clinical chorioamnionitis by itself is not an indication for cesarean delivery. Oxytocin is often administered for labor augmentation, and it is prudent to have uterotonic agents at hand to manage postpartum hemorrhage. Infants born to mothers with clinical chorioamnionitis near term are at risk for early-onset neonatal sepsis and for long-term disability such as cerebral palsy. A frontier is the noninvasive assessment of amniotic fluid to diagnose intraamniotic inflammation with a transcervical amniotic fluid collector and a rapid bedside test for IL-8 for patients with ruptured membranes. This approach promises to improve diagnostic accuracy and to provide a basis for antimicrobial administration.

Intra-amniotic infection and/or inflammation is associated with fetal cardiac concentric hypertrophy and diastolic dysfunction in preterm labor and preterm prelabor rupture of membranes.

BACKGROUND: Preterm delivery is associated with cardiovascular remodeling and dysfunction in children and adults. However, it is unknown whether these effects are caused by the neonatal consequences of preterm birth or if these are already present in utero. OBJECTIVE: We evaluated fetal cardiac morphology and function in fetuses of mothers admitted for preterm labor or preterm prelabor rupture of membranes and the association of these changes with the presence of intra-amniotic infection and/or inflammation. STUDY DESIGN: In this prospective cohort study, fetal echocardiography and amniocentesis were performed at admission in singleton pregnant women with preterm labor and/or preterm prelabor rupture of membranes between 24.0 and 34.0 weeks' gestation with (intra-amniotic infection and/or inflammation group, n=41) and without intra-amniotic infection and/or inflammation (non-intra-amniotic infection and/or inflammation, n=54). Controls (n=48) were outpatient pregnant women without preterm labor or preterm prelabor rupture of membranes. Intra-amniotic infection was defined by a positive amniotic fluid culture or positive 16S ribosomal RNA gene. Intra-amniotic inflammation was defined by using the amniotic fluid interleukin-6 cutoff levels previously reported by our group being >1.43 ng/mL in preterm prelabor rupture of membranes and >13.4 ng/mL in preterm labor. Fetal cardiac morphology and function was evaluated using echocardiography, and troponin-I and N-terminal pro-brain natriuretic peptide concentrations were measured in amniotic fluid from women with preterm labor or preterm prelabor rupture of membranes and compared with 20 amniotic fluid Biobank samples obtained for reasons other than preterm labor or preterm prelabor rupture of membranes or cardiac pathology. The data were adjusted for the estimated fetal weight below the 10th percentile and for preterm prelabor rupture of membranes at admission and also for gestational age at amniocentesis when amniotic fluid biomarkers were compared. RESULTS: From 2018 to 2021, 143 fetuses were included; 95 fetuses were from mothers admitted with a diagnosis of preterm labor or preterm prelabor rupture of membranes, and among those, 41 (28.7%) were in the intra-amniotic infection and/or inflammation group and 54 (37.8%) were in the non-intra-amniotic infection and/or inflammation group. A total of 48 (33.6%) fetuses were included in the control group. Fetuses with preterm labor and/or preterm prelabor rupture of membranes had signs of subclinical cardiac concentric hypertrophy (median left wall thickness of 0.93 [interquartile range, 0.72-1.16] in the intra-amniotic infection and/or inflammation group; 0.79 [0.66-0.92] in the non-intra-amniotic infection and/or inflammation group; and 0.69 [0.56-0.83] in controls; P<.001) and diastolic dysfunction (tricuspid A duration 0.23 seconds [0.21-0.25], 0.24 [0.22-0.25], and 0.21 [0.2-0.23]; P=.007). Systolic function was similar among groups. Higher values of amniotic fluid troponin I (1413 pg/mL [927-2334], 1190 [829-1636], and 841 [671-959]; P<.001) and N-terminal pro-brain natriuretic peptide were detected (35.0%, 17%, and 0%; P=.005) in fetuses with preterm labor or preterm prelabor rupture of membranes when compared with the control group. The highest N-terminal pro-brain natriuretic peptide concentrations were found in the intra-amniotic infection and/or inflammation group. CONCLUSION: Fetuses with preterm labor or preterm prelabor rupture of membranes showed signs of cardiac remodeling and subclinical dysfunction, which were more pronounced in those exposed to intra-amniotic infection and/or inflammation. These findings support that the cardiovascular effects observed in children and adults born preterm have, at least in part, a prenatal origin.

Childhood atopic disorders in relation to placental changes-A systematic review and meta-analysis.

Fetal programming may arise from prenatal exposure and increase the risk of diseases later in life, potentially mediated by the placenta. The objective of this systematic review was to summarize and critically evaluate publications describing associations between human placental changes and risk of atopic disorders during childhood. The review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. The inclusion criteria were original research articles or case reports written in English describing a human placental change in relation to disease occurring in offspring during childhood. The MEDLINE and EMBASE databases were searched for eligible studies. Risk of bias (RoB) was assessed using the ROBINS-I tool. The results were pooled both in a narrative way and by a meta-analysis. Nineteen studies were included (n = 12,997 participants). All studies had an overall serious RoB, and publication bias could not be completely ruled out. However, five studies showed that histological chorioamnionitis in preterm-born children was associated with asthma-related problems (pooled odds ratio = 3.25 (95% confidence interval = 2.22-4.75)). In term-born children, a large placenta (≥750 g) increased the risk of being prescribed anti-asthma medications during the first year of life. Placental histone acetylation, DNA methylation, and gene expression differences were found to be associated with different atopic disorders in term-born children. There is some evidence supporting the idea that the placenta can mediate an increased risk of atopic disorders in children. However, further studies are needed to validate the findings, properly control for confounders, and examine potential mechanisms.

Latency Antibiotics in Preterm Prelabor Rupture of Membranes: A Comparison of Azithromycin Regimens.

BACKGROUND: Treatment with antibiotics at the time of preterm prelabor rupture of membranes (PPROM) has been shown to prolong pregnancy. Due to the recurrent shortage of erythromycin, azithromycin has been substituted in the traditional regimen; however, there are little data on optimal dosing. OBJECTIVE: The objective of this study was to determine whether there is a difference in latency from onset of PPROM to delivery in patients who received a single dose of azithromycin compared with a 5-day course. METHODS: This was a single-center, multisite, retrospective, IRB approved analysis of patients admitted with a diagnosis of PPROM. Patients were included if rupture occurred between 22 0/7 and 33 6/7 weeks of gestation and received either a single dose or a 5-day course of azithromycin along with a beta lactam. RESULTS: A total of 376 patients were reviewed with 296 patients included in the final analysis. There was no statistical difference in the primary outcome of latency days in patients who received the 5-day versus the single-dose course (4 vs 5 days, P = 0.641). There was a significantly higher rate of histologic chorioamnionitis in the single-dose course of azithromycin (46.4% vs 62.6%, P = 0.006). CONCLUSIONS AND RELEVANCE: There was no difference in latency for patients who received a 5-day course of azithromycin versus a single dose for the treatment of PPROM. A higher rate of histologic chorioamnionitis was observed in those who received the single-day course. Prospective follow-up studies are needed to confirm these findings.

Syndecan-1 Level, a Marker of Endothelial Glycocalyx Degradation, Is Associated With Fetal Exposure to Chorioamnionitis and Is a Potential Biomarker for Early-Onset Neonatal Sepsis.

The goal of this investigation was to identify the association between Syndecan-1 (S1) serum levels in preterm newborns exposed to chorioamnionitis (CA) in utero and the potential of S1 as a biomarker of early-onset neonatal sepsis. A cohort of preterm newborns born <33 weeks gestational age was recruited. Within 48 hours of birth, 0.5 mL of blood was drawn to obtain S1 levels, measured via ELISA. Placentas were examined and classified as having (1) no CA, (2) CA without umbilical cord involvement, or (3) CA with inflammation of the umbilical cord (funisitis). S1 levels were compared between preterm newborns without exposure to CA verus newborns with exposure to CA (including with and without funisitis). Preterm newborns exposed to CA were found to have significantly elevated S1 levels compared to those unexposed. Although S1 levels could not differentiate fetal exposure to CA from exposure to CA with funisitis, the combined CA groups had significantly higher S1 levels compared to those not exposed to CA. S1 level has the potential to become a clinically useful biomarker that could assist in the management of mothers and preterm newborns with CA and funisitis. Furthermore, S1 level could aid in the diagnosis and treatment of early-onset neonatal sepsis.

The influence of chorioamnionitis on respiratory drive and spontaneous breathing of premature infants at birth: a narrative review.

Most very premature infants breathe at birth but require respiratory support in order to stimulate and support their breathing. A significant proportion of premature infants are affected by chorioamnionitis, defined as an umbrella term for antenatal inflammation of the foetal membranes and umbilical vessels. Chorioamnionitis produces inflammatory mediators that potentially depress the respiratory drive generated in the brainstem. Such respiratory depression could maintain itself by delaying lung aeration, hampering respiratory support at birth and putting infants at risk of hypoxic injury. This inflammatory-mediated respiratory depression may contribute to an association between chorioamnionitis and increased requirement of neonatal resuscitation in premature infants at birth. This narrative review summarises mechanisms on how respiratory drive and spontaneous breathing could be influenced by chorioamnionitis and provides possible interventions to stimulate spontaneous breathing.  Conclusion: Chorioamnionitis could possibly depress respiratory drive and spontaneous breathing in premature infants at birth. Interventions to stimulate spontaneous breathing could therefore be valuable. What is Known: • A large proportion of premature infants are affected by chorioamnionitis, antenatal inflammation of the foetal membranes and umbilical vessels. What is New: • Premature infants affected by chorioamnionitis might be exposed to higher concentrations of respiratory drive inhibitors which could depress breathing at birth. • Premature infants affected by chorioamnionitis seem to be associated with a higher and more extensive requirement of resuscitation at birth.

Placental pathology and neonatal morbidity: exploring the impact of gestational age at birth.

AIM: To evaluate placental pathology in term and post-term births, investigate differences in clinical characteristics, and assess the risk of adverse neonatal outcome. METHODS: This prospective observational study included 315 singleton births with gestational age (GA) > 36 weeks + 6 days meeting the local criteria for referral to placental histopathologic examination. We applied the Amsterdam criteria to classify the placentas. Births were categorized according to GA; early-term (37 weeks + 0 days to 38 weeks + 6 days), term (39 weeks + 0 days to 40 weeks + 6 days), late-term (41 weeks + 0 days to 41 weeks + 6 days), and post-term births (≥ 42 weeks + 0 days). The groups were compared regarding placental pathology findings and clinical characteristics. Adverse neonatal outcomes were defined as 5-minute Apgar score < 7, umbilical cord artery pH < 7.0, admission to the neonatal intensive care unit or intrauterine death. A composite adverse outcome included one or more adverse outcomes. The associations between placental pathology, adverse neonatal outcomes, maternal and pregnancy characteristics were evaluated by logistic regression analysis. RESULTS: Late-term and post-term births exhibited significantly higher rates of histologic chorioamnionitis (HCA), fetal inflammatory response, clinical chorioamnionitis (CCA) and transfer to neonatal intensive care unit (NICU) compared to early-term and term births. HCA and maternal smoking in pregnancy were associated with adverse outcomes in an adjusted analysis. Nulliparity, CCA, emergency section and increasing GA were all significantly associated with HCA. CONCLUSIONS: HCA was more prevalent in late and post-term births and was the only factor, along with maternal smoking, that was associated with adverse neonatal outcomes. Since nulliparity, CCA and GA beyond term are associated with HCA, this should alert the clinician and elicit continuous intrapartum monitoring for timely intervention.

Soluble urokinase plasminogen activator receptor in vaginally collected amniotic fluid predicting fetal inflammatory response syndrome: a prospective cohort study.

BACKGROUND: Improving noninvasive antenatal diagnosis of fetal inflammatory response syndrome (FIRS) can assist in the evaluation of prenatal risk and reduce perinatal outcomes. This study aimed to determine whether soluble urokinase-type plasminogen activator receptor (suPAR) in vaginally collected amniotic fluid is significant in identifying FIRS after preterm premature rupture of membranes before 34 weeks of gestation. METHODS: This was a prospective cohort study of 114 pregnant women and their newborns after preterm premature rupture of membranes at 22-34+6 weeks of gestation. SuPAR was evaluated using an enzyme-linked immunosorbent assay in vaginally collected amniotic fluid. Patients were classified according to the presence or absence of FIRS. FIRS was defined by umbilical cord blood interleukin-6 level > 11 pg/mL or histological funisitis. The data were analyzed using the R package (R-4.0.5). RESULTS: SuPAR was detected in all amniotic fluid samples with a median of 26.23 ng/mL (interquartile range (IQR), 15.19-51.14). The median level of suPAR was higher in the FIRS group than in the non-FIRS group, 32.36 ng/mL (IQR, 17.27-84.16) vs. 20.46 ng/mL (IQR, 11.49-36.63) (P = 0.01), respectively. The presence of histological chorioamnionitis significantly increased the suPAR concentration in the FIRS group (P < 0.001). The areas under the curve for FIRS and FIRS with histological chorioamnionitis were 0.65 and 0.74, respectively, with an optimum cutoff value of 27.60 ng/mL. Controlling for gestational age, the cutoff of suPAR more than 27.60 ng/mL predicted threefold higher odds for FIRS and sixfold higher odds for FIRS with histologic chorioamnionitis. CONCLUSION: Soluble urokinase-type plasminogen activator receptor in vaginally obtained amniotic fluid may assist in evaluating prenatal risk of FIRS in patients after preterm premature rupture of membranes before 34 weeks of gestation.

Anaphylaxis-induced premature uterine contractions: a case report and literature review.

BACKGROUND: Preterm labor is caused by multiple etiologies, including intra-amniotic infection and/or intra-amniotic inflammation, vascular disorders, cervical disease, decidual senescence, and breakdown of maternal-fetal tolerance. Accumulating evidence in vivo and in vitro has shown that an allergic reaction, including anaphylaxis, can induce preterm uterine contractions. This report describes a case of a pregnant woman who developed anaphylaxis and regular uterine contractions after the ingestion of a strawberry-coated biscuit. We also review the mechanism of allergic reaction (hypersensitivity)-induced preterm labor. Case presentation A 31-year-old woman (gravida 1, para 0) at 30+2 weeks of gestation was admitted to the labor and delivery unit with regular uterine contractions and anaphylactic symptoms after she ingested a strawberry-coated biscuit as a snack. The uterine contractions resolved after the treatment of anaphylaxis by administering antihistamines and epinephrine. The patient subsequently delivered at 39+3 weeks of gestation. The amniotic fluid profile showed no infection or inflammation. A postpartum skin-prick test confirmed a positive type 1 hypersensitivity reaction to the strawberry-coated biscuit. CONCLUSIONS: We report a case of anaphylaxis-induced uterine contractility in which uterine contractions subsided after the treatment of anaphylaxis. The absence of intra-amniotic infection and/or intra-amniotic inflammation and the cause of the anaphylaxis were confirmed. Our findings indicate that maternal allergic reactions may be one of the mechanisms of preterm labor.

Angiogenic imbalance in pregnancies with preterm prelabor rupture of membranes between 34 and 37 weeks of gestation.

INTRODUCTION: This study aimed to identify whether microbial invasion of the amniotic cavity and/or intra-amniotic inflammation in women with late preterm prelabor rupture of membranes (PPROM) was associated with changes in concentrations of soluble fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PlGF) and its ratio in maternal serum, and whether placental features consistent with maternal vascular malperfusion further affect their concentrations. MATERIAL AND METHODS: This historical study included 154 women with singleton pregnancies complicated by PPROM between gestational ages 34+0 and 36+6 weeks. Transabdominal amniocentesis was performed as part of standard clinical management to evaluate the intra-amniotic environment. Women were categorized into two subgroups based on the presence of microorganisms and/or their nucleic acids in amniotic fluid (determined by culturing and molecular biology method) and intra-amniotic inflammation (by amniotic fluid interleukin-6 concentration evaluation): (1) those with the presence of microorganisms and/or inflammation (at least one present) and (2) those with negative amniotic fluid for infection/inflammation (absence of both). Concentrations of sFlt-1 and PlGF were assessed using the Elecsys® sFlt-1 and Elecsys® PlGF immunoassays and converted into multiples of medians. RESULTS: Women with the presence of microorganisms and/or inflammation in amniotic fluid had lower serum concentrations of sFlt-1 and sFlt-1/PlGF ratios and higher concentrations of PlGF compared with those with negative amniotic fluid. (sFlt-1: presence: median 1.0 multiples of the median (MoM), vs negative: median: 1.5 MoM, P = 0.003; PlGF: presence: median 0.7 MoM, vs negative: median 0.4 MoM, P = 0.02; sFlt-1/PlGF: presence: median 8.9 vs negative 25.0, P = 0.001). Higher serum concentrations of sFlt-1 and sFlt-1/PlGF ratios as well as lower concentrations of PlGF were found in the subsets of women with maternal vascular malperfusion than in those without maternal vascular malperfusion. CONCLUSIONS: Among women experiencing late PPROM, angiogenic imbalance in maternal serum is primarily observed in those without both microbial invasion of the amniotic cavity and intra-amniotic inflammation. Additionally, there is an association between angiogenic imbalance and the presence of maternal vascular malperfusion.

Placental inflammation in a fetal demise of a SARS-CoV-2-asymptomatic, COVID-19-unvaccinated pregnant woman: a case-report.

BACKGROUND: Intrauterine fetal demise is a recognized complication of coronavirus disease 2019 in pregnant women and is associated with histopathological placental lesions. The pathological mechanism and virus-induced immune response in the placenta are not fully understood. A detailed description of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-induced inflammation in the placenta during fetal demise is crucial for improved clinical management. CASE PRESENTATION: We report the case of a 27-week gestation SARS-CoV-2-asymptomatic unvaccinated pregnant woman without comorbidities or other risk factors for negative pregnancy outcomes with a diagnosis of intrauterine fetal demise. Histopathological findings corresponded to patterns of subacute inflammation throughout the anatomic compartments of the placenta, showing severe chorioamnionitis, chronic villitis and deciduitis, accompanied by maternal and fetal vascular malperfusion. Our immunohistochemistry results revealed infiltration of CD68+ macrophages, CD56+ Natural Killer cells and scarce CD8+ T cytotoxic lymphocytes at the site of placental inflammation, with the SARS-CoV-2 nucleocapsid located in stromal cells of the chorion and chorionic villi, and in decidual cells. CONCLUSION: This case describes novel histopathological lesions of inflammation with infiltration of plasma cells, neutrophils, macrophages, and natural killer cells associated with malperfusion in the placenta of a SARS-CoV-2-infected asymptomatic woman with intrauterine fetal demise. A better understanding of the inflammatory effects exerted by SARS-CoV-2 in the placenta will enable strategies for better clinical management of pregnant women unvaccinated for SARS-CoV-2 to avoid fatal fetal outcomes during future transmission waves.

Neonatal morbidity and mortality in birth centers in the United States 2018-2021: An observational study of low-risk birthing individuals.

BACKGROUND: Many studies reporting neonatal outcomes in birth centers include births with risk factors not acceptable for birth center care using the evidence-based CABC criteria. Accurate comparisons of outcomes by birth setting for low-risk patients are needed. METHODS: Data from the public Natality Detailed File from 2018 to 2021 were used. Logistic regression, including adjusted and unadjusted odds ratios, compared neonatal outcomes (chorioamnionitis, Apgar scores, resuscitation, intensive care, seizures, and death) between centers and hospitals. Covariates included maternal diabetes, body mass index, age, parity, and demographic characteristics. RESULTS: The sample included 8,738,711 births (8,698,432 (99.53%) in hospitals and 40,279 (0.46%) in birth centers). There were no significant differences in neonatal deaths (aOR 1.037; 95% CI [0.515, 2.088]; p-value 0.918) or seizures (aOR 0.666; 95% CI [0.315, 1.411]; p-value 0.289). Measures of morbidity either not significantly different or less likely to occur in birth centers compared to hospitals included chorioamnionitis (aOR 0.032; 95% CI [0.020, 0.052]; p-value < 0.001), Apgar score < 4 (aOR 0.814, 95% CI [0.638, 1.039], p-value 0.099), Apgar score < 7 (aOR 1.075, 95% CI [0.979, 1.180], p-value 0.130), ventilation >6 h (aOR 0.349; [0.281,0.433], p-value < 0.001), and intensive care admission (aOR 0.356; 95% CI [0.328, 0.386], p-value < 0.001). Birth centers had higher odds of assisted neonatal ventilation for <6 h as compared to hospitals (aOR 1.373; 95% CI [1.293, 1.457], p-value < 0.001). CONCLUSION: Neonatal deaths and seizures were not significantly different between freestanding birth centers and hospitals. Chorioamnionitis, Apgar scores < 4, and intensive care admission were less likely to occur in birth centers.

Relationship between chorioamnionitis or funisitis and lung injury among preterm infants: meta-analysis involved 16 observational studies with 68,397 participants.

BACKGROUND: Chorioamnionitis (CA) can cause multiple organ injuries in premature neonates, particularly to the lungs. Different opinions exist regarding the impact of intrauterine inflammation on neonatal respiratory distress syndrome (NRDS) and bronchopulmonary dysplasia (BPD). We aim to systematically review the relationship between CA or Funisitis (FV) and lung injury among preterm infants. METHODS: We electronically searched PubMed, EMbase, the Cochrane library, CNKI, and CMB for cohort studies from their inception to March 15, 2023. Two reviewers independently screened literature, gathered data, and did NOS scale of included studies. The meta-analysis was performed using RevMan 5.3. RESULTS: Sixteen observational studies including 68,397 patients were collected. Meta-analysis showed CA or FV increased the lung injury risk (OR = 1.43, 95%CI: 1.06-1.92). Except for histological chorioamnionitis (HCA) (OR = 0.72, 95%CI: 0.57-0.90), neither clinical chorioamnionitis (CCA) (OR = 1.86, 95%CI: 0.93-3.72) nor FV (OR = 1.23, 95%CI: 0.48-3.15) nor HCA with FV (OR = 1.85, 95%CI: 0.15-22.63) had statistical significance in NRDS incidence. As a result of stratification by grade of HCA, HCA (II) has a significant association with decreased incidence of NRDS (OR = 0.48, 95%CI: 0.35-0.65). In terms of BPD, there is a positive correlation between BPD and CA/FV (CA: OR = 3.18, 95%CI: 1.68-6.03; FV: OR = 6.36, 95%CI: 2.45-16.52). Among CA, HCA was positively associated with BPD (OR = 2.70, 95%CI: 2.38-3.07), whereas CCA was not associated with BPD (OR = 2.77, 95%CI: 0.68-11.21). HCA and moderate to severe BPD (OR = 25.38, 95%CI: 7.13-90.32) showed a positive correlation, while mild BPD (OR = 2.29, 95%CI: 0.99-5.31) did not. CONCLUSION: Currently, evidence suggests that CA or FV increases the lung injury incidence in premature infants. For different types of CA and FV, HCA can increase the incidence of BPD while decreasing the incidence of NRDS. And this "protective effect" only applies to infants under 32 weeks of age. Regarding lung injury severity, only moderate to severe cases of BPD were positively correlated with CA.