Subclinical histologic chorioamnionitis and related clinical and laboratory parameters in preterm deliveries

Development and validation of models for predicting preterm birth and gestational latency following emergency cervical cerclage: A multicenter cohort study

INTRODUCTION

Emergency cervical cerclage is a recognized method for preventing mid-trimester pregnancy loss and premature birth; however, its benefits remain controversial. This study aimed to establish preoperative models predicting preterm birth and gestational latency following emergency cervical cerclage in singleton pregnant patients with a high risk of preterm birth.

MATERIAL AND METHODS

We retrospectively reviewed data from patients who received emergency cerclage between 2015 and 2023 in three institutions. Patients were grouped into a derivation cohort (n = 141) and an independent validation cohort (n = 61). Univariate and multivariate logistic and Cox regression analyses were used to identify independent predictive variables and establish the models. Harrell's C-index, time-dependent receiver operating characteristic curves and areas under the curves, calibration curve, and decision curve analyses were performed to assess the models.

RESULTS

The models incorporated gestational weeks at cerclage placement, history of prior second-trimester loss and/or preterm birth, cervical dilation, and preoperative C-reactive protein level. The C-index of the model for predicting preterm birth before 28 weeks was 0.87 (95% CI: 0.82-0.93) in the derivation cohort and 0.82 (95% CI: 0.71-0.92) in the independent validation cohort; The C-index of the model for predicting gestational latency was 0.70 (95% CI: 0.66-0.75) and 0.78 (95% CI: 0.71-0.84), respectively. In the derivation set, the areas under the curves were 0.84, 0.81, and 0.84 for predicting 1-, 3- and 5-week pregnancy prolongation, respectively. The corresponding values for the external validation were 0.78, 0.78, and 0.79, respectively. Calibration curves showed a good homogeneity between the observed and predicted ongoing pregnant probabilities. Decision curve analyses revealed satisfactory clinical usefulness.

CONCLUSIONS

These novel models provide reliable and valuable prognostic predictions for patients undergoing emergency cerclage. The models can assist clinicians and patients in making personalized clinical decisions before opting for the cervical cerclage.

Amniotic fluid interleukin-6 and neutrophil gelatinase-associated lipocalin for predicting fetal inflammatory response syndrome based on histological chorioamnionitis and funisitis

OBJECTIVE

We aimed to analyze the predictive efficacy of amniotic fluid interleukin-6 (IL-6) and neutrophil gelatinase-associated lipocalin (NGAL) for fetal inflammatory response syndrome (FIRS)-related infection.

MATERIALS AND METHODS

We included singleton pregnancies classified into FIRS and non-FIRS groups. FIRS was defined as histologic chorioamnionitis and funisitis. Amniotic fluid samples were collected during vaginal delivery (VD) or cesarean section (CS). We compared amniotic fluid IL-6 and NGAL levels between the groups.

RESULTS

Forty-six pregnancies were analyzed and classified into 20 (43.5%) FIRS and 26 (56.5%) non-FIRS pregnancies. We observed significant differences in amniotic fluid IL-6 and NGAL. Amniotic fluid collection significantly influenced NGAL levels (p < 0.001). The area under the concentration-time curve (AUC), with optimal cutoff values, for amniotic fluid IL-6 and NGAL (VD and CS) levels was 0.948 (11,344 pg/mL), 0.800 (1180 ng/mL), and 0.946 (708 ng/mL), respectively.

CONCLUSION

Amniotic fluid IL-6 and NGAL levels showed equivalent predictive ability for FIRS-related infection.

[Oxytocin: a new target for neuroprotection?]

Every year, 30 million infants worldwide are delivered after intra-uterine growth restriction (IUGR) and 15 million are born preterm. These two conditions are the leading causes of ante-/perinatal stress and brain injury responsible for neurocognitive and behavioral disorders affecting more than 9 million children each year. Most pharmacological candidates to prevent perinatal brain damage have failed to demonstrate substantial benefits. In contrast, environment enrichment based on developmental care, skin-to-skin contact and vocal/music exposure appear to exert positive effects on brain structure and function. However, mechanisms underlying these effects remain unknown. There is strong evidence that an adverse environment during pregnancy and the neonatal period can influence hormonal responses of the newborn with long-lasting neurobehavioral consequences in infancy and adulthood. In particular, excessive cortisol release in response to perinatal stress associated with prematurity or IUGR is recognized to induce brain-programming effects and neuroinflammation, a key predictor of subsequent neurological impairments. These deleterious effects are known to be balanced by oxytocin (OT), a neuropeptide released by the hypothalamus, which plays a role during the perinatal period and in social behavior. In addition, preclinical studies suggest that OT is able to regulate the central inflammatory response to injury in the adult brain. Using a rodent model of IUGR associated with developing white matter damage, we recently reported that carbetocin, a brain permeable OT receptor (OTR) agonist, induced a significant reduction of activated microglia, the primary immune cells of the brain. Moreover, this reduced microglia reactivity was associated with long-term neuroprotection. These findings make OT a promising candidate for neonatal neuroprotection through neuroinflammation regulation. However, the mechanisms linking endogenous OT and central inflammation response to injury have not yet been established. Further studies are needed to assess the protective role of OT in the developing brain through modulation of microglial activation, a key feature of brain injury observed in infants born preterm or growth-restricted. They are expected to have several impacts in the near future not only for improving knowledge of microglial cell physiology and reactivity during brain development, but also to design clinical trials testing interventions associated with endogenous OT release as a relevant strategy to alleviate neuroinflammation in neonates.

Prenatal exposure to nitrate from drinking water and the risk of preterm birth

Evidence is emerging that preterm birth (PTB, birth before 37 completed weeks of gestation), a risk factor for neonatal mortality and future morbidity, may be induced by maternal nitrate (NO3−) exposure from drinking water. The objective of this study is to assess the association between maternal exposure to nitrate and the risk of PTB in a nationwide study of liveborn singletons.

Loss of CXC-Chemokine Receptor 1 Expression in Chorioamnionitis Is Associated with Adverse Perinatal Outcomes

Background: Chorioamnionitis complicates about 1−5% of deliveries at term and causes about one-third of stillbirths. CXC-chemokine receptor 1 (CXCR1) binds IL-8 with high affinity and regulates neutrophil recruitment. We aimed to determine the immunoexpression of CXCR1 in placentas with chorioamnionitis, and its association with adverse perinatal outcomes. Methods: A total of 101 cases of chorioamnionitis and 32 cases of non-chorioamnionitis were recruited over a period of 2 years. CXCR1 immunohistochemistry was performed, and its immunoexpression in placentas was evaluated. The adverse perinatal outcomes included intrauterine death, poor APGAR score, early neonatal death, and respiratory complications. Results: Seventeen cases (17/101, 16.8%) with chorioamnionitis presented as preterm deliveries. Lung complications were more common in mothers who were >35 years (p = 0.003) and with a higher stage in the foetal inflammatory response (p = 0.03). Notably, 24 cases (23.8%) of histological chorioamnionitis were not detected clinically. Interestingly, the loss of CXCR1 immunoexpression in the umbilical cord endothelial cells (UCECs) was significantly associated with foetal death (p = 0.009). Conclusion: The loss of CXCR1 expression in UCECs was significantly associated with an increased risk of adverse perinatal outcomes and could be used as a biomarker to predict adverse perinatal outcomes in chorioamnionitis. Further study is warranted to study the pathophysiology involved in the failure of CXCR1 expression in these cells.

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.

Neutrophil to Lymphocyte Ratio in Maternal Blood: A Clue to Suspect Amnionitis

There is no information about whether maternal neutrophil to lymphocyte ratios (NLRs) progressively increase with respect to the progression of acute histologic chorioamnionitis (acute-HCA) and increased maternal NLR is a risk factor for amnionitis, known as advanced acute-HCA, in pregnant women at risk for spontaneous preterm birth (PTB). The objective of the current study is to examine this issue. The study population included 132 singleton PTB (<34 weeks) due to either preterm labor or preterm-PROM with both placental pathology and maternal CBC results within 48 h before delivery. We examined maternal NLRs according to the progression of acute-HCA in extra-placental membranes (EPM) (i.e., group-0, inflammation-free EPM; group-1, inflammation restricted to decidua; group-2, inflammation restricted to the membranous trophoblast of chorion and the decidua; group-3, inflammation in the connective tissue of chorion but not amnion; group-4, amnionitis). Maternal NLRs significantly and progressively increased with the progression of acute-HCA (Spearman’s rank correlation test, γ = 0.363, p = 0.000019). Moreover, the increased maternal NLR (≥7.75) (Odds-ratio 5.56, 95% confidence-interval 1.26-24.62, p < 0.05) was a significant independent risk factor for amnionitis even after the correction for potential confounders. In conclusion, maternal NLRs significantly and progressively increased according to the progression of acute-HCA and the increased maternal NLR (≥7.75) was an independent risk factor for amnionitis in spontaneous PTB. The evaluation of the performance of NLR should clearly require a prospective description of this parameter in a cohort of patients with either threatened PTL or preterm-PROM.

Placental origins of neonatal diseases: toward a precision medicine approach

The placenta is the single most reliable source for precise information on intrauterine environment, as well as maternal and fetal health. It mediates the physiology of two distinct yet highly interconnected individuals. The pathology that develops in the placenta, and the adaptations the placenta undergoes to mitigate this pathology, may influence the later life health of the mother and baby. Pathological placental examination provides a unique opportunity to explore and understand the intrauterine environment, as well as providing a record of events that may be associated with adverse pregnancy outcomes. A number of placental lesions have been described in association with various neonatal morbidities. The purpose of this review is to summarize the evidence for the association of placental pathologic lesions with neurodevelopmental outcomes infants with specific neonatal morbidities, including (1) neonatal encephalopathy, (2) bronchopulmonary dysplasia, (3) congenital heart diseases, and (4) autism spectrum disorders. For each of these disease processes, we will also propose specific research priorities in future studies. We conclude with a hospital-specific protocol for triaging which placentas should receive histological evaluation as a fundamental first step for the field of neuroplacentology to guide precision-based therapeutic approaches in the affected newborns. IMPACT: The purpose of this review is to summarize the evidence for placental origins of neonatal diseases. We propose specific research priorities in the field of neuroplacentology in future studies. We also present a targeted hospital-based approach for triaging which placentas should receive histological evaluation.

Clinical predictive factors of histological chorioamnionitis: case-control study

Introduction

Histological chorioamnionitis or "intrauterine inflammation or infection" (Triple I) it is an acute inflammation of amniotic membrane, chorionic plate and umbilical cord.

Subject

To assess in the event of the clinical predictive factors associated to histological chorioamnionitis.

Methods

Prospective examination of 50 placentas from aberrant pregnancies, and 50 placentas from 'normal' deliveries. The Placentas analyzed by the conventional histopathology method, and the severity of chorioamnionitis was classified histologically according to the intensity and the topography of placental inflammation.The clinical and histopathological features of the study groups were introduced into the SPSS 13 database (License University Mohammed V-Rabat).

Results

36/50 placentas of aberrant pregnancies showed a histological chorioamnionitis often associated to a funisitis, and 11/50 normal placentas have shown some lesions of histological chorioamnionitis mainly grade one without funisitis.On the other hand we noted a statistically significant association between histological chorioamnionitis and premature rupture of the membranes (PROM) over than 12h (p < 0.001).

Conclusions

Our study confirmed the predominance of histological chorioamnionitis lesions in clinically suspected cases of chorioamnionitis with 72% versus 22% in the controls group.Among the clinical parameters studied, only the premature rupture of the Membranes was shown a statistically significant association with the appearance of histological signs of chorioamnionitis.In conclusion, chorioamnionitis is sometimes clinically silent. Morphological placental study could be a confirmation of this pathology, which is predominantly associated to PROM over than 12 h.

Chorioamnionitis: Establishing a correlation between clinical and histological diagnosis

Introduction

Chorioamnionitis that is associated with high rates of morbidity and mortality needs an early diagnosis for effective treatment. However, views are conflicting on the effectiveness of a clinical versus a histological diagnosis of the disease. The accuracy of clinical diagnoses should be evaluated by determining their correlation with histopathological data.

Methods

A total of 696 placental records from single and multiple pregnancies between January 2011 and February 2018 were collected and reviewed to determine if chorioamnionitis was present.

Results

Of the 696 records, 255 had histological data available, and of these, histological evidence for chorioamnionitis was recorded in 135 (52.9%). Clinical chorioamnionitis diagnosis was insensitive (26.7%; 95% confidence interval 19.43%-34.96%) and inaccurate (61.1%; 95% confidence interval 54.90%-67.19%). As well, 73.3% of histologically positive chorioamnionitis cases were missed using clinical indicators.

Discussion

Clinical diagnosis for chorioamnionitis is inaccurate; in our study, most of the positive cases were not diagnosed using clinical indicators. However, of the clinical indicators examined, maternal and fetal tachycardia were the most reliable.

Decreased microglial Wnt/β-catenin signalling drives microglial pro-inflammatory activation in the developing brain

Microglia of the developing brain have unique functional properties but how their activation states are regulated is poorly understood. Inflammatory activation of microglia in the still-developing brain of preterm-born infants is associated with permanent neurological sequelae in 9 million infants every year. Investigating the regulators of microglial activation in the developing brain across models of neuroinflammation-mediated injury (mouse, zebrafish) and primary human and mouse microglia we found using analysis of genes and proteins that a reduction in Wnt/β-catenin signalling is necessary and sufficient to drive a microglial phenotype causing hypomyelination. We validated in a cohort of preterm-born infants that genomic variation in the Wnt pathway is associated with the levels of connectivity found in their brains. Using a Wnt agonist delivered by a blood-brain barrier penetrant microglia-specific targeting nanocarrier we prevented in our animal model the pro-inflammatory microglial activation, white matter injury and behavioural deficits. Collectively, these data validate that the Wnt pathway regulates microglial activation, is critical in the evolution of an important form of human brain injury and is a viable therapeutic target.

Histological chorioamnionitis is predicted by early infant C-reactive protein in preterm infants and correlates with neonatal outcomes

AIM

Histological chorioamnionitis (HCA) is associated with preterm birth and adverse neonatal outcomes. We evaluated the rise in C-reactive protein (CRP) in preterm infants as a predictor of HCA severity and outcomes.

METHODS

Consecutive preterm infants, born January 2009 to January 2014 in the National Maternity Hospital, Dublin, under 32 weeks' gestation or <1.5 kg birthweight, were included. Histological chorioamnionitis was staged as maternal inflammatory response, foetal inflammatory response and non-HCA.

RESULTS

Preterm infants (n = 518) were included with a mean gestational age 28.5 ± 2.8 weeks, birthweight 1.1 ± 0.3 kg, and 53.5% were male. Histological chorioamnionitis was found in 25.4%. Histological chorioamnionitis was present in 93.7% when CRP > 5 mg/L, 65.2% when CRP 1-5 mg/L and in 19.4% when CRP < 1 mg/L. When both the immature to total neutrophil (IT) ratio was >0.2 and the CRP > 1 mg/L the positive predictive value and negative predictive value for HCA were 92.5% and 84.9%, respectively. Histological chorioamnionitis was associated with more resuscitation and respiratory distress syndrome (both P < .001). A CRP > 10 mg/L was associated with a foetal inflammatory response and increased early-onset sepsis.

CONCLUSION

Higher early CRP was a surrogate predictor of HCA and correlated with the severity of HCA. Higher CRP and HCA were associated with adverse early outcomes.

In-line filtration in very preterm neonates: a randomized controlled trial

In-line filtration is increasingly used in critically-ill infants but its benefits, by preventing micro-particle infusion in very preterm neonates, remain to be demonstrated. We conducted a randomized controlled trial among very preterm infants allocated to receive either in-line filtration of all the intra-venous lines or standard care without filters. The primary outcome was differences greater than 20% in the median changes in pro-inflammatory cytokine serum concentrations measured at day 3 and day 8 (+/-1) using a Luminex multianalytic profiling technique. Major neonatal complications were analyzed as secondary predefined outcomes. We randomized 146 infants, assigned to filter (n = 73) or control (n = 73) group. Difference over 20% in pro-inflammatory cytokine concentration between day 3 and day 8 was not found statistically different between the two groups, both in intent-to-treat (with imputation) and per protocol (without imputation) analyses. The incidences of most of neonatal complications were found to be similar. Hence, this trial did not evidence a beneficial effect of in-line filtration in very preterm infants on the inflammatory response syndrome and neonatal morbidities. These data should be interpreted according to local standards in infusion preparation and central line management.

The prevalence of histologic acute chorioamnionitis among HIV infected pregnant women in Uganda and its association with adverse birth outcomes

BACKGROUND

Preterm birth (PTB) is a leading cause of neonatal mortality and longer-term morbidity. Acute chorioamnionitis (ACA) is a common cause of PTB, however, there are limited data on the prevalence of ACA and its association with PTB in resource limited settings.

METHODS

Data and samples came from a clinical trial evaluating novel strategies for the prevention of malaria in HIV infected pregnant women in Uganda. Women were enrolled between 12-28 weeks of gestation and followed through delivery. For each placenta delivered, three placental tissue types (membrane roll, umbilical cord and chorionic plate/villous parenchyma) were collected. Slides were assessed for diagnosis of maternal and fetal ACA by microscopic evaluation of neutrophilic infiltration using a standardized grading scale. The primary outcomes were PTB (<37 weeks), low birth weight (LBW, <2500 grams), and small-for-gestational age (SGA, birth weight <10th percentile for age). Univariate and multivariate logistic regression were used to estimate associations between 1) maternal characteristics (age, education, wealth, gravidity, gestational age at enrollment, placental malaria, anti-malarial prophylaxis treatment regimen, HIV disease parameters) and ACA, and 2) associations between ACA and adverse birth outcomes.

FINDINGS

A total of 193 placentas were included in the analysis. The prevalence of maternal and fetal ACA was 44.5% and 28.0%, respectively. HIV infected women between 28-43 years of age had a higher risk of maternal ACA compared to those between 17-21 years of age (50.9% vs. 19.1%; aOR = 4.00 (1.10-14.5), p = 0.04) and the diagnosis of severe maternal ACA was associated with a significantly higher risk of PTB (28.6% vs. 6.0%; aOR = 6.04 (1.87-19.5), p = 0.003), LBW (33.3% vs. 9.4%; aOR = 4.86 (1.65-14.3); p = 0.004), and SGA (28.6% vs. 10.1%; aOR = 3.70 (1.20-11.4), p = 0.02). No maternal characteristics were significantly associated with fetal ACA and the diagnosis of fetal ACA was not associated with adverse birth outcomes.

CONCLUSIONS

Histological evidence of severe maternal ACA was associated with an increased risk of PTB, LBW, and SGA in HIV infected, pregnant Ugandan women.

Neuroprotection of the preterm brain

Despite notable advances in the care and survival of preterm infants, a significant proportion of preterm neonates will have life-long cognitive, behavioral, and motor deficits, and robustly effective neuroprotective strategies are still missing. These therapies must target the pathophysiologic mechanisms observed in contemporaneous infants and rely on modern epidemiology, imaging, and experimental models and assessment techniques. Two drugs, magnesium sulfate and caffeine, are already in use in several units, and although their targets are apnea of prematurity and myometrial contractility (respectively), they do offer improved odds of positive outcomes. Nevertheless, these drugs have limited efficacy, and NICU-to-NICU administration varies greatly. As such, there is an obvious need for additional specific neurotherapeutic strategies to further enhance the outcome of this very fragile population of neonates. The chapter reviews these issues, highlights bottlenecks that need to be solved for meaningful progress in the field, and proposes future innovative avenues for intervention, including delayed interventions.

Neuroinflammation in preterm babies and autism spectrum disorders

Genetic anomalies have a role in autism spectrum disorders (ASD). Each genetic factor is responsible for a small fraction of cases. Environment factors, like preterm delivery, have an important role in ASD. Preterm infants have a 10-fold higher risk of developing ASD. Preterm birth is often associated with maternal/fetal inflammation, leading to a fetal/neonatal inflammatory syndrome. There are demonstrated experimental links between fetal inflammation and the later development of behavioral symptoms consistent with ASD. Preterm infants have deficits in connectivity. Most ASD genes encode synaptic proteins, suggesting that ASD are connectivity pathologies. Microglia are essential for normal synaptogenesis. Microglia are diverted from homeostatic functions towards inflammatory phenotypes during perinatal inflammation, impairing synaptogenesis. Preterm infants with ASD have a different phenotype from term born peers. Our original hypothesis is that exposure to inflammation in preterm infants, combined with at risk genetic background, deregulates brain development leading to ASD.

Myelination induction by a histamine H3 receptor antagonist in a mouse model of preterm white matter injury

Fifteen million babies are born preterm every year and a significant number suffer from permanent neurological injuries linked to white matter injury (WMI). A chief cause of preterm birth itself and predictor of the severity of WMI is exposure to maternal-fetal infection-inflammation such as chorioamnionitis. There are no neurotherapeutics for this WMI. To affect this healthcare need, the repurposing of drugs with efficacy in other white matter injury models is an attractive strategy. As such, we tested the efficacy of GSK247246, an H3R antagonist/inverse agonist, in a model of inflammation-mediated WMI of the preterm born infant recapitulating the main clinical hallmarks of human brain injury, which are oligodendrocyte maturation arrest, microglial reactivity, and hypomyelination. WMI is induced by mimicking the effects of maternal-fetal infection-inflammation and setting up neuroinflammation. We induce this process at the time in the mouse when brain development is equivalent to the human third trimester; postnatal day (P)1 through to P5 with i.p. interleukin-1β (IL-1β) injections. We initiated GSK247246 treatment (i.p at 7 mg/kg or 20 mg/kg) after neuroinflammation was well established (on P6) and it was administered twice daily through to P10. Outcomes were assessed at P10 and P30 with gene and protein analysis. A low dose of GSK247246 (7 mg/kg) lead to a recovery in protein expression of markers of myelin (density of Myelin Basic Protein, MBP & Proteolipid Proteins, PLP) and a reduction in macro- and microgliosis (density of ionising adaptor protein, IBA1 & glial fibrillary acid protein, GFAP). Our results confirm the neurotherapeutic efficacy of targeting the H3R for WMI seen in a cuprizone model of multiple sclerosis and a recently reported clinical trial in relapsing-remitting multiple sclerosis patients. Further work is needed to develop a slow release strategy for this agent and test its efficacy in large animal models of preterm infant WMI.

New Evidence to Support Antibiotic Prophylaxis in Meconium-Stained Amniotic Fluid in Low-Risk Women in Labor a Prospective Cohort Study

Purpose of study

To assess the maternal and perinatal complications associated with meconium-stained amniotic fluid (MSAF) in low-risk women in labor.

Methods

This prospective cohort study was conducted at CMC Hospital, Vellore, India. Two hundred low-risk women who had artificial or spontaneous rupture of membranes after admission with MSAF were included in the study. Two hundred similar women with clear liquor were taken as controls. The primary outcomes considered were the incidence of chorioamnionitis and endomyometritis in the mothers. The secondary outcomes included postpartum hemorrhage and retained placenta in the mothers and respiratory distress, meconium aspiration, sepsis, and NICU admission in the newborn. Statistical analysis was done using Fischer exact test. Odds ratio, 95% confidence interval, and P value were estimated.

Results

Compared to controls, those with MSAF had significantly higher rates of chorioamnionitis (2 vs. 8%, P = 0.006) and endomyometritis (3 vs. 9.5% P = 0.007). Among the secondary end points, only neonatal respiratory distress (8.5 vs. 1.5%; P = 0.001) and meconium aspiration (4 vs. 0%; P = 0.007) were found to be significantly increased in the meconium group.

Conclusion

Statistically significant increased incidence of chorioamnionitis and endomyometritis in women with MSAF in labor established in our study strongly supports the use of prophylactic antibiotics in these women to prevent immediate and long-term consequences.

Amniotic fluid rapid biomarkers are associated with intra-amniotic infection in preterm pregnancies regardless of the membrane status

OBJECTIVE

The objective of this study was to evaluate the association of amniotic fluid lactate dehydrogenase and glucose concentrations with microbial invasion of amniotic cavity and histologic chorioamnionitis before 37 pregnancy weeks in women with or without preterm premature rupture of membranes.

STUDY DESIGN

Amniocentesis was performed on 70 women with suspected intra-amniotic infection. Standard biochemical methods, molecular microbiology and culture techniques were used. Histopathological examination of the placenta was performed.

RESULTS

Thirty (48%) women had microbial invasion of the amniotic cavity (MIAC), 53 (76%) women had histological chorioamnionitis and 28 women had both. The cutoff values for MIAC and histological chorioamnionitis were 429 IU l(-1) for lactate dehydrogenase and 0.7 mmol l(-1) for glucose. Both end points occurred equally often regardless of the membrane status.

CONCLUSION

Increased amniotic fluid lactate dehydrogenase and decreased glucose were associated with MIAC and histological chorioamnionitis. However, test performance was of limited value.

Related factors and adverse neonatal outcomes in women with preterm premature rupture of membranes complicated by histologic chorioamnionitis

Background

The aim of this study was to identify factors predicting histologic chorioamnionitis (HCA) in women with preterm premature rupture of membranes (PPROM).

Material/Methods

We retrospectively enrolled 371 women diagnosed with PPROM at less than 34 weeks of gestation at the Second Affiliated Hospital of Wenzhou Medical University between January 2008 and December 2012. HCA was diagnosed by placental histopathology in 70% of participants. Binary logistic regression was used to identify factors associated with HCA and neonatal outcomes.

Results

Patient age, rate of parity, tocolysis, cesarean section, serum C reactive protein (CRP) level at admission, white blood cell count, and latency duration did not significantly differ between the 2 groups. Binary logistic regression revealed that oligohydramnios at admission, gestational age at PPROM, and serum CRP >8 mg/L before delivery were significantly associated with HCA. Gestational age at delivery and birth weight were significantly lower in HCA patients than control patients. The rate of 1-min Apgar score <7, abnormal neonatal intracranial ultrasound findings, neonatal pneumonia, bronchopulmonary dysplasia, early-onset neonatal sepsis, and mortality were higher in HCA patients, but no significant difference was observed in the incidence of neonatal respiratory distress syndrome, necrotizing enterocolitis, hyperbilirubinemia, or hypoglycemia.

Conclusions

Younger gestational age at time of PPROM, higher CRP level before delivery, and oligohydramnios at admission in women with PPROM are associated with HCA, and HCA is associated with some adverse neonatal outcomes.

Chorioamnionitis (ChA) modifies CX3CL1 (fractalkine) production by human amniotic epithelial cells (HAEC) under normoxic and hypoxic conditions

Background

Chemokine CX3CL1 possesses unique properties, including combined adhesive and chemotactic functions. Human amniotic epithelial cells (HAEC) show expression of CX3CL1 receptor (CX3CR1) and produce CX3CL1 in response to both physiologic and pathologic stimuli. Chorioamnionitis (ChA) is a common complication of pregnancy and labour. ChA is often accompanied by local hypoxia because of the high oxygen consumption at the site of inflammation. We examined comparatively (ChA-complicated vs. normal pregnancy) CX3CR1 expression and the effects of hypoxia, lipopolysaccharide (LPS), and CX3CR1 blockade on CX3CL1 production in HAEC cultured in vitro.

Methods

HAEC have been isolated using trypsinization, and cultured under normoxia (20% O₂) vs. hypoxia (5% O₂). According to the experimental design, LPS (1 μg/ml) and neutralizing anti-CX3CR1 antibodies were added at respective time points. Mean CX3CL1 concentration in the supernatant samples were determined by ELISA. Expression of immunostained CX3CR1 was analyzed using quantitative morphometry.

Results

We have found that the mean levels of CX3CL1 and CX3CR1 expression were remarkably (p < 0.05) higher in ChA, compared to normal pregnancy. Significantly increased expression of CX3CR1 was observed in ChA during both normoxia and hypoxia. Hypoxia exposure produced decrease in the mean concentration of CX3CL1 in both groups, however this reduction was stronger in normal pregnancy. In normoxia, LPS-evoked rise in the mean concentration of CX3CL1 was higher (p < 0.05) in normal pregnancy. This response was positively correlated with CX3CR1 expression. Blockade of CX3CR1 canceled the secretory response to LPS in all groups.

Conclusions

ChA-complicated pregnancy up-regulates CX3CR1 in HAEC cultured in vitro with simultaneous increase in CX3CL1 production. Hypoxia-resistant production of CX3CL1 may be responsible for ChA-related complications of pregnancy and labor.

Failure of thyroid hormone treatment to prevent inflammation-induced white matter injury in the immature brain

Preterm birth is very strongly associated with maternal/foetal inflammation and leads to permanent neurological deficits. These deficits correlate with the severity of white matter injury, including maturational arrest of oligodendrocytes and hypomyelination. Preterm birth and exposure to inflammation causes hypothyroxinemia. As such, supplementation with thyroxine (T4) seems a good candidate therapy for reducing white matter damage in preterm infants as oligodendrocyte maturation and myelination is regulated by thyroid hormones. We report on a model of preterm inflammation-induced white matter damage, in which induction of systemic inflammation by exposure from P1 to P5 to interleukin-1β (IL-1β) causes oligodendrocyte maturational arrest and hypomyelination. This model identified transient hypothyroidism and wide-ranging dysfunction in thyroid hormone signalling pathways. To test whether a clinically relevant dose of T4 could reduce inflammation-induced white matter damage we concurrently treated mice exposed to IL-1β from P1 to P5 with T4 (20 μg/kg/day). At P10, we isolated O4-positive pre-oligodendrocytes and gene expression analysis revealed that T4 treatment did not recover the IL-1β-induced blockade of oligodendrocyte maturation. Moreover, at P10 and P30 immunohistochemistry for markers of oligodendrocyte lineage (NG2, PDGFRα and APC) and myelin (MBP) similarly indicated that T4 treatment did not recover IL-1β-induced deficits in the white matter. In summary, in this model of preterm inflammation-induced white matter injury, a clinical dose of T4 had no therapeutic efficacy. We suggest that additional pre-clinical trials with T4 covering the breadth and scope of causes and outcomes of perinatal brain injury are required before we can correctly evaluate clinical trials data and understand the potential for thyroid hormone as a widely implementable clinical therapy.

Placental macrophages are impaired in chorioamnionitis, an infectious pathology of the placenta

Pregnancy is dependent on maternal-fetal tolerance that may be compromised because of infections or inflammation of the placenta. In this study, we examined whether the context of placental immune tolerance affected the functions of resident macrophages and if their functions were altered during chorioamnionitis, an infectious pathology of the placenta. Macrophages from at-term placentas expressed CD14, exhibited macrophage microbicidal functions, but were less inflammatory than monocyte-derived macrophages. Moreover, placental macrophages spontaneously matured into multinucleated giant cells (MGCs), a property not exhibited by monocyte-derived macrophages, and we detected MGCs of myeloid origin in placental tissue. Compared with placental macrophages, MGCs exhibited a specific phenotype and gene expression signature, consisting of increased cytoskeleton-associated gene expression along with depressed expression of inflammatory response genes. Furthermore, placental macrophages from patients with chorioamnionitis were unable to form MGCs, but this defect was partially corrected by incubating these placental macrophages with control trophoblast supernatants. MGCs formation likely serves to regulate their inflammatory and cytocidal activities in a context that imposes semiallograft acceptance and defense against pathogens.

Development of monocyte Toll-like receptor 2 and Toll-like receptor 4 in preterm newborns during the first few months of life

BACKGROUND

Although the immaturity of Toll-like receptor 2 (TLR2) and Toll-like receptor 4 (TLR4) at birth in preterm newborns is known, their development during the first few months of life remains unclear.

METHODS

Blood monocytes of preterm newborns (gestational age: 24-36 wk) were obtained every 2 wk when possible in order to perform serial measurements of TLR2 and TLR4 surface expression, as well as lipopolysaccharide (LPS)-induced cytokine production. Measurements using monocytes from term newborns and adults were also performed.

RESULTS

The monocytes of preterm newborns obtained at birth displayed reduced surface expression of TLR2 and TLR4, and diminished responses of tumor necrosis factor-α (TNF-α) and interleukin (IL)-8 to LPS stimulation. Regardless of gestational age, monocyte expression of TLR2 and TLR4 in preterm newborns increased rapidly within the first 2 wk after birth, quickly reaching those of term newborns. These increases continued for the following 4-6 wk, although the increase began to plateau. By contrast, LPS-induced production of TNF-α and IL-8 did not elevate over this period in preterm newborns.

CONCLUSION

The blood monocytes of preterm newborns display rapid increase in TLR2 and TLR4 expression during the first few months of life, whereas LPS-induced cytokine production functionality did not improve in parallel.

Bleeding per vaginam is associated with funisitis in women with preterm prelabour rupture of the fetal membranes

OBJECTIVE

To evaluate the risk of funisitis among women with preterm prelabour rupture of the membranes (PPROM) and subsequent bleeding per vaginam.

DESIGN

Prospective cohort study.

SETTING

A University Hospital in the USA.

POPULATION

A total of 157 women with PPROM, divided into those with bleeding per vaginam during the hospital admission (n = 46) and those without bleeding per vaginam (n = 111).

METHODS

Pathologist blinded to bleeding status assessed placental pathology for funisitis.

MAIN OUTCOME MEASURES

Funisitis.

RESULTS

Women with bleeding per vaginam were more likely to have funisitis (67.4% versus 36%, P < 0.001) compared with those without bleeding. Logistic regression demonstrated that bleeding per vaginam predicted funisitis after controlling for gestational age at admission, latency period and gestational age at delivery.

CONCLUSIONS

Among women with PPROM, those with bleeding per vaginam are more likely to have funisitis than those without bleeding per vaginam.

HISTOLOGICAL CHORIOAMNIONITIS: CURRENT CONCEPTS OF DIAGNOSIS, CLASSIFICATION AND CLINICAL SIGNIFICANCE

Interest in the clinical associations between maternal intrapartum fever and adverse neonatal outcome has been longstanding, with publications of a relationship between maternal fever and cerebral palsy dating from the 1950s. Further recognition of the associations between either clinically or histologically characterised chorioamnionitis, ascending infection and neonatal wellbeing followed, with numerous reports in the 1960s and 70s, particularly as the neonatal significance of group B streptococcal infections became apparent. Similarly, with the systematic introduction of diagnostic light microscopy into clinical medicine, chorioamnionitis (inflammation of the placental membranes) and funisitis (inflammation of the umbilical cord) were recognised as distinct histological entities, with increasing recognition that the aetiology was likely to be infective. There are numerous texts discussing in detail the pathogenesis and histological features of chorioamnionitis and funisitis. The aim of this review is to provide an overview of the salient associated issues for clinical practitioners and to highlight areas of ongoing uncertainty and recent developments in understanding.

Diagnosis and management of clinical chorioamnionitis

Chorioamnionitis is a common complication of pregnancy associated with significant maternal, perinatal, and long-term adverse outcomes. Adverse maternal outcomes include postpartum infections and sepsis whereas adverse infant outcomes include stillbirth, premature birth, neonatal sepsis, chronic lung disease, and brain injury leading to cerebral palsy and other neurodevelopmental disabilities. Research in the past 2 decades has expanded understanding of the mechanistic links between intra-amniotic infection and preterm delivery as well as morbidities of preterm and term infants. Recent and ongoing clinical research into better methods for diagnosing, treating, and preventing chorioamnionitis is likely to have a substantial impact on short and long-term outcomes in the neonate.