Chronic Placental Inflammation Research Articles

Inhibition of BCAT1 expression improves recurrent miscarriage by regulating cellular dysfunction and inflammation of trophoblasts.

Sustained or chronic inflammation in the placenta can result in placental insufficiency, leading to adverse reproductive outcomes such as pregnancy loss. Branched-chain amino acid transaminase 1 (BCAT1) expresses in the placenta and is involved in the pathological inflammatory response, but its role in recurrent miscarriage (RM) has not been fully investigated. In the present study, we delved into the effects of BCAT1 on trophoblast inflammation induced by lipopolysaccharide (LPS) and a mouse model of pregnancy loss induced by LPS. In vitro, after the HTR-8/SVneo cells were treated with LPS and BCATc inhibitor 2 (a selective BCAT inhibitor), the cell apoptosis was verified by TUNEL assay, and the activity of caspase-3 and caspase-9 was detected. Real-time PCR, enzyme-linked immunosorbent assay (ELISA), and immunofluorescence (IF) were used to determine the expression of inflammatory cytokines (TNF-α, IL-6, and IL-1β) and inflammasomes (NLRP3 and ASC) in LPS-treated trophoblast cells. Western blot analysis was performed to verify the expression of phospho-IκBα (p-IκBα) in cells and NF-κB p65 in the nuclei. IF staining was used to detect the nuclear translocation of NF-κB p65. The DNA binding activity of NF-κB was detected by an electrophoretic mobility shift assay (EMSA). The results demonstrated that inhibition of BCAT1 reduced trophoblast apoptosis, suppressed the release of proinflammatory cytokines, and prevented NLRP3 inflammasome activation in response to LPS. Additionally, BCAT1 inhibition blocked the activation of the NF-κB pathway in trophoblasts. This study highlights the potential therapeutic role of targeting BCAT1 in preventing adverse reproductive outcomes associated with chronic placental inflammation.

Update on hydroxychloroquine use in pregnancy.

It is well-known that hydroxychloroquine (HCQ) treats malaria, systemic lupus erythematosus, and rheumatoid arthritis in women for its immunomodulatory and anti-inflammatory action. Additionally, HCQ was used in cases with refractory antiphospholipid syndrome. HCQ safety was reinforced in pregnant women owing to insignificant reports of adverse pregnancy outcomes and major congenital malformation. Recently, HCQ was tested in cases with chronic placental inflammation with a promising result of increased life birth; however, its benefit needs further validation. We aimed to highlight the recent updates for HCQ use in various conditions in pregnancy.

PO1_01. Chronic placental inflammation, hypertensive disorders of pregnancy, infant sex and placental and newborn growth at term

PO1_01. Chronic placental inflammation, hypertensive disorders of pregnancy, infant sex and placental and newborn growth at term

Immunosequencing and Profiling of T Cells at the Maternal-Fetal Interface of Women with Preterm Labor and Chronic Chorioamnionitis.

T cells are implicated in the pathophysiology of preterm labor and birth, the leading cause of neonatal morbidity and mortality worldwide. Specifically, maternal decidual T cells infiltrate the chorioamniotic membranes in chronic chorioamnionitis (CCA), a placental lesion considered to reflect maternal anti-fetal rejection, leading to preterm labor and birth. However, the phenotype and TCR repertoire of decidual T cells in women with preterm labor and CCA have not been investigated. In this study, we used phenotyping, TCR sequencing, and functional assays to elucidate the molecular characteristics and Ag specificity of T cells infiltrating the chorioamniotic membranes in women with CCA who underwent term or preterm labor. Phenotyping indicated distinct enrichment of human decidual effector memory T cell subsets in cases of preterm labor with CCA without altered regulatory T cell proportions. TCR sequencing revealed that the T cell repertoire of CCA is characterized by increased TCR richness and decreased clonal expansion in women with preterm labor. We identified 15 clones associated with CCA and compared these against established TCR databases, reporting that infiltrating T cells may possess specificity for maternal and fetal Ags, but not common viral Ags. Functional assays demonstrated that choriodecidual T cells can respond to maternal and fetal Ags. Collectively, our findings provide, to our knowledge, novel insight into the complex processes underlying chronic placental inflammation and further support a role for effector T cells in the mechanisms of disease for preterm labor and birth. Moreover, this work further strengthens the contribution of adaptive immunity to the syndromic nature of preterm labor and birth.

Prepregnancy obesity and risk of placental inflammation at term: a selection bias analysis

Placental histopathology is a resource for investigating obesity-associated pregnancy conditions. However, studies oversample adverse pregnancies, biasing findings. We examine the association between prepregnancy obesity (risk factor for inflammation) and histologic placental inflammation (correlated with impaired infant neurodevelopment) and how selection bias may influence the association. Singleton term deliveries between 2008 and 2012 from the Magee Obstetric Maternal and Infant database were analyzed. Prepregnancy body mass index (BMI) was categorized as underweight, lean (referent), overweight, and obese. Outcomes were diagnoses of acute (acute chorioamnionitis and fetal inflammation) and chronic placental inflammation (chronic villitis). Risk ratios for associations between BMI and placental inflammation were estimated using selection bias approaches: complete case, exclusion of pregnancy complications, multiple imputation, and inverse probability weighting. E-values approximated how susceptible estimates were to residual selection bias. Across methods, obesity was associated with an 8-15% lower risk of acute chorioamnionitis, a 7%-14% lower risk of acute fetal inflammation, and a 12%-30% higher risk of chronic villitis relative to lean women. E-values indicated modest residual selection bias could explain away associations, though few measured indications of placental evaluations met this threshold. Obesity may contribute to placental inflammation, and we highlight robust methods to analyze clinical data susceptible to selection bias.

Placental Findings in Infants Gestational Age < 34 Weeks and Impact on Short-Term Outcomes.

To analyse placental changes in infants' gestational age < 34 weeks and its correlation to short-term respiratory outcomes or death until hospital discharge. Information regarding all in-house born preterm infants born before 34 weeks gestation and born from January 2009 until December 2014 were collected and included among others, placental pathology and relevant data on demographics and outcomes of infants. Placental abnormalities was found in 157/253 (65.05%) cases. Acute placental inflammation was found to be the most common in both groups of premature neonates, followed by maternal vascular underperfusion. Maternal vascular underperfusion was significantly more common in GA ≤ 27 weeks compared to infants GA 28-33 weeks (35.2% vs. 13.7%; p = 0.018). Similarly, chronic placental inflammation was more common in infants GA ≤ 27 weeks compared to infants GA 28-33 weeks (14.3% vs. 3.3%; p = 0.014). Infants with placental pathology had a lower median birth weight (1460g vs. 1754g; p = 0.001, and were of shorter median GA at birth (31 vs. 32; p = 0.001). Infants with any placental disease had higher rates of death until hospital discharge (10.2% vs. 3.1%; p = 0.039) and higher rates of any stage of bronchopulmonary dysplasia (41.4% vs. 26.0%; p = 0.013). There were no significant differences in mechanical ventilation rates, duration of mechanical ventilation and duration of supplemental oxygen therapy. Identifiable placental abnormalities were found in most infants born < 34 weeks gestation. Placental pathology is associated with increased rates of bronchopulmonary dysplasia and death until hospital discharge.

Low first-trimester fetal fraction is associated with chronic inflammation in the placenta

Some data suggest an association between abnormal fetal fraction on noninvasive prenatal screening and adverse pregnancy outcomes, including low birthweight, preeclampsia, and preterm birth in the absence of aneuploidy. These findings suggest that abnormal fetal fraction may be associated with placental pathologic processes in early gestation. This study aimed to determine the independent association of fetal fraction on genetic noninvasive prenatal screening with histologic placental types. This was a retrospective cohort study at a single institution in the period between January 2017 and March 2021, including live births at ≥24 weeks for which noninvasive prenatal screening was performed and placental pathology results were available. Results were stratified by trimester of noninvasive prenatal screening. Clinical characteristics were compared by quartile of fetal fraction using chi-square tests. Linear regression was used to model continuous fetal fraction as a function of 3 histologic types representing chronic placental injury-chronic inflammation, maternal vascular malperfusion, and fetal vascular malperfusion. Inverse probability weighting was used to account for selection bias in characteristics of patients with placental pathology examination. A total of 1374 patients had noninvasive prenatal screening in the first trimester and 262 in the second trimester. Preterm birth and hypertensive disorders of pregnancy were most common in the lowest quartile of fetal fraction. Chronic inflammation was associated with a 0.56 percentage point reduction in fetal fraction (95% confidence interval, -0.95 to -0.16), and maternal vascular malperfusion was associated with a 0.48 percentage point reduction in fetal fraction (95% confidence interval, -0.91 to -0.04) in adjusted models. The association with maternal vascular malperfusion was no longer statistically significant after accounting for selection bias in placentas sent for pathologic examination. Second-trimester fetal fraction was not associated with placental pathology. Chronic inflammation is associated with lower first-trimester fetal fraction even after accounting for selection bias. Higher fetal fraction in the second trimester was associated with fetal vascular pathology, although this association was no longer statistically significant after inverse probability weighting to account for selection bias. First-trimester fetal fraction may be a biomarker of adverse outcomes associated with chronic inflammation.

Placental inflammation and overweight or obesity in term singleton stillbirths in Stockholm County 2002-2018; a case control study.

Stillbirth is a severe pregnancy complication. Maternal obesity is one of the most important modifiable risk factors of stillbirth, yet the biological mechanisms behind this association remain unclear. The adipose tissue is an endocrine organ which, in persons with obesity, causes a hyperinflammatory state. The aim of this study was to investigate inflammation as a contributing mechanism to the risk of stillbirth in women with obesity and if there are possible signs of different BMI phenotypes with different risk. This was a case control study based on all cases of term singleton stillbirth without major fetal malformation in Stockholm County between 2002-2018. Placentas have been examined according to a standardized protocol. Placental inflammatory lesions were compared both between placentas from pregnancies with live born and stillborn infants with different class of body mass index (BMI) as well as among women with stillborn and live born infants with different classes of BMI, respectively. All inflammatory placental lesions were more common in placentas from women with stillbirth compared to placentas from women with live born infants. Vasculitis, funisitis and chronic villitis as well as overall fetal and maternal inflammatory response were present with a significantly increased proportion with increasing BMI in placentas from women with term stillbirth however, there were no differences between placentas from women in different BMI classes with term live born infants. Both acute and chronic inflammatory placental lesions were more common in cases of stillbirth compared to pregnancies with live born infants. There were increased proportions of both acute and chronic placental inflammation (vasculitis, chronic villitis, funisitis and overall fetal and maternal inflammatory response) with increasing BMI among cases with term stillbirth, however no differences among controls with term live born infants.

Association between physical activity level and chronic inflammatory and vascular pathology in the placenta

Chronic placental inflammation (CI) and maternal vascular malperfusion (MVM) are associated with adverse pregnancy outcomes. While regular physical activity is recommended in pregnancy, the association between activity level and placental histology is unknown, and may reflect underlying effects of activity level on pregnancy. The objective of this study is to characterize the association between activity level and placental CI and MVM in obese and non-obese patients.

Placental pathologic lesions associated with stroke in term neonates.

ObjectiveTo determine the birth prevalence of perinatal stroke in term born infants at our high-volume delivery center and assess the frequency of both gross and histologic placental pathologies associated with perinatal stroke using the Amsterdam Placental Workshop Group Consensus Statement guidelines and definitions.Study DesignA single-center retrospective cohort study spanning 2010-2020.ResultsThere were 129,759 live births at Parkland Hospital during the study period and a total of 18 term born infants leading to a birth prevalence of 1 in 6,829 infants. Perinatal risk factors were found in all but one patient, and 74% presented with seizures. Pathologic placental examination was available in 56% of the cohort and only one patient had normal placental examination. Acute histologic chorioamnionitis was described in five placentas (50%) and an additional two had isolated umbilical and/or chorionic plate vasculitis with or without funisitis compared to a rate of 28% with acute inflammation in a Control group. Chronic inflammation in the form of villitis of unknown etiology was described in three of the acutely inflamed placentas and was high-grade in each of those while none of the placentas from our Control group showed evidence of any chronic lesion.ConclusionBoth acute and chronic placental inflammation are common in perinatal stroke; placental examination should be considered an essential component to the diagnostic workup.

A comprehensive analysis of the association between placental pathology and recurrent preterm birth

Histologic examination of the placenta is often performed after preterm birth. Although placental examination cannot change the index pregnancy outcome, it may inform the risk of adverse outcomes in a subsequent pregnancy. Previous research has examined the association between individual histologic lesions and pregnancy outcomes without consistent results. This study aimed to determine the independent contributions of the major placental pathology histologic types to recurrent preterm birth. This was a retrospective cohort study of deliveries at a tertiary care center from January 2009 to March 2018. Individuals with ≥2 births, an index birth of <37 weeks of gestation, and a placental pathology report from the index pregnancy were included. The presence of maternal vascular malperfusion, fetal vascular malperfusion, acute inflammation, and chronic inflammation was extracted from the pathology reports for each index placenta and classified as none, low grade, or high grade. A log-binomial model incorporating all 4 placental pathology histologic types, index gestational age, race, and maternal age was used to estimate the associations between each placental histologic type and risk of recurrent preterm birth. Moreover, 2-way interaction terms were studied among placental histologic types. In addition, 2 stratified analyses were completed on the basis of characteristics of the index preterm birth: (1) by late preterm (gestational age of 34-36 weeks) vs early-to-moderate preterm birth (<34 weeks) and (2) a subgroup analysis of those with spontaneous preterm birth. A total of 924 pregnancy pairs met the inclusion criteria. Only high-grade chronic inflammation was independently associated with an increased risk of recurrent preterm birth (adjusted risk ratio, 1.37; 95% confidence interval, 1.03-1.81). Stratified analysis by gestational age group demonstrated maternal vascular malperfusion was associated with recurrent preterm birth only among those with early preterm birth (adjusted risk ratio, 1.40; 95% confidence interval, 1.01-1.93). Among participants with spontaneous preterm labor, no association was found between pathology histologic types and risk of preterm birth. Among index preterm pregnancies, high-grade chronic placental inflammation was associated with recurrent preterm birth. Low-grade maternal vascular malperfusion was associated with recurrent preterm birth only among those with an early or moderate index preterm birth (<34 weeks of gestation). These findings may be useful in determining the risk profile for individual patients and may generate hypotheses as to the pathogenesis of recurrent preterm birth.

The Potential Benefit of Hydroxychloroquine in Chronic Placental Inflammation of Unknown Etiology Associated with Adverse Pregnancy Outcomes.

The placenta is the site of connection between maternal and fetal circulation, and the liaison is established early in pregnancy. A large variety of pregnancy complications such as preterm birth, fetal growth restriction, or pregnancy loss have placental expression and can be accompanied in some cases of acute or chronic identifiable placental inflamatory lesions. Chronic placental inflammatory (CPI) lesions include chronic villitis of unknow etiology (CVUE), chronic intervillositis of unknown etiology, CIUE (also described as chronic histiocytic intervillositis, CHI), and chronic deciduits. Hydroxychloroquine (HCQ) has been prescribed with good results during pregnancy to prevent adverse perinatal outcomes in maternal autoimmune conditions. Its success has paved the way to its use in CPI as CIUE/CHI; however, to date, there are no prospective, informatively designed, controlled studies on its value in these setting. This review aims to explore the potential role of HCQ in CPI of unknown etiology. Ideally, properly designed, probably multicentric studies should be undertaken to fully understand HCQ’s role for prevention of adverse pregnancy outcomes after a chronic placental inflammation.

Distinctive Neuroimaging Pattern in Term Newborns With Neonatal Placental Encephalopathy: A Case Series

BackgroundIdentifying antepartum versus intrapartum timing and the cause of neonatal encephalopathy (NE) often remains elusive owing to our limited understanding of the underlying pathophysiological processes and lack of appropriate biomarkers. ObjectivesThis retrospective observational study describes a case series of term newborns with NE who displayed a recognizable magnetic resonance imaging pattern of immediately postnatal brain abnormalities that rapidly evolved toward cavitation. Our aim is to (1) report this neuroimaging pattern, (2) look for placental determinants, and (3) depict the outcome. Design/MethodsThis is a unicentric retrospective case series reporting the clinical, radiological, and laboratory findings of NE associated with a distinctive neuroimaging pattern, that is, immediately postnatal extensive corticosubcortical T2 hyperintensities, followed by rapid corticosubcortical cavitation that does not match the neuroimaging picture of intrapartum hypoxic-ischemic encephalopathy (HIE). ResultsSeven term newborns presented bilateral corticosubcortical hyperintensities that were detected on T2 between day of life (DOL) 1-4, which rapidly evolved toward cystic encephalomalacia, that is, between DOL9 and DOL12. All these newborns presented with moderate/severe NE. The outcome was either neonatal death or quadriplegic cerebral palsy and epilepsy. None of the reported patients fulfilled the criteria of a high likelihood of acute intrapartum hypoxic-ischemic or quadriplegic cerebral palsy. All these newborns were exposed to chronic and/or acute placental inflammation and/or hypoxic-ischemic. ConclusionsTo further define the antepartum causes of NE, early neuroimaging and a placental examination are recommended. Brain T2 hyperintense injuries before DOL4 followed by rapid cavitation before DOL12 might be biomarkers of NE from an antepartum/placental origin.

Platelet alloimmunization is associated with low grade chronic histiocytic intervillositis - A new link to a rare placental lesion?

IntroductionMaternal alloimmunization against human platelet antigen (HPA)-1a has been implied to mediate both reduced birth weight and chronic placental inflammation. Fetal growth restriction is associated with different types of chronic inflammation in the placenta, mainly chronic histiocytic intervillositis and chronic villitis. The aim of this prospective study was to do a systematic examination of placentas from HPA-1a alloimmunized pregnancies, with focus on the histopathological and immunohistochemical diagnosis of variants of chronic inflammation. Material and methodsIn a Polish-Norwegian study, 48 placentas were examined. The histopathology of placentas from 27 HPA-1a immunized women was compared with 21 placentas from non-immunized HPA-1a negative women (controls). In the group of alloimmunized women, ten received antenatal intravenous immunoglobulin G (IVIg). Tissue sections from formalin fixed paraffin embedded placental tissue were stained with hematoxylin and eosin and microscopically examined with focus on various types of chronic placental inflammations. ResultsChronic histiocytic intervillositis was observed in 40.7% of placentas from HPA-1a alloimmunized pregnancies, compared to none in the control group (p ​= ​0.001). Chronic villitis of unknown etiology was more frequently found in the alloimmunized group, however this difference was not statistically significant. Maternal administration of IVIg did not seem to protect against chronic inflammatory lesions. DiscussionPlacentas with detectable maternal anti-HPA-1a antibodies are associated with highly increased risk of low-grade chronic histiocytic intervillositis.

Adverse Pregnancy Outcomes Following the Assassination of John F. Kennedy in 1963.

Women exposed to stressful events during pregnancy are thought to be at increased risk of adverse birth outcomes. However, studies investigating stressful events are often unable to control for important confounders, such as behavioral and genetic characteristics, or to isolate the impact of the stressor from other secondary effects. We used a discordant-sibling design, which provides stronger inferences about causality, to examine whether a widespread stressor with limited impact on day-to-day life (John F. Kennedy assassination) resulted in an increased risk of adverse birth outcomes. Data were obtained from the Collaborative Perinatal Project, a prospective, multi-site cohort study conducted in the US from 1959 to 1965. Our analysis was restricted to singleton live births ≥24weeks born before the assassination (n = 24,406) or in utero at the time (n = 5833). We also evaluated associations within siblings discordant for exposure (n = 1144). We used survival analysis to evaluate associations between exposure and preterm birth and marginal models to evaluate associations with birthweight and placental pathology. First trimester exposure was associated with preterm birth (hazard ratio (HR): 1.17; 95% CI: 1.05, 1.31). In the discordant-sibling model, the point estimate was similar (HR: 1.22; 95% CI: 0.36, 4.06). Third trimester exposure was associated with increased odds of fetal acute inflammation in the placenta (odds ratio (OR): 1.34, 95% CI: 1.05, 1.71). First trimester exposure to an acute stressor was associated with preterm birth. We did not observe increased odds of placental pathology with first trimester exposure; however, stress may increase preterm birth risk through chronic placental inflammation, which was not evaluated in this sample.

337 High grade chronic placental inflammation is independently associated with increased risk of recurrent preterm birth

Histologic examination of the placenta is often performed following delivery. Although placental examination cannot change the index pregnancy outcome, it may inform risk assessment for subsequent pregnancy. Prior research has examined the association between individual histologic lesions and pregnancy outcomes. The purpose of this study is to determine the association of combinations of histologic findings and risk of subsequent preterm birth (PTB). This was a retrospective cohort study of deliveries at a tertiary care center from January 2009 to March 2018. Individuals with two births and an index placental pathology report during the study period were included. The presence of maternal vascular malperfusion (MVM), fetal vascular malperfusion (FVM), maternal and/or fetal acute inflammation (AI) and chronic inflammation (CI) was extracted from the pathology report for each index placenta, classified as none, low, or high grade. A logistic model incorporating all four placental components was used to estimate associations between each histologic lesion category and risk of subsequent preterm birth, while controlling for the other lesion categories. Analysis was repeated restricting the sample only to those with an index PTB. 3926 women were included. Among all index pregnancies, presence of high grade CI and low grade MVM were associated with increased odds of subsequent PTB. AI (both low- and high-grade) and low grade FVM were associated with lower odds of subsequent PTB (Table). Among 924 index pregnancies delivering preterm, only high grade CI was independently associated with recurrent PTB (OR 1.57, 95% CI 1.02- 2.41, Figure). High-grade chronic placental inflammation in an index pregnancy is the only pathology independently associated with an increased risk of subsequent PTB, regardless of whether the index delivery is preterm or term. Decreased odds of PTB with AI and FVM in the full sample were not replicated when evaluating recurrent PTB.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Brief Report: Chronic Placental Inflammation Among Women Living With HIV in Uganda.

HIV-exposed, uninfected (HEU) children have poorer early-life outcomes than HIV-unexposed children. The determinants of adverse health outcomes among HEU children are poorly understood but may result from chronic placental inflammation (CPI). We enrolled 176 pregnant women living with HIV (WLWH) taking antiretroviral therapy in southwestern Uganda and 176 HIV-uninfected women to compare CPI prevalence by maternal HIV serostatus. Placentas were evaluated histologically by an expert pathologist for presence of CPI, defined as chronic chorioamnionitis, plasma cell deciduitis, villitis of unknown etiology, or chronic histiocytic intervillositis. Placentas with CPI were additionally immunostained with CD3 (T cell), CD20 (B cell), and CD68 (macrophage) markers to characterize inflammatory cell profiles. WLWH and HIV-uninfected women had similar age, parity, and gestational age. Among WLWH, the mean CD4 count was 480 cells/µL, and 74% had an undetectable HIV viral load. We detected CPI in 16 (9%) placentas from WLWH and 24 (14%) from HIV-uninfected women (P = 0.18). Among WLWH, CPI was not associated with the CD4 count or HIV viral load. Villitis of unknown etiology was twice as common among HIV-uninfected women than WLWH (10 vs. 5%, P = 0.04). Among placentas with CPI, more villous inflammatory cells stained for CD3 or CD68 among HIV-uninfected women than WLWH (79% vs. 46%, P = 0.07). CPI prevalence did not differ by HIV serostatus. T-cell (CD3) and macrophage (CD68) markers were more prevalent in placental inflammatory cells from HIV-uninfected women. Our results do not support CPI as a leading mechanism for poor outcomes among HEU children in the antiretroviral therapy era.

Population-based study of serum ferritin in early pregnancy and adverse perinatal outcomes.

Chronic placental inflammation is associated with preterm birth (PTB) and perinatal mortality. Ferritin is often elevated in chronic inflammatory conditions, but prior studies of its relation to PTB were restricted to ferritin measurement within pregnancy, were underpowered to detect rarer outcomes, and did not account for pre-existing maternal inflammatory conditions, such as inflammatory bowel or rheumatological disease. To evaluate whether an elevated ferritin level prior to pregnancy is associated with major adverse pregnancy outcomes. A population-based cohort study was completed using Ontario, Canada. Included were all Ontarian women with a hospital livebirth or stillbirth at ≥20weeks' gestation, 2007-2018, and serum haemoglobin and ferritin measured as an outpatient within 120days before conception. Excluded were women with a diagnosed iron overload disorder or a ferritin concentration <15µg/L. The main exposure was a pre-pregnancy serum ferritin ≥95th percentile. Study outcomes included PTB<37weeks' gestation, including clinician-initiated and spontaneous PTB; PTB<32weeks; chorioamnionitis; and perinatal death. Relative risks (RR) and 95% confidence intervals (CI) were calculated for each study outcome, comparing a serum ferritin concentration ≥95th vs <5th percentile (the referent), while adjusting maternal age, residence, haemoglobin concentration, diabetes mellitus, inflammatory bowel disease, illicit drug/tobacco use, chronic kidney disease, chronic hypertension, sickle-cell disease or thalassaemia, and rheumatological conditions. Among 89847 births, a preconceptional maternal serum ferritin ≥95th (112.0μg/L) vs <5th (16.9μg/L) percentile was associated with an adjusted relative risk (aRR) of 1.34 (95% CI 1.15, 1.57) for PTB, including spontaneous and clinician-initiated PTB. Results were equivocal for chorioamnionitis (aRR 1.23, 95% CI 0.81, 1.86), and there was no association with perinatal mortality (aRR 0.94, 95% CI 0.55, 1.61). A high preconceptional ferritin concentration is associated with some adverse perinatal outcomes.

Fetal cord blood and tissue immune responses to chronic placental inflammation and chorioamnionitis

BackgroundChorioamnionitis is a risk factor for future asthma development. Animal models of chorioamnionitis demonstrate increased TH17-to-Treg ratios associated with proinflammatory cytokine elevations. The association of chorioamnionitis on human neonatal immune cells systemically and within tissues is not known.MethodsWe enrolled two cohorts to evaluate TH17 and regulatory T cell (Treg) phenotypic markers in chorioamnionitis. From a cohort of 19 live birth infants, we collected cord blood and placenta samples to evaluate for signs of acute and chronic histologic inflammation and cell phenotype characterization. We analyzed a second cohort of stillborn infants with and without chorioamnionitis to classify and enumerate cell infiltrate phenotypes in the spleen, thymus, and lung. We used linear regression analysis determine the association of retinoic acid-related orphan receptor gamma t positive (RORγt+) and Treg cell frequency with different types of inflammation seen in the live cohort subjects. Using linear mixed models, we evaluated for any associations between chorioamnionitis and T- and B-cell with a logarithmic scale for level of expression of cellular markers. We then performed Wilcoxon rank sum tests to assess the associations between cell count and chorioamnionitis.ResultsIn the live birth subjects with chronic placental inflammation we observed an increased proportion of RORγt+ cells in Foxp3+ cells, regardless of the presence of acute inflammation, compared to subjects with neither acute nor chronic inflammation. We also found an increased proportion of RORγt+ cells within Foxp3+ cells in subjects with acute high stage fetal and maternal inflammation compared to those without acute or chronic inflammation. In the stillborn subjects with chorioamnionitis, we observed a decrease in splenic Foxp3+ cells and an increase in lung CD3+ cells compared with subjects that did not have chorioamnionitis.ConclusionExposure to chorioamnionitis in utero may affect immune activation in neonates with an increased frequency of RORγt+ cells systemically as well as lymphocytic infiltrate in the lung. Our findings suggest an increase in RORγt+ cells during chorioamnionitis and thus may support the known associations between chorioamnionitis with asthma.

The frequency and type of placental histologic lesions in term pregnancies with normal outcome.

Objective To determine the frequency and type of histopathologic lesions in placentas delivered by women with a normal pregnancy outcome. Methods This retrospective cohort study included placental samples from 944 women with a singleton gestation who delivered at term without obstetrical complications. Placental lesions were classified into the following four categories as defined by the Society for Pediatric Pathology and by our unit: (1) acute placental inflammation, (2) chronic placental inflammation, (3) maternal vascular malperfusion and (4) fetal vascular malperfusion. Results (1) Seventy-eight percent of the placentas had lesions consistent with inflammatory or vascular lesions; (2) acute inflammatory lesions were the most prevalent, observed in 42.3% of the placentas, but only 1.0% of the lesions were severe; (3) acute inflammatory lesions were more common in the placentas of women with labor than in those without labor; (4) chronic inflammatory lesions of the placenta were present in 29.9%; and (5) maternal and fetal vascular lesions of malperfusion were detected in 35.7% and 19.7%, respectively. Two or more lesions with maternal or fetal vascular features consistent with malperfusion (high-burden lesions) were present in 7.4% and 0.7%, respectively. Conclusion Most placentas had lesions consistent with inflammatory or vascular lesions, but severe and/or high-burden lesions were infrequent. Mild placental lesions may be interpreted either as acute changes associated with parturition or as representative of a subclinical pathological process (intra-amniotic infection or sterile intra-amniotic inflammation) that did not affect the clinical course of pregnancy.