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.

The interplay of inflammation and placenta in maternal diabetes: insights into Hofbauer cell expression patterns

Introduction

Inflammation of the placenta is harmful to both the fetus and the mother. Inflammation is strongly associated with diabetes, a common complication of pregnancy. Hofbauer cells (HBCs), unique immune system cells of fetal origin in the placenta, play complex roles, including growth of placental villi and their branching, stromal remodelling, and angiogenesis.

Methods

Our study investigated the expression of IL-1β, IL-10, CYP2C8, CYP2C9, CYP2J2 and sEH in HBCs from patients with type 1 diabetes mellitus (T1DM) and gestational diabetes mellitus (GDM) compared to healthy controls using immunohistochemistry. We also assessed the structure of the villus stroma using Masson´s trichrome.

Results

In T1DM, HBCs showed inflammatory activation characterised by increased IL-1β and decreased CYP epoxygenase expression compared to normal placentas. Conversely, significant inflammation in HBCs appeared less likely in GDM, as levels of IL-1β and CYP epoxygenases remained stable compared to normal placentas. However, GDM showed a significant increase in sEH expression. Both types of diabetes showed delayed placental villous maturation and hypovascularisation, with GDM showing a more pronounced effect.

Conclusion

The expression profiles of IL-1β, CYP epoxygenases and sEH significantlly differ between controls and diabetic placentas and between T1DM and GDM. These facts suggest an association of the CYP epoxygenase-EETs-sEH axis with IL-1β expression as well as villous stromal hypovascularisation. Given the stable high expression of IL-10 in both controls and both types of diabetes, it appears that immune tolerance is maintained in HBCs.

c-Myc Drives inflammation of the maternal-fetal interface, and neonatal lung remodeling induced by intra-amniotic inflammation

Background: Intra-amniotic inflammation (IAI) is associated with increased risk of preterm birth and bronchopulmonary dysplasia (BPD), but the mechanisms by which IAI leads to preterm birth and BPD are poorly understood, and there are no effective therapies for preterm birth and BPD. The transcription factor c-Myc regulates various biological processes like cell growth, apoptosis, and inflammation. We hypothesized that c-Myc modulates inflammation at the maternal-fetal interface, and neonatal lung remodeling. The objectives of our study were 1) to determine the kinetics of c-Myc in the placenta, fetal membranes and neonatal lungs exposed to IAI, and 2) to determine the role of c-Myc in modulating inflammation at the maternal-fetal interface, and neonatal lung remodeling induced by IAI. Methods: Pregnant Sprague-Dawley rats were randomized into three groups: 1) Intra-amniotic saline injections only (control), 2) Intra-amniotic lipopolysaccharide (LPS) injections only, and 3) Intra-amniotic LPS injections with c-Myc inhibitor 10058-F4. c-Myc expression, markers of inflammation, angiogenesis, immunohistochemistry, and transcriptomic analyses were performed on placenta and fetal membranes, and neonatal lungs to determine kinetics of c-Myc expression in response to IAI, and effects of prenatal systemic c-Myc inhibition on lung remodeling at postnatal day 14. Results: c-Myc was upregulated in the placenta, fetal membranes, and neonatal lungs exposed to IAI. IAI caused neutrophil infiltration and neutrophil extracellular trap (NET) formation in the placenta and fetal membranes, and neonatal lung remodeling with pulmonary hypertension consistent with a BPD phenotype. Prenatal inhibition of c-Myc with 10058-F4 in IAI decreased neutrophil infiltration and NET formation, and improved neonatal lung remodeling induced by LPS, with improved alveolarization, increased angiogenesis, and decreased pulmonary vascular remodeling. Discussion: In a rat model of IAI, c-Myc regulates neutrophil recruitment and NET formation in the placenta and fetal membranes. c-Myc also participates in neonatal lung remodeling induced by IAI. Further studies are needed to investigate c-Myc as a potential therapeutic target for IAI and IAI-associated BPD.

Liposome-Encapsulated Anti-inflammatory Proteins for Targeted Delivery to the Placenta to Treat Fetal Growth Restriction

Fetal growth restriction (FGR), the failure of a fetus to reach its genetically determined growth potential, is a serious complication affecting up to 10% of pregnancies. FGR is a major risk factor for stillbirth and, in the survivors, neurodevelopmental disorders. We have recently identified that the anti-inflammatory and pro-resolving molecule, lipoxin A4 (LXA4) and its soluble receptor, formyl-peptide receptor-2 (FPR-2) are significantly decreased in human placentas from FGR pregnancy. The LXA4 synthetic analog Compound 43 (C43) is considered a safe, anti-inflammatory therapy and is being developed as a treatment for disease conditions with an inflammatory basis, for example, asthma in children. Identification of therapies to treat FGR in utero comes with the need to mitigate their potential side effects and the use of nanoparticle-mediated delivery systems could facilitate this. Our current studies are focused on targeting the resolution of inflammation observed in FGR placentas, by synthesizing liposome-encapsulated C43 as a novel therapeutic to improve placental function in FGR. In this chapter, we provide a detailed methodological procedure for the preparation of liposomes and conjugation of the peptide sequences, which selectively bind to the outer placental syncytiotrophoblast layer or the vascular endothelium of the uterine spiral arterioles.

Bioinformatics Prediction and Experimental Validation of the Role of Macrophage Polarization and Ferroptosis in Gestational Diabetes Mellitus

Purpose

Gestational diabetes mellitus (GDM) is a common metabolic disorder during pregnancy that is associated with placental inflammation and adverse pregnancy outcomes. However, the mechanisms of inflammation in GDM are still unclear.

Methods

Bulk transcriptome, single-cell transcriptome, clinical information, and samples were collected from GSE154414, GSE70493, GSE173193 and a retrospective cohort. Bioinformatics prediction was used to explore the mechanisms of placental inflammation, and multiplex immunofluorescence was used to validate the results.

Results

First, we found that GDM is characterized by low-grade inflammation and is linked to several adverse pregnancy outcomes, as supported by our collected clinical data. Additionally, we identified ten hub genes (FCGR3B, CXCR1, MMP9, ITGAX, CCL5, GZMB, S100A8, LCN2, TGFB1, and LTF) as potential therapy targets and confirmed the binding of corresponding predictive therapeutic agents by molecular docking. Transcriptome sequencing analysis has shown that macrophages are primarily responsible for the emergence of placental inflammation, and that M1 macrophage polarization increased while M2 macrophage polarization decreased in GDM when compared to the control sample. Multiplex immunofluorescence staining of CD68, CD80, and ACSL4 was performed and suggested that ferroptosis of macrophages may contribute to placental inflammation in GDM.

Conclusion

In conclusion, our findings provide a better understanding of the mechanisms of inflammation in GDM and suggest potential therapeutic targets for this condition.

Inflammatory markers in serum and placenta in a randomized controlled trial of group prenatal care

BACKGROUND

Racial and socioeconomic disparities in preterm birth and small for gestational age births are growing in the United States, increasing the burden of morbidity and mortality particularly among Black women and birthing persons and their infants. Group prenatal care is one of the only interventions to show potential to reduce the disparity, but the mechanism is unclear.

OBJECTIVE

The goal of this project was to identify if group prenatal care, when compared with individual prenatal care, was associated with a reduction in systemic inflammation during pregnancy and a lower prevalence of inflammatory lesions in the placenta at delivery.

STUDY DESIGN

The Psychosocial Intervention and Inflammation in Centering Study was a prospective cohort study that exclusively enrolled participants from a large randomized controlled trial of group prenatal care (the Cradle study, R01HD082311, ClinicalTrials.gov: NCT02640638) that was performed at a single site in Greenville, South Carolina, from 2016 to 2020. In the Cradle study, patients were randomized to either group prenatal care or individual prenatal care, and survey data were collected during the second and third trimesters. The Psychosocial Intervention and Inflammation in Centering Study cohort additionally provided serum samples at these 2 survey time points and permitted collection of placental biopsies for inflammatory and histologic analysis, respectively. We examined associations between group prenatal care treatment and a composite of z scored serum inflammatory biomarkers (C-reactive protein, interleukin-6, interleukin-1 receptor antagonist, interleukin-10, and tumor necrosis factor α) in both the second and third trimesters and the association with the prevalence of acute and chronic maternal placental inflammatory lesions. Analyses were conducted using the intent to treat principle, and the results were also examined by attendance of visits in the assigned treatment group (modified intent to treat and median or more number of visits) and were stratified by race and ethnicity.

RESULTS

A total of 1256 of 1375 (92%) Cradle participants who were approached enrolled in the Psychosocial Intervention and Inflammation in Centering Study, which included 54% of all the Cradle participants. The Psychosocial Intervention and Inflammation in Centering Study cohort did not differ from the Cradle cohort by demographic or clinical characteristics. Among the 1256 Psychosocial Intervention and Inflammation in Centering Study participants, 1133 (89.6%) had placental data available for analysis. Among those, 549 were assigned to group prenatal care and 584 of 1133 were assigned to individual prenatal care. In the intent to treat and modified intent to treat cohorts, participation in group prenatal care was associated with a higher serum inflammatory score, but it was not associated with an increased prevalence of placental inflammatory lesions. In the stratified analyses, group prenatal care was associated with a higher second trimester inflammatory biomarker composite (modified intent to treat: B=1.17; P=.02; and median or more visits: B=1.24; P=.05) among Hispanic or Latine participants.

CONCLUSION

Unexpectedly, group prenatal care was associated with higher maternal serum inflammation during pregnancy, especially among Hispanic or Latine participants.

Placental inflammation and pregnancy outcomes: A prospective, observational study in South Asia: The PURPOSe study

OBJECTIVE

To examine inflammatory lesions in placentas of stillbirths, preterm neonatal deaths and term controls in India and Pakistan.

DESIGN

Prospective, observational study.

SETTING

Three hospitals in India and a large maternity hospital in Pakistan.

POPULATION

The enrolled participants with placentas available for histology evaluation included stillbirths (n = 814), preterm live births who died within 28 days of birth (n = 618) and term live birth controls (n = 201). From this same population, polymerase chain reaction (PCR) analysis for pathogens was performed on 809 stillbirth placentas, 614 neonatal death placentas and the placentas of 201 term controls. Placentas from preterm infants who lived beyond day 28 (n = 1432) were only available from India.

METHODS

A prospective observational study of placental inflammatory lesions defined by the Amsterdam criteria and on the same placentas, multiplex PCR evaluation for 75 pathogens using TaqMan Array Cards.

MAIN OUTCOME MEASURES

Any placental inflammatory lesions, including chorioamnionitis, funisitis, villitis and intervillitis and their association with various pathogens.

RESULTS

In the Indian liveborn preterm infants, placental inflammation of any kind was present in 26.2% of those who died versus 16.6% of those who lived (p = 0.0002). Chorioamnionitis was present in 25.8% of those who died versus 16.3% of those who lived (p = 0.0002) and funisitis was present in 4.1% of those who died versus 1.5% of those who lived, (p = 0.005). Across all three sites, in the placentas of the 201 term controls, 18.9% had any inflammation, 16.9% had chorioamnionitis, 5.5% had funisitis, 0.5% had intervillitis and none had villitis. Overall, for stillbirths, any inflammation was observed in 30.2%, chorioamnionitis in 26.9%, funisitis in 5.7%, intervillitis in 6.0% and villitis in 2.2%. For the neonatal deaths, any inflammation was present in 24.9%, chorioamnionitis in 23.3%, funisitis in 8.1%, intervillitis in 1.9% and villitis in 0.5%. Compared with the placentas of term controls, in neonatal deaths, only chorioamnionitis was significantly increased (23.3% versus 16.9%, p = 0.05). Among stillbirths, the rates of any inflammation, chorioamnionitis, intervillitis and villitis were similar across the birthweight groups. However, funisitis was more common in the placentas of stillborn fetuses weighing 2500 g or more (13.8%) compared with 1.0% for those weighing less than 1000 g and 4.8% for stillborn fetuses weighing 1000-2499 g. In the PCR studies, Ureaplasma spp. were by far the most common pathogens found and generally were more commonly found in association with inflammatory lesions.

CONCLUSIONS

Chorioamnionitis was the most common type of placental inflammatory lesion regardless of whether the placentas evaluated were from term controls, stillbirths or neonatal deaths. For stillbirths, inflammation in each inflammation category was more common than in the term controls and significantly more so for any inflammation, chorioamnionitis, intervillitis and villitis. For neonatal deaths, compared with the placentas of term controls, all inflammation categories were more common, but only significantly so for chorioamnionitis. Ureaplasma spp. were the most common organisms found in the placentas and were significantly associated with inflammation.

Could placental inflammation be key?

In fetal/neonatal alloimmune thrombocytopenia (FNAIT), maternal alloantibodies against paternal human platelet antigens (HPA) cross the placenta and lead to platelet destruction. The extent of thrombocytopenia varies among neonates, and inflammation may constitute an important trigger. A set of stable inflammatory markers was measured in serum samples from neonates with low platelet counts, of which n = 50 were diagnosed with FNAIT due to anti-HPA-1a antibodies and n = 50 were thrombocytopenic without detectable maternal HPA antibodies. Concentrations of C-reactive protein, soluble CD14, procalcitonin, and sFlt-1 did not differ between the two cohorts. There was no correlation between C-reactive protein or soluble CD14 and the platelet count, but a negative correlation between procalcitonin concentrations and the neonatal platelet count in both cohorts. sFlt-1 concentration and the platelet count were correlated in FNAIT cases exclusively. None of the inflammatory markers was statistically different between cases with and without intracranial haemorrhage. We were unable to identify systemic inflammation as a relevant factor for thrombocytopenia in FNAIT. The antiangiogenic enzyme sFlt-1, released by the placenta, did correlate with the platelet count in FNAIT cases. Our findings may give rise to the hypothesis that placental inflammation rather than systemic inflammation modulates disease severity in FNAIT.

Immune and pathophysiologic profiling of antenatal coronavirus disease 2019 in the GIFT cohort: A Singaporean case-control study

COVID-19 can be severe in pregnant women, and have adverse consequences for the subsequent infant. We profiled the post-infectious immune responses in maternal and child blood as well as breast milk in terms of antibody and cytokine expression and performed histopathological studies on placentae obtained from mothers convalescent from antenatal COVID-19. Seventeen mother-child dyads (8 cases of antenatal COVID-19 and 9 healthy unrelated controls; 34 individuals in total) were recruited to the Gestational Immunity For Transfer (GIFT) study. Maternal and infant blood, and breast milk samples were collected over the first year of life. All samples were analyzed for IgG and IgA against whole SARS-CoV-2 spike protein, the spike receptor-binding domain (RBD), and previously reported immunodominant epitopes, as well as cytokine levels. The placentae were examined microscopically. The study is registered at clinicaltrials.gov under the identifier NCT04802278. We found high levels of virus-specific IgG in convalescent mothers and similarly elevated titers in newborn children. Thus, antenatal SARS-CoV-2 infection led to high plasma titers of virus-specific antibodies in infants postnatally. However, this waned within 3-6 months of life. Virus neutralization by plasma was not uniformly achieved, and the presence of antibodies targeting known immunodominant epitopes did not assure neutralization. Virus-specific IgA levels were variable among convalescent individuals' sera and breast milk. Antibody transfer ratios and the decay of transplacentally transferred virus-specific antibodies in neonatal circulation resembled that for other pathogens. Convalescent mothers showed signs of chronic inflammation marked by persistently elevated IL17RA levels in their blood. Four placentae presented signs of acute inflammation, particularly in the subchorionic region, marked by neutrophil infiltration even though > 50 days had elapsed between virus clearance and delivery. Administration of a single dose of BNT162b2 mRNA vaccine to mothers convalescent from antenatal COVID-19 increased virus-specific IgG and IgA titers in breast milk, highlighting the importance of receiving the vaccine even after natural infection with the added benefit of enhanced passive immunity.

Placental Characteristics of a Large Italian Cohort of SARS-CoV-2-Positive Pregnant Women

The variety of placental morphological findings with SARS-CoV-2 maternal infections has raised the issue of poor agreement in histopathological evaluation. The aims of this study were: to describe the histopathological placental features of a large sample of SARS-CoV-2-positive women who gave birth in Italy during the COVID-19 pandemic, to analyse the factors underlying these lesions, and to analyse the impact of placental impairment on perinatal outcomes. From 25 February 2020 to 30 June 2021, experienced perinatal pathologists examined 975 placentas of SARS-CoV-2-positive mothers enrolled in a national prospective study, adopting the Amsterdam Consensus Statement protocol. The main results included the absence of specific pathological findings for SARS-CoV-2 infections, even though a high proportion of placentas showed signs of inflammation, possibly related to a cytokine storm induced by the virus, without significant perinatal consequences. Further research is needed to better define the clinical implications of placental morphology in SARS-CoV-2 infections, but the results of this large cohort suggest that placentas do not seem to be a preferential target for the new Coronavirus infection.

Vitamin D Supplementation Improves Mitochondrial Function and Reduces Inflammation in Placentae of Obese Women

Background

About 30% of women entering pregnancy in the US are obese. We have previously reported mitochondrial dysregulation and increased inflammation in the placentae of obese women. Vitamin D (VitD) is a major player in calcium uptake and was shown to modulate mitochondrial respiration and the immune/inflammation system. Studies show decreased VitD levels in obese individuals; however, the effect of maternal obesity on VitD metabolism and its association with placental function remains understudied.

Methods

Maternal and cord blood plasma and placental samples were collected upon C-section from normal-weight (NW, body mass index [BMI]<25) and obese (OB, BMI>30) women with uncomplicated pregnancies at term. We measured 25(OH)D3 (calcidiol) levels in maternal and cord blood plasma using ELISA. We assessed the expression of CYP27B1, an activator of calcidiol, and Vitamin D receptor (VDR) in placentae from NW and OB, and women with gestational diabetes and preeclampsia. In addition, we examined the effects of VitD supplementation on mitochondrial function and inflammation in trophoblasts from NW and OB, using the Seahorse Bioanalyzer and Western blot, respectively.

Results

Vitamin D levels in blood from OB but not NW women and in cord blood from babies born to NW and OB women showed a significant inverse correlation with maternal pre-pregnancy BMI (r=-0.50, p<0.1 and r=-0.55, p=0.004 respectively). Cord plasma VitD levels showed a positive correlation with placental efficiency, i.e., the ratio between fetal and placental weight, as well as with maternal blood VitD levels (r=0.69 and 0.83 respectively, p<0.00). While we found no changes in CYP27B1 in OB vs. NW women, VDR expression were decreased by 50% (p<0.03) independent of fetal sex. No changes in VDR expression relative to BMI-matched controls were observed in the placentae of women with gestational diabetes or preeclampsia. Cytotrophoblasts isolated from placentae of OB women showed a dose-dependent increase in VDR expression after 24-hour treatment with calcitriol (10 nM and 100 nM), an active form of VitD. Trophoblasts isolated from OB women and treated with calcitriol improved mitochondrial respiration (p<0.05). We also found a two-fold increase in expression of the NLRP3 inflammasome and the pro-inflammatory cytokine IL-18 in trophoblasts isolated from placentae of OB women (p<0.05), with IL-18 expression being reversed by calcitriol treatment (100 nM).

Conclusions

We show that VitD deficiency is at least partially responsible for mitochondrial dysfunction and increased inflammation in the placentae of obese women. Vitamin D supplementation could be beneficial in improving placental dysfunction seen in obese women.

Placental vascular malperfusion lesions in fetal congenital heart disease

BACKGROUND

Fetuses with congenital heart disease are at increased risk of perinatal morbidity and mortality, which is highly influenced by their prenatal health. Placental function is vital for the health of the fetus, but increased rates of pathologic lesions of the placenta have been observed in pregnancies complicated by fetal congenital heart disease.

OBJECTIVE

This study aimed to determine the prevalence of both gross and histologic placental pathologies in a cohort of pregnancies complicated by fetal congenital heart disease vs healthy controls using the Amsterdam Placental Workshop Group Consensus Statement sampling and definitions of placental lesions.

STUDY DESIGN

This single-center retrospective cohort study included placental examinations from pregnancies diagnosed prenatally with fetal congenital heart disease between 2010 and 2019; moreover, control placentas were collected from pregnancies without maternal or fetal complications. Placentas were sampled and evaluated according to the Amsterdam Placental Workshop Group Consensus Statement and gross and histopathologic diagnoses determined.

RESULTS

Approximately 80% of fetuses diagnosed with congenital heart disease (n=305) had a placental examination for comparison with controls (n=40). Of note, 239 placentas (78%) in the group with fetal congenital heart disease had at least 1 gross or histopathologic lesion compared with 11 placentas (28%) in the control group (P<.01). One-third of placentas complicated by fetal congenital heart disease met the criteria for small for gestational age, and 48% of placentas had one or more chronic lesions, including maternal vascular malperfusion (23% vs 0%; P<.01), villitis of unknown etiology (22% vs 0%; P<.01), fetal vascular malperfusion (20% vs 0%; P<.01), and other chronic lesions (16% vs 0%; P<.01). Acute inflammation was equally present in both the group with fetal congenital heart disease and the control group (28% vs 28%; P=1.00). Although gestational age and birthweight z score were similar between the 2 groups, birth head circumference was 1.5 cm less in pregnancies complicated by fetal congenital heart disease with a significantly lower z score compared with the control group (-0.52±1.22 vs 0.06±0.69; P<.01).

CONCLUSION

Vascular malperfusion lesions and chronic forms of inflammation occur at markedly higher rates in placentas complicated by fetal congenital heart disease, which may contribute to the decreased head circumference at birth. Further work in neuroplacentology is needed to explore connections among cardiac defects, placental vascular malperfusion lesions, and fetal brain development.

Dendrimer-Based N-Acetyl Cysteine Maternal Therapy Ameliorates Placental Inflammation via Maintenance of M1/M2 Macrophage Recruitment

Intrauterine inflammation (IUI) is the primary cause of spontaneous preterm birth and predisposes neonates to long-term sequelae, including adverse neurological outcomes. N-acetyl-L-cysteine (NAC) is the amino acid L-cysteine derivative and a precursor to the antioxidant glutathione (GSH). NAC is commonly used clinically as an antioxidant with anti-inflammatory properties. Poor bioavailability and high protein binding of NAC necessitates the use of high doses resulting in side effects including nausea, vomiting, and gastric disruptions. Therefore, dendrimer-based therapy can specifically target the drug to the cells involved in inflammation, reducing side effects with efficacy at much lower doses than the free drug. Towards development of the new therapies for the treatment of maternal inflammation, we successfully administered dendrimer-based N-Acetyl Cysteine (DNAC) in an animal model of IUI to reduce preterm birth and perinatal inflammatory response. This study explored the associated immune mechanisms of DNAC treatment on placental macrophages following IUI, especially on M1/M2 type macrophage polarization. Our results demonstrated that intraperitoneal maternal DNAC administration significantly reduced the pro-inflammatory cytokine mRNA of Il1β and Nos2, and decreased CD45⁺ leukocyte infiltration in the placenta following IUI. Furthermore, we found that DNAC altered placental immune profile by stimulating macrophages to change to the M2 phenotype while decreasing the M1 phenotype, thus suppressing the inflammatory responses in the placenta. Our study provides evidence for DNAC therapy to alleviate IUI via the maintenance of macrophage M1/M2 imbalance in the placenta.

Association of increased C-Reactive Protein and hypocomplementemia with risk factors for thrombosis in women who have susceptibility for poor gestational outcome; importance of preconceptional counseling

This study aimed to investigate the association of increased C-Reactive Protein (CRP) and hypocomplementemia with risk factors for thrombosis such as Factor V Leiden (FVLP) and Prothrombin G20210A polymorphisms (PP), increased Activated Protein C Resistance (APCR) and decreased anti-thrombin III (ATIII) activity in women who have metabolic (MTHFR polymorphisms) and immunological risk factors (autoimmune antibody positivity, autoimmune disorders, and chronic inflammatory diseases). All patients (n= 197) were evaluated in terms of risk factors for thrombosis including FVLP, PP, increased APCR, and decreased ATIII activity as well as CRP and complement (C) 3 and C4 levels within a framework of preconceptional care program. Patients with high CRP levels together with hypocomplementemia were included to the study group (n= 13), while women with normal levels of CRP, C3, and C4 were accepted as controls (n= 184). Decreased ATIII activity was found to be statistically more frequent in the study group compared to controls (p= 0.036). There were no significant differences between the study and control groups in terms of the presence of FVLP, PP and increased APCR (p= 0.386, p= 0.462, p= 0.625, respectively). Decreased ATIII activity should be the concern of preconceptional and antenatal care programs in risky patients with increased CRP levels and hypocomplementemia in order to prevent placental inflammation related gestational complications.

Maternal Low-Grade Chronic Inflammation and Intrauterine Programming of Health and Disease

Overweight and obesity during pregnancy have been associated with increased birth weight, childhood obesity, and noncommunicable diseases in the offspring, leading to a vicious transgenerational perpetuating of metabolic derangements. Key components in intrauterine developmental programming still remain to be identified. Obesity involves chronic low-grade systemic inflammation that, in addition to physiological adaptations to pregnancy, may potentially expand to the placental interface and lead to intrauterine derangements with a threshold effect. Animal models, where maternal inflammation is mimicked by single injections with lipopolysaccharide (LPS) resembling the obesity-induced immune profile, showed increased adiposity and impaired metabolic homeostasis in the offspring, similar to the phenotype observed after exposure to maternal obesity. Cytokine levels might be specifically important for the metabolic imprinting, as cytokines are transferable from maternal to fetal circulation and have the capability to modulate placental nutrient transfer. Maternal inflammation may induce metabolic reprogramming at several levels, starting from the periconceptional period with effects on the oocyte going through early stages of embryonic and placental development. Given the potential to reduce inflammation through inexpensive, widely available therapies, examinations of the impact of chronic inflammation on reproductive and pregnancy outcomes, as well as preventive interventions, are now needed.

The Influence of Obesity and Associated Fatty Acids on Placental Inflammation

PURPOSE

Maternal obesity, affecting nearly 1 in 4 pregnancies, is associated with increased circulating saturated fatty acids, such as palmitate. These fatty acids are implicated in placental inflammation, which may in turn exacerbate both maternal-fetal tolerance and responses to pathogens, such as group B Streptococcus. In this review, we address the question, "How do obesity and associated fatty acids influence placental inflammation?"

METHODS

In this narrative review, we searched PubMed and Google Scholar using combinations of the key words placental inflammation or pregnancy and lipids, fatty acids, obesity, palmitate, or other closely related search terms. We also used references found within these articles that may have been absent from our original search queries. We analyzed methods and key results of these articles to compare and contrast their findings, which were occasionally at odds with each other.

FINDINGS

Although obesity can be studied as a whole, complex phenomena with in vivo mouse models and human samples from patients with obesity, in vitro modeling often relies on the treatment of cells or tissues with ≥1 fatty acids and occasionally other compounds (eg, glucose and insulin). We found that palmitate, most commonly used in vitro to recreate hallmarks of obesity, induces apoptosis, oxidative stress, mitochondrial dysfunction, autophagy defects, and inflammasome activation in many placental cell types. We compare this to in vivo models of obesity wherever possible. We found that obesity as a whole may have more complex regulation of these phenomena (apoptosis, oxidative stress, mitochondrial dysfunction, autophagy defects, and inflammasome activation) compared with in vitro models of fatty acid treatment (primarily palmitate) because of the presence of unsaturated fatty acids (ie, oleate), which may have anti-inflammatory effects.

IMPLICATIONS

The interaction of unsaturated fatty acids with saturated fatty acids may ameliorate many inflammatory effects of saturated fatty acids alone, which complicates interpretation of in vitro studies that focus on a particular fatty acid in isolation. This complication may explain why certain studies of obesity in vivo have differing outcomes from studies of specific fatty acids in vitro.

Altered cord serum 25-hydroxyvitamin D signaling and placental inflammation is associated with pre-term birth

PROBLEM

Vitamin D is well-known for having anti-inflammatory and immunomodulatory properties. Impaired maternal vitamin D status has been known to increase the risk of adverse pregnancy outcomes like pre-term birth. The present study aims to evaluate the impact of fetal cord serum 25-hydroxyvitamin D-mediated signaling in mediating inflammatory responses in placenta during pre-term birth.

METHOD OF STUDY

For the above purpose, cord serum 25 hydroxyvitamin D 25(OH)D were measured in term (n = 20) and pre-term (n = 20) born babies using ELISA. Vitamin D downstream signaling has also been checked in placenta (VDR, CYP27B1, cathelicidin LL37) along with expression of inflammatory markers (S100A8, HMGB1, TLR2, p-NF-kappaB) using Western blotting and immunohistochemistry. Pearson correlation model was used to do correlation study.

RESULTS

Compared with term born babies (59.31 ± 3.476), decline in cord serum 25(OH)D levels is observed in pre-term born babies (22.26 ± 1.083, P = <0.0001) that showed strong positive correlation with gestational age (r = .9368***) and birthweight (r = .9559***). On the other hand, vitamin D signaling markers were found to be downregulated and inflammatory markers were upregulated in placental tissue of pre-term born babies.

CONCLUSION

Thus, our study demonstrated that insufficient cord 25(OH)D levels may disturb the homeostasis of inflammation in placenta. Altered cord serum 25(OH)D mediated anti-inflammatory signaling may be acting as trigger signals in modulating inflammatory responses in placenta and eliciting premature activation of spontaneous labor in pre-term birth.

Cellular immune responses in amniotic fluid of women with preterm labor and intra-amniotic infection or intra-amniotic inflammation

PROBLEM

Preterm birth is commonly preceded by preterm labor, a syndrome that is causally linked to both intra-amniotic infection and intra-amniotic inflammation. However, the stereotypical cellular immune responses in these two clinical conditions are poorly understood.

METHOD OF STUDY

Amniotic fluid samples (n = 26) were collected from women diagnosed with preterm labor and intra-amniotic infection (amniotic fluid IL-6 concentrations ≥2.6 ng/mL and culturable microorganisms, n = 10) or intra-amniotic inflammation (amniotic fluid IL-6 concentrations ≥2.6 ng/mL without culturable microorganisms, n = 16). Flow cytometry was performed to evaluate the phenotype and number of amniotic fluid leukocytes. Amniotic fluid concentrations of classical pro-inflammatory cytokines, type 1 and type 2 cytokines, and T-cell chemokines were determined using immunoassays.

RESULTS

Women with spontaneous preterm labor and intra-amniotic infection had (a) a greater number of total leukocytes, including neutrophils and monocytes/macrophages, in amniotic fluid; (b) a higher number of total T cells and CD4⁺ T cells, but not CD8⁺ T cells or B cells, in amniotic fluid; and (c) increased amniotic fluid concentrations of IL-6, IL-1β, and IL-10, compared to those with intra-amniotic inflammation. However, no differences in amniotic fluid concentrations of T-cell cytokines and chemokines were observed between these two clinical conditions.

CONCLUSION

The cellular immune responses observed in women with preterm labor and intra-amniotic infection are more severe than in those with intra-amniotic inflammation, and neutrophils, monocytes/macrophages, and CD4⁺ T cells are the main immune cells responding to microorganisms that invade the amniotic cavity. These findings provide insights into the intra-amniotic immune mechanisms underlying the human syndrome of preterm labor.

Impact of extractable nuclear antigen, anti-double stranded DNA, antiphospholipid antibody, and anticardiolipin antibody positivity on obstetrical complications and pregnancy outcomes

BACKGROUND

Extractable nuclear antigen (ENA) and anti-double stranded DNA (anti-dsDNA) positivity and related diseases like systemic lupus erythematosus, Sjögren syndrome, and other autoimmune diseases are known to be associated with obstetrical complications and poor perinatal outcomes.

OBJECTIVE

To demonstrate the importance of ENA, anti-dsDNA, antiphospholipid (APL), and anticardiolipin (ACL) antibody positivity on pregnancy outcomes.

METHODS

Ninety one pregnant women with known ENA, anti-dsDNA, APL IgG and IgM, and ACL IgG and IgM antibody positivity were retrospectively compared with 91 randomly selected pregnant woman in terms of obstetrical complications and pregnancy outcomes. Beksac Obstetrics Index-pregnancy (BOIp), calculated as (number of children + (π/10))/gravidity in the current pregnancy, was used to compare the risk level between groups.

RESULTS

Significant differences were found in the median maternal age, gravidity, number of previous miscarriages, and BOIp between the groups (p= 0.04, p< 0.001, p< 0.001, and p< 0.001, respectively). Significant differences were also found between the study and control groups in the median gestational age at birth, birth weight, and APGAR1 score (p< 0.001 for all). Similarly, significant differences were found between groups in the rates of intra-uterine growth restriction, oligohydramnios, and gestational hypertension (p< 0.001, p= 0.05, and p= 0.05, respectively). There were 3 (3.3%) stillbirths in the study group and none in the control group (p= 0.123).

CONCLUSION

We evaluated the impact of anti-dsDNA, ENA, APL, and ACL antibody positivity, which may cause immunologic inflammation at placenta and thereby affect pregnancy outcomes.

Are B cells altered in the decidua of women with preterm or term labor?

PROBLEM

The immunophenotype of B cells at the maternal-fetal interface (decidua) in labor at term and preterm labor is poorly understood.

METHOD OF STUDY

Decidual tissues were obtained from women with preterm or term labor and from non-labor gestational age-matched controls. Immunophenotyping of decidual B cells was performed using multicolor flow cytometry.

RESULTS

(a) In the absence of acute or chronic chorioamnionitis, total B cells were more abundant in the decidua parietalis of women who delivered preterm than in those who delivered at term, regardless of the presence of labor; (b) decidual transitional and naïve B cells were the most abundant B-cell subsets; (c) decidual B1 B cells were increased in women with either labor at term or preterm labor and chronic chorioamnionitis compared to those without this placental lesion; (d) decidual transitional B cells were reduced in women with preterm labor compared to those without labor; (e) naïve, class-switched, and non-class-switched B cells in the decidual tissues underwent mild alterations with the process of preterm labor; (f) decidual plasmablasts seemed to increase in women with either labor at term or preterm labor with chronic chorioamnionitis; and (g) decidual B cells expressed high levels of interleukin (IL)-12, IL-6, and/or IL-35.

CONCLUSION

Total B cells are not increased with the presence of preterm or term labor; yet, specific subsets (B1 and plasmablasts) undergo alterations in women with chronic chorioamnionitis. Therefore, B cells are solely implicated in the pathological process of preterm labor in a subset of women with chronic inflammation of the placenta. These findings provide insight into the immunology of the maternal-fetal interface in preterm and term labor.

Placental Barrier-on-a-Chip: Modeling Placental Inflammatory Responses to Bacterial Infection

Placental inflammation, as a recognized cause of preterm birth and neonatal mortality, displays extensive placental involvement or damage with the presence of organisms. The inflammatory processes are complicated and tightly associated with increased inflammatory cytokine levels and innate immune activation. However, the deep study of the underlying mechanisms was limited by conventional cell and animal models because of great variations in the architecture and function of placenta. Here, we established a microengineered model of human placental barrier on the chip and investigated the associated inflammatory responses to bacterial infection. The multilayered design of the microdevice mimicked the microscopic structure in the fetal-maternal interfaces of human placenta, and the flow resembled the dynamic environment in the mother's body. Escherichia coli (E. coli), one of the predominant organisms found in fetal organs, were applied to the maternal side, modeling acute placental inflammation. The data demonstrated the complex responses including the increased secretion of inflammatory cytokines by trophoblasts and the adhesion of maternal macrophages following bacterial infection. Particularly, transplacental communication was observed between two placental cells, and implied the potential role of trophoblast in fetal inflammatory response syndrome in clinic. These complex responses are of potential significance to placental dysfunctions, even abnormal fetal development and preterm birth. Collectively, placental barrier-on-a-chip microdevice presents a simple platform to explore the complicated inflammatory responses in human placenta, and might help our understanding of the mechanisms underlying reproductive diseases.

Pathophysiology of placental-derived fetal growth restriction

Placental-related fetal growth restriction arises primarily due to deficient remodeling of the uterine spiral arteries supplying the placenta during early pregnancy. The resultant malperfusion induces cell stress within the placental tissues, leading to selective suppression of protein synthesis and reduced cell proliferation. These effects are compounded in more severe cases by increased infarction and fibrin deposition. Consequently, there is a reduction in villous volume and surface area for maternal-fetal exchange. Extensive dysregulation of imprinted and nonimprinted gene expression occurs, affecting placental transport, endocrine, metabolic, and immune functions. Secondary changes involving dedifferentiation of smooth muscle cells surrounding the fetal arteries within placental stem villi correlate with absent or reversed end-diastolic umbilical artery blood flow, and with a reduction in birthweight. Many of the morphological changes, principally the intraplacental vascular lesions, can be imaged using ultrasound or magnetic resonance imaging scanning, enabling their development and progression to be followed in vivo. The changes are more severe in cases of growth restriction associated with preeclampsia compared to those with growth restriction alone, consistent with the greater degree of maternal vasculopathy reported in the former and more extensive macroscopic placental damage including infarcts, extensive fibrin deposition and microscopic villous developmental defects, atherosis of the spiral arteries, and noninfectious villitis. The higher level of stress may activate proinflammatory and apoptotic pathways within the syncytiotrophoblast, releasing factors that cause the maternal endothelial cell activation that distinguishes between the 2 conditions. Congenital anomalies of the umbilical cord and placental shape are the only placental-related conditions that are not associated with maldevelopment of the uteroplacental circulation, and their impact on fetal growth is limited.

Bile acids evoke placental inflammation by activating Gpbar1/NF-κB pathway in intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is a cholestatic disorder with potentially deleterious consequences for fetuses. Although a clear correlation between the elevated levels of maternal serum bile acids and deficient fetal outcome has been established in clinical practice, the underlying mechanisms remain elusive. Herein, we report that bile acids induce NF-κB pathway activation via G protein-coupled bile acid receptor 1 (Gpbar1), with consequent upregulation of inflammatory genes in trophoblasts, leading to aberrant leukocyte infiltration and inflammation in placenta. Ursodeoxycholic acid (UDCA), a drug used clinically to treat ICP, competes with other bile acids for binding with Gpbar1 and thus inhibits bile acid-induced inflammatory response in trophoblasts and improves fetal survival in pregnant rats with obstructive cholestasis. Notably, inhibition of NF-κB by andrographolide is more effective than UDCA in benefiting placentas and fetuses. Thus, anti-inflammation therapy targeting Gpbar1/NF-κB pathway could be effective in suppressing bile acid-induced inflammation and alleviating ICP-associated fetal disorders.

Association between maternal genital mycoplasma colonization and histologic chorioamnionitis in preterm births

OBJECTIVE

Genital mycoplasmas (GMs) can be associated with chorioamnionitis and preterm birth, but are viewed as commensal organisms with low virulence. We sought to determine if cervical GM colonization is associated with histologic chorioamnionitis independent of infection with other bacteria.

STUDY DESIGN

Retrospective study of patients who delivered preterm, had cervical cultures for GMs, and placental cultures for bacteria other than GM. GM positive patients were compared to GM negative patients. Histologic grading of placentas was compared between GM negative patients with negative placental cultures (Group 1), GM positive patients with negative placental cultures (Group 2), GM negative patients with positive placental cultures (Group 3) and GM positive patients with positive placental cultures (Group 4).

RESULTS

GM positive patients were less likely than GM negative patients to have placental cultures positive for other bacteria (39% versus 47%, P = 0.0071). Group 2 had higher rates of membrane inflammation compared to Group 1 (p = 0.0079), and no significant difference in rates of membrane inflammation compared to Groups 3 or 4 (p = 0.36, p = 0.18). GM positivity was independently associated with increased membrane inflammation and decreased inflammation in the chorionic plate.

CONCLUSIONS

GM colonization is associated decreased inflammation of the chorionic plate, and increased inflammation of the membranes.

Isolated Placental Inflammation and Vasculopathy: Clinical Implications in the Extremely Low Birth Weight Infants

The predictive values of placental histopathologies are compromised by a non-segregation of common anomalies. The effects of isolated pure placental inflammation (PI) and vasculopathy-coagulopathy (PV) were compared with normal (NL) placentas in extremely premature infants (ELBW, birth weight < 1000 g). PI infants required lower peak inspiratory pressure on day 3. More infants in PV were oxygen dependence on day 28. PV had an increased risk of intraventricular-periventricular hemorrhage (IVH, OR 4.9, 95% CI 1-24.7, p = 0.05). NL infants were unexposed to PPROM or maternal hypertension, had highest requirement for surfactant, did not develop IVH and periventricular leukomalacia (PVL) and none of them were Caucasian.

CONCLUSIONS

In ELBW infants (1) pure placental vasculopathy-coagulopathy is a risk factor for IVH, (2) a non- pathological intrauterine environment is nonconducive to IVH and PVL, (3) pure placental inflammation is protective for acute pulmonary disease, (4) Caucasian mothers are more susceptible to adverse intrauterine environment.

A toll-like receptor 9 (rs352140) variant is associated with placental inflammation in newborn infants

OBJECTIVE

Chorioamnionitis contributes to premature birth and associated postnatal morbidity. The genetic basis of altered immune responses underlying placental inflammation (PI) remains understudied. The aim of this study was to evaluate the relationship among TLR signaling pathway polymorphisms and different patterns of PI.

METHODS

Prospective cohort study in infants involving cord blood collection and placental examination for PI. One hundred and fifty-nine infants enrolled in study out of which 28 were term (eight with PI) and 131 preterm (47 with PI). DNA from blood was genotyped for SNPs in TLR2, 4, 5, 9, NFKBI, NFKBIA, TIRAP, and IRAK1 genes using multiplexed single base extension assay.

RESULTS

While there were no differences in BW, GA, gender, race, and SPL among infants with or without PI, there was a higher incidence of PPROM, maternal smoking, drug use, and clinical chorioamnionitis among infants with PI. Out of nine TLR variants, only CT and/or TT genotypes of the TLR9 variant (rs352140) were significantly associated (p = 0.004) with any PI and maternal pattern of inflammation (p = 0.012) both by univariate analysis and logistic regression.

CONCLUSIONS

The presence of a variant T allele in a common SNP (rs352140) in the TLR9 gene whose product recognizes bacterial DNA is associated with increased PI.

Maternal high-fat diet is associated with impaired fetal lung development

Maternal nutrition has a profound long-term impact on infant health. Poor maternal nutrition influences placental development and fetal growth, resulting in low birth weight, which is strongly associated with the risk of developing chronic diseases, including heart disease, hypertension, asthma, and type 2 diabetes, later in life. Few studies have delineated the mechanisms by which maternal nutrition affects fetal lung development. Here, we report that maternal exposure to a diet high in fat (HFD) causes placental inflammation, resulting in placental insufficiency, fetal growth restriction (FGR), and inhibition of fetal lung development. Notably, pre- and postnatal exposure to maternal HFD also results in persistent alveolar simplification in the postnatal period. Our novel findings provide a strong association between maternal diet and fetal lung development.

Effects of placental inflammation on neonatal outcome in preterm infants

BACKGROUND

Intrauterine infection is the most commonly identified cause of preterm birth. In this study, our aim was to determine the association between placental inflammation and neonatal outcome in a prospective observational cohort of preterm infants of less than 34 weeks gestational age. We especially focused on the distinct effects of maternal inflammatory response (MIR) with and without fetal inflammatory response (FIR).

METHODS

Clinical characteristics and placental histological results were prospectively collected from 216 singleton infants born at a gestational age of less than 34 weeks.

RESULTS

Of the 216 newborns, 104 (48.1%) infants had histological placental inflammation. Based on their pathological findings, the premature infants were divided into three groups: (1) the MIR negative-FIR negative (MIR-FIR-) group; (2) the MIR positive-FIR positive (MIR+FIR+) group; and (3) the MIR positive-FIR negative (MIR+FIR-) group. The incidence of neonatal respiratory distress syndrome (RDS) in the MIR+FIR- group (5.7%) and in the MIR+FIR+ group (2.0%) was significantly lower than in the MIR-FIR- group (19.6%) (p < 0.05). Logistic regression analysis showed that MIR+FIR+ group had a decreased incidence of neonatal RDS (OR = 0.076; 95% CI 0.009-0.624; p = 0.016). The incidence of intraventricular hemorrhage (IVH) Grade 2 or greater was significantly higher in the MIR+FIR+ group (42.3%) than in the MIR+FIR- group (13.0%) (p < 0.05) or in the MIR-FIR- group (15.2%) (p < 0.05). Logistic regression analysis also showed that MIR+FIR+ was associated with an increased incidence of IVH Grade 2 or greater (OR = 4.08; 95% CI 1.259-13.24; p = 0.019).

CONCLUSION

A positive MIR in association with a positive FIR decreases the risk of RDS, but increases the risk of IVH Grade 2 or greater in preterm infants with a gestational age of less than 34 weeks. However, a positive MIR alone has little effect on neonatal outcome.

Maternal overweight induced by a diet with high content of saturated fat activates placental mTOR and eIF2alpha signaling and increases fetal growth in rats

The mammalian target of rapamycin (mTOR) and the eukaryotic initiation factor 2 (eIF2) signaling pathways control protein synthesis in response to nutrient availability. Moreover, mTOR is a positive regulator of placental nutrient transport and is involved in the regulation of fetal growth. We hypothesized that maternal overweight, induced by a diet with high saturated fat content, i) up-regulates placental mTOR activity and nutrient transport, resulting in fetal overgrowth; ii) inhibits phosphorylation of eIF2 at its alpha subunit (eIF2alpha); and iii) leads to placental inflammation. Albino Wistar female rats were fed a control or high-saturated-fat (HF) diet for 7 wk before mating and during pregnancy. At gestational day 21, the HF diet significantly increased maternal and fetal triglyceride, leptin, and insulin (but not glucose) levels and maternal and fetal weights, and placental weights trended to increase. Phosphorylated 4EBP1 (T37/46 and S65) was significantly higher, and phosphorylated rpS6 (S235/236) tended to increase, in the placentas of dams fed an HF diet, indicating an activation of mTOR complex 1 (mTORC1). Phosphorylation of AMPK and eIF2alpha was reduced in the HF diet group compared to the control. The expression and activity of placental nutrient transporters and lipoprotein lipase (LPL), as well as the activation of inflammatory pathways, were not altered by the maternal diet. We conclude that maternal overweight induced by an HF diet stimulates mTORC1 activity and decreases eIF2alpha phosphorylation in rat placentas. We speculate that these changes may up-regulate protein synthesis and contribute to placental and fetal overgrowth.