Placenta accreta spectrum: biomarker discovery using plasma proteomics

Single-cell and spatial transcriptomics reveal alterations in trophoblasts at invasion sites and disturbed myometrial immune microenvironment in placenta accreta spectrum disorders

BACKGROUND

Placenta accreta spectrum disorders (PAS) are a severe complication characterized by abnormal trophoblast invasion into the myometrium. The underlying mechanisms of PAS involve a complex interplay of various cell types and molecular pathways. Despite its significance, both the characteristics and intricate mechanisms of this condition remain poorly understood.

METHODS

Spatial transcriptomics (ST) and single-cell RNA sequencing (scRNA-seq), were performed on the tissue samples from four PAS patients, including invasive tissues (ST, n = 3; scRNA-seq, n = 4), non-invasive normal placenta samples (ST, n = 1; scRNA-seq, n = 2). Three healthy term pregnant women provided normal myometrium samples (ST, n = 1; scRNA-seq, n = 2). ST analysis characterized the spatial expression landscape, and scRNA-seq was used to identify specific cellular components in PAS. Immunofluorescence staining was conducted to validate the findings.

RESULTS

ST slices distinctly showed the myometrium in PAS was invaded by three subpopulations of trophoblast cells, extravillous trophoblast cells, cytotrophoblasts, and syncytiotrophoblasts, especially extravillous trophoblast cells. The pathways enriched by genes in trophoblasts, smooth muscle cells (SMC), and immune cells of PAS were mainly associated with immune and inflammation. We identified elevated expression of the angiogenesis-stimulating gene PTK2, alongside the cell proliferation-enhancing gene EGFR, within the trophoblasts of PAS group. Trophoblasts mainly contributed the enhancement of HLA-G and EBI3 signaling, which is crucial in establishing immune escape. Meanwhile, SMC regions in PAS exhibited upregulation of immunomodulatory markers such as CD274, HAVCR2, and IDO1, with CD274 expression experimentally verified to be increased in the invasive SMC areas of the PAS group.

CONCLUSIONS

This study provided information of cellular composition and spatial organization in PAS at single-cell and spatial level. The dysregulated expression of genes in PAS revealed a complex interplay between enhanced immune escape in trophoblasts and immune tolerance in SMCs during invasion in PAS. These findings will enhance our understanding of PAS pathogenesis for developing potential therapeutic strategies.

Customizing EV-CATCHER to Purify Placental Extracellular Vesicles from Maternal Plasma to Detect Placental Pathologies

Placenta Accreta Spectrum (PAS) is a life-threatening condition in which placental trophoblastic cells abnormally invade the uterus, often up to the uterine serosa and, in extreme cases, tissues beyond the uterine wall. Currently, there is no clinical assay for the non-invasive detection of PAS, and only ultrasound and MRI can be used for its diagnosis. Considering the subjectivity of visual assessment, the detection of PAS necessitates a high degree of expertise and, in some instances, can lead to its misdiagnosis. In clinical practice, up to 50% of pregnancies with PAS remain undiagnosed until delivery, and it is associated with increased risk of morbidity/mortality. Although many studies have evaluated the potential of fetal biomarkers circulating in maternal blood, very few studies have evaluated the potential of circulating placental extracellular vesicles (EVs) and their miRNA contents for molecular detection of PAS. Thus, to purify placental EVs from maternal blood, we customized our robust ultra-sensitive immuno-purification assay, termed EV-CATCHER, with a monoclonal antibody targeting the membrane Placental Alkaline Phosphatase (PLAP) protein, which is unique to the placenta and present on the surface of placental EVs. Then, as a pilot evaluation, we compared the miRNA expression profiles of placental EVs purified from the maternal plasma of women diagnosed with placenta previa (controls, n = 16); placenta lying low in uterus but not invasive) to those of placental EVs purified from the plasma of women with placenta percreta (cases, n = 16), PAS with the highest level of invasiveness. Our analyses reveal that miRNA profiling of PLAP+ EVs purified from maternal plasma identified 40 differentially expressed miRNAs when comparing these two placental pathologies. Preliminary miRNA pathway enrichment and gene ontology analysis of the top 14 upregulated and top nine downregulated miRNAs in PLAP+ EVs, purified from the plasma of women diagnosed with placenta percreta versus those diagnosed with placenta previa, suggests a potential role in control of cellular invasion and motility that will require further investigation.

Placenta accreta spectrum disorder at single-cell resolution: a loss of boundary limits in the decidua and endothelium

BACKGROUND

Placenta accreta spectrum disorders are associated with severe maternal morbidity and mortality. Placenta accreta spectrum disorders involve excessive adherence of the placenta preventing separation at birth. Traditionally, this condition has been attributed to excessive trophoblast invasion; however, an alternative view is a fundamental defect in decidual biology.

OBJECTIVE

This study aimed to gain insights into the understanding of placenta accreta spectrum disorder by using single-cell and spatially resolved transcriptomics to characterize cellular heterogeneity at the maternal-fetal interface in placenta accreta spectrum disorders.

STUDY DESIGN

To assess cellular heterogeneity and the function of cell types, single-cell RNA sequencing and spatially resolved transcriptomics were used. A total of 12 placentas were included, 6 placentas with placenta accreta spectrum disorder and 6 controls. For each placenta with placenta accreta spectrum disorder, multiple biopsies were taken at the following sites: placenta accreta spectrum adherent and nonadherent sites in the same placenta. Of note, 2 platforms were used to generate libraries: the 10× Chromium and NanoString GeoMX Digital Spatial Profiler for single-cell and spatially resolved transcriptomes, respectively. Differential gene expression analysis was performed using a suite of bioinformatic tools (Seurat and GeoMxTools R packages). Correction for multiple testing was performed using Clipper. In situ hybridization was performed with RNAscope, and immunohistochemistry was used to assess protein expression.

RESULTS

In creating a placenta accreta cell atlas, there were dramatic difference in the transcriptional profile by site of biopsy between placenta accreta spectrum and controls. Most of the differences were noted at the site of adherence; however, differences existed within the placenta between the adherent and nonadherent site of the same placenta in placenta accreta. Among all cell types, the endothelial-stromal populations exhibited the greatest difference in gene expression, driven by changes in collagen genes, namely collagen type III alpha 1 chain (COL3A1), growth factors, epidermal growth factor-like protein 6 (EGFL6), and hepatocyte growth factor (HGF), and angiogenesis-related genes, namely delta-like noncanonical Notch ligand 1 (DLK1) and platelet endothelial cell adhesion molecule-1 (PECAM1). Intraplacental tropism (adherent versus non-adherent sites in the same placenta) was driven by differences in endothelial-stromal cells with notable differences in bone morphogenic protein 5 (BMP5) and osteopontin (SPP1) in the adherent vs nonadherent site of placenta accreta spectrum.

CONCLUSION

Placenta accreta spectrum disorders were characterized at single-cell resolution to gain insight into the pathophysiology of the disease. An atlas of the placenta at single cell resolution in accreta allows for understanding in the biology of the intimate maternal and fetal interaction. The contributions of stromal and endothelial cells were demonstrated through alterations in the extracellular matrix, growth factors, and angiogenesis. Transcriptional and protein changes in the stroma of placenta accreta spectrum shift the etiologic explanation away from "invasive trophoblast" to "loss of boundary limits" in the decidua. Gene targets identified in this study may be used to refine diagnostic assays in early pregnancy, track disease progression over time, and inform therapeutic discoveries.

Pregnancy-specific beta-1-glycoprotein 6 is a potential novel diagnostic biomarker of placenta accreta spectrum

Early diagnosis is essential for the safer perinatal management of placenta accreta spectrum (PAS). We used transcriptome analysis to investigate diagnostic maternal serum biomarkers and the mechanisms of PAS development. We analyzed eight formalin-fixed paraffin-embedded placental specimens from two placenta increta and three placenta percreta cases who underwent cesarean hysterectomy at Sapporo Medical University Hospital between 2013 and 2019. Invaded placental regions were isolated from the uterine myometrium and RNA was extracted. The transcriptome difference between normal placenta and PAS was analyzed by microarray analysis. The PAS group showed markedly decreased expression of placenta-specific genes such as LGALS13 and the pregnancy-specific beta-1-glycoprotein (PSG) family. Term enrichment analysis revealed changes in genes related to cellular protein catabolic process, female pregnancy, autophagy, and metabolism of lipids. From the highly dysregulated genes in the PAS group, we investigated the expression of PSG family members, which are secreted into the intervillous space and can be detected in maternal serum from the early stage of pregnancy. The gene expression level of PSG6 in particular was progressively decreased from placenta increta to percreta. The PSG family, especially PSG6, is a potential biomarker for PAS diagnosis.

Determination of biomarker candidates for the placenta accreta spectrum by plasma proteomic analysis

Placenta accreta spectrum (PAS) presents a significant obstetric challenge, associated with considerable maternal and fetal-neonatal morbidity and mortality. Nevertheless, it is imperative to acknowledge that a noteworthy subset of PAS cases remains undetected until the time of delivery, thereby contributing to an augmented incidence of morbidity among the affected individuals. The delayed identification of PAS not only hinders timely intervention but also exacerbates the associated health risks for both the maternal and fetal outcomes. This underscores the urgency to innovate strategies for early PAS diagnosis. In this study, we aimed to explore plasma proteins as potential diagnostic biomarkers for PAS. Integrated transcriptome and proteomic analyses were conducted to establish a novel diagnostic approach. A cohort of 15 pregnant women diagnosed with PAS and delivering at Inonu University Faculty of Medicine between 01/04/2021 and 01/01/2023, along with a matched control group of 15 pregnant women without PAS complications, were enrolled. Plasma protein identification utilized enzymatic digestion and liquid chromatography-tandem mass spectrometry techniques. Proteomic analysis identified 228 plasma proteins, of which 85 showed significant differences (P < 0.001) between PAS and control cases. We refined this to a set of 20 proteins for model construction, resulting in a highly accurate classification model (96.9% accuracy). Notable associations were observed for proteins encoded by P01859 (Immunoglobulin heavy constant gamma 2), P02538 (Keratin type II cytoskeletal 6A), P29622 [Kallistatin (also known as Serpin A4)], P17900 (Ganglioside GM2 activator Calmodulin-like protein 5), and P01619 (Immunoglobulin kappa variable 3-20), with fold changes indicating their relevance in distinguishing PAS from control groups. In conclusion, our study has identified novel plasma proteins that could serve as potential biomarkers for early diagnosis of PAS in pregnant women. Further research and validation in larger PAS cohorts are necessary to determine the clinical utility and reliability of these proteomic biomarkers for diagnosing PAS.

Uterus-preserving surgical management of placenta accreta spectrum disorder: a large retrospective study

BACKGROUND

The two-child policy implemented in China resulted in a surge of high-risk pregnancies among advanced maternal aged women and presented a window of opportunity to identify a large number of placenta accreta spectrum (PAS) cases, which often invoke severe blood loss and hysterectomy. We thus had an opportunity to evaluate the surgical outcomes of a unique conservative PAS management strategy for uterus preservation, and the impacts of magnetic resonance imaging (MRI) in PAS surgical planning.

METHODS

Cross-sectional study, comparing the outcomes of a new uterine artery ligation combined with clover suturing technique (UAL + CST) with the existing conservative surgical approaches in a maternal public hospital with an annual birth of more than 20,000 neonates among all placenta previa cases suspecting of PAS between January 1, 2015 and December 31, 2018.

RESULTS

From a total of 89,397 live births, we identified 210 PAS cases from 400 singleton pregnancies with placenta previa. Aside from 2 self-requested natural births (low-lying placenta), all PAS cases had safe cesarean deliveries without any total hysterectomy. Compared with the existing approaches, the evaluated UAL + CST had a significant reduction in intraoperative blood loss (β=-312 ml, P < .001), RBC transfusion (β=-1.08 unit, P = .001), but required more surgery time (β = 16.43 min, P = .01). MRI-measured placenta thickness, when above 50 mm, can increase blood loss (β = 315 ml, P = .01), RBC transfusion (β = 1.28 unit, P = .01), surgery time (β = 48.84 min, P < .001) and hospital stay (β = 2.58 day, P < .001). A majority of percreta patients resumed normal menstrual cycle within 12 months with normal menstrual fluid volume, without abnormal urination or defecation.

CONCLUSIONS

A conservative surgical management approach of UAL + CST for PAS is safe and effective with a low complication rate. MRI might be useful for planning PAS surgery.

CLINICAL TRIAL REGISTRATION NUMBER

ChiCTR2000035202.

Screening of placenta accreta spectrum disorder using maternal serum biomarkers and clinical indicators: a case-control study

BACKGROUND

Placenta accreta spectrum (PAS) disorder is a major cause of postpartum hemorrhage-associated maternal and fetal death, and novel methods for PAS screening are urgently needed for clinical application.

METHODS

The purpose of this study was to develop new methods for PAS screening using serum biomarkers and clinical indicators. A total of 95 PAS cases and 137 controls were enrolled in a case-control study as cohort one, and 44 PAS cases and 35 controls in a prospective nested case-control study were enrolled as cohort two. All subjects were pregnant women of Chinese Han population. Biomarkers for PAS from maternal blood samples were screened based on high-throughput immunoassay and were further validated in three phases of cohort one. Screening models for PAS were generated using maternal serum biomarkers and clinical indicators, and were validated in two cohorts. The expression levels of biomarkers were analyzed using histopathological and immunohistochemical (IHC) techniques, and gene expression was examined by QPCR in the human placenta. Binary logistic regression models were built, and the area under the curve (AUC), sensitivity, specificity, and Youden index were calculated. Statistical analyses and model building were performed in SPSS and graphs were generated in GraphPad Prism. The independent-sample t test was used to compare numerical data between two groups. For nonparametric variables, a Mann-Whitney U test or a X² test was used.

RESULTS

The results demonstrated that the serum levels of matrix metalloproteinase-1 (MMP-1), epidermal growth factor (EGF), and vascular endothelial growth factor-A (VEGF-A) were consistently higher, while the level of tissue-type plasminogen activator (tPA) was significantly lower in PAS patients compared with normal term controls and patients with pre-eclampsia (PE) and placenta previa (PP). IHC and QPCR analysis confirmed that the expression of the identified biomarkers significantly changed during the third trimester in human placenta. The generated screening model combining serum biomarkers and clinical indicators detected 87% of PAS cases with AUC of 0.94.

CONCLUSIONS

Serum biomarkers can be used for PAS screening with low expense and high clinical performance; therefore, it may help to develop a practicable method for clinical prenatal PAS screening.

Placenta Accreta Spectrum

Placenta accreta spectrum (PAS) is one of the most dangerous conditions in pregnancy and is increasing in frequency. The risk of life-threatening bleeding is present throughout pregnancy but is particularly high at the time of delivery. Although the exact cause is unknown, the result is clear: Severe PAS distorts the uterus and surrounding anatomy and transforms the pelvis into an extremely high-flow vascular state. Screening for risk factors and assessing placental location by antenatal ultrasonography are essential for timely diagnosis. Further evaluation and confirmation of PAS are best performed in referral centers with expertise in antenatal imaging and surgical management of PAS. In the United States, cesarean hysterectomy with the placenta left in situ after delivery of the fetus is the most common treatment for PAS, but even in experienced referral centers, this treatment is often morbid, resulting in prolonged surgery, intraoperative injury to the urinary tract, blood transfusion, and admission to the intensive care unit. Postsurgical complications include high rates of posttraumatic stress disorder, pelvic pain, decreased quality of life, and depression. Team-based, patient-centered, evidence-based care from diagnosis to full recovery is needed to optimally manage this potentially deadly disorder. In a field that has relied mainly on expert opinion, more research is needed to explore alternative treatments and adjunctive surgical approaches to reduce blood loss and postoperative complications.

The Need for Presurgical Evaluation for Placenta Accreta Spectrum

Staging or grading of placenta accreta spectrum has historically relied on histopathologic evaluation of placental and uterine specimens. This approach has limited utility, since it is retrospective in nature and does not allow for presurgical planning. Here, we argue for a paradigm shift to use of clinical and imaging characteristics to define the presurgical stage. We summarize past attempts at staging, and define a new data-driven approach to determining the stage prior to delivery. Use of this model may help hospitals direct patients to the most appropriate level of care for workup and management of placenta accreta spectrum. KEY POINTS: · Staging systems that rely on histopathologic grade (accreta, increta, percreta) are unhelpful in antenatal planning for placenta accreta spectrum.. · Past attempts at pre-delivery (pre-surgical) staging have failed to account for key factors that contribute to risk and morbidity.. · We developed a data-driven model that could be easily incorporated as a decision aid into clinical practice to help clinicians decide an individual patient's risk for placenta accreta spectrum..

Knowledge Gaps in Placenta Accreta Spectrum

Since its first description early in the 20th Century, placenta accreta and its variants have changed substantially in incidence, risk factor profile, clinical presentation, diagnosis and management. While systematic use of diagnostic tools and a multidisciplinary team care approach has begun to improve patient outcomes, the condition's pathophysiology, epidemiology, and best practices for diagnosis and management remain poorly understood. The use of large databases with broadly accepted terminology and diagnostic criteria should accelerate research in this area. Future work should focus on non-traditional phenotypes, such as those without placenta previa-preventive strategies, and long term medical and emotional support for patients facing this diagnosis. KEY POINTS: · Placenta accreta spectrum research may be improved with standardized terminology and use of large databases.. · Placenta accreta prediction should move beyond ultrasound with the addition of biomarkers, and needs to extend to those without traditional risk factors.. · Future research should identify practices that can prevent future accreta development..

Animal models of the placenta accreta spectrum: current status and further perspectives

Placenta accreta spectrum disorder (PAS) is a kind of disease of placentation defined as abnormal trophoblast invasion of part or all of the placenta into the myometrium, even penetrating the uterus. Decidual deficiency, abnormal vascular remodeling in the maternal-fetal interface, and excessive invasion by extravillous trophoblast (EVT) cells contribute to its onset. However, the mechanisms and signaling pathways underlying such phenotypes are not fully understood, partly due to the lack of suitable experimental animal models. Appropriate animal models will facilitate the comprehensive and systematic elucidation of the pathogenesis of PAS. Due to the remarkably similar functional placental villous units and hemochorial placentation to humans, the current animal models of PAS are based on mice. There are various mouse models induced by uterine surgery to simulate different phenotypes of PAS, such as excessive invasion of EVT or immune disturbance at the maternal-fetal interface, which could define the pathological mechanism of PAS from the perspective of the "soil." Additionally, genetically modified mouse models could be used to study PAS, which is helpful to exploring the pathogenesis of PAS from the perspectives of both "soil" and "seed," respectively. This review details early placental development in mice, with a focus on the approaches of PAS modeling. Additionally, the strengths, limitations and the applicability of each strategy and further perspectives are summarized to provide the theoretical foundation for researchers to select appropriate animal models for various research purposes. This will help better determine the pathogenesis of PAS and even promote possible therapy.

The amniotic fluid proteome changes with term labor and informs biomarker discovery in maternal plasma

The intra-uterine components of labor, namely, myometrial contractility, cervical ripening, and decidua/membrane activation, have been extensively characterized and involve a local pro-inflammatory milieu of cellular and soluble immune mediators. Targeted profiling has demonstrated that such processes extend to the intra-amniotic space, yet unbiased analyses of the proteome of human amniotic fluid during labor are lacking. Herein, we utilized an aptamer-based platform to characterize 1,310 amniotic fluid proteins and found that the proteome undergoes substantial changes with term labor (251 proteins with differential abundance, q < 0.1, and fold change > 1.25). Proteins with increased abundance in labor are enriched for immune and inflammatory processes, consistent with prior reports of labor-associated changes in the intra-uterine space. By integrating the amniotic fluid proteome with previously generated placental-derived single-cell RNA-seq data, we demonstrated the labor-driven upregulation of signatures corresponding to stromal-3 and decidual cells. We also determined that changes in amniotic fluid protein abundance are reflected in the maternal plasma proteome. Collectively, these findings provide novel insights into the amniotic fluid proteome in term labor and support its potential use as a source of biomarkers to distinguish between true and false labor by using maternal blood samples.

Ultrasonographic Prediction of Placental Invasion in Placenta Previa by Placenta Accreta Index

This study aimed to investigate the diagnostic accuracy of the placenta accreta index (PAI) for predicting placenta accreta spectrum (PAS) in women with placenta previa. We analyzed 33 pregnancies with placenta previa at Keio University Hospital. The PAI was assessed in the early third trimester, and PAS was diagnosed histologically or clinically defined as retained placenta after manual removal attempts. The PAI and incidence of PAS were analyzed. Ten women (30%) were diagnosed with PAS and had higher volumes of perioperative bleeding (p = 0.016), higher rate of requiring uterine artery embolization (p = 0.005), and peripartum hysterectomy (p = 0.0002) than women without PAS. A PAI > 2 was the most useful cut-off point for predicting PAS and was more sensitive than prediction values using traditional evaluation (history of cesarean section and placental location). Post-hoc analysis revealed a higher rate of previous history of cesarean delivery (30% vs. 4.4%, p = 0.038), severe placental lacunae (≥grade2) (70% vs. 8.7%, p = 0.0003), thin myometrial thickness (90% vs. 22%, p = 0.0003), anterior placenta (100% vs. 30%, p = 0.0002), and presence of bridging vessels (30% vs. 0%, p = 0.0059) in PAS women. PAI could help predict the outcomes of women with placenta previa with and without a history of cesarean delivery to reduce PAS-induced perinatal complications.

Perinatal mood and anxiety disorders: biomarker discovery using plasma proteomics

BACKGROUND

Perinatal mood and anxiety disorders encompass a range of mental health disorders that occur during pregnancy and up to 1 year postpartum, affecting approximately 20% of women. Traditional risk factors, such as a history of depression and pregnancy complications including preeclampsia, are known. Their predictive utility, however, is not specific or sensitive enough to inform clinical decision-making or prevention strategies for perinatal mood and anxiety disorders. Better diagnostic and prognostic models are needed for early identification and referral to treatment.

OBJECTIVE

This study aimed to determine if a panel of novel third-trimester plasma protein biomarkers in pregnant women can be used to identify those who have a high predisposed risk for perinatal mood and anxiety disorders within 3 months postpartum.

STUDY DESIGN

We studied 52 women (n=34 with a risk for perinatal mood and anxiety disorders and n=18 controls) among whom mental health screening was conducted at 2 time points, namely in the third trimester and again at 3 months postdelivery. An elevated perinatal mood and anxiety disorder risk was identified by screening individuals with above-validated cutoffs for depression (Edinburgh Postnatal Depression Scale ≥12), anxiety (Overall Anxiety Severity and Impairment Scale ≥7), and/or posttraumatic stress disorder (Impact of Events Scale >26) at both time points. Plasma samples collected in the third trimester were screened using the aptamer-based SomaLogic SomaScan proteomic assay technology to evaluate perinatal mood and anxiety disorder-associated changes in the expression of 1305 protein analytes. Ingenuity Pathway Analysis was conducted to highlight pathophysiological relationships between perinatal mood and anxiety disorder-specific proteins found to be significantly up- or down-regulated in all subjects with perinatal mood and anxiety disorder and in those with perinatal mood and anxiety disorders and no preeclampsia.

RESULTS

From a panel of 53 significant perinatal mood and anxiety disorder-associated proteins, a unique 20-protein signature differentiated perinatal mood and anxiety disorder cases from controls in a principal component analysis (P<.05). This protein signature included NCAM1, NRCAM, and NTRK3 that converge around neuronal signaling pathways regulating axonal guidance, astrocyte differentiation, and maintenance of GABAergic neurons. Interestingly, when we restricted the analysis to subjects without preeclampsia, a 30-protein signature differentiated perinatal mood and anxiety disorder cases from all controls without overlap on the principal component analysis (P<.001). In the nonpreeclamptic perinatal mood and anxiety disorder group, we observed increased expression of proteins, such as CXCL11, CXCL6, MIC-B, and B2MG, which regulate leucocyte migration, inflammation, and immune function.

CONCLUSION

Participants with perinatal mood and anxiety disorders had a unique and distinct plasma protein signature that regulated a variety of neuronal signaling and proinflammatory pathways. Additional validation studies with larger sample sizes are needed to determine whether some of these molecules can be used in conjunction with traditional risk factors for the early detection of perinatal mood and anxiety disorders.

Circulating microparticle proteins predict pregnancies complicated by placenta accreta spectrum

Placenta accreta spectrum (PAS) is characterized by abnormal attachment of the placenta to the uterus, and attempts at placental delivery can lead to catastrophic maternal hemorrhage and death. Multidisciplinary delivery planning can significantly improve outcomes; however, current diagnostics are lacking as approximately half of pregnancies with PAS are undiagnosed prior to delivery. This is a nested case-control study of 35 cases and 70 controls with the primary objective of identifying circulating microparticle (CMP) protein panels that identify pregnancies complicated by PAS. Size exclusion chromatography and liquid chromatography with tandem mass spectrometry were used for CMP protein isolation and identification, respectively. A two-step iterative workflow was used to establish putative panels. Using plasma sampled at a median of 26 weeks' gestation, five CMP proteins distinguished PAS from controls with a mean area under the curve (AUC) of 0.83. For a separate sample taken at a median of 35 weeks' gestation, the mean AUC was 0.78. In the second trimester, canonical pathway analyses demonstrate over-representation of processes related to iron homeostasis and erythropoietin signaling. In the third trimester, these analyses revealed abnormal immune function. CMP proteins classify PAS well prior to delivery and have potential to significantly reduce maternal morbidity and mortality.

Feto-placental Unit: From Development to Function

The placenta is an intriguing organ that allows us to survive intrauterine life. This essential organ connects both mother and fetus and plays a crucial role in maternal and fetal well-being. This chapter presents an overview of the morphological and functional aspects of human placental development. First, we describe early human placental development and the characterization of the cell types found in the human placenta. Second, the human placenta from the second trimester to the term of gestation is reviewed, focusing on the morphology and specific pathologies that affect the placenta. Finally, we focus on the placenta's primary functions, such as oxygen and nutrient transport, and their importance for placental development.

Human Plasma Proteome During Normal Pregnancy

The human plasma proteome is underexplored despite its potential value for monitoring health and disease. Herein, using a recently developed aptamer-based platform, we profiled 7288 proteins in 528 plasma samples from 91 normal pregnancies (Gene Expression Omnibus identifier GSE206454). The coefficient of variation was <20% for 93% of analytes (median 7%), and a cross-platform correlation for selected key angiogenic and anti-angiogenic proteins was significant. Gestational age was associated with changes in 953 proteins, including highly modulated placenta- and decidua-specific proteins, and they were enriched in biological processes including regulation of growth, angiogenesis, immunity, and inflammation. The abundance of proteins corresponding to RNAs specific to populations of cells previously described by single-cell RNA-Seq analysis of the placenta was highly modulated throughout gestation. Furthermore, machine learning-based prediction of gestational age and of time from sampling to term delivery compared favorably with transcriptomic models (mean absolute error of 2 weeks). These results suggested that the plasma proteome may provide a non-invasive readout of placental cellular dynamics and serve as a blueprint for investigating obstetrical disease.

Toward a new taxonomy of obstetrical disease: improved performance of maternal blood biomarkers for the great obstetrical syndromes when classified according to placental pathology

BACKGROUND

The major challenge for obstetrics is the prediction and prevention of the great obstetrical syndromes. We propose that defining obstetrical diseases by the combination of clinical presentation and disease mechanisms as inferred by placental pathology will aid in the discovery of biomarkers and add specificity to those already known.

OBJECTIVE

To describe the longitudinal profile of placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1), and the PlGF/sFlt-1 ratio throughout gestation, and to determine whether the association between abnormal biomarker profiles and obstetrical syndromes is strengthened by information derived from placental examination, eg, the presence or absence of placental lesions of maternal vascular malperfusion.

STUDY DESIGN

This retrospective case cohort study was based on a parent cohort of 4006 pregnant women enrolled prospectively. The case cohort of 1499 pregnant women included 1000 randomly selected patients from the parent cohort and all additional patients with obstetrical syndromes from the parent cohort. Pregnant women were classified into six groups: 1) term delivery without pregnancy complications (n=540; control); 2) preterm labor and delivery (n=203); 3) preterm premature rupture of the membranes (n=112); 4) preeclampsia (n=230); 5) small-for-gestational-age neonate (n=334); and 6) other pregnancy complications (n=182). Maternal plasma concentrations of PlGF and sFlt-1 were determined by enzyme-linked immunosorbent assays in 7560 longitudinal samples. Placental pathologists, masked to clinical outcomes, diagnosed the presence or absence of placental lesions of maternal vascular malperfusion. Comparisons between mean biomarker concentrations in cases and controls were performed by utilizing longitudinal generalized additive models. Comparisons were made between controls and each obstetrical syndrome with and without subclassifying cases according to the presence or absence of placental lesions of maternal vascular malperfusion.

RESULTS

1) When obstetrical syndromes are classified based on the presence or absence of placental lesions of maternal vascular malperfusion, significant differences in the mean plasma concentrations of PlGF, sFlt-1, and the PlGF/sFlt-1 ratio between cases and controls emerge earlier in gestation; 2) the strength of association between an abnormal PlGF/sFlt-1 ratio and the occurrence of obstetrical syndromes increases when placental lesions of maternal vascular malperfusion are present (adjusted odds ratio [aOR], 13.6 vs 6.7 for preeclampsia; aOR, 8.1 vs 4.4 for small-for-gestational-age neonates; aOR, 5.5 vs 2.1 for preterm premature rupture of the membranes; and aOR, 3.3 vs 2.1 for preterm labor (all P<0.05); and 3) the PlGF/sFlt-1 ratio at 28 to 32 weeks of gestation is abnormal in patients who subsequently delivered due to preterm labor with intact membranes and in those with preterm premature rupture of the membranes if both groups have placental lesions of maternal vascular malperfusion. Such association is not significant in patients with these obstetrical syndromes who do not have placental lesions.

CONCLUSION

Classification of obstetrical syndromes according to the presence or absence of placental lesions of maternal vascular malperfusion allows biomarkers to be informative earlier in gestation and enhances the strength of association between biomarkers and clinical outcomes. We propose that a new taxonomy of obstetrical disorders informed by placental pathology will facilitate the discovery and implementation of biomarkers as well as the prediction and prevention of such disorders.

Potential Serum Biomarkers in Prenatal Diagnosis of Placenta Accreta Spectrum

Placenta accreta spectrum (PAS) refers to the abnormal invasion of trophoblastic tissues. Because of its increasing morbidity and possibility of catastrophic outcomes, PAS requires an antenatal diagnosis and making full preparations in advance to realize safe delivery. Current clinical screening modalities for PAS are not always conclusive. Recently, it has been reported that bio-markers detected in maternal serum have the potential for predicting PAS during pregnancy. Some of these biomarkers, such as β-hcg, AFP, PAPP-A, and cffDNA, can be clinically detected. It is convenient for us to test and compare with standard threshold. However, how can we distinguishing PAS from other pregnancy complications through these biomarkers remains complicated. Some biomarkers are specific, such as microRNA and placenta-specific mRNA. They are stability and reliability. These biomarkers are currently research hotspots. This study aims to summarize the characteristics of the newly reported biomarkers and to point out their potential application and current limitations to provide a basis for future research. Finally, the combination of imageological examination and biomarkers will be an attractive future theme to study in diagnosing this challenging condition.

The role of fetal fibronectin and plasminogen activator inhibitor 1 biomarkers in antenatal prediction of placenta accreta spectrum

In this study, we aimed to assess the determining role of foetal fibronectin (FFN) and plasminogen activator inhibitor type (PAI-1) levels in the antenatal prediction of placenta accreta spectrum in cases with risk factors for placenta accreta spectrum. Singleton live pregnancies with placenta previa or low-lying placenta within 32-34 weeks of gestation were included in the study. The cases were divided into two groups after delivery as those with PAS and those with normal placentation. 54 cases diagnosed with placenta previa or low-lying placenta were included in the study. 17 of the cases underwent peripartum hysterectomy due to placenta accreta spectrum. 37 cases with normal placentation underwent caesarean delivery. Foetal fibronectin (p:.03) and PAI-1 (p:.02) levels were determined to be significantly different between cases with placenta accreta spectrum and cases with normal placentation. AUC for foetal FFN was calculated to be 0.69, while the AUC for, PAI-1was 0.66. Results for both FFN and PAI-1 were not found useful enough for the diagnosis of PAS. IMPACT STATEMENTWhat is already known on this subject? We lack biomarkers which can identify placenta accreta spectrum.What do the results of this study add? Maternal plasma levels of FFN and PAI-1 significantly altered in PASWhat are the implications of these findings for clinical practice and/or future research? If multiple of median values of FFN and PAI-1 levels in maternal blood are determined in future studies, it can be used in the antenatal diagnosis of PAS cases.

New insights into the etiopathology of placenta accreta spectrum

Placenta accreta has been described as a spectrum of abnormal attachment of villous tissue to the uterine wall, ranging from superficial attachment to the inner myometrium without interposing decidua to transmural invasion through the entire uterine wall and beyond. These descriptions have prevailed for more than 50 years and form the basis for the diagnosis and grading of accreta placentation. Accreta placentation is essentially the consequence of uterine remodeling after surgery, primarily after cesarean delivery. Large cesarean scar defects in the lower uterine segment are associated with failure of normal decidualization and loss of the subdecidual myometrium. These changes allow the placental anchoring villi to implant, and extravillous trophoblast cells to migrate, close to the serosal surface of the uterus. These microscopic features are central to the misconception that the accreta placental villous tissue is excessively invasive and have led to much confusion and heterogeneity in clinical data. Progressive recruitment of large arteries in the uterine wall, that is, helicine, arcuate, and/or radial arteries, results in high-velocity maternal blood entering the intervillous space from the first trimester of pregnancy and subsequent formation of placental lacunae. Recently, guided sampling of accreta areas at delivery has enabled accurate correlation of prenatal imaging data with intraoperative features and histopathologic findings. In more than 70% of samples, there were thick fibrinoid depositions between the tip of most anchoring villi and the underlying uterine wall and around all deeply implanted villi. The distortion of the uteroplacental interface by these dense depositions and the loss of the normal plane of separation are the main factors leading to abnormal placental attachment. These data challenged the classical concept that placenta accreta is simply owing to villous tissue sitting atop the superficial myometrium without interposed decidua. Moreover, there is no evidence in accreta placentation that the extravillous trophoblast is abnormally invasive or that villous tissue can cross the uterine serosa into the pelvis. It is the size of the scar defect, the amount of placental tissue developing inside the scar, and the residual myometrial thickness in the scar area that determine the distance between the placental basal plate and the uterine serosa and thus the risk of accreta placentation.

Maternal serum Lamin A is a potential biomarker that can predict adverse pregnancy outcomes

Background

Maternal serum Lamin A (LMNA) was reported to have potential diagnostic value in the prenatal diagnosis of congenital heart disease (CHD). In this study, we aimed to further assess the prognostic value of maternal serum LMNA in predicting adverse pregnancy outcomes.

Methods

A prospective screening study was performed on singleton pregnancies at 15–18 weeks of gestation. After a routine test for alpha fetoprotein (AFP), chorionic gonadotropin (hCG), and unconjugated estriol (uE3), serum LMNA levels were measured. Serum LMNA levels were then converted into multiples of the median (MoM). The median MoM values for adverse pregnancy outcomes were compared with those in normal pregnancies. For diseases with differential LMNA expression in the prospective study, another case-control cohort was recruited. The diagnostic value of LMNA in these diseases was further evaluated.

Findings

Between January 1, 2017 and June 30, 2018, a total of 2906 singleton pregnancies were recruited. Of the 2,906 cases, 2711 had data available for analysis. Congenital structural abnormalities, chromosomal abnormalities, and obstetric complications were observed in 152 (5·6%), 15 (0·6%), and 278 (10·3%) patients, respectively. LMNA was downregulated in pregnancies with fetal CHD, fetal neural tube defects (NTD), and preeclampsia (PE). The case-control study cohort included 256 CHD, 60 NTD, 67 PE, and 400 normal pregnancies. The areas under the curve for the prenatal diagnoses of CHD, NTD, and PE were 0·875, 0·871, and 0·816, respectively.

Interpretation

Maternal serum LMNA was found to be a potential biomarker for the prenatal diagnosis of fetal CHD, NTD, and PE.

Funding

National Key Research and Development Program, National Natural Science Foundation of China, LiaoNing Revitalization Talents Program, National Natural Science Foundation of Liaoning, and 345 Talent Project of Shengjing Hospital.

Developing and Validating Nomogram to Predict Severe Postpartum Hemorrhage in Women With Placenta Previa Undergoing Cesarean Delivery: A Multicenter Retrospective Case-Control Study

Objective

Developing and validating nomogram to predict severe postpartum hemorrhage (SPPH) in women with placenta previa (PP) undergoing cesarean delivery.

Methods

We conducted a multicenter retrospective case-control study in five hospitals. In this study, 865 patients from January, 2018 to June, 2020 were enrolled in the development cohort, and 307 patients from July, 2020 to June, 2021 were enrolled in the validation cohort. Independent risk factors for SPPH were obtained by using the multivariate logistic regression, and preoperative nomogram and intraoperative nomogram were developed, respectively. We compared the discrimination, calibration, and net benefit of the two nomograms in the development cohort and validation cohort. Then, we tested whether the intraoperative nomogram could be used before operation.

Results

There were 204 patients (23.58%) in development cohort and 80 patients (26.06%) in validation cohort experienced SPPH. In development cohort, the areas under the receiver operating characteristic (ROC) curve (AUC) of the preoperative nomogram and intraoperative nomogram were 0.831 (95% CI, 0.804, 0.855) and 0.880 (95% CI, 0.854, 0.905), respectively. In validation cohort, the AUC of the preoperative nomogram and intraoperative nomogram were 0.825 (95% CI, 0.772, 0.877) and 0.853 (95% CI, 0.808, 0.898), respectively. In the validation cohort, the AUC was 0.839 (95% CI, 0.789, 0.888) when the intraoperative nomogram was used before operation.

Conclusion

We developed the preoperative nomogram and intraoperative nomogram to predict the risk of SPPH in women with PP undergoing cesarean delivery. By comparing the discrimination, calibration, and net benefit of the two nomograms in the development cohort and validation cohort, we think that the intraoperative nomogram performed better. Moreover, application of the intraoperative nomogram before operation can still achieve good prediction effect, which can be improved if the severity of placenta accreta spectrum (PAS) can be accurately distinguished preoperatively. We expect to conduct further prospective external validation studies on the intraoperative nomogram to evaluate its application value.

The amniotic fluid proteome changes with gestational age in normal pregnancy: a cross-sectional study

The cell-free transcriptome in amniotic fluid (AF) has been shown to be informative of physiologic and pathologic processes in pregnancy; however, the change in AF proteome with gestational age has mostly been studied by targeted approaches. The objective of this study was to describe the gestational age-dependent changes in the AF proteome during normal pregnancy by using an omics platform. The abundance of 1310 proteins was measured on a high-throughput aptamer-based proteomics platform in AF samples collected from women during midtrimester (16-24 weeks of gestation, n = 15) and at term without labor (37-42 weeks of gestation, n = 13). Only pregnancies without obstetrical complications were included in the study. Almost 25% (320) of AF proteins significantly changed in abundance between the midtrimester and term gestation. Of these, 154 (48.1%) proteins increased, and 166 (51.9%) decreased in abundance at term compared to midtrimester. Tissue-specific signatures of the trachea, salivary glands, brain regions, and immune system were increased while those of the gestational tissues (uterus, placenta, and ovary), cardiac myocytes, and fetal liver were decreased at term compared to midtrimester. The changes in AF protein abundance were correlated with those previously reported in the cell-free AF transcriptome. Intersecting gestational age-modulated AF proteins and their corresponding mRNAs previously reported in the maternal blood identified neutrophil-related protein/mRNA pairs that were modulated in the same direction. The first study to utilize an aptamer-based assay to profile the AF proteome modulation with gestational age, it reveals that almost one-quarter of the proteins are modulated as gestation advances, which is more than twice the fraction of altered plasma proteins (~ 10%). The results reported herein have implications for future studies focused on discovering biomarkers to predict, monitor, and diagnose obstetrical diseases.

Association Between Pre-delivery Coagulation Indicators and Invasive Placenta Accreta Spectrum

Objectives

To analyze the association between pre-operational coagulation indicators and the severity of placenta accreta spectrum (PAS), as well as blood loss volume during operation.

Methods

Hospitalized patients of the obstetric department in a major hospital from 2018 to 2020 who were clinically and/or pathologically diagnosed with invasive PAS were included. Univariate and multivariate logistic regression and Poisson regression models were used to quantify the association between each of the 6 coagulation indicators and PAS severity (measured by FIGO grade) as well as maternal outcomes.

Results

Ninety-five patients (46 FIGO grade 2 and 49 FIGO grade 3) were included. Higher PT [adjusted OR (aOR): 5.54; 95% CI, 1.80 to 17.07] and FDP (aOR: 1.19; 95% CI, 1.01–1.42) levels were associated with an increased risk of FIGO grade 3 after adjusting for covariates. D-dimer [incidence rate ratio (IRR): 1.19; 95% CI, 1.05 to 1.35)] and FDP (IRR: 1.03; 95% CI, 1.01–1.04) levels were significantly associated with higher blood loss volume after adjusting for covariates.

Conclusion

Preoperative coagulation indicators, especially PT, D-dimer and FDP, are associated with disease severity and blood loss volume during operation of invasive PAS. The underlying mechanism for the coagulation profile of PAS patients warrants further analysis.

Synopsis

Preoperative coagulation indicators, especially PT, D-dimer and FDP, are associated with disease severity and blood loss volume during operation among invasive placenta accreta spectrum patients.

Placenta Accreta Spectrum

Placenta accreta spectrum (PAS) refers to the range of pathologic adherence of the placenta to the uterine myometrium, including the placenta accreta, increta, and percreta. The incidence of PAS is rising primarily because of an increase in related risk factors, such as the rate of cesarean deliveries and pregnancies resulting from assisted reproductive technology. The maternal risks associated with PAS are significant, including hemorrhage, hysterectomy, and death. Fetal and neonatal risks are primarily the result of premature delivery. Antenatal diagnosis via ultrasonography and magnetic resonance imaging remains imperfect. Management of PAS varies, however, and there is a clear improvement in maternal outcomes with an antenatal diagnosis compared with unexpected diagnosis at the time of delivery. Studies that evaluate the balance between maternal and fetal/neonatal risks of expectant management versus preterm delivery have found that planned delivery between 34 and 35 weeks' gestation optimizes outcomes. Multidisciplinary PAS care teams have become the norm and recommended approach to management, given the complexity of caring for this obstetrical condition. Although significant advances have been made over the years, large knowledge gaps remain in understanding the pathophysiology, diagnosis, and clinical management.

The "rail sign": an ultrasound finding in placenta accreta spectrum indicating deep villous invasion and adverse outcomes

BACKGROUND

Ultrasound has demonstrated a high accuracy in the prenatal diagnosis of placenta accreta spectrum. However, it is not known whether ultrasound findings can pinpoint the depths of villous invasion, recommend surgical strategies, and predict clinical outcomes.

OBJECTIVE

We described an ultrasound descriptor for the placenta accreta spectrum and investigated whether it can predict the severity of villous invasion and clinical outcomes.

STUDY DESIGN

The patients with placenta accreta spectrum in this retrospective cross-sectional study were diagnosed and managed in our hospital from 2002 to 2017. The placenta, with overlying myometrium and bladder, was mapped with color Doppler sonography while the patient's bladder was full. A "rail sign" was defined as 2 parallel neovascularizations depicted by color Doppler sonography over the uterovesical junction and bladder mucosa, with interconnecting bridging vessels perpendicular to both. The patients received serial ultrasound examinations and surgery at our hospital. An unpaired t test and Pearson chi-square test compared the pathology subtypes, surgical strategies, and clinical outcomes in patients with or without a rail sign.

RESULTS

We enrolled 133 consecutive cases of placenta accreta spectrum confirmed either by surgical inspection or pathology examination. Patients with a rail sign had a significantly higher risk of an abnormally invasive placenta (placenta increta or placenta percreta) than those patients without a rail sign (83.3% [60 of 72] vs 27.9% [17 of 61]; odds ratio, 12.94; P<.001). In addition, patients with a rail sign had a higher probability of perioperative approaches, including preoperative vascular control (58.3% [42 of 72] vs 21.3% [13 of 61]; odds ratio, 5.17; P<.001) and uterine artery embolization (34.7% [25 of 72] vs 11.5% [7 of 61]; odds ratio, 4.1; P=.0002]. Furthermore, patients with a rail sign carried a higher risk of adverse clinical outcomes than patients without a rail sign, such as blood transfusion (80.6% [58 of 72] vs 36.1% [22 of 61]; odds ratio, 7.34; P<.001], admission to the intensive care unit (33.3% [24 of 72] vs 16.4% [10 of 61]; odds ratio, 2.55; P=.026), hysterectomy (75% [54 of 72] vs 24.6% [15 of 61]; odds ratio, 9.2; P<.001), and bladder invasion (16.7% [12 of 72] vs 4.9% [3 of 61]; odds ratio, 3.86; P=.033). Notably, the negative predictive value of bladder invasion was 95.1%, indicating a high confidence to reject bladder invasion while the rail sign was negative. When the rail sign was used as a screening test, the positive likelihood ratio of predicting deep villous invasion was 3.64 and correlated with an increased probability of 20% to 25%. Patients with a rail sign also had a greater blood loss (2944±2748 mL vs 1530±1895 mL; P<.001) and a longer hospital stay (11.9±10.9 days vs 8.6±7.1 days; P=.036) than patients without a rail sign.

CONCLUSION

A "rail sign" depicted by color Doppler sonography correlates with deeper villous invasion, additional perioperative approaches, and more adverse outcomes.

Circulating trophoblast cell clusters for early detection of placenta accreta spectrum disorders

Placenta accreta spectrum (PAS) is a high-risk obstetrical condition associated with significant morbidity and mortality. Current clinical screening modalities for PAS are not always conclusive. Here, we report a nanostructure-embedded microchip that efficiently enriches both single and clustered circulating trophoblasts (cTBs) from maternal blood for detecting PAS. We discover a uniquely high prevalence of cTB-clusters in PAS and subsequently optimize the device to preserve the intactness of these clusters. Our feasibility study on the enumeration of cTBs and cTB-clusters from 168 pregnant women demonstrates excellent diagnostic performance for distinguishing PAS from non-PAS. A logistic regression model is constructed using a training cohort and then cross-validated and tested using an independent cohort. The combined cTB assay achieves an Area Under ROC Curve of 0.942 (throughout gestation) and 0.924 (early gestation) for distinguishing PAS from non-PAS. Our assay holds the potential to improve current diagnostic modalities for the early detection of PAS.

Placenta accreta spectrum (PAS) is a high-risk obstetrical complication associated with significant morbidity and mortality. Here the authors discover a uniquely high prevalence of circulating trophoblasts clusters in PAS and explore their diagnostic potential to augment current diagnostic modalities for the early detection of PAS.

Proteome Characterization of Glaucoma Aqueous Humor

Glaucoma is the leading cause of irreversible blindness worldwide. The proteome characterization of glaucoma is not clearly understood. A total of 175 subjects, including 57 primary acute angle-closure glaucoma (PAACG), 50 primary chronic angle-closure glaucoma (PCACG), 35 neovascular glaucoma (NVG), and 33 cataract patients, were enrolled and comparison proteomic analysis was provided. The samples were randomly divided into discovery group or validation group, whose aqueous humor proteome was analyzed by data-independent acquisition or by parallel reaction monitoring. The common proteome features of three types of glaucoma were immune response, lipid metabolism, and cell death. Three proteins, VTN, SERPIND1, and CD14, showed significant upregulation in glaucoma and could discriminate glaucoma from cataract. Mutual differential proteomic analysis of PAACG, PCACG, and NVG showed different proteome characterization of the three types of glaucoma. NVG was characterized with activated angiogenesis. PAACG was characterized with activation of inflammation response. SERPIND1 was discovered to play vital role in glaucoma occurrences, which is associated with eye transparency decrease and glucose metabolism. This study would provide insights in understanding proteome characterization of glaucoma and benefit the clinical application of AH proteome.

•

Aqueous humor proteome of different glaucoma (PACG, NVG) was profiled.

•

Potential protein biomarkers for glaucoma were proposed.

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Potential mechanism of glaucoma was described.

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SERPIND1 was discovered to have potential value for glaucoma diagnosis.

Maternal Serum Placental Protein-13 Levels in the Prediction of Pregnancies with Abnormal Invasive Placentation

OBJECTIVE

To evaluate whether placental protein-13 (PP-13) measured in the serum of pregnant women could predict abnormal invasive placentation (AIP) detected by color Doppler ultrasound (US) and magnetic resonance imaging scan in addition to the routine US scan during the third trimester.

MATERIALS AND METHODS

The prospective case-control study included patients subdivided in 2 groups: 42 pregnant women with a singleton pregnancy at 28-32 weeks of gestation with only suspected AIP, and 32 healthy pregnant women. The serum PP-13 levels were measured in both groups using an enzyme-linked immunosorbent assay (ELISA) method and statistically compared. The cases of AIP were confirmed by placental histopathological examination and/or the uterus removed by hysterectomy after elective caesarean section.

RESULTS

Serum PP-13 levels of pregnant women with AIP were significantly higher (p<0.001) than those of controls (650.32±387.33 vs. 231.43±94.33). Statistical analysis of maternal serum PP-13 levels above the threshold of 312 pg/ml (measured in the early third trimester) predicted AIP with 76.2% sensitivity and 75% specificity.

CONCLUSION

Maternal serum PP-13 may have a role in the pathophysiology of AIP owing to its high serum value in the AIP group. The maternal serum dosage of PP-13 levels could improve pregnancy management in those patients suspected of having AIP.

Placenta accreta spectrum disorder: updates on anesthetic and surgical management strategies

Placenta accreta spectrum (PAS) is a leading contributor to major obstetric hemorrhage and severe maternal morbidity in the developed world. In the United States, PAS has become the most common cause of peripartum hysterectomy. Over the last 40 years, clinicians have also witnessed a dramatic increase in the incidence of PAS. In the 1950s, the incidence of PAS was reported to be 0.03 per 1000 pregnancies. Recent epidemiological studies estimate that the PAS incidence is between 0.79 and 3.11 in 1000 pregnancies. As a consequence, obstetric anesthesiologists are increasingly likely to be called upon to manage women with suspected PAS for delivery. Given the increasing incidence and the morbidity burden associated with PAS, anesthesiologists play a vital role in optimizing maternal outcomes for women with PAS. This review will provide up-to-date information on nomenclature, pathophysiology, risk factors, antenatal detection, systemic preparations (includes timing of delivery, location of surgery, pre-operative evaluation and patient positioning), surgical and anesthetic approach, intra-operative management, invasive radiology and postoperative plans.

Parenteral lipid emulsions induce unique ileal fatty acid and metabolomic profiles but do not increase the risk of necrotizing enterocolitis in preterm pigs

Necrotizing enterocolitis (NEC) is a manifestation of maladaptive intestinal responses in preterm infants centrally medicated by unattenuated inflammation. Early in the postnatal period, preterm infants develop a deficit in arachidonic and docosahexaenoic acid, both potent regulators of inflammation. We hypothesized that the fatty acid composition of parenteral lipid emulsions uniquely induces blood and intestinal fatty acid profiles which, in turn, modifies the risk of NEC development. Forty-two preterm pigs were randomized to receive one of three lipid emulsions containing 100% soybean oil (SO), 15% fish oil (MO15), or 100% fish oil (FO100) with enteral feedings over an 8-day protocol. Blood and distal ileum tissue were collected for fatty acid analysis. The distal ileum underwent histologic, proteomic, and metabolomic analyses. Eight pigs [3/14 SO (21%), 3/14 MO15 (21%), and 2/14 FO100 (14%)] developed NEC. No differences in NEC risk were evident between groups despite differences in induced fatty acid profiles in blood and ileal tissue. Metabolomic analysis of NEC versus no NEC tissue revealed differences in tryptophan metabolism and arachidonic acid-containing glycerophospholipids. Proteomic analysis demonstrated no differences by lipid group; however, 15 proteins differentiated NEC versus no NEC in the domains of tissue injury, glucose uptake, and chemokine signaling. Exposure to parenteral lipid emulsions induces unique intestinal fatty acid and metabolomic profiles; however, these profiles are not linked to a difference in NEC development. Metabolomic and proteomic analyses of NEC versus no NEC intestinal tissue provide mechanistic insights into the pathogenesis of NEC in preterm infants.NEW & NOTEWORTHY Exposure to parenteral lipid emulsions induces unique intestinal fatty acid and metabolomic profiles; however, these profiles are not linked to a difference in NEC risk in preterm pigs. Metabolomic and proteomic analyses provide mechanistic insights into NEC pathogenesis. Compared with healthy ileal tissue, metabolites in tryptophan metabolism and arachidonic acid-containing glycerophospholipids are increased in NEC tissue. Proteomic analysis differentiates NEC versus no NEC in the domains of tissue injury, glucose uptake, and chemokine signaling.

Preliminary RNA-microarray analysis of long non-coding RNA expression in abnormally invasive placenta

Long non-coding RNAs (lncRNAs) are reported to have important roles in placental development and function, but the role of lncRNAs in abnormally invasive placenta (AIP) remains elusive. In the present study, the differential expression profiles of lncRNAs were analyzed to identify novel targets for further study of AIP. A total of 10 lncRNAs were chosen for validation by reverse transcription-quantitative PCR. To further determine the functions of dysregulated lncRNAs and their corresponding mRNAs, functional enrichment analysis, coexpression analysis were performed. A total of 329 lncRNAs and 179 mRNAs were identified to be differently expressed between the invasive and control group. Gene ontology analysis revealed that the 10 most significantly enriched functions included upregulated mRNAs and the most significantly enriched term was related to the proteinaceous extracellular matrix (ECM). In the pathway analysis, the two most significantly enriched pathways were the TGF-β signaling pathway for upregulated mRNAs and the pentose phosphate pathway for downregulated mRNAs. Furthermore, for certain dysregulated lncRNAs, their associated mRNAs were also dysregulated. Of note, BMP and activin membrane-bound inhibitor and TGF-β-induced, as the target genes of the TGF-β pathway, were indicated to be closely related to the ECM and invasive placental cells. Their nearby lncRNAs G008916 and vault RNA2-1 were also significantly dysregulated. In conclusion, significant lncRNAs with the potential to serve as biomarkers for AIP were identified.

Placenta Accreta Spectrum Disorders: Challenges, Risks, and Management Strategies

The worldwide incidence of placenta accreta spectrum (PAS) is rapidly increasing, following the trend of rising cesarean delivery. PAS is an heterogeneous condition associated with a high maternal morbidity and mortality rate, presenting unique challenges in its diagnosis and management. So far, the rarity of this condition, together with the absence of high quality evidence and the lack of a standardized approach in reporting PAS cases for the ultrasound, clinical, and pathologic diagnosis, represented the main challenges for a deep understanding of this condition. The study of the available management strategies of PAS has been hampered by the heterogeneity of the available epidemiological data on this condition. The aim of this review is to provide a critical view of the current available evidence on the screening, the diagnosis, and the management options for PAS disorders, with a special focus on the challenges we foresee for the near future.