Maternal vascular malperfusion of the placental bed

The roles of maternal one-carbon metabolism and placental imprinted gene expression in placental development and somatic growth in a longitudinal birth cohort

OBJECTIVES

One-carbon nutrients and imprinted genes both play critical roles in placental development and somatic growth. We aimed to examine (1) the impact of maternal one-carbon nutrition on placental imprinted gene expression, placental development, and infant growth and (2) interactions between one-carbon nutrients and imprinted genes in placental development and infant growth.

METHODS

Women were interviewed prenatally about demographics and their alcohol, smoking, and drug use during pregnancy in a prospective longitudinal cohort study examining developmental effects of prenatal alcohol exposure in Cape Town, South Africa (N = 158). Erythrocyte folate, serum vitamin B12, and plasma choline concentrations were assayed at recruitment. Infant weight and height were assessed at age 2 weeks. Placental histopathology exams and placental expression of 109 imprinted genes (Nanostring) were assessed (n = 65).

RESULTS

In limma tests, women with plasma choline concentrations below the median had lower placental expression of EPS15, IGF2R, LINC00657, SGCE, ZC3H12C, and ZNF264 than women above the median (p < 0.05, FDR<0.10). In regression models adjusted for potential confounders, plasma choline (μM) was associated with larger placental weight (g) (B = 14.0(1.9, 26.2)) and reduced maternal vascular underperfusion (MVU) prevalence (B = -0.07(-0.12, -0.02). Trends were seen for mediation of the relation between choline and MVU by decreased LINC00657, ZC3H12C, and ZNF264 expression. In regression models examining plasma cholineXimprinted gene expression interaction effects, plasma choline modified relations of EPS15, ZC3H12C, and ZNF264 to placental weight and fetal growth.

CONCLUSIONS

These findings suggest maternal choline status may impact placental and fetal development, with imprinted genes playing potential mechanistic roles.

Placental Findings in Term Singleton Stillbirths in a Public Hospital in Emalahleni Sub-District in Mpumalanga Province: A Descriptive Study

OBJECTIVE

This study was carried out to investigate the macroscopical and microscopical placental findings in term singleton stillbirths at a selected public hospital.

METHODS

A quantitative non-experimental observational descriptive study was conducted by examining the placentas of 89 term singleton stillbirth babies in the labor ward for macroscopic lesions. A data collection tool was used to capture clinical data from patient files on variables of interest related to placental lesions for stillbirth cases. The IBM SPSS Statistics version 28 package was used to analyze the data.

RESULTS

A significant relationship was found between the following variables (p < 0.05): stillbirth and number of antenatal care visits (p = 0.0035); birth weight and mid-upper arm circumference (p = 0.013); birth weight and maternal vascular malperfusion (MVM) (p = 0.001); birth weight and birth attendant (p = 0.034); type of stillbirth and birth attendant (p = 0.033); type of stillbirth and previous obstetric history (p = 0.038); cord insertion and smoking/substance abuse (p = 0.012); cord insertion and hemoglobin (p = 0.029); cord length and meconium histiocytes (p = 0.031); cord diameter and syphilis (p = 0.030); placental weight and onset of labor (p = 0.012); placental weight and fetal vascular malperfusion (FVM) (p = 0.004); color of membranes and maternal inflammatory response (MIF) (p = 0.002); color of membranes and meconium histiocytes (p = 0.000), and color of membranes and syphilis (p = 0.053).

CONCLUSION

The study provides essential insights into the placental findings associated with term singleton stillbirths in the Emalahleni Sub-District. Examination of the placenta may help to define the causes in more than 90% of stillbirth cases, inform the research, and decrease stillbirth rates.

Gestational diabetes mellitus and vascular malperfusion lesions in the placenta: A systematic review and meta-analysis

BACKGROUND

Gestational diabetes mellitus (GDM) can result in increased placental lesions related to high maternal blood glucose, but these relationships are not well understood.

OBJECTIVE

To examine the relationship between GDM and placental vascular malperfusion lesions: accelerated villous maturation, increased syncytial knots, delayed villous maturation, and increased fibrin deposition.

SEARCH STRATEGY

PubMed, BIOSIS, and Web of Science databases were systematically searched for full-text articles in English from inception until August 21, 2024.

SELECTION CRITERIA

Our inclusion criteria were randomized controlled trials, case-control, cohort, and cross-sectional studies that examined the relationship between GDM and selected placental vascular malperfusion lesions. The outcome must have been reported as a total proportion.

DATA COLLECTION AND ANALYSIS

We included all eligible studies in narrative synthesis. If an outcome of interest was in at least three studies, we calculated the odds ratios (ORs) by GDM diagnosis, with 95% confidence intervals (CIs), using mixed-effects logistic regression with random study effects. We evaluated the risk of bias with the Newcastle-Ottawa Scale.

MAIN RESULTS

We screened 151 studies, of which eight were included (n = 1291), and six met the criteria for meta-analysis (n = 561). Unadjusted odds (95% CI) of delayed villous maturation were six-fold higher (OR: 6.37 [3.28-12.37]) in pregnancies with GDM than in those without GDM. The narrative synthesis of the literature found higher proportions of increased syncytial knots, delayed villous maturation, and increased fibrin deposition, but not accelerated villous maturation, in pregnancies with versus without GDM.

CONCLUSIONS

GDM was associated with a higher risk of three placental malperfusion lesions, although there is a small number of studies in this area. Future investigations should examine if these vascular malperfusions are associated with adverse pregnancy outcomes often linked with GDM.

Difference in adverse neonatal outcomes between preterm singletons and twins possibly explained by placental abnormalities

INTRODUCTION

The purpose of this study was to compare microscopic placental characteristics between preterm twins and singletons, and between preterm monochorionic and dichorionic twins, in order to explore the effect of placental pathology on adverse neonatal outcomes.

METHODS

This study included 566 neonates born ≤32 weeks and/or ≤1500 g, of whom 429 were singletons and 137 were twins (38 monochorionic and 99 dichorionic). Clinical data was retrospectively collected, and placentas were prospectively examined for maternal vascular malperfusion, fetal vascular malperfusion and placental inflammation (acute and chronic).

RESULTS

Singletons had increased rates of maternal vascular malperfusion, fetal hypoxia, funisitis (in umbilical cord and chorial plate), chronic deciduitis, and villitis of unknown etiology compared to twins. Delayed villous maturation and ischemia were more frequently present in monochorionic placentas than in dichorionic. Singletons had a significant lower birthweight and were more often small for gestational age than twins. Multivariate linear regression analysis adjusting for singleton pregnancy, gestational hypertension and placental abnormalities showed that gestational hypertension (β = -114.8), infarct (β = -130.1), decidual necrosis (β = -115.4), fetal hypoxia (β = -59.3) and chronic deciduitis (β = -118.8) were independently associated with lower birthweight. Multivariate regression analysis revealed five independent risk factors of small for gestational age: gestational hypertension (OR 4.4), infarct (OR 3.7), decidual necrosis (OR 2.7), fetal hypoxia (OR 1.9) and villitis (OR 5.2).

DISCUSSION

Singleton pregnancies vary in histological placental abnormality rates from twin pregnancies. This study demonstrated that differences in birthweight and small for gestational age rates between preterm twins and singletons can be attributed to gestational hypertension and histological placental abnormalities.

A retrospective analysis of placental histopathological findings in gestational diabetes mellitus (GDM)

INTRODUCTION

The placenta plays a pivotal role in supporting fetal growth and disruptions in its development and function can impact fetal outcomes. While placental pathology has been extensively studied in clinical conditions such as pre-eclampsia and fetal growth restriction (FGR), the association between placental abnormalities and gestational diabetes mellitus (GDM) is still unclear. This study aims to explore the placental pathology associated with GDM, shedding light on potential links to adverse perinatal outcomes.

METHODS

A retrospective cohort study was conducted using electronic patient data from the Fetal Medicine and Neonatal Units at University College London Hospital. Placental samples were obtained and analysed at Great Ormond Street Hospital. Maternal demographics, obstetric history and placental histopathology were reviewed. Statistical analyses were performed to identify associations and risk factors.

RESULTS

Of the 2580 pregnancies analysed, 341 were GDM pregnancies, 549 had FGR and 66 had both GDM and FGR. GDM pregnancies required increased rates of obstetric intervention and neonatal care admission. Placental pathology in GDM revealed a higher prevalence of maternal vascular malperfusion (MVM) lesions, whilst GDM-related FGR showed further associations with MVM lesions and adverse perinatal outcomes.

DISCUSSION

Our study highlights MVM lesions as a prominent feature in the placentas of GDM pregnancies, especially when associated with FGR. These lesions are linked to adverse perinatal outcomes, emphasizing the need for enhanced antenatal care in these cases. The study contributes insights into the complex relationship between GDM, placental pathology and adverse fetal outcomes, laying the foundation for future investigations into early interventional strategies.

Vascular Placental Pathology and Cardiac Structure in Stillborn Fetuses

OBJECTIVE

 Adverse pregnancy outcomes, including preterm birth and preeclampsia, are associated with worse cardiovascular outcomes for offspring. Examination of the placenta is important for understanding how the prenatal period shapes long-term cardiovascular health. We sought to investigate the association between placental vascular malperfusion and fetal cardiac structure.

STUDY DESIGN

 Data obtained from the Stillbirth Collaborative Research Network included stillbirths with placental pathology and autopsy. Stillbirths were classified in two ways: based on the severity of placental maternal vascular malperfusion (MVM) and based on the cause of death (MVM, fetal vascular malperfusion [FVM], or acute infection/controls). Organ weight and heart measures were standardized by gestational age (GA) and compared across groups.

RESULTS

 We included 329 stillbirths in the analysis by MVM severity and 76 in the analysis by cause of death (COD). While z-scores for most organ weights/heart measures were smaller when COD was attributed to MVM as compared with FVM or controls, heart weight and brain weight z-scores did not differ by COD (p > 0.05). In analyses accounting for body size, the difference between heart and body weight z-score was -0.05 (standard deviation [SD]: 0.53) among those with MVM as a COD and -0.20 (SD: 0.95) among those with severe MVM. Right and left ventricle thicknesses and tricuspid, pulmonary, mitral, and aortic valve circumferences were consistently as expected or larger than expected for GA and body weight. In the analysis investigating the severity of MVM, those with the most severe MVM had heart measures that were as expected or larger than expected for body weight while those with only mild to moderate MVM had heart measures that were generally small relative to body weight.

CONCLUSION

 When assessed as COD or based on severity, MVM was associated with heart measures that were as expected or larger than expected for GA and body weight, indicating possible heart sparing.

KEY POINTS

· Fetal deaths with MVM show smaller organ weights.. · Heart weight sparing is seen with fetal death attributed to MVM.. · Heart weight sparing is more pronounced with severe MVM..

Placenta and Intestinal Injury in Preterm Infants

Necrotizing enterocolitis (NEC) is one of the most common gastrointestinal conditions affecting 6 to 10% of low-birth-weight infants and remains a leading cause of death. The risk factors associated with NEC are complex and multifactorial, including preterm birth and intrauterine exposure to inflammation and hypoxia. Chorioamnionitis has been associated with intestinal injury in animal and human clinical studies. This review presents current evidence about the clinical impact of the intrauterine environment on intestinal injury during pregnancy and postpregnancy. We present information from our own clinical and laboratory research in conjunction with information collected from an extensive search in the databases PubMed, EMBASE, and Scopus. Prospective multicenter studies, including accurate and precise clinical, maternal, and laboratory predictors (e.g., inflammatory biomarkers), will help identify the mechanisms associated with the placental pathology, the development of NEC, and the impact of in utero-triggered inflammation on the clinical outcomes. Filling the knowledge gap to link the inflammatory surge to postnatal life will aid in identifying at-risk infants for NEC in a timely manner and facilitate the development of novel immunomodulatory treatments or interventions to improve the outcomes of these vulnerable infants. KEY POINTS: · Placental inflammatory and vascular lesions are associated with NEC severity.. · Higher grade chorioamnionitis with a fetal response is associated with an increased risk of surgical NEC.. · There is a need for routine bedside utilization of placenta pathology in clinical decision-making..

Placental Vascular Malperfusion in Pregnancies With Congenital Heart Disease: A Prospective Comparative Study

BACKGROUND

Advances in congenital heart disease (CHD) management have improved survival rates, resulting in a growing population of women of childbearing age with CHD. These women face higher risk of obstetric and neonatal complications during pregnancy. While the underlying mechanisms remain unclear, previous studies have identified maternal vascular malperfusion (MVM) in their placentas.

OBJECTIVES

This study aimed to compare the prevalence of MVM in pregnant women with CHD to those without CHD, assess its association with obstetric and neonatal outcomes, and explore potential risk factors for MVM.

METHODS

In this prospective single-center study, we enrolled pregnant women with CHD who were followed from March 2021 to June 2023, along with a control group matched for age, parity, and body mass index. Placentas were analyzed for MVM using a scoring system based on the Amsterdam Placental Workshop Group Consensus guidelines. N-terminal pro b-type natriuretic peptide assays in the second trimester and echocardiography in the third trimester were performed to evaluate maternal cardiovascular health.

RESULTS

Placentas from 39 CHD and 67 control women were analyzed. MVM prevalence was significantly higher in the CHD group compared to controls (56.4% vs 13.4%, P < 0.001). CHD pregnancies had a higher incidence of adverse obstetric and neonatal outcomes, which were independently associated with MVM (RR: 7.2, P = 0.002). No clinical or paraclinical factors were associated with MVM in CHD women.

CONCLUSIONS

Women with CHD had a higher prevalence of MVM compared to controls, which was associated with adverse pregnancy outcomes. However, no clinical or paraclinical risk factors for MVM were identified.

The placenta in fetal death: molecular evidence of dysregulation of inflammatory, proliferative, and fetal protective pathways

BACKGROUND

It is estimated that over 2 million cases of fetal death occur worldwide every year, but, despite the high incidence, several basic and clinical characteristics of this disorder are still unclear. Placenta is suggested to play a central role in fetal death. Placenta produces hormones, cytokines and growth factors that modulate functions of the placental-maternal unit. Fetal death has been correlated with impaired secretion of some of these regulatory factors.

OBJECTIVE

The aim of the present study was to evaluate, in placentas collected from fetal death, the gene expression of inflammatory, proliferative and protective factors.

STUDY DESIGN

Cases of fetal death in singleton pregnancy were retrospectively selected, excluding pregnancies complicated by fetal anomalies, gestational diabetes, intrauterine growth restriction and moderate to severe maternal diseases. A group of placentas collected from healthy singleton term pregnancies were used as controls. Groups were compared regarding maternal and gestational age, fetal sex and birthweight. Placental messenger RNA expression of inflammatory (interleukin 6), proliferative (activin A, transforming growth factor β1) and regulatory (vascular endothelial growth factor, vascular endothelial growth factor receptor 2, ATP-binding cassette transporters (ABC) ABCB1 and ABCG2, sphingosine 1-phosphate signaling pathway) markers was conducted using real-time polymerase chain reaction. Statistical analysis and graphical representation of the data were performed using the GraphPad Prism 5 software. For the statistical analysis, Student's t test was used, and P values<.05 were considered significant.

RESULTS

Placental mRNA expression of interleukin 6 and vascular endothelial growth factor receptor 2 resulted significantly higher in the fetal death group compared to controls (P<.01), while activin A, ABCB1, and ABCG2 expression resulted significantly lower (P<.01). A significant alteration in the sphingosine 1-phosphate signaling pathway was found in the fetal death group, with an increased expression of the specific receptor isoforms sphingosine 1-phosphate receptor 1, 3, and 4 (sphingosine 1-phosphate1, sphingosine 1-phosphate3, sphingosine 1-phosphate4) and of sphingosine kinase 2, 1 of the enzyme isoforms responsible for sphingosine 1-phosphate synthesis (P<.01).

CONCLUSION

The present study confirmed a significantly increased expression of placental interleukin 6 and vascular endothelial growth factor receptor 2 mRNA, and for the first time showed an increased expression of sphingosine 1-phosphate receptors and sphingosine kinase 2 as well as a decreased expression of activin A and of selected ATP-binding cassette transporters, suggesting that multiple inflammatory and protective factors are deranged in placenta of fetal death.

SARS-CoV-2 Infection and Its Association with Maternal and Fetal Redox Status and Outcomes: A Prospective Clinical Study

Background: The impact of the SARS-CoV-2 viral infection during pregnancy on the fetus can be direct-transmitted through the placenta-and indirect-creating unfavorable conditions for the development of the fetus because of inflammation, micro-thrombosis, and hypercoagulation. Our study aimed to determine the types and frequency of pathohistological changes in placental tissue in SARS-CoV-2-positive pregnant women and to examine the possible role of oxidative stress in the prognosis of the delivery and its maternal and fetal complications. Methods: This prospective clinical study included 50 pregnant women divided into two groups, SARS-CoV-2 positive (COVID-19 group) and SARS-CoV-2 negative (control group), from who we collected demographic, clinical, obstetric, biochemical and pathologic data. Data about the newborn characteristics were also collected, which included anamnestic, clinical, and biochemical data. Results: The values of the superoxide anion radical and index of lipid peroxidation were significantly different in mothers concerning the presence of the SARS-CoV-2 infection, while the levels of the nitric oxide, index of lipid peroxidation, reduced glutathione, and superoxide dismutase were significantly different in the newborns depending on the SARS-CoV-2 infection. Newborn characteristics were similar between groups except for concentrations of IgM antibody. The incidence of pathohistological changes of the FVM type in the COVID-19 group of pregnant women was 46%, while in the control group, the incidence was 18%. Conclusions: This study confirmed the significant impact of the SARS-CoV-2 viral infection on maternal and fetal biochemical parameters and oxidative stress-mediated placental dysfunction. Future studies should be performed with more participants and follow-up neonatal development.

Association of Placental Pathology and antibiotic exposure after birth with the Severity of Necrotizing Enterocolitis in Preterm infants - A Matched Case-Control Study

Objective

To determine the association between antibiotic exposure following birth and necrotizing enterocolitis (NEC) severity in preterm infants.

Methods

This single center matched case-control study included infants with NEC (n=107) and matched controls (n= 130) with antibiotic exposure =< 3 days and > 3 days after birth.

Results

Out of 212 infants,103 infants (48.5%) received antibiotics =< 3 days, and 109 infants (51.5%) received antibiotics >3 days. On the multivariate regression, Infants receiving antibiotics for >3 day had higher risk for medical NEC (aOR 2.61,95% CI 1.35 -5.16; p=0.005) and surgical NEC (aOR 3.33, CI 1.57-7.40; p=0.02) than controls. In NEC cohort, those receiving antibiotics for >3 days were like to die (OR 7.88,95% CI 1.99- 53.74; p=0.010) than those receiving antibiotics <3 days.

Conclusion

Infants exposed with early antibiotics >3 days after birth were more likely associated with NEC and were at greater risk of death.

Placental Pathology and Blood Pressure at Age 7: A Longitudinal Discordant Twin Analysis

BACKGROUND

Evidence suggests that the intrauterine environment shapes offspring cardiovascular disease risk. Although placental dysfunction may be an important pathophysiologic pathway, numerous parental and pregnancy characteristics that influence offspring blood pressure are strong confounders of the mechanistic role of the placenta in observational analyses of singletons. Therefore, we leverage twin- and sibling-based comparison designs to determine whether placental pathology is associated with offspring blood pressure at age 7 while mitigating major sources of confounding.

METHODS

Data are from pregnant participants and their offspring in the Collaborative Perinatal Project, a longitudinal pregnancy cohort conducted from 1959 to 1965 in the United States. After delivery, placentas were systematically examined for lesions indicative of maternal vascular malperfusion (MVM) and acute inflammation. Blood pressure was assessed at a follow-up research visit when the offspring were 7 years old. Linear fixed-effects models were used to estimate associations between within-twin or sibling discordance in placental pathology and differences in blood pressure at age 7.

RESULTS

Overall, 193 twin pairs were eligible for inclusion, and 23.3% had placentas discordant for MVM. In a fixed-effect analysis, a twin with high-grade MVM had a higher systolic blood pressure Z score by 0.56 SDs than their co-twin without MVM (95% CI, 0.06-1.05) or a 5.7-mm Hg difference (95% CI, 0.6-10.8). Associations were consistent in a sensitivity analysis restricted to dichorionic twins and in a secondary analysis of 759 MVM-discordant sibling pairs. Acute placental inflammation was not associated with blood pressure at age 7.

CONCLUSIONS

MVM in the placenta is associated with higher offspring blood pressure in mid-childhood, independent of parental and pregnancy characteristics that twins have in common. The findings support the role of the placenta and the intrauterine environment in the developmental origins of cardiovascular health.

Congenital Heart Disease Fetuses Have Decreased Mid-Gestational Placental Flow, Placental Malperfusion Defects, and Impaired Growth

Background

Placental health may impact the development and outcomes of congenital heart disease (CHD). CHD fetuses have been shown retrospectively to have decreased placental blood flow.

Objectives

The purpose of this study was to determine if CHD fetuses with decreased placental blood flow have placental pathology at birth and if there is a relationship between placental blood flow, placental pathology, and outcomes.

Methods

We performed a prospective case-control study of 38 CHD fetuses, including 28 with single ventricle physiology and 36 controls. Demographic, clinical, and postnatal biometric data were collected. Umbilical venous volume flow (UVVF) was measured from 2nd trimester fetal echocardiograms. Placentas underwent standardized pathological analysis. Standard descriptive statistics and regression analyses were performed to analyze the relationship between UVVF, placental defects, and outcomes.

Results

CHD fetuses had a 15% decrease in mid-gestational UVVF indexed to fetal weight (P < 0.01), and a 27% reduction in UVVF as a proportion of fetal cardiac output (P < 0.01) compared to controls. CHD fetuses had increased placental maternal vascular malperfusion (MVM) lesions (44% vs 18%, P < 0.05), especially high-grade MVM (39% vs 9.1%, P = 0.05), and a trend toward increased placental fetal vascular malperfusion lesions (42% vs 23%, P = 0.10). Placental MVM but not fetal vascular malperfusion lesions were associated with decreased birth weight in CHD fetuses (P < 0.001). There was no association between UVVF and placental pathologic findings or fetal growth.

Conclusions

CHD (particularly single ventricle) fetuses have decreased mid-gestational placental blood flow, increased placental malperfusion defects, and impaired fetal growth. Placental MVM may influence impaired fetal growth in CHD.

Predicting Thrombophilia in Preeclampsia: Is Universal Testing Necessary?

IntroductionThrombophilia (TP) has been proposed as a potential contributor to preeclampsia (PE). However, there is not a clear consensus on testing PE patients for TP due to contradictory evidences on this association. This study aims to identify what conditions of women with PE are associated with acquired and hereditary TP, and, additionally, to build a model of TP probability using these characteristics.Material and MethodsRetrospective unicentric analysis of women diagnosed with PE referred for TP testing between May 2019 and May 2024.ResultsIn 95 women, 19 (20%) tested positive for TP, of which nine (47%) had antiphospholipid syndrome (APS), six (32%) were heterozygous for PT G20210A, two (11%) had ADAMTS13 deficiency, one (5%) had PS deficiency and one (5%) had heterozygous FV Leiden. In multivariate analysis, intrauterine growth retardation (IUGR; odds ratio (OR) 0.08, 95% confidence interval (CI) 0.01-0.55) and history of previous abortions (OR 0.22, 95%CI 0.06-0.96) were negatively associated with TP. The group of women with both, one or none of those traits showed respectively a TP prevalence of 0%, 15% and 32%. The higher the prevalence of TP, the lower the incidence of placental insufficiency and prematurity (P < .05).ConclusionsIn pregnant women with PE, a history of previous abortions and IUGR were independently associated with the absence of TP. Women without these characteristics would probably benefit most from a Hematology consultation that includes a TP screening. A multinational standard TP screening framework for future studies is warranted to further our understanding of the role of TP in PE and to identify risk-groups for testing.

Placental lesions in stillbirth following the Amsterdam consensus: A systematic review and meta-analysis

Placental disorders remain one of the main causes of stillbirth. However, the lack of standardised nomenclature has significantly limited the clinical utility of placental histology. Following the Amsterdam consensus classification, which now allows proper comparisons of placenta histology across the world, we conducted the first systematic review and meta-analysis (Prospero CRD42023410469) to assess the commonest stillbirth-associated placental lesions worldwide. Eighteen studies with 3082 placentas were included. Maternal vascular malperfusion and fetal vascular malperfusion were the most prevalent placental lesions in stillbirth, and significantly more frequent in stillbirths than livebirths [OR 3.0 (95 % CI 2.0-4.5), p < 0.001 and OR 5.12 (95 % CI 3.09-8.47), p < 0.001, respectively]. However, when adjusting for gestational age, only maternal vascular malperfusion remained significant at term. Better understanding of the pathophysiology underlying placental lesions is needed to inform timely risk assessment and therapeutic interventions capable of reducing placental-related stillbirths.

Placenta a potential gateway of prenatal SARS-CoV-2 infection: A review

SARS-CoV-2, the causative agent of COVID-19, can infect various tissues in the body apart from the lungs. Although placental infection remains controversial, COVID-19-associated placental abnormalities have been reported worldwide. Therefore, COVID-19 poses a significant risk for fetal distress as well. Scientists are currently debating whether such distress results from direct viral induced assault or placental damage caused by the mother's immune response. The placenta develops different histopathological lesions in response to maternal SARS-CoV-2 infection. While some studies support both theories, the transmission rate through the placenta remains low. Therefore, a more in-depth study is necessary to determine the primary cause of maternal SARS-CoV-2-induced fetal distress. This comprehensive review is aimed to shed light on the possible reasons towards fetal distress among mothers with COVID-19. This review describes the various mechanisms of viral entry along with the mechanisms by which the virus could affect the placenta. Reported cases of placental abnormalities and fetal distress symptoms have been collated to provide an overview of the current state of knowledge on vertical transmission of COVID-19.

Association between placental location and cord insertion site with pre-eclampsia: a retrospective cohort study

OBJECTIVE

The relationship between placental location in pregnancies without previa and adverse pregnancy outcomes has not been well studied. Additionally, the impact of abnormal cord insertion sites remains controversial. Therefore, the objective of this study was to explore the adverse outcomes associated with placental location and abnormal cord insertion in nulliparous women and to assess their impact on pregnancy outcomes.

METHODS

This retrospective cohort study was conducted at a single tertiary hospital between January 2019 and June 2022. The study included nulliparous women with singleton pregnancies who delivered live infants and had available data on placental location and umbilical cord insertion site from a second- or third-trimester ultrasound. Placental location was categorized as anterior or posterior using transabdominal ultrasonography. The association between placental location/cord insertion site and pre-eclampsia was evaluated using multivariate logistic regression analysis. We compared the area under the curve to evaluate the impact of placental location and cord insertion site on pre-eclampsia.

RESULTS

A total of 2219 pregnancies were included in the study. Pre-eclampsia occurred significantly more frequently in the anterior group than in the posterior group (8.21% vs. 3.04%, p < .001). In multivariate analysis investigating the association between placental location and pre-eclampsia, anterior placenta and marginal cord insertion showed increased odds ratios for pre-eclampsia of 3.05 (95% confidence interval [CI] 1.68-6.58) and 3.64 (95% CI 1.90-6.97), respectively. Receiver operating characteristic (ROC) curves were constructed to predict pre-eclampsia using independent factors from multivariate analyses. Model I, including maternal age, pre-pregnancy body mass index, in vitro fertilization, chronic hypertension, overt diabetes, kidney disease, and hematologic diseases, achieved an area under the ROC curve of 0.70 (95% CI 0.65-0.75). Adding cord insertion site and placental location to the model (Model II) improved its predictive performance, resulting in an area under the ROC curve of 0.749 (95% CI 0.70-0.79, p = .02).

CONCLUSIONS

Anterior placenta and marginal cord insertion were associated with an increased risk of pre-eclampsia. Further studies on prospective cohorts are necessary to validate these findings.

Incorporating placental pathology into clinical care and research

Despite recent standardization of placental evaluation and establishment of criteria for diagnosis of major patterns of placental injury, placental pathological examination remains undervalued and under-utilized. The placenta can harbor a significant amount of information relevant to both the pregnant person and offspring. Placental pathology can also provide a significant context for pathophysiological study of adverse pregnancy outcomes, helping to optimally subcategorize the 'great obstetric syndromes' of pre-eclampsia (PE), spontaneous preterm birth (sPTB), and fetal growth restriction (FGR), and to identify causes of stillbirth. We hereby propose that placental evaluation should be incorporated into routine delivery of obstetric and neonatal care, and further suggest that its integration into clinical, translational, and basic research could significantly advance our understanding of pregnancy complications and adverse neonatal outcomes.

Decreased Alpha Klotho Expression in Placentas Exposed to Severe Maternal Vascular Malperfusion

BACKGROUND

Placental maternal vascular malperfusion (MVM) is characterized by accelerated villous maturation and has been associated with a decrease in the antiaging protein, alpha-klotho (AK). Our aim was to characterize AK protein and gene expression in the placenta and fetal organs.

METHODS

We utilized 2 cohorts. First, we characterized AK protein expression in an autopsy cohort where cases were defined as MVM as the cause of fetal death compared to a stillborn control population. Second, we characterized placental and umbilical cord blood AK gene expression in a liveborn population with and without MVM.

RESULTS

We found decreased protein expression in the villous trophoblastic cells of placentas exposed to severe MVM and decreased AK gene expression in placental tissue exposed to MVM. We did not see any statistically significant differences in fetal organ or umbilical cord blood AK expression based on the presence or absence of MVM. Furthermore, in liveborn infants, we also found increased odds of preterm birth with lower placental AK expression.

CONCLUSIONS

Decreased AK gene and protein expression in the placenta in the setting of MVM is consistent with the theory of placental aging in MVM and is associated with increased odds of preterm birth.

Advancing our knowledge of placental function and how it relates to the developing fetal brain

Perinatal medicine has made significant advancements in recent decades. This has improved care and outcomes for infants. As we strive to improve neurodevelopmental outcomes, we must understand the influence the maternal/placental/fetal (MPF) triad has on fetal development and postnatal health and disease. Our understanding of the MPF triad remains incomplete, however research is continuing to develop our understanding. Through further research and incorporating what is currently known into how we deliver perinatal care, we have the opportunity to improve outcomes for infants. This review focuses on what is currently known about the structure and function of the placenta and the influence of the MPF triad. Current modalities for assessment of the MPF triad and future avenues for research will also be discussed. Understanding the relationship between the MPF triad, neurodevelopment and long-term health and disease has the potential to open new avenues for disease prevention and treatment through the lifespan.

Inhibition of NFAT promotes loss of tissue resident uterine natural killer cells and attendant pregnancy complications in humans

Uterine natural killer cells (uNKs) are a tissue resident lymphocyte population that are critical for pregnancy success. Although mouse models have demonstrated that NK deficiency results in abnormal placentation and poor pregnancy outcomes, the generalizability of this knowledge to humans remains unclear. Here we identify uterus transplant (UTx) recipients as a human population with reduced uNK cells and altered pregnancy phenotypes. We show that the NK reduction in UTx correlates with impaired transcriptional programming of NK tissue residency arising from the inhibition of NFAT-mediated signaling. Our observations suggest that NFAT-dependent genes modulate multiple molecular tissue residency programs in uNKs. These include early residency programs involving AP-1-family transcription factors and TGF-β-mediated upregulation of surface integrins. Collectively, our data identify a previously undescribed role for NFAT in uterine NK tissue residency and provide novel mechanistic insights into the biologic basis of pregnancy complications due to alteration of tissue resident NK subsets in humans.

One Sentence Summary

Role of NFAT in uterine NK cell tissue residency.

Emergency cesarean section in pregnant trauma patients presenting after motor vehicle collision

Background

Most pregnant trauma patients (PTPs) present after motor vehicle collision (MVC). The national rate and risk factors for emergency cesarean section (ECS) during the index hospitalization for pregnant trauma patients (PTPs) are unknown. We sought to investigate the national rate of ECS in PTPs presenting after MVC, hypothesizing a higher risk of ECS among those with severe injuries or elevated shock index (SI).

Methods

The 2020-2021 TQIP was queried for PTPs presenting after MVC. PTPs that underwent ECS were compared to patients that did not undergo ECS. Elevated SI was defined as ≥1. Severe injury was defined by abbreviated injury scale grade ≥3. Bivariate and multivariable logistic regression analyses were performed.

Results

From 1183 PTPs, 95 (8.0 %) underwent ECS. The median time to ECS was 115 min. The ECS group had higher rates of lung (27.4 % vs. 12.2 %, p < 0.001) injury, spleen (18.9 % vs. 5.5 %, p < 0.001) injury, and elevated SI (22.1 % vs. 9.8 %, p < 0.001). ECS patients had higher rates of complication (9.5 % vs. 2.1 %, p < 0.001) and death (4.2 % vs. 1.1 %, p = 0.012). Independently associated risk factors for ECS included severe head (OR 2.65, CI 1.14-6.17, p = 0.023) or abdominal (OR 2.07, CI 1.08-3.97, p = 0.028) injuries and elevated SI (OR 2.17 CI 1.25-3.79, p = 0.006).

Conclusion

The national rate of ECS among PTPs presenting after MVC is 8 % with most occurring within the first 2 hours of arrival. Severe head and abdominal injuries as well as elevated SI are risk factors for ECS.

Histological Evaluation of Placentas in Idiopathic Intrauterine Growth Restriction

Background Idiopathic intrauterine growth restriction (IUGR) is a condition in which there is no discernible cause, such as problems with the mother's health, and the fetus does not grow to the expected size for its gestational age. In cases of IUGR, the placental trophoblast exhibits reduced invasiveness, leading to a less extensive invasion of uterine spiral arteries and increased resistance in the uteroplacental circulation. The consequences of these early histopathological alterations are long-lasting, resulting in compromised blood flow to the placenta and diminished transport of nutrients and oxygen from the mother to the fetus. The placentas of neonates with idiopathic IUGR may provide crucial insights into the underlying causes of this growth restriction. The present study was designed to evaluate various microscopical changes in placentas of idiopathic intrauterine growth-restricted cases, qualitatively and quantitatively. Methods After getting the ethics committee's approval, the placental samples were collected from Duhok Obstetrics and Gynecology Hospital, Duhok, Iraq. A total of 55 placentas were gathered from women aged 20-40 years who had full-term (37-40 weeks) singleton pregnancies. Control cases were selected randomly, while idiopathic IUGR cases were selected purposively. Out of 55, 35 placentas were taken from idiopathic IUGR (birth weight less than 2500 g), and 20 placentas were taken from normal pregnancies (control group) with no history of confounding maternal and fetal factors. The maternal and neonatal data (age, weight of neonate, gestational period, and gender of neonate) were recorded. Immediately after delivery of the baby, the placenta was taken, washed with tap water, and dried. Then central and peripheral biopsies were taken for qualitative and quantitative histopathological examination, which includes the following: the number of terminal villi, stromal fibrosis, fibrinoid necrosis, syncytial knots, hyalinization, chorangiosis, congestion, and calcification. Statistical analyses were done using Student's t-tests and chi-square tests. Results In the idiopathic IUGR group, the qualitative features of the microscopic study corresponded with quantitative measurements. There was a significant decrease in the mean number of terminal villi (p=0.02), a highly significant increase in syncytial knots (p=0.001), a highly significant increase in fibrinoid necrosis (p=0.003), a highly significant increase in the mean number of stromal fibrosis (p=0.001), and a significant decrease in hyalinization (p=0.05). There was an insignificant increase in the calcification, medial coat proliferation of medium-sized blood vessels, chorangiosis, congestion, and fatty degeneration. Conclusions The reduction of terminal villi, accompanied by an increase in syncytial knots, fibrinoid necrosis, and stromal fibrosis, may have reduced the surface area for fetomaternal exchange. This led to chronic placental insufficiency. As a result, fetal growth and development are restricted. Therefore, IUGR infants may need more scientific and clinical attention.

Utility of placental biomarkers and fetoplacental Dopplers in predicting likely placental pathology in early and late fetal growth restriction - A prospective study

INTRODUCTION

The aim of this study was to evaluate the association between placental abnormalities, placental biomarkers, and fetoplacental Dopplers in a cohort of pregnancies complicated by fetal growth restriction (FGR). We also ascertained the risk of perinatal mortality, severe neurological morbidity, and severe non-neurological morbidity by type of placental abnormality.

METHODS

This was a prospective cohort study. Multivariable logistic regression was used to evaluate the effect of early vs. late FGR, placental biomarkers and fetoplacental Dopplers on Maternal Vascular Malperfusion (MVM) which was the commonest placental abnormality identified.

RESULTS

There were 161 (53.5 %) early FGR and 140 (46.5 %) late FGR cases. MVM abnormalities were present in 154 (51.2 %), VUE in 45 (14.6 %), FVM in 16 (5.3 %), DVM in 14 (4.7 %) and CHI in 4 (1.3 %) cases. The odds of MVM were higher in early compared to late FGR cohort (OR 1.89, 95%CI 1.14, 3.14, p = 0.01). Low maternal PlGF levels <100 ng/L (OR 2.34, 95%CI 1.27,4.31, p = 0.01), high sFlt-1 level (OR 2.13, 95%CI 1.35, 3.36, p = 0.001) or elevated sFlt-1/PlGF ratio (OR 3.48, 95%CI 1.36, 8.91, p = 0.01) were all associated with MVM. Increased UA PI > 95th centile (OR 2.91, 95%CI 1.71, 4.95, p=<0.001) and mean UtA PI z-score (OR 1.74, 95%CI 1.15, 2.64, p = 0.01) were associated with higher odds of MVM. Rates of severe non-neurological morbidity were highest in the MVM, FVM, and CHI cohorts (44.8 %, 50 %, and 50 % respectively).

CONCLUSION

MVM was the commonest placental abnormality in FGR, particularly in early-onset disease. Low maternal PlGF levels, high sFlt-1 levels, elevated sFlt-1/PlGF ratio, and abnormal fetoplacental Dopplers were also significantly associated with MVM. MVM, FVM, and CHI abnormalities were associated with lower median birthweight, higher rates of preterm birth, operative birth for non-reassuring fetal status, and severe neonatal non-neurological morbidity.

Placental pathological findings and their association with maternal and fetal clinical outcomes: A cross-sectional study

Background

Placental pathological changes can occur in both normal and high-risk pregnancies, leading to adverse maternal and neonatal outcomes.

Objective

This study aimed to investigate the relationship between placental histopathological findings and maternal and fetal clinical outcomes, as well as to determine if there is an association between maternal comorbidities and placental pathologies.

Materials and Methods

In this study, 250 placenta samples were evaluated. The slides and paraffin blocks were retrieved from the archive of the pathology department of Shariati and Yas hospitals, Tehran, Iran. The placental histopathological findings were analyzed in relation to maternal and fetal clinical data.

Results

The average age of pregnant women was 31.84 yr. The average gestational age at birth was 28 wk. The most prevalent pathological finding was maternal vascular malperfusion, observed in 59.6% of cases. The presence of nucleated red blood cells (NRBC) in umbilical cord blood vessels was observed in 16.4% of cases. Fetal vascular malperfusion was significantly associated with intrauterine fetal demise. Maternal inflammatory response was associated with premature rupture of membranes. Maternal vascular malperfusion and the presence of NRBC in umbilical cord blood vessels was significantly associated with pre-eclampsia and preterm labor. Furthermore, a history of maternal malignancy was associated with placental infarction and the presence of NRBC in umbilical cord blood vessels.

Conclusion

The findings of this study underscore the importance of evaluating placental histopathological findings in relation to maternal and fetal clinical outcomes. Therefore, understanding these placental pathological changes will be crucial in predicting and preventing complications in subsequent pregnancies.

Placental and umbilical cord anomalies detected by ultrasound as clinical risk factors of adverse perinatal outcome: Case series review of selected conditions. Part 1: Placental abnormalities

BACKGROUND

The aim of this extended review of multicenter case series is to describe the prenatal ultrasound features and pathogenetic mechanisms underlying placental and umbilical cord anomalies and their relationship with adverse perinatal outcome. From an educational point of view, the case series has been divided in three parts; Part 1 is dedicated to placental abnormalities.

METHODS

Multicenter case series of women undergoing routine and extended prenatal ultrasound and perinatal obstetric care.

RESULTS

Prenatal ultrasound findings, perinatal care, and pathology documentation in cases of placental pathology are presented.

CONCLUSIONS

Our case series review and that of the medical literature confirms the ethiopathogenetic role and involvement of placenta abnormalities in a wide variety of obstetrics diseases that may jeopardize the fetal well-being. Some of these specific pathologies are strongly associated with a high risk of poor perinatal outcome.

Maternal Vascular Malperfusion and Anatomic Cord Abnormalities Are Prevalent in Pregnancies With Fetal Congenital Heart Disease

OBJECTIVE

Impairments in the maternal-fetal environment are associated with adverse postnatal outcomes among infants with congenital heart disease. Therefore, we sought to investigate placental anomalies as they related to various forms of fetal congenital heart disease (FCHD).

METHODS

We reviewed the placental pathology in singleton pregnancies with and without FCHD. FCHD was divided into separate categories (transposition physiology, obstructive left, obstructive right, biventricular without obstruction, and others). Exclusion criteria included other prenatally known structural malformations and/or aneuploidy. The significance threshold was set at p < 0.05 or False Discovery rate q < 0.05 when multiple tests were performed.

RESULTS

The cohort included 215 FCHD and 122 non-FCHD placentas. FCHD placentas showed increased rates of maternal vascular malperfusion (24% vs. 5%, q < 0.001) and cord anomalies (27% vs. 1%, q < 0.001). Placentas with fetal TGA demonstrated a lower rate of hypoplasia when compared with other FCHD types (1/39 vs. 51/176, Fisher's exact p = 0.015).

CONCLUSION

Placental maternal vascular malperfusion is increased in FCHD. The prevalence of vascular malperfusion did not differ by FCHD type, indicating that CHD type does not predict the likelihood of placental vascular dysfunction. Further investigation of the placental-fetal heart axis in FCHD is warranted given the importance of placental health.

Can the neutrophil-to-lymphocyte ratio be used as an early marker of small fetuses for gestational age? A prospective study

Background

Small-for-gestational-age (SGA) fetuses are at increased risk of mortality and morbidity, and less than 30% will be detected by any ultrasound scan within 4 weeks before delivery. Our aim was to evaluate the relationship between neutrophil/lymphocyte ratio (NLR) in the first trimester of pregnancy and SGA fetuses.

Method

We performed a prospective study between June 2021 and August 2022, to evaluate the relationship between the neutrophil to lymphocyte ratio in maternal blood in the first trimester of pregnancy, with the birth of an SGA fetus. One hundred ninety-four participants with singleton pregnancies between 11 + 1 and 13 + 6 weeks of gestation were recruited. Pregnancies affected with diagnosed fetal chromosomal abnormalities, or chronic pathologies were excluded. SGA was defined as birthweight less than the 10th centile (N = 42) and severe SGA as birthweight less than the 3rd centile for gestation (N = 10) according to a locally derived descriptive charts. The NLR value measured in the first trimester was compared between these two groups and controls.

Results

We found no statistically significant difference in NLR, (3.5 +/-1.2 vs. 3.4+/-1.2, p-value of 0.78) when comparing the SGA less than the 10th centile group to the control group. NLR was also not different between severe SGA and controls (3.6+/-1.4 vs. 3.4+/-1.2 p-value of 0.78).

Conclusion

We found no association between first-trimester NLR ratio and SGA.

Behind the Curtain of Abnormal Placentation in Pre-Eclampsia: From Molecular Mechanisms to Histological Hallmarks

Successful human pregnancy needs several highly controlled steps to guarantee an oocyte's fertilization, the embryo's pre-implantation development, and its subsequent implantation into the uterine wall. The subsequent placenta development ensures adequate fetal nutrition and oxygenation, with the trophoblast being the first cell lineage to differentiate during this process. The placenta sustains the growth of the fetus by providing it with oxygen and nutrients and removing waste products. It is not surprising that issues with the early development of the placenta can lead to common pregnancy disorders, such as recurrent miscarriage, fetal growth restriction, pre-eclampsia, and stillbirth. Understanding the normal development of the human placenta is essential for recognizing and contextualizing any pathological aberrations that may occur. The effects of these issues may not become apparent until later in pregnancy, during the mid or advanced stages. This review discusses the process of the embryo implantation phase, the molecular mechanisms involved, and the abnormalities in those mechanisms that are thought to contribute to the development of pre-eclampsia. The review also covers the histological hallmarks of pre-eclampsia as found during the examination of placental tissue from pre-eclampsia patients.

Postnatal Cerebral Hemodynamics and Placental Vascular Malperfusion Lesions in Neonates With Congenital Heart Disease

BACKGROUND

Neonates with congenital heart disease (CHD) have smaller brain volume at birth. High rates of placental vascular malperfusion lesions may play a role in disrupted brain development.

METHODS

This is a single-center retrospective cohort study of infants born between 2010 and 2019 who were diagnosed with a major cardiac defect requiring surgery in the first year of life. Doppler ultrasound RI of the middle cerebral artery (MCA) and anterior cerebral artery were calculated within the first 72 hours of life. Placentas were evaluated using a standardized approach.

RESULTS

Over the study period, there were 52 patients with hypoplastic left heart syndrome (HLHS), 22 with single-ventricle right ventricular outflow tract obstruction (SV-RVOTO), 75 with a two-ventricle cardiac defect (2V), and 25 with transposition of the great arteries (TGA). MCA Doppler RI were significantly higher for all subgroups of CHD compared with control subjects (0.68 ± 0.11 in control subjects compared with 0.78 ± 0.13 in HLHS, P = 0.03; 0.77 ± 0.10 in SV-RVOTO, P = 0.002; 0.78 ± 0.13 in 2V, P = 0.03; and 0.80 ± 0.14 in TGA; P = 0.001) with the highest average MCA RI in the TGA group. In subgroup analyses, placental fetal vascular malperfusion in the 2V group was associated with higher MCA RI, but this relationship was not present in other subgroups, nor in regards to maternal vascular malperfusion.

CONCLUSIONS

Major forms of CHD are associated with significantly higher cerebral artery RI postnatally, but placental vascular malperfusion lesions may not contribute to this hemodynamic adaptation.

Potential molecular mechanisms and clinical implications of piRNAs in preeclampsia: a review

Preeclampsia is a multisystem progressive condition and is one of the most serious complications of pregnancy. Owing to its unclear pathogenesis, there are no precise and effective therapeutic targets for preeclampsia, and the only available treatment strategy is to terminate the pregnancy and eliminate the clinical symptoms. In recent years, non-coding RNAs have become a hotspot in preeclampsia research and have shown promise as effective biomarkers for the early diagnosis of preeclampsia over conventional biochemical markers. PIWI-interacting RNAs, novel small non-coding RNA that interact with PIWI proteins, are involved in the pathogenesis of various diseases at the transcriptional or post-transcriptional level. However, the mechanisms underlying the role of PIWI-interacting RNAs in the pathogenesis of preeclampsia remain unclear. In this review, we discuss the findings of existing studies on PIWI-interacting RNA biogenesis, functions, and their possible roles in preeclampsia, providing novel insights into the potential application of PIWI-interacting RNAs in the early diagnosis and clinical treatment of preeclampsia.

Interdependence of placenta and fetal cardiac development

The placenta and fetal heart undergo development concurrently during early pregnancy, and, while human studies have reported associations between placental abnormalities and congenital heart disease (CHD), the nature of this relationship remains incompletely understood. Evidence from animal studies suggests a plausible cause and effect connection between placental abnormalities and fetal CHD. Biomechanical models demonstrate the influence of mechanical forces on cardiac development, whereas genetic models highlight the role of confined placental mutations that can cause some forms of CHD. Similar definitive studies in humans are lacking; however, placental pathologies such as maternal and fetal vascular malperfusion and chronic deciduitis are frequently observed in pregnancies complicated by CHD. Moreover, maternal conditions such as diabetes and pre-eclampsia, which affect placental function, are associated with increased risk of CHD in offspring. Bridging the gap between animal models and human studies is crucial to understanding how placental abnormalities may contribute to human fetal CHD. The next steps will require new methodologies and multidisciplinary approaches combining innovative imaging modalities, comprehensive genomic testing, and histopathology. These studies may eventually lead to preventative strategies for some forms of CHD by targeting placental influences on fetal heart development.

Association between maternal and perinatal outcomes and histological changes in the placenta of patients with Covid-19: A cohort study

Although studies evaluated placental involvement in Covid-19 patients, few have assessed its association with clinical repercussions. The study aimed to determine the association between the clinical status and maternal and perinatal outcomes of patients with Covid-19 at delivery and changes in placental histology. It is so far the largest cohort evaluating placentas of patients infected by the SARS-CoV-2. A secondary analysis was conducted of a database from which a cohort of 226 patients, who tested real-time polymerase chain reaction-positive for Covid-19 at delivery and whose placentas were collected and submitted to pathology, was selected for inclusion. One or more types of histological changes were detected in 44.7% of the 226 placentas evaluated. The most common abnormalities were maternal vascular malperfusion (38%), evidence of inflammation/infection (9.3%), fetal vascular malperfusion (0.8%), fibrinoid changes and intervillous thrombi (0.4%). Oxygen use (P = .01) and need for admission to an intensive care unit (ICU) (P = .04) were less common in patients with placental findings, and hospital stay was shorter in these patients (P = .04). There were more fetal deaths among patients with evidence of inflammation/infection (P = .02). Fetal death, albeit uncommon, is associated with findings of inflammation/infection. Oxygen use and need for admission to an ICU were less common among patients with placental findings, probably due to the pregnancy being interrupted early. None of the other findings was associated with maternal clinical status or with adverse perinatal outcome.

Comparison of 2D and 3D oxygen-enhanced MRI of the placenta

Oxygen-Enhanced Magnetic Resonance Imaging (OE-MRI) of the human placenta is potentially a sensitive marker of in vivo oxygenation. This methodological study shows that full coverage of the placenta is possible using 3D mapping of the change in longitudinal relaxation rate (ΔR1), in a group of healthy pregnant subjects breathing elevated levels of oxygen. Twelve pregnant subjects underwent a comparison of 2D and 3D OE-MRI. ΔR1 was mapped for a single 2D slice (ss-2D), a single matched-slice from the 3D volume (ss-3D) and the full 3D volume (vol-3D). The group-average median ΔR1 values for ss-3D (0.023 s-1) and vol-3D (0.022 s-1) do not differ significantly from ss-2D (0.020 s-1), when compared using a two-tailed paired t-test (ss-3D (p = 0.58) and vol-3D (p = 0.70)). However, median baseline T1 (T1b) for ss-2D was higher (1603 ms) than T1b for ss-3D (1540 ms, p = 0.07) and significantly higher than vol-3D (1515 ms, p = 0.02), when compared using a two-tailed paired t-test. In contrast with previous studies, no correlation of median ΔR1 with gestation age at scan for the normal group (N = 10) was observed for ss-2D, likely due to the smaller gestational range. Full volume OE-MRI maps reveal sensitivity to changes in ΔR1, with some participants showing an enhanced gradient in the intermediate space between the fetal and maternal sides of the placenta in the 3D data. This study shows that it is feasible to acquire whole placental volume OE-MRI data in women with healthy pregnancy.

iPSC-based modeling of preeclampsia identifies epigenetic defects in extravillous trophoblast differentiation

Preeclampsia (PE) is a hypertensive pregnancy disorder with increased risk of maternal and fetal morbidity and mortality. Abnormal extravillous trophoblast (EVT) development and function is considered to be the underlying cause of PE, but has not been previously modeled in vitro. We previously derived induced pluripotent stem cells (iPSCs) from placentas of PE patients and characterized abnormalities in formation of syncytiotrophoblast and responses to changes in oxygen tension. In this study, we converted these primed iPSC to naïve iPSC, and then derived trophoblast stem cells (TSCs) and EVT to evaluate molecular mechanisms underlying PE. We found that primed (but not naïve) iPSC-derived PE-EVT have reduced surface HLA-G, blunted invasive capacity, and altered EVT-specific gene expression. These abnormalities correlated with promoter hypermethylation of genes associated with the epithelial-mesenchymal transition pathway, specifically in primed-iPSC derived PE-EVT. Our findings indicate that abnormal epigenetic regulation might play a role in PE pathogenesis.

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

AIM

To evaluate placental pathology in term and post-term births, investigate differences in clinical characteristics, and assess the risk of adverse neonatal outcome.

METHODS

This prospective observational study included 315 singleton births with gestational age (GA) > 36 weeks + 6 days meeting the local criteria for referral to placental histopathologic examination. We applied the Amsterdam criteria to classify the placentas. Births were categorized according to GA; early-term (37 weeks + 0 days to 38 weeks + 6 days), term (39 weeks + 0 days to 40 weeks + 6 days), late-term (41 weeks + 0 days to 41 weeks + 6 days), and post-term births (≥ 42 weeks + 0 days). The groups were compared regarding placental pathology findings and clinical characteristics. Adverse neonatal outcomes were defined as 5-minute Apgar score < 7, umbilical cord artery pH < 7.0, admission to the neonatal intensive care unit or intrauterine death. A composite adverse outcome included one or more adverse outcomes. The associations between placental pathology, adverse neonatal outcomes, maternal and pregnancy characteristics were evaluated by logistic regression analysis.

RESULTS

Late-term and post-term births exhibited significantly higher rates of histologic chorioamnionitis (HCA), fetal inflammatory response, clinical chorioamnionitis (CCA) and transfer to neonatal intensive care unit (NICU) compared to early-term and term births. HCA and maternal smoking in pregnancy were associated with adverse outcomes in an adjusted analysis. Nulliparity, CCA, emergency section and increasing GA were all significantly associated with HCA.

CONCLUSIONS

HCA was more prevalent in late and post-term births and was the only factor, along with maternal smoking, that was associated with adverse neonatal outcomes. Since nulliparity, CCA and GA beyond term are associated with HCA, this should alert the clinician and elicit continuous intrapartum monitoring for timely intervention.

Placental Pathology Contributes to Impaired Volumetric Brain Development in Neonates With Congenital Heart Disease

BACKGROUND

Neonates with congenital heart disease are at risk for impaired brain development in utero, predisposing children to postnatal brain injury and adverse long-term neurodevelopmental outcomes. Given the vital role of the placenta in fetal growth, we assessed the incidence of placental pathology in fetal congenital heart disease and explored its association with total and regional brain volumes, gyrification, and brain injury after birth.

METHODS AND RESULTS

Placentas from 96 term singleton pregnancies with severe fetal congenital heart disease were prospectively analyzed for macroscopic and microscopic pathology. We applied a placental pathology severity score to relate placental abnormalities to neurological outcome. Postnatal, presurgical magnetic resonance imaging was used to analyze brain volumes, gyrification, and brain injuries. Placental analyses revealed the following abnormalities: maternal vascular malperfusion lesions in 46%, nucleated red blood cells in 37%, chronic inflammatory lesions in 35%, delayed maturation in 30%, and placental weight below the 10th percentile in 28%. Severity of placental pathology was negatively correlated with cortical gray matter, deep gray matter, brainstem, cerebellar, and total brain volumes (r=-0.25 to -0.31, all P<0.05). When correcting for postmenstrual age at magnetic resonance imaging in linear regression, this association remained significant for cortical gray matter, cerebellar, and total brain volume (adjusted R2=0.25-0.47, all P<0.05).

CONCLUSIONS

Placental pathology occurs frequently in neonates with severe congenital heart disease and may contribute to impaired brain development, indicated by the association between placental pathology severity and reductions in postnatal cortical, cerebellar, and total brain volumes.

Unravelling the impact of COVID-19 on pregnancy: In aspect of placental histopathology and umbilical cord macrophage immunoactivity with neonatal outcomes

COVID-19 has turned into a global pandemic since it was first detected in 2019, causing serious public health problems. Our objective was to investigate the impact of COVID-19 on pregnant women and newborns, who belong to the vulnerable segments of society. Our study involved the histopathological examination of placentas and umbilical cords from two groups of pregnant women. Group I consisted of pregnant women who had never tested positive for COVID-19 during their pregnancy (n: 20). Group II consisted of pregnant women who had contracted COVID-19, exhibited moderate and mild symptoms, and recovered from the disease before giving birth (n: 23). Furthermore, we employed immunofluorescence techniques to detect macrophage activity in the umbilical cord. Prenatal assessments were based on maternal complete blood counts and coagulation assays (n:40 in both groups). Newborn conditions were evaluated using birth weight, height, head circumference, and APGAR (n:40 in both groups). Our analyses reveal that COVID-19 causes placental and umbilical cord inflammation and maternal and foetal vascular malperfussion. Our immunofluorescence investigations demonstrate a notable increase in macrophage numbers and the macrophage-to-total cell ratio within the COVID-19 group. In this aspect, this study provides the initial report incorporating macrophage activity results from Warton's jelly in pregnants who have recovered from COVID-19. We have also ascertained that COVID-19 abbreviates gestation periods and concurrently diminishes maternal haemoglobin concentrations. Consequently, COVID-19 with mild and moderate symptoms during pregnancy, causes significant changes to the placenta and umbilical cord, but propitiously does not cause a significant difference in the neonatal outcomes.

Associations between placental pathology and poor intrauterine growth among a cohort of mother-infant singleton pairs in Leyte, the Philippines

OBJECTIVE

Poor intrauterine growth has negative impacts for child growth and development and disproportionately affects children living in low-resource settings. In the present study, we investigated relationships between placental pathologies and indicators of poor intrauterine growth.

METHODS

We enrolled a longitudinal cohort of 279 mother-infant pairs from Leyte, the Philippines. Placental measures included characteristics, pathological findings, and immunohistochemistry. At birth, intrauterine growth was assessed using anthropometric measures, weight-for-gestational age, and the clinical assessment of nutritional status score (CANSCORE) for determining fetal malnutrition. Multivariate linear regression and log-binomial regression models were applied, controlling for potential confounding factors.

RESULTS

Maternal vascular malperfusion (MVM) was related to reduced birthweight (P < 0.0001), birth length (P = 0.002), head circumference (P = 0.001), and weight-to-length ratio (P = 0.016). MVM increased the risk for preterm delivery (P = 0.0005) and small for gestational age (SGA) (P = 0.016). Acute chorioamnionitis (P = 0.013) and MVM (P = 0.021) both led to an increased risk for fetal malnutrition defined by CANSORE<25. Villous tissue activated caspase-3 was associated with lower birth length (P = 0.0006), higher weight-to-length ratio (P = 0.004), reduced risks for SGA (P = 0.011) and low weight-to-length ratio for gestational age (P = 0.004).

CONCLUSION

The present study applied comprehensive measures for intrauterine growth and demonstrates that low placental weight and placental pathology, chiefly MVM, contribute to poor intrauterine growth. A better understanding of the mechanistic role of specific placental pathologies on adverse newborn outcomes will provide opportunities for reducing incidence of poor intrauterine growth and associated long-term morbidities.

Diffusion-sensitized magnetic resonance imaging highlights placental microstructural damage in patients with previous SARS-CoV-2 pregnancy infection

INTRODUCTION

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been a major global health problem since December 2019. This work aimed to investigate whether pregnant women's mild and moderate SARS-CoV-2 infection was associated with microstructural and vascular changes in the placenta observable in vivo by Intravoxel Incoherent Motion (IVIM) at different gestational ages (GA).

METHODS

This was a retrospective, nested case-control of pregnant women during the SARS-CoV-2 pandemic (COVID-19 group, n = 14) compared to pre-pandemic healthy controls (n = 19). MRI IVIM protocol at 1.5T was constituted of diffusion-weighted (DW) images with TR/TE = 3100/76 ms and 10 b-values (0,10,30,50,75,100,200,400,700,1000s/mm2). Differences between IVIM parameters D (diffusion), and f (fractional perfusion) quantified in the two groups were evaluated using the ANOVA test with Bonferroni correction and linear correlation between IVIM metrics and GA, COVID-19 duration, the delay time between a positive SARS-CoV-2 test and MRI examination (delay-time exam+) was studied by Pearson-test.

RESULTS

D was significantly higher in the COVID-19 placentas compared to that of the age-matched healthy group (p < 0.04 in fetal and p < 0.007 in maternal site). No significant difference between f values was found in the two groups suggesting no-specific microstructural damage with no perfusion alteration (potentially quantified by f) in mild/moderate SARS-Cov-2 placentas. A significant negative correlation was found between D and GA in the COVID-19 placentas whereas no significant correlation was found in the control placentas reflecting a possible accelerated senescence process due to COVID-19.

DISCUSSION

We report impaired microstructural placental development during pregnancy and the absence of perfusion-IVIM parameter changes that may indicate no perfusion changing through microvessels and microvilli in the placentas of pregnancies with mild/moderate SARS-Cov-2 after reaching negativity.

Placental Lesions Associated With Stillbirth by Gestational Age, as Related to Cause of Death: Follow-Up Results From the Stillbirth Collaborative Research Network

BACKGROUND

We previously identified placental lesions associated with stillbirths of varying gestational ages (GA) using advanced feature analysis. We further investigated the relationships between placental lesions and cause of death in stillbirths within these GA ranges.

METHODS

Using data from the Stillbirth Collaborative Research Network, we derived a sample of stillbirths who underwent placental examination and Initial Causes of Fetal Death (INCODE) evaluation for determining cause of death. We then compared the rates of causes of death within and among GA ranges (extreme preterm stillbirth [PTSB] [<28 weeks], early PTSB [28-336/7 weeks], late PTSB [34-366/7 weeks], term stillbirth [≥37 weeks]) according to the presence of these lesions.

RESULTS

We evaluated 352 stillbirths. In extreme PTSB, obstetric complications and infections were associated with acute funisitis. In early PTSB, uteroplacental insufficiency was associated with parenchymal infarcts. In term stillbirth (vs early PTSB), increased syncytial knots were associated with umbilical cord causes and infection.

CONCLUSIONS

Placental lesions of high importance in distinguishing stillbirths at different GAs are associated with specific causes of death. This information is important in relating the presence of placental lesions and fetal death and in helping to understand etiologies of stillbirths at different GAs.

Molecular detection of bacteria, placental inflammation, and neonatal sepsis risk

OBJECTIVE

To identify bacteria in umbilical cord tissue and investigate the association with placental inflammation and neonatal sepsis risk score.

STUDY DESIGN

Retrospective cohort study from 2017-2019. RNA was extracted from umbilical cord tissue and NanoString nCounter used to identify seven bacteria genera. Sepsis risk score was calculated using the Kaiser sepsis calculator. Placental histopathology was abstracted from medical records.

RESULTS

Detection of bacterial RNA in the umbilical cord (n = 96/287) was associated with high-stage maternal and fetal acute placental inflammation (maternal 35.4% vs 22.5%, p = 0.03 and fetal 34.4% vs 19.4%, p < 0.01) and maternal vascular malperfusion (36.5% vs 23.0%, p = 0.02). Detection of Ureaplasma spp. was also associated with increased sepsis risk score (1.5/1000 [0.6, 8.6] vs 0.9/1000 [0.2, 2.9], p = 0.04).

CONCLUSION

Umbilical cord bacterial pathogens are linked to fetal and maternal placental inflammation and maternal vascular malperfusion during gestation and associated with increased sepsis risk score in the neonate.

COVID-19 during pregnancy could potentially affect placental function

OBJECTIVE

COVID-19 is an ongoing pandemic and has been extensively studied. However, the effects of COVID-19 during pregnancy, particularly on placental function, have not been verified. In this study, we used blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI) to evaluate whether COVID-19 incidence during pregnancy has any lasting effects with respect to placental oxygenation.

METHODS

This is a case-control study, in which eight cases of singleton pregnancies before 30 weeks gestation with COVID-19 mothers were included. Placental oxygenation was evaluated using BOLD-MRI after 32 weeks of gestation. BOLD-MRI was consecutively performed under normoxia (21% O2), hyperoxia (100% O2), and normoxia for 4 min each. Individual placental time-activity curves were evaluated to calculate the peak score (peakΔR2*) and the time from the start of maternal oxygen administration to the time of peakΔR2* (time to peakΔR2*). Eighteen COVID-19-free normal pregnancies from a previous study were used as the control group.

RESULTS

No significant differences were found between the two groups regarding maternal background, number of days of delivery, birth weight, and placental weight. The parameter peakΔR2* was significantly decreased in the COVID-19 group (8 ± 3 vs. 5 ± 1, p < .001); however, there was no significant difference in time to peakΔR2* (458 ± 74 s vs. 471 ± 33 s, p = .644).

CONCLUSIONS

In this study, BOLD-MRI was used to evaluate placental oxygenation during pregnancy in COVID-19-affected patients. COVID-19 during pregnancy decreased placental oxygenation even post-illness, but had no effect on fetal growth; further investigation of the possible effects of COVID-19 on the fetus and mother is warranted.

Placental Histopathologic Findings in the Setting of Prenatally Diagnosed Major Congenital Heart Disease

Objectives: Studies suggest an association between placenta and congenital heart disease (CHD). We evaluated placental pathologies associated with major CHD. Methods: A prospective study included fetuses with major CHD, identified by fetal echocardiography. Fetal Doppler of umbilical artery (UA), middle cerebral artery (MCA), and placental histopathology were assessed. Outcome was measured by mortality at one month of age. Results: 21 cases were analyzed. Hypoplastic left heart syndrome was the commonest lesion (23.8%). Significant differences were detected among categories regarding MCA systolic/diastolic (S/D) ratio & pulsatility index (p = 0.023; 0.036), respectively. Placental histopathologies were demonstrated in 18(85.7%), predominately involved fetal malperfusion lesions 16/21(76.2%), especially chorangiosis (33.3%). No significant association was detected between placental histopathological abnormalities and Doppler parameter, diagnostic category, or mortality. Conclusion: The high prevalence of abnormal placental histopathological findings in major fetal CHD provides additional evidence of placental-cardiac interlinkage. No association was detected between abnormal placental histopathology and fetal Doppler measurements or neonatal outcome of CHD.

Comparative clinical and placental pathologic characteristics in pregnancies with and without SARS-CoV-2 infection

OBJECTIVES

To compare the clinical and morphological characteristics of the "mother-placenta-fetus" system in high risk pregnant women of three groups: no SARS-CoV-2 infection, mild SARS-CoV-2 infection, and severe SARS-CoV-2 infection.

METHODS

A case-control study was performed for all deliveries, at 28 weeks' gestation or greater, who had standard indications for placental pathologic examination. Three groups were formed: (1) control group (no SARS-CoV-2 infection), (2) mild SARS-CoV-2 infection, (3) severe SARS-CoV-2 infection. High-risk pregnancies were registered in all cases in the study groups. The examination of the placenta and the selection of fragments of placental tissue were carried out in accordance with the consensus recommendations of the Amsterdam Placental Workshop Group. The sections were subjected to standard processing and stained with hematoxylin and eosin according to the standard protocol. All cases were reviewed by two pathologists, which did not know any information on pregnancy outcome and clinical data. Statistical analysis was performed using SPSS, p<0.05 was considered statistically significant.

RESULTS

Women with severe SARS-CoV-2 infection had an increased rate of multimorbidity including diabetes, chronic hypertension and obesity (p<0.01) compared with the other groups. Placentas at severe COVID-19 course were damaged by both chronic and acute injuries, in comparison to the mild and control groups (p<0.001). Also an important finding in severe COVID-19 was diffuse necrosis of the villous trophoblast - homogenization, diffuse circular eosinophilic masses surrounding the chorionic villi.

CONCLUSIONS

Women with multimorbidity are an "at-risk" subgroup for severe SARS-CoV-2 infection and greater likelihood of both placental damage and perinatal hypoxic-ischemic events. These results suggest that patient education, SARS-CoV-2 disease monitoring and preventive measures would be of benefit to this group.

High maternal-fetal HLA eplet compatibility is associated with severe manifestation of preeclampsia

Introduction

Preeclampsia is responsible for more than 70 000 and 500 000 maternal and fetal deaths, respectively each year. Incomplete remodelling of the spiral arteries in placenta is the most accepted theory of preeclampsia pathogenesis. However, the process is complexed with immunological background, as pregnancy resembles allograft transplantation. Fetus expresses human leukocyte antigens (HLA) inherited from both parents, thus is semiallogeneic to the maternal immune system. Therefore, induction of fetal tolerance is crucial for physiological outcome of pregnancy. Noteworthy, the immunogenicity of discordant HLA antigens is determined by functional epitopes called eplets, which are continuous and discontinuous short sequences of amino acids. This way various HLA molecules may express the same eplet and some HLA incompatibilities can be more immunogenic due to different eplet combination. Therefore, we hypothesized that maternal- fetal HLA incompatibility may be involved in the pathogenesis of gestational hypertension and its progression to preeclampsia. We also aimed to test if particular maternal-fetal eplet mismatches are more prone for induction of anti- fetal HLA antibodies in gestational hypertension and preeclampsia.

Methods

High resolution next-generation sequencing of HLA-A, -B, -C, -DQB1 and -DRB1 antigens was performed in mothers and children from physiological pregnancies (12 pairs) and from pregnancies complicated with gestational hypertension (22 pairs) and preeclampsia (27 pairs). In the next step HLA eplet identification and analysis of HLA eplet incompatibilities was performed with in silico approach HLAMatchmaker algorithm. Simultaneously maternal sera were screened for anti-fetal HLA class I, class II and anti-MICA antibodies with Luminex, and data were analyzed with HLA-Fusion software.

Results

We observed that high HLA-C, -B, and DQB1 maternal-fetal eplet compatibility was associated with severe preeclampsia (PE) manifestation. Both quantity and quality of HLA epletmismatches affected the severity of PE. Mismatches in HLA-B eplets: 65QIA+76ESN, 70IAO, 180E, HLA-C eplets: 193PL3, 267QE, and HLA-DRB1 eplet: 16Y were associated with a mild outcome of preeclampsia if the complication occurred.

Conclusions

High HLA-C, HLA-DQB1 and HLA-B eplet compatibility between mother and child is associated with severe manifestation of preeclampsia. Both quantity and quality of maternal-fetal HLA eplet mismatches affects severity of preeclampsia.

Impact of ferroptosis on preeclampsia: A review

Preeclampsia (PE) is usually associated with the accumulation of reactive oxygen species (ROS) resulting from heightened oxidative stress (OS). Ferroptosis is a unique type of lipid peroxidation-induced iron-dependent cell death distinct from traditional apoptosis, necroptosis, and pyroptosis and most likely contributes considerable to PE pathogenesis. At approximately 10-12 weeks of gestation, trophoblasts create an environment rich in oxygen and iron. In patients with PE, ferroptosis-related genes such as HIF1 and MAPK8 are downregulated, whereas PLIN2 is upregulated. Furthermore, miR-30b-5p overexpression inhibits solute carrier family 11 member 2, resulting in a decrease in glutathione levels and an increase in the labile iron pool. At the maternal-fetal interface, physiological hypoxia/reperfusion and excessive iron result in lipid peroxidation and ROS production. Owing to the high expression of Fpn and polyunsaturated fatty acid-containing phospholipid-related enzymes, including acyl-CoA synthetase long-chain family member 4, lysophosphatidylcholine acyl-transferase 3, and spermidine/spermine N1-acetyltransferase 1, trophoblasts become more susceptible to OS and ROS damage. In stage 1, the injured trophoblasts exhibit poor invasion and incomplete uterine spiral artery remodeling caused by ferroptosis, leading to placental ischemia and hypoxia. Subsequently, ferroptosis marked by OS occurs in stage 2, eventually causing PE. We aimed to explore the new therapeutic target of PE through OS in ferroptosis.

Histomorphometric features of placentae from women having malaria and HIV coinfection with preterm births

Background

Malaria and HIV are associated with preterm births possibly due to partial maternal vascular malperfusion resulting from altered placental angiogenesis. There is a paucity of data describing structural changes associated with malaria and HIV coinfection in the placentae of preterm births thus limiting the understanding of biological mechanisms by which preterm birth occurs.

Objectives

This study aimed to determine the differences in clinical characteristics, placental parenchymal histological, and morphometric features of the terminal villous tree among women with malaria and HIV coinfection having preterm births.

Methods

Twenty-five placentae of preterm births with malaria and HIV coinfection (cases) were randomly selected and compared to twenty-five of those without both infections (controls). Light microscopy was used to determine histological features on H&E and MT-stained sections while histomorphometric features of the terminal villous were analyzed using image analysis software. Clinical data regarding maternal age, parity, marital status, level of education, gestational age and placental weight were compared.

Results

Placental weight, villous perimeter and area were significantly lower in cases as compared to controls 454g vs. 488g, 119.32μm vs. 130.47μm, and 937.93μm2 vs. 1132.88μm2 respectively. Increased syncytial knots and accelerated villous maturity were significantly increased in the cases. The relative risk of development of partial maternal vascular malperfusion was 2.1 (CI: 1.26-3.49).

Conclusion

These findings suggest that malaria and HIV coinfection leads to partial maternal vascular malperfusion that may lead to chronic hypoxia in the placenta and altered weight, villous perimeter and surface area. This may represent a mechanism by which malaria and HIV infection results in pre-term births.

Hereditary Thrombotic Thrombocytopenic Purpura

Hereditary thrombotic thrombocytopenic purpura (hTTP), also known as Upshaw-Schulman syndrome, is a rare genetic disorder caused by mutations in the ADAMTS13 gene that leads to decreased or absent production of the plasma von Willebrand factor (VWF)-cleaving metalloprotease ADAMTS13. The result is circulating ultra-large multimers of VWF that can cause microthrombi, intravascular occlusion and organ damage, especially at times of turbulent circulation. Patients with hTTP may have many overt or clinically silent manifestations, and a high index of suspicion is required for diagnosis. For the treatment of hTTP, the goal is simply replacement of ADAMTS13. The primary treatment is prophylaxis with plasma infusions or plasma-derived factor VIII products, providing sufficient ADAMTS13 to prevent acute episodes. When acute episodes occur, prophylaxis is intensified. Recombinant ADAMTS13, which is near to approval, will immediately be the most effective and also the most convenient treatment. In this review, we discuss the possible clinical manifestations of this rare disease and the relevant differential diagnoses in different age groups. An extensive discussion on prophylaxis and treatment strategies is also presented. Unique real patient cases have been added to highlight critical aspects of hTTP manifestations, diagnosis and treatment.

Comparison of Placental Pathology Reports From Spontaneous Preterm Births Finalized by General Surgical Pathologists Versus Perinatal Pathologist: A Call to Action

Placental examination, frequently performed by general surgical pathologists, plays an important role in understanding patient outcomes and explaining the underlying mechanisms leading to preterm birth (PTB). This secondary analysis of a larger study recurrent PTB aimed to compare diagnoses between general surgical pathologists (GSP) and a perinatal pathologist (PP) in preterm placentas examined between 2009 and 2018 at a single institution. Pathology diagnoses were coded into 4 categories (acute inflammation [AI], chronic inflammation, fetal vascular malperfusion, maternal vascular malperfusion) based on original reports for the GSP and second review by the single PP. A total of 331 placentas were included, representing placentas finalized by 17 GSPs. The prevalence of all 4 placental diagnostic categories was higher for the PP, and nearly half (49.2%) of placentas finalized by GSP had no diagnostic findings. Agreement was highest for AI at κ=0.50 (weak agreement). However, there was no agreement for maternal vascular malperfusion (κ=0.063), chronic inflammation (κ=0.0026), and fetal vascular malperfusion (κ = -0.018). Chronic basal deciduitis with plasma cells had the highest false-negative rate (missed in 107 cases by GSP). Villous infarction had the highest false-positive rate (overcalled in 28/41 [68%] cases) with the majority of the "infarcts" representing intervillous thrombi. In conclusion, there is no agreement between GSP and PP when assessing placental pathology other than AI, and weak agreement even for AI. These findings are a call to action to implement educational efforts and structural/organizational changes to improve consistency of placental pathology reporting.