Predictors of High Grade and Other Clinically Significant Placental Findings by Indication for Submission in Singleton Placentas From Term Births

Pathologic findings of the placenta and clinical implications - recommendations for placental examination

The placenta is a unique and complex organ that combines the circulatory systems of two or more individuals within a single dynamic organ with a set, short lifespan. A diverse spectrum of disorders, including infections as well as metabolic, genetic, circulatory, and maturation defects, may affect its function. Pathology investigation of the placenta is key for identifying several pathogenic processes in both the mother and the foetus. Aberrant placentation, maternal and foetal vascular compromise, infection, inflammatory immunologic conditions, and disorders of maturation are elements of newly proposed classification schemes. The clinical impact of placental examination consists of diagnosing maternal and foetal disease, identifying the potential for recurrence, correlating clinical pathological findings with distinct morphologic features, and identifying the aetiology responsible for growth restriction or foetal death. Gestational trophoblastic disease occurs more frequently in the first trimester; however, in very rare cases, it can affect the term or third-trimester placenta. The application of reproducible nomenclature is expected to facilitate progress in the diagnosis and treatment of obstetric and foetal disorders with placental manifestation. Therefore, this review aims to facilitate communication between obstetricians, neonatologists, and pathologists involved in this diagnostic process.

Ultrasonographic diagnosis of fetal hemodynamic parameters in pregnant women with diabetes mellitus in the third trimester of pregnancy

Objective

It was to investigate the diagnosis of fetal hemodynamics in pregnant women with diabetes mellitus in the third trimester of pregnancy by color Doppler ultrasonography.

Methods

55 women with gestational diabetes mellitus (GDM) in the third trimester of pregnancy who were clinically diagnosed and treated in Haian City People's Hospital of Jiangsu Province were selected as the observation group, and 55 pregnant women with normal prenatal examination results were selected as the controls. The hemodynamic parameters of fetal middle cerebral artery (MCA), umbilical artery (UA), and renal artery (RA) were detected, including the ratio of maximum systolic blood flow velocity to end-diastolic blood flow velocity (S/D), resistance index (RI) and arterial pulsation index (PI). Fasting serum levels of maternal patients were collected for detecting Cystain C (Cys C) and homocysteine (Hcy) to analyze the predictive value of serological indexes and target arterial hemodynamics parameters for adverse pregnancy outcome (APO).

Results

The results showed that compared with controls, in the observation group, RI, PI, and S/D of MCA and RA increased significantly, while RI, PI and S/D of UA decreased obviously (P < 0.05), the levels of serum Cys C and Hcy were clearly increased (P < 0.05). The APO rate of controls and observation group was 10.91 % and 25.45 %, respectively. It was found that the area under the curve of serum Cys C, Hcy, and the APO predicted by the hemodynamic parameters of fetal MCA, UA, and RA were all greater than 0.75 (P < 0.05). Multiple Logistic regression analysis showed that serum Cys C and Hcy, and the hemodynamic parameters of fetal MCA, UA and RA were correlated with APO (P < 0.05).

Conclusion

In summary, maternal blood glucose level can affect fetal hemodynamic parameters. In the third trimester of pregnancy, the changes of blood flow parameters of fetal MCA, UA, RA, and maternal serum Cys C and Hcy levels are helpful to understand fetal status in utero, and can be used to predict APO.

Maternal Factors and Placental Pathologies Associated with a Diagnosis of Chronic Villitis

OBJECTIVE

 To evaluate maternal risk factors associated with chronic villitis of unknown etiology (VUE) and to describe cooccurring placental pathologies.

STUDY DESIGN

 A retrospective case-control study was conducted using placental pathology records from deliveries ≥ 20 weeks between 2010 and 2018. Cases were placentas with documented chronic villitis without infectious cause, hereafter called VUE. Controls were placentas without this diagnosis, matched to the cases 2:1. Maternal and neonatal demographic and clinical data were collected. Descriptive statistics are reported with Fisher's exact test or a chi-squared test, as appropriate, and multivariable conditional logistic regression was conducted.

RESULTS

 Our study included 352 cases with VUE and 657 controls. A diagnosis of gestational diabetes (p = 0.03) and gestational hypertension (p = 0.06) was 1.5 times more likely to occur in those with a VUE diagnosis. A trend was also seen for chronic hypertension (odds ratio [OR] = 1.7, p = 0.07) and preeclampsia (OR = 1.5, p = 0.09) compared with controls. Placentas with VUE, specifically high-grade VUE, were more likely to be small for gestational age (p = 0.01), and to be diagnosed with other placental findings including lymphoplasmacytic or chronic deciduitis (p < 0.01), maternal (p < 0.01) and fetal vascular malperfusion (p = 0.02), and chorionitis (acute or chronic; p < 0.01).

CONCLUSION

 Gestational diabetes and hypertension were associated with a diagnosis of VUE, and overall, VUE placentas have more abnormal placental findings compared with control. Understanding VUE risk factors may facilitate prenatal care strategies and counseling to achieve the best outcomes for pregnant patients and their neonates.

KEY POINTS

· VUE is a common inflammatory lesion of the placenta.. · Gestational diabetes and hypertension are associated with a VUE diagnosis.. · Findings of other placental pathologies increase in VUE..

Perinatal arterial ischemic stroke: how informative is the placenta?

Neuroplacentology is an expanding field of interest that addresses the placental influence on fetal and neonatal brain lesions and on further neurodevelopment. The objective of this study was to clarify the link between placental pathology and perinatal arterial ischemic stroke (PAIS). Prior publications have reported different types of perinatal stroke with diverse methodologies precluding firm conclusions. We report here the histological placental findings in a series of 16 neonates with radiologically confirmed PAIS. Findings were grouped into 3 categories of lesions: (1) inflammation, (2) placental and fetal hypoxic lesions, and (3) placentas with a high birthweight/placenta weight ratio. Matched control placentas were compared to the pathological placentas when feasible. The eight term singleton placentas were compared to a series of 20 placentas from a highly controlled amniotic membrane donation program; in three twin pregnancies, the placental portions from the affected twin and unaffected co-twin were compared. Slightly more than half (9/16, 56%) had histopathological features belonging to more than one category, a feature shared by the singleton control placentas (13/20, 65%). More severe and extensive lesions were however observed in the pathological placentas. One case occurring in the context of SARS-CoV-2 placentitis further expands the spectrum of COVID-related perinatal disease. Our study supports the assumption that PAIS can result from various combinations and interplay of maternal and fetal factors and confirms the value of placenta examination. Yet, placental findings must be interpreted with caution given their prevalence in well-designed controls.

Outcome-Based Risk Stratification Model for the Diagnosis of Placental Maternal Vascular Malperfusion

The Amsterdam Consensus Statement introduced the term maternal vascular malperfusion (MVM) to group a constellation of findings associated with impaired maternal-placental circulation. In isolation, these findings are relatively common in placentas from normal gestations, and there is uncertainty on how many, and which, are required. We aimed to determine the criteria essential for MVM diagnosis in correlation with obstetrical outcomes. A total of 200 placentas (100 with a reported diagnosis of MVM and 100 controls matched by maternal age and gravida-para-abortus status) were reviewed to document MVM features. Obstetrical outcomes in the current pregnancy were recorded including hypertension, pre-eclampsia with or without severe features, gestational diabetes, prematurity, fetal growth restriction, and intrauterine fetal demise. On univariate logistic regression analysis, adverse outcome was associated with low placental weight (LPW, <10% percentile for gestational age), accelerated villous maturation (AVM), decidual arteriopathy (DA), infarcts (presence and volume), distal villous hypoplasia, and excess multinucleated trophoblast in basal plate ≥2 mm (all P < .01) but not with retroplacental hemorrhage. In a multivariable model DA, infarcts and AVM were significantly associated with adverse outcomes, whereas LPW showed a trend toward significance. A receiver-operating characteristic curve including these 4 parameters showed good predictive ability (area under the curve [AUC], 0.8256). Based on the probability of an adverse outcome, we recommend consistent reporting of DA, AVM, infarcts, and LPW, summarizing them as "diagnostic of MVM" (DA or AVM plus any other feature, yielding a probability of 65%-97% for adverse obstetrical outcomes) or "suggestive of MVM" (if only 1 feature is present, or only 2 features are infarcts plus LPW, yielding a probability of up to 52%). Other features such as distal villous hypoplasia, excess (≥2 mm) multinucleated trophoblast, and retroplacental hemorrhage can also be reported, and their role in MVM diagnosis should be further studied.

Placental Histologic Abnormalities and 2-Year Outcomes in Neonatal Hypoxic-Ischemic Encephalopathy

OBJECTIVE

We aimed to examine the association between placental abnormalities and neurodevelopmental outcomes in a multicenter cohort of newborn infants with hypoxic-ischemic encephalopathy (HIE) that underwent therapeutic hypothermia. We hypothesized that subjects with acute placental abnormalities would have reduced risk of death or neurodevelopmental impairment (NDI) at 2 years of age after undergoing therapeutic hypothermia compared to subjects without acute placental changes.

STUDY DESIGN

Among 500 subjects born at ≥36 weeks gestation with moderate or severe HIE enrolled in the High-dose Erythropoietin for Asphyxia and Encephalopathy (HEAL) Trial, a placental pathologist blinded to clinical information reviewed clinical pathology reports to determine the presence of acute only, chronic only, or both acute and chronic histologic abnormalities. We calculated adjusted relative risks (aRRs) for associations between placental pathologic abnormalities and death or NDI at age 2 years, adjusting for HIE severity, treatment assignment, and site.

RESULT

321/500 subjects (64%) had available placental pathology reports. Placental abnormalities were characterized as acute only (20%), chronic only (21%), both acute and chronic (43%), and none (15%). The risk of death or NDI was not statistically different between subjects with and without an acute placental abnormality (46 vs. 53%, aRR 1.1, 95% confidence interval (CI): 0.9, 1.4). Subjects with two or more chronic lesions were more likely to have an adverse outcome than subjects with no chronic abnormalities, though this did not reach statistical significance (55 vs. 45%, aRR 1.24, 95% CI: 0.99, 1.56).

CONCLUSION

Placental pathologic findings were not independently associated with risk of death or NDI in subjects with HIE. The relationship between multiple chronic placental lesions and HIE outcomes deserves further study.

The Placenta in Congenital Heart Disease: Form, Function and Outcomes

The maternal-fetal environment, controlled and modulated by the placenta, plays a critical role in the development and well-being of the fetus, with long-term impact through programming of lifelong health. The fetal cardiovascular system and placenta emerge at the same time embryologically, and thus placental form and function are altered in the presence of congenital heart disease (CHD). In this review, we report on what is known about the placenta from a structural and functional perspective when there is CHD. We describe the various unique pathologic findings as well as the diagnostic imaging tools used to characterize placental function in utero. With growing interest in the placenta, a standardized approach to characterizing placental pathology has emerged. Furthermore, application of ultrasonography techniques and magnetic resonance imaging now allow for insights into placental blood flow and functionality in vivo. An improved understanding of the intriguing relationship between the placenta and the fetal cardiovascular system will provide opportunities to develop novel ways to optimize outcomes. Once better understood, therapeutic modulation of placental function offered during the vulnerable period of fetal plasticity may be one of the most impactful ways to alter the course of CHD and its complications.

Placental pathology is necessary to understand common pregnancy complications and achieve an improved taxonomy of obstetrical disease

The importance of a fully functioning placenta for a good pregnancy outcome is unquestioned. Loss of function can lead to pregnancy complications and is often detected by a thorough placental pathologic examination. Placental pathology has advanced the science and practice of obstetrics and neonatal-perinatal medicine by classifying diseases according to underlying biology and specific patterns of injury. Many past obstacles have limited the incorporation of placental findings into both clinical studies and day-to-day practice. Limitations have included variability in the nomenclature used to describe placental lesions, a shortage of perinatal pathologists fully competent to analyze placental specimens, and a troubling lack of understanding of placental diagnoses by clinicians. However, the potential use of placental pathology for phenotypic classification, improved understanding of the biology of adverse pregnancy outcomes, the development of treatment and prevention, and patient counseling has never been greater. This review, written partly in response to a recent critique published in a major obstetrics-gynecology journal, reexamines the role of placental pathology by reviewing current concepts of biology; explaining the most recent terminology; emphasizing the usefulness of specific diagnoses for obstetrician-gynecologists, neonatologists, and patients; previewing upcoming changes in recommendations for placental submission; and suggesting future improvements. These improvements should include further consideration of overall healthcare costs, cost-effectiveness, the clinical value added of placental assessment, improvements in placental pathology education and practice, and leveraging of placental pathology to identify new biomarkers of disease and evaluate novel therapies tailored to specific clinicopathologic phenotypes of both women and infants.

Criteria for placental examination for obstetrical and neonatal providers

Pathologic examination of the placenta can provide insight into likely (and unlikely) causes of antepartum and intrapartum events, diagnoses with urgent clinical relevance, prognostic information for mother and infant, support for practice evaluation and improvement, and insight into advancing the sciences of obstetrics and neonatology. Although it is true that not all placentas require pathologic examination (although alternative opinions have been expressed), prioritization of placentas for pathologic examination should be based on vetted indications such as maternal comorbidities or pregnancy complications in which placental pathology is thought to be useful for maternal or infant care, understanding pathophysiology, or practice modifications. Herein we provide placental triage criteria for the obstetrical and neonatal provider based on publications and expert opinion of 16 placental pathologists and a pathologists' assistant, formulated using a modified Delphi approach. These criteria include indications in which placental pathology has clinical relevance, such as pregnancy loss, maternal infection, suspected abruption, fetal growth restriction, preterm birth, nonreassuring fetal heart testing requiring urgent delivery, preeclampsia with severe features, or neonates with early evidence of multiorgan system failure including neurologic compromise. We encourage a focused gross examination by the provider or an attendant at delivery for all placentas and provide guidance for this examination. We recommend that any placenta that is abnormal on gross examination undergo a complete pathology examination. In addition, we suggest practice criteria for placental pathology services, including a list of critical values to be used by the relevant provider. We hope that these sets of triage indications, criteria, and practice suggestions will facilitate appropriate submission of placentas for pathologic examination and improve its relevance to clinical care.

Histopathologic evaluation of dichorionic twin placentas in unassisted and in vitro fertilized pregnancies affected by preeclampsia

OBJECTIVE

Pregnancies achieved with assisted reproductive technology have an increased risk of multiple gestations, preeclampsia, and placental morphologic abnormalities. Inflammatory processes affect dichorionic twin pregnancies disproportionately more than singleton gestations and have been associated with adverse pregnancy outcomes, such as fetal growth restriction and preeclampsia. Our objective is to investigate the placental morphology of dichorionic twin pregnancies complicated by preeclampsia conceived with in vitro fertilization (IVF) versus unassisted.

METHODS

This is a retrospective analysis of placentas from dichorionic twin pregnancies affected by preeclampsia conceived with IVF versus without assistance from 2010 to 2016 at a tertiary care university hospital. Placental pathology findings were analyzed both independently and in aggregate stratified into composite outcome scores using a modified placental synoptic framework. Individual placental abnormalities were grouped into composite categories based on the site of origin: anatomic placental abnormalities; maternal vascular malperfusion; placental villous maldevelopment; fetal vascular malperfusion; chronic utero-placental separation; maternal-fetal interface disturbance; inflammation of infectious etiology; and inflammation of idiopathic etiology. Placental histopathological statistical analysis was performed using Fisher's exact test. Demographic variables and pregnancy outcomes were compared between groups using the Student's t test or Mann-Whitney U test, where appropriate. p < .05 defined statistical significance.

RESULTS

Of 117 dichorionic twin pregnancies, 60 resulted from IVF (Group A) and 57 were conceived without assistance (Group B). Patients in Group A were older (36 [29-37] vs. 33 [32-38] respectively; p = .042) and less parous (18.3% vs. 38.6% percent parous in Group A and Group B, respectively p = .009) than Group B, respectively. No differences were found between groups regarding mode of delivery, gestational age at delivery, placental weight/birthweight, fetal growth restriction, and discordance of fetal growth. There were significantly more inflammatory changes of unknown etiology and composite inflammatory abnormalities in Group A versus Group B (26.7% vs. 10.5%, p = .02). The cumulative number of inflammatory abnormalities per patient had a significantly different distribution among groups (p = .005), and Composite Chronic Inflammation and Infection were found to be significantly more abundant in Group A versus Group B (p = .02). The distribution of placental composite anatomic placental abnormalities, maternal vascular malperfusion, placental villous maldevelopment, fetal vascular malperfusion, chronic utero-placental separation, or maternal-fetal interface disturbance was not statistically different between groups. The distribution of placental abnormalities was not different between groups for any individually analyzed pathological condition. Due to the relatively small sample size, adjustment for potential confounders was not performed.

CONCLUSION

Dichorionic twin pregnancies affected by preeclampsia are associated with more placental inflammatory abnormalities if conceived with IVF versus unassisted. Further research is needed to ascertain the underlying mechanisms of these observed differences.

Characteristics of Placental Histopathology in Women with Uncomplicated Pregnancies Affected by SARS-CoV-2 Infection at the Time of Delivery: A Single-Center Experience

The aim of this study was, firstly, to analyze the histopathological characteristics of placentas in women with uneventful pregnancies and affected by COVID-19 at the time of delivery; and secondly, to correlate histological findings to maternal and neonatal characteristics. In our single-center prospective observational study, 46 placentas from term uncomplicated singleton pregnancies of patients with a documented SARS-CoV-2 infection at the time of delivery underwent histological examination. Despite a normal feto-maternal outcome, most of the placentas (82.6%) presented signs of maternal vascular malperfusion, while features of fetal vascular malperfusion were found in 54% of cases. No correlation was detected between maternal and neonatal characteristics and the severity of blood circulation disease, and abnormal findings were also described in asymptomatic patients. Moreover, we did not find any maternal symptoms or clinical details allowing for the prediction of abnormal placental findings in pregnancy complicated by COVID-19 infection. Our results suggest that SARS-CoV-2 infection during pregnancy could lead to acute placental dysfunction.

Placental pathology associated with lenticulostriate vasculopathy (LSV) in preterm infants

OBJECTIVE

Our aim was to examine the frequency and type of placental abnormalities in neonates with LSV.

STUDY DESIGN

We prospectively reviewed cranial ultrasounds (cUS) from neonates born at ≤32 weeks of gestation at Parkland Hospital between 2012 and 2014. Our cohort included neonates with LSV and gestational age and sex matched controls with normal cUS. We retrieved placental pathology reports retrospectively and compared placental abnormalities in both groups.

RESULTS

We reviewed 1351 cUS from a total of 407 neonates. Placental pathology evaluations were complete for 64/65 (98%) neonates with LSV and 68/70 (97%) matched controls. There were no significant differences for any type of placental abnormities between LSV and control groups. However, infants with highest stage LSV were more likely to have large for gestational age (LGA) placentas (p = 0.01).

CONCLUSION

The association between LSV and LGA placenta may indicate a shared vascular response to an adverse prenatal environment.

Placenta, the Key Witness of COVID-19 Infection in Premature Births

Adverse perinatal outcomes, such as increased risks of pre-eclampsia, miscarriage, premature birth, and stillbirth have been reported in SARS-CoV-2 infection. For a better understanding of COVID-19 complications in pregnancy, histopathological changes in the placenta, which is the interface between mother and foetus, could be the place to look at. The aim of this study was to determine placental histopathological changes and their role in preterm birth in pregnant women with SARS-CoV-2 infection. We performed a prospective, observational study in a COVID-only hospital, which included 39 pregnant women with SARS-CoV-2 infection and preterm birth compared with a control group of 39 women COVID-19 negative with preterm birth and a placental pathology exam available. The microscopic examination of all placentas revealed placental infarction (64.1% vs. 30.8%), decidual arteriopathy (66.7% vs. 23.1%), intervillous thrombi (53.8% vs. 38.5%), perivillous fibrin deposits (59% vs. 46.2%), inflammatory infiltrate (69.2% vs. 46.2%), chorangiosis (17.9% vs. 10.3%), and accelerated maturation of the villi (23.1% vs. 28.2%).

Diffuse and Localized SARS-CoV-2 Placentitis: Prevalence and Pathogenesis of an Uncommon Complication of COVID-19 Infection During Pregnancy

Coronavirus disease 2019 (COVID-19) infection in pregnancy has been associated with preterm delivery and preeclampsia. A less frequent and underrecognized complication is extensive placental infection which is associated with high rates of perinatal morbidity and mortality. The frequency, early pathogenesis, and range of lesions associated with this infection are poorly understood. We conducted a population-based study of placental pathology from all mothers with COVID-19 (n=271) over an 18-month period delivering within our health system. The overall prevalence of diffuse severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) placentitis, as defined by typical histology and immunohistochemical (IHC) staining for SARS-CoV-2 spike protein, was 14.8/1000, but increased to 59/1000 in preterm births. We also identified 3 cases with isolated small foci of localized SARS-CoV-2 placentitis, characterized by focal perivillous fibrin and intervillositis, which illustrate the early pathogenesis and suggest that infection may be contained in some cases. Two other placental lesions were more common in mothers with COVID-19, high-grade maternal vascular malperfusion in preterm deliveries and high-grade chronic villitis at term (5/5 cases tested of the latter were negative by IHC for SARS-CoV-2). Additional investigation of diffuse and localized SARS-CoV-2 placentitis by IHC showed loss of BCL-2, C4d staining in surrounding villi, and an early neutrophil-predominant intervillous infiltrate that later became dominated by monocyte-macrophages. We propose a model of focal infection of syncytiotrophoblast by virally infected maternal leukocytes leading to loss of BCL-2 and apoptosis. Infection is then either contained by surrounding fibrinoid (localized) or initiates waves of aponecrosis and immune activation that spread throughout the villous parenchyma (diffuse).

The placental pathology in Coronavirus disease 2019 infected mothers and its impact on pregnancy outcome

Introduction

This study aims at observing placental pathologies in COVID-19 infected women, and analyzing its impact on pregnancy outcome.

Method

This is a descriptive-analytical study done at a tertiary centre of Northern India. All COVID-19 positive pregnant women with gestational age ≥20 weeks, with placental histopathological reporting, were included in this study. A total of 173 COVID-19 pregnant women were included in the study.

Results

Placental abnormalities were noticed in 49·16% of total 179 placentae examined. Maternal vascular malperfusion (27·93%) was the most observed placental pathology followed by villous fibrin deposits (22·90%), fetal vasculopathy (16·75%), and acute inflammation (6·70%). Stillbirths were 22 and NICU admissions were seen in 50 neonates. Abnormal placental abnormalities led to higher stillbirths (p value 0·011) and lower Apgar scores at 1 and 5 min (p-value 0·028; p-value 0·002, respectively). Intervillous fibrin deposits had higher risk associated with lower Apgar score at 1 and 5 min [RR 2·05 (95% CI 1·21–3·48, p-value 0·010) and RR 5·52 (95% CI 2·58–11·81, p-value <0·001), respectively]. RP clot/hemorrhage was also associated with lower Apgar score at 1 and 5 min [RR 2·61 (95% CI 1·52–4·49, p-value 0·002) and RR 3.54 (95% CI 1·66–7·55, p-value 0·001), respectively].

Discussion

Placental abnormalities in COVID-19 infection were associated with significant higher incidence of unexplained stillbirths, and lower Apgar scores. Although, this is the largest descriptive-analytical study done so far, comparative studies are required to draw a clear conclusion regarding the impact of COVID-19 infection on human placenta and its effect on pregnancy outcomes.

Placental Findings in Pregnancies Complicated by Maternal Cardiovascular Disease

Background

The incidence of pregnancy in women with cardiovascular disease (CVD) has increased, yet little is known about placental pathology in these women.

Objectives

The objectives of this study were to describe placental pathology in pregnancies complicated by maternal CVD and to compare findings among categories of maternal CVD.

Methods

A retrospective, single-center study was conducted. Pathology reports for 264 placentas from pregnancies complicated by maternal CVD were reviewed for prespecified pathologic findings which were then compared against maternal characteristics.

Results

Placentas were from pregnancies associated with maternal congenital heart disease (n = 171), arrhythmia (n = 43), cardiomyopathy (n = 20), connective tissue disease (n = 20), and valvular heart disease (n = 10). Median maternal age at delivery was 32 years (range: 19-49). Median gestational age at delivery was 39 weeks (range: 25-41). Placental pathology was identified in 75% (199/264) of placentas. Anatomic pathology, primarily small placenta by weight, was present in 45% (119/264) of placentas. Vascular pathology, primarily maternal vascular malperfusion or fetal vascular malperfusion, was seen in 41% (107/264) of placentas. Acute chorioamnionitis and villitis of unknown etiology (VUE) were seen in 23% (61/264) and 11% (28/264) of placentas, respectively. Prevalence of VUE differed across CVD categories (P = 0.008) and was most common in maternal congenital heart disease; there were no differences in anatomic, infectious, and vascular pathologies across CVD categories.

Conclusions

Pregnancies among women with CVD commonly demonstrate abnormal placental findings, especially anatomic and vascular pathology. Prevalence of VUE differed across CVD categories. Otherwise, the incidence of specific pathology findings did not differ based on maternal characteristics.

Maternal SARS-CoV-2 Infection, its Vertical Transmission, and Impact on Overall Perinatal Outcomes: A Narrative Review

BACKGROUND

COVID-19 pandemic caused by single-stranded RNA containing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) started in early December 2019 from the Wuhan city of China and has been affected millions of people, including pregnant women worldwide. Research from all over the world has shown that the SARS-CoV-2 infection can be transmitted vertically from mother to fetus but is very rare. Neonatal infection with COVID-19 accounts for only a small proportion of the total population infected. Furthermore, very few studies have observed the impact of maternal SARS-CoV-2 infection on neonatal outcomes. Thus, the literature about neonatal transmission and outcomes in COVID-19 infected antenatal women is very scattered and limited. The present review briefs on the transmission of SARS-CoV-2 infection from mother to fetus and its impact on perinatal outcomes.

METHODOLOGY

English language articles from various databases including PubMed, Scopus, EMBASE, Scholar, MedRxiv, and Web of Science and from the World Health Organization site were searched from the beginning of the COVID-19 pandemic up to June 2021. The search terms used were "SARS-CoV-2 and pregnancy outcome, "COVID-19 and neonatal outcome", "Placental changes in COVID-19 infected pregnant women", "Vertical transmission of COVID-19".

CONCLUSION

Maternal SARS-CoV-2 infection can be transmitted to the fetus, though uncommon, and can lead to adverse perinatal outcomes, including preterm births, intrauterine growth restriction, NICU admission, stillbirths. The data on transmission and the adverse neonatal outcome is sparse, and many more studies are needed to fully understand the mechanism by which maternal COVID-19 infection can affect fetuses and neonates.

Placental pathology: Pathways leading to or associated with perinatal brain injury in experimental neurology, special issue: Placental mediated mechanisms of perinatal brain injury

Perinatal brain injury is a multifactorial process. In utero placental physiology plays a major role in neuroprotection and the normal development of the fetal central nervous system. Advances in placental pathology have clarified several specific mechanisms of injury and the histologic lesions most strongly associated with them. This review provides an updated summary of the relevant placental anatomy and physiology, the specific placental pathways leading to brain injury, the revised Amsterdam classification system for placental pathology, and the known associations of specific placental lesions with subtypes of adverse neurologic outcomes.

Comparison of early postnatal clinical outcomes of newborns born to pregnant women with COVID-19: a case-control study

BACKGROUND

The ongoing COVID-19 pandemic has infected millions of people, including pregnant women and newborns and caused many deaths. Studies examining the effects of COVID-19 infection in pregnancy have mostly focused on maternal outcomes and there are limited data on neonatal outcomes.

OBJECTIVES

This study aims to compare the early postnatal period clinical outcomes of newborns born to pregnant women with and without COVID-19.

METHODS

A retrospective case-control study was used to compare the clinical characteristics of newborns born to pregnant women with and without COVID-19. This study was conducted between 11 March 2020 and 11 March 2021 at Denizli State Hospital, Turkey. This study included 202 newborns selected with a nonprobability method. The clinical records and laboratory results of 202 newborns were reviewed by applying a retrospective questionnaire. Neonatal outcomes were compared between the groups.

RESULTS

There were 101 newborns born to pregnant women with COVID-19 in the case group and 101 without COVID-19 in the control group in the study. A considerably higher rate of newborns born to pregnant women with COVID-19 had cesarean delivery (79.2 versus 35.6%, p < .001), premature birth (28.7 versus 10.9%, p = .001), low birth weight (15.8 versus 6.9%, p = .046), neonatal respiratory distress syndrome (RDS) (37.6 versus 19.8%, p = .005), oxygen need (19.8 versus 37.6, p = .005), and neonatal intensive care unit admission (10.9 versus 37.6%, p = .001). Breastfeeding (1.0 versus 67.3%, p < .001) and nutrition with breast milk rates (33.7 versus 80.2%, p < .001) of newborns born to pregnant women with COVID-19 were significantly lower. The results of 101 newborns who received nasopharyngeal swab samples for COVID-19 were negative.

CONCLUSION

Newborns born to pregnant women with COVID-19 were more likely to experience preterm birth, cesarean delivery, low birth weight, neonatal RDS, oxygen demand, need for intensive care, and breastfeeding problems. There was no vertical contamination according to the nasopharyngeal swab samples of the newborns.

Acute and Chronic Placental Abnormalities in a Multicenter Cohort of Newborn Infants with Hypoxic-Ischemic Encephalopathy

OBJECTIVE

To examine the frequency of placental abnormalities in a multicenter cohort of newborn infants with hypoxic-ischemic encephalopathy (HIE) and to determine the association between acuity of placental abnormalities and clinical characteristics of HIE.

STUDY DESIGN

Infants born at ≥36 weeks of gestation (n = 500) with moderate or severe HIE were enrolled in the High-dose Erythropoietin for Asphyxia and Encephalopathy Trial. A placental pathologist blinded to clinical information reviewed clinical pathology reports to determine the presence of acute and chronic placental abnormalities using a standard classification system.

RESULTS

Complete placental pathologic examination was available for 321 of 500 (64%) trial participants. Placental abnormalities were identified in 273 of 321 (85%) and were more common in infants ≥40 weeks of gestation (93% vs 81%, P = .01). A combination of acute and chronic placental abnormalities (43%) was more common than either acute (20%) or chronic (21%) abnormalities alone. Acute abnormalities included meconium staining of the placenta (41%) and histologic chorioamnionitis (39%). Chronic abnormalities included maternal vascular malperfusion (25%), villitis of unknown etiology (8%), and fetal vascular malperfusion (6%). Infants with chronic placental abnormalities exhibited a greater mean base deficit at birth (-15.9 vs -14.3, P = .049) than those without such abnormalities. Patients with HIE and acute placental lesions had older mean gestational ages (39.1 vs 38.0, P < .001) and greater rates of clinically diagnosed chorioamnionitis (25% vs 2%, P < .001) than those without acute abnormalities.

CONCLUSIONS

Combined acute and chronic placental abnormalities were common in this cohort of infants with HIE, underscoring the complex causal pathways of HIE.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02811263.

Interobserver Reliability for Identifying Specific Patterns of Placental Injury as Defined by the Amsterdam Classification

CONTEXT.—

Placental pathology is an essential tool for understanding neonatal illness. The recent Amsterdam international consensus has standardized criteria and terminology, providing harmonized data for research and clinical care.

OBJECTIVE.—

To evaluate the interobserver reliability of these criteria between pathologists at different levels of experience using digitally scanned slides from placentas in a birth population including a large proportion of normal deliveries.

DESIGN.—

This was a secondary analysis of selected placentas from a large case-control study of placental lesions associated with neonatal encephalopathy. Histologic slides from 80 placentas were digitally scanned and blindly evaluated by 6 pathologists. Interobserver reliability was assessed by positive and negative agreement, Fleiss κ, and interrater correlation coefficients.

RESULTS.—

Overall agreement on the diagnosis, grading, and staging of acute chorioamnionitis and villitis of unknown etiology was moderate to good for all observers and good to excellent for a subset of 4 observers. Agreement on the diagnosis and subtyping of fetal vascular malperfusion was poor to fair for all observers and fair to moderate for the subset of 4 pathologists. Agreement on accelerated villous maturation was poor.

CONCLUSIONS.—

This study critically evaluates interobserver reliability for lesions defined by the Amsterdam consensus using scanned images with a low frequency of pathologic lesions. Although reliability was good to excellent for inflammatory lesions, lower reliability for vascular lesions emphasizes the need to more explicitly define the specific histologic features and boundaries for these patterns.

Four major patterns of placental injury: a stepwise guide for understanding and implementing the 2016 Amsterdam consensus

The Amsterdam classification system defines four major patterns of placental injury, maternal vascular malperfusion, fetal vascular malperfusion, acute chorioamnionitis, and villitis of unknown etiology, and lists the histologic findings that characterize each. However, there continues to be uncertainty regarding specific definitions, histologic mimics, grading and staging, and what combination of findings is required to diagnose each pattern of injury in a reproducible fashion. The purpose of this review is to clarify some of these issues by suggesting a stepwise approach to more fully realize the potential of this new classification system. In our view, the critical steps for correctly identifying and communicating each pattern of injury are (1) familiarity with the underlying pathophysiology and known clinical associations, (2) incorporation of important gross findings, (3) learning to recognize underlying architectural alterations and defining features at low power, (4) using higher magnification to narrow the differential diagnosis and assess severity (grading) and duration (staging), and (5) adopting a template for generating standardized placental reports that succinctly provide useful information for patient care and research applications.

Is the First of the Two Born Saved? A Rare and Dramatic Case of Double Placental Damage from SARS-CoV-2

The current coronavirus pandemic has affected, in a short time, various and different areas of medicine. Among these, the obstetric field has certainly been touched in full, and the knowledge of the mechanisms potentially responsible for placental damage from SARS-CoV-2 occupy a certain importance. Here we present here a rare case of dichorionic twins born at 30 weeks and 4 days of amenorrhea, one of whom died in the first few hours of life after placental damages potentially related to SARS-CoV-2. We also propose a brief review of the current literature giving ample emphasis to similar cases described.

Third trimester stillbirth during the first wave of the SARS-CoV-2 pandemic: Similar rates with increase in placental vasculopathic pathology

Whether early SARS-CoV-2 definitively increases the risk of stillbirth is unknown, though studies have suggested possible trends of stillbirth increase during the pandemic. This study of third trimester stillbirth does not identify an increase in rates during the first wave of the pandemic period, however investigation of the placental pathology demonstrates trends towards more vascular placental abnormalities.

Placental Pathology in COVID-19

OBJECTIVES

To describe histopathologic findings in the placentas of women with coronavirus disease 2019 (COVID-19) during pregnancy.

METHODS

Pregnant women with COVID-19 delivering between March 18, 2020, and May 5, 2020, were identified. Placentas were examined and compared to historical controls and women with placental evaluation for a history of melanoma.

RESULTS

Sixteen placentas from patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were examined (15 with live birth in the third trimester, 1 delivered in the second trimester after intrauterine fetal demise). Compared to controls, third trimester placentas were significantly more likely to show at least one feature of maternal vascular malperfusion (MVM), particularly abnormal or injured maternal vessels, and intervillous thrombi. Rates of acute and chronic inflammation were not increased.The placenta from the patient with intrauterine fetal demise showed villous edema and a retroplacental hematoma.

CONCLUSIONS

Relative to controls, COVID-19 placentas show increased prevalence of decidual arteriopathy and other features of MVM, a pattern of placental injury reflecting abnormalities in oxygenation within the intervillous space associated with adverse perinatal outcomes. Only 1 COVID-19 patient was hypertensive despite the association of MVM with hypertensive disorders and preeclampsia. These changes may reflect a systemic inflammatory or hypercoagulable state influencing placental physiology.