Maternal floor infarction of the placenta: association with central nervous system injury and adverse neurodevelopmental outcome

Clinical value of placental examination for paediatricians

The placenta contains valuable clinical information that is linked to fetal development, neonatal morbidity and mortality, and future health outcomes. Both gross inspection and histopathological examination of the placenta may identify intrinsic or secondary placental lesions, which can contribute directly to adverse neonatal outcomes or indicate the presence of an unfavourable intrauterine environment. Placental examination therefore forms an essential component of the care of high-risk neonates and at perinatal post-mortem examination. In this article, we describe the clinical value of placental examination for paediatricians and perinatal clinicians. We discuss common pathological findings on general inspection of the placenta with photographic examples and provide an overview of the placental pathological examination, including how to interpret key findings. We also address the medico-legal and financial implications of placental examinations and describe current and future clinical considerations for clinicians in regard to placental examination.

Assessment of role of cranial ultrasound (CUS) in the evaluation of high-risk preterm and term neonates

Background

Cranial ultrasonography (CUS) has become an important tool to depict normal brain anatomy and to detect the ischemic and hemorrhagic brain injury patterns in high-risk neonates. The present study aimed to assess the utility of CUS to diagnose the spectrum of brain injury patterns in high-risk preterm and term neonates admitted to the neonatal intensive care unit (NICU) and to find the association of CUS findings in various adverse antenatal and perinatal feto-maternal factors.

Results

Out of the 200 neonates, 76 (38%) neonates had abnormal CUS findings and 124 (62%) had a normal CUS. Germinal matrix hemorrhage-intraventricular hemorrhage (GMH-IVH) (28/76; 36.8 %) was the commonest abnormality with GMH (grade 1) in 14/76 (18.4%), grade 2 in 7 (9.2%), grade 3 in 5 (6.5%), and grade 4 in 2 (2.63%). The other findings observed were cerebral edema (14/76; 18.4%), thalamic hyperechogenicity (10/76; 13.1%), periventricular leukomalacia (PVL) (4/76; 5.2%), and congenital anomalies (8; 10.5%). Abnormal CUS findings had a statistically significant association with birth weight <2000 g, prematurity, Apgar score <7, and adverse peri-natal fetal and maternal factors (all p-values <0.05). Abnormal CUS findings had a statistically significant association with poor cry, poor activity, abnormal tone, and presence of cyanosis (all p-values <0.05).

Conclusion

In this cohort study of high-risk preterm and term infants GMH-IVH, cerebral edema, thalamic hyperechogenicity, PVL, and congenital malformations were the commonest lesions detected on CUS. Abnormal CUS findings were found to have a statistically significant association with various adverse peri-natal fetal and maternal factors.

Placental Pathology and the Developing Brain

Abnormal neurodevelopmental outcomes are associated with multiple factors including prematurity, intrauterine infection, maternal comorbidities as well as fetal anomalies. Within the past decade, new standardized terminology in placental pathology has emerged, emphasizing the current understanding of processes that play a role in placental dysfunction. Factors playing a major role in the abnormal development of the placenta include abnormalities in blood flow and perfusion of the fetal and maternal compartments of the placenta termed fetal vascular malperfusion and maternal vascular malperfusion, respectively. Concepts reviewed include massive perivillous fibrin deposition, chronic villitis, meconium-associated injury as well as chorioamnionitis. Each have a temporal effect on the placental vascular tree and may reflect an altered maternal inflammatory response. In this article we highlight pathologic placental findings which when present can serve to explain, at least in part, altered neurodevelopment in the child, adolescent and adult. Lesions with a propensity for recurrence in future pregnancies are discussed.

Chronic Inflammatory Placental Disorders Associated With Recurrent Adverse Pregnancy Outcome

Chronic inflammatory placental disorders are a group of rare but devastating gestational syndromes associated with adverse pregnancy outcome. This review focuses on three related conditions: villitis of unknown etiology (VUE), chronic histiocytic intervillositis (CHI) and massive perivillous fibrin deposition (MPFD). The hallmark of these disorders is infiltration of the placental architecture by maternal immune cells and disruption of the intervillous space, where gas exchange between the mother and fetus occurs. Currently, they can only be detected through histopathological examination of the placenta after a pregnancy has ended. All three are associated with a significant risk of recurrence in subsequent pregnancies. Villitis of unknown etiology is characterised by a destructive infiltrate of maternal CD8+ T lymphocytes invading into the chorionic villi, combined with activation of fetal villous macrophages. The diagnosis can only be made when an infectious aetiology has been excluded. VUE becomes more common as pregnancy progresses and is frequently seen with normal pregnancy outcome. However, severe early-onset villitis is usually associated with fetal growth restriction and recurrent pregnancy loss. Chronic histiocytic intervillositis is characterised by excessive accumulation of maternal CD68+ histiocytes in the intervillous space. It is associated with a wide spectrum of adverse pregnancy outcomes including high rates of first-trimester miscarriage, severe fetal growth restriction and late intrauterine fetal death. Intervillous histiocytes can also accumulate due to infection, including SARS-CoV-2, although this infection-induced intervillositis does not appear to recur. As with VUE, the diagnosis of CHI requires exclusion of an infectious cause. Women with recurrent CHI and their families are predisposed to autoimmune diseases, suggesting CHI may have an alloimmune pathology. This observation has driven attempts to prevent CHI with a wide range of maternal immunosuppression. Massive perivillous fibrin deposition is diagnosed when >25% of the intervillous space is occupied by fibrin, and is associated with fetal growth restriction and late intrauterine fetal death. Although not an inflammatory disorder per se, MPFD is frequently seen in association with both VUE and CHI. This review summarises current understanding of the prevalence, diagnostic features, clinical consequences, immune pathology and potential prophylaxis against recurrence in these three chronic inflammatory placental syndromes.

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.

Fetal akinesia deformation sequence and massive perivillous fibrin deposition resulting in fetal death in six fetuses from one consanguineous couple, including literature review

Background

Massive perivillous fibrin deposition (MPFD) is associated with adverse pregnancy outcomes and is mainly caused by maternal factors with limited involvement of fetal or genetic causes. We present one consanguineous couple with six fetuses developing Fetal Akinesia Deformation Sequence (FADS) and MPFD, with a possible underlying genetic cause. This prompted a literature review on prevalence of FADS and MPFD.

Methods

Fetal ultrasound examination, motor assessment, genetic testing, postmortem examination, and placenta histology are presented (2009–2019). Literature was reviewed for the association between congenital anomalies and MPFD.

Results

All six fetuses developed normally during the first trimester. Thereafter, growth restriction, persistent flexed position, abnormal motility, and contractures in 4/6, consistent with FADS occurred. All placentas showed histologically confirmed MPFD. Genetic analyses in the five available cases showed homozygosity for two variants of unknown significance in two genes, VARS1 (OMIM*192150) and ABCF1 (OMIM*603429). Both parents are heterozygous for these variants. From 63/1999 manuscripts, 403 fetal outcomes were mobilized. In 14/403 fetuses, congenital abnormalities in association with MPFD were seen of which two fetuses with contractures/FADS facial anomalies.

Conclusion

The low prevalence of fetal contractures/FADS facial anomalies in association with MPFD in the literature review supports the possible fetal or genetic contribution causing FADS and MPFD in our family. This study with literature review supports the finding that fetal, fetoplacental, and/or genetic components may play a role in causing a part of MPFDs.

Defining Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Placentitis: A Report of 7 Cases with Confirmatory In Situ Hybridization, Distinct Histomorphologic Features, and Evidence of Complement Deposition

CONTEXT

-Case reports and rare case series have demonstrated variable placental pathology in the setting of maternal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In rare small studies demonstrating infection of the placental parenchyma, histologic manifestations have included variable degrees of histiocytic intervillositis, perivillous fibrin deposition, and syncytiotrophoblast necrosis.

OBJECTIVE

-To characterize the placental pathological features of SARS-CoV-2 infected placentas, irrespective of fetal-maternal transmission, and to examine the frequency of C4d activation in such cases.

DESIGN

-Retrospective study of seven placentas from mothers with active SARS-CoV-2 infection and placental infection as demonstrated by RNA in situ hybridization.

RESULTS

-Six placentas were from live-born neonates (5 singletons, 1 non-fused diamniotic-dichorionic twin placenta), and one was from a stillbirth. Five of the eight neonates (including the stillbirth) tested negative for SARS-CoV-2, and all were negative for neonatal infection. The remaining three neonates were well at time of discharge. All placentas were positive for SARS-CoV-2 infection by RNA in situ hybridization and demonstrated variable degrees of histiocytic intervillositis, perivillous fibrin deposition, and trophoblast necrosis. Three cases demonstrated features of fetal vascular malperfusion. CD68 highlighted intervillous histiocytes. C4d expression was present along the villous borders in 6 of 7 cases.

CONCLUSIONS

-SARS-CoV-2 placentitis is defined by the triad of histiocytic intervillositis, perivillous fibrin deposition, and trophoblast necrosis. The features may occur in cases without confirmed transplacental transmission. The damage caused by SARS-CoV-2 placentitis is likely mediated by complement activation.

COVID-19 as an independent risk factor for subclinical placental dysfunction

Background

The pandemic of the severe acute respiratory distress syndrome-associated Coronavirus-2 (SARS-CoV-2) has affected millions around the world. In pregnancy the dangers to the mother and fetus are still being explored. SARS-CoV2 can potentially compromise maternal and neonatal outcomes and this may be dependent on the pregnancy stage during which the infection occurs.

Objective

The present study was done to find the histopathological alterations in the placenta of SARS-CoV-2 positive pregnancies with either no symptoms or mild coronavirus disease (COVID)-19 related symptoms and its association with neonatal outcomes.

Study design

This was a prospective analytical study. Twenty seven asymptomatic or mildly symptomatic SARS-CoV-2 positive pregnant women with a singleton pregnancy delivered between 1^st July 2020 and 15^th September 2020, were included as cases. An equal number of SARS-CoV-2 negative singleton pregnancies matched for maternal and gestational age during the same period were included as controls. After delivery the histopathological examination of the placenta of these women was done and the findings recorded on a predesigned proforma based on the Amsterdam consensus criteria for evidence of maternal and fetal vascular malperfusion changes.

Results

The baseline characteristics were comparable between the cases and controls. The following features of maternal vascular malperfusion (MVM) were significantly higher in the placentae of COVID-19 positive pregnancies: retroplacental hematomas (RPH), accelerated villous maturation (AVM), distal villous hyperplasia (DVH), atherosis, fibrinoid necrosis, mural hypertrophy of membrane arterioles (MHMA), vessel ectasia and persistence of intramural endovascular trophoblast (PIEVT). Fetal vascular malperfusion (FVM) significantly associated with the positive pregnancies were chorioangiosis, thrombosis of the fetal chorionic plate (TFCP), intramural fibrin deposition (IMFD) and vascular ectasia. Additionally, perivillous fibrin deposition was also significantly higher in the placentae of cases.

The percentage of spontaneously delivered women was comparable in the two groups. The sex and weight of the newborn and the number of live births were comparable between the two groups.

Conclusions

Asymptomatic or mildly symptomatic SARS-CoV-2 positive pregnant women, with otherwise uncomplicated pregnancies, show evidence of placental injury at a microscopic level. Similar findings have been demonstrated in other studies too. This placental injury apparently does not lead to poor pregnancy outcomes. The extent of this injury in symptomatic cases of COVID-19 pregnancies and its consequences on the outcomes need to be analysed.

The impact of placental massive perivillous fibrin deposition on neonatal outcome in pregnancies complicated by fetal growth restriction

INTRODUCTION

Massive perivillous fibrin deposition (MPDD) is an uncommon placental lesion which has been associated with an increased risk of adverse pregnancy outcome in retrospective series. The purpose of the study was to evaluate the frequency and consequences of MPFD in pregnancies complicated by fetal growth restriction (FGR).

MATERIALS AND METHODS

A cohort study of 355 pregnancies complicated by FGR diagnosed according to standard ultrasonographic criteria, enrolled, followed and delivered at a single obstetric unit. Pathological placental lesions were classified according to the Amsterdam Placental Workshop Consensus. Penalized logistic regression models were used to evaluate the association of MPFD with maternal risk factors, other pathological lesions and neonatal outcome.

RESULTS

The rates of moderate (25-50% of villi) and severe (>50% of villi) MPFD were 8.7% (31/355) and 3.1% (11/355), respectively. Compared to other FGR cases, MPFD pregnancies were characterized by higher placental volume (450 ± 144.5 SD as compared to 412.2 ± 151 cm³,p < 0.001) and lower birthweight/placental weight ratio (5.32 ± 1.53 compared to 6.1 ± 1.52,p < 0.001). The rates of abnormal Doppler ultrasound studies of umbilical and middle cerebral artery were similar in MPFD subjects and controls. After correction for gestational age and birthweight, MPFD was associated with an increased risk of neonatal intraventricular hemorrhage (>grade II) (OR = 5.66,95% CI = 1.69-18.97), sepsis (OR = 5.9, 95% CI = 1.27-27.12), proven necrotizing enterocolitis (OR = 9.84,95% CI = 2.49-38.8) and overall severe adverse neonatal outcome (OR = 5.71,95% CI = 2.05-15.87).

CONCLUSIONS

Moderate-to-severe MPFD was relatively common among FGR pregnancies and was associated with morphometric modifications of placenta and with an increased risk of severe adverse neonatal outcome.

Clinicopathological characteristics of miscarriages featuring placental massive perivillous fibrin deposition

INTRODUCTION

Massive perivillous fibrin deposition (MPFD) is frequently associated with detrimental pregnancy outcomes, and extensive perivillous fibrin deposition results in severe placental dysfunction and loss of maternofetal interface. Unfortunately, the fundamental pathogenesis of MPFD remains unknown, and systematic analyses of MPFD in miscarriage is lacking. We analyzed the frequency and clinicopathological characteristics of MPFD in first trimester miscarriages.

METHODS

We analyzed a consecutive series of miscarriages (n = 582) gathered between March 2012 and June 2016. MPFD was classified as fibrin-type (f-MPFD) and matrix-type (m-MPFD) by immunostaining for fibrin and collagen type IV. The control group consisted of miscarriage cases (MC, n = 18) that were matched to f-MPFD with normal chromosome (f-MPFD-nc) for number of previous miscarriages and placental chromosomal status.

RESULTS

MPFD was identified in 2.7% of miscarriages. f-MPFD was associated with recurrent abortions. Compared with miscarriages without fibrin deposition, MPFD cases had higher proportion of those with normal placental chromosome (69.2% vs. 27.4%, P < 0.005) and higher frequency of villous syncytiotrophoblast C4d deposition (73.3% vs. 33.9%, P < 0.005). All C4d(+) f-MPFD patients had more than three recurrent miscarriages, whereas C4d(-) f-MPFD patients had no history of recurrent miscarriage (P < 0.05). Patients with f-MPFD-nc had significantly higher HLA PRA immunopositivity rate than did MC patients (P = 0.005).

DISCUSSION

MPFD was more common in miscarriages than in preterm and term pregnancies. Placental massive fibrin-type fibrinoid deposition and villous C4d immunoreactivity were associated with recurrent miscarriage.

MRI features of the placenta in fetuses with and without CNS abnormalities

AIM

To investigate if magnetic resonance imaging (MRI) features of the placenta are different in fetuses with and without central nervous system (CNS) abnormalities.

MATERIAL AND METHODS

Institutional research ethics board approval was obtained. Fetal MRI of 97 singleton pregnancies were analysed retrospectively (19-25 weeks gestation), 65 with CNS morphological abnormalities and 32 controls. Placental T2 signal intensity, placental and fetal volumes, placental-to-fetal volume ratio, and placental apparent diffusion coefficient (ADC) values were assessed. Measurements were compared with the presence or absence of CNS fetal abnormalities using the Mann-Whitney test. Separate slopes models and intercept models were used to check for significant differences in the slopes and intercepts, respectively, among the groups.

RESULTS

Placental ADC values were significantly lower in placentas of fetuses with CNS abnormalities compared to controls (p=0.04). Placental T2 signal intensity, fetal and placental volumes did not differ between the two groups. The rate of increase in fetal-to-placental volume ratio with gestational age (GA) was greater among the controls.

CONCLUSION

The presence of fetal CNS abnormalities is associated with reduced ADC values of the placenta. Moreover, placentas of fetuses with CNS abnormalities show a less rapid increase in fetal to placental volume ratio with GA. Therefore, ADC mapping, as well as different growth kinetics of the placenta relative to the fetus, may potentially serve as early markers of pathological neurodevelopment.

Growth Restriction, Osteopenia, Placental Massive Perivillous Fibrin Deposition With (or Without) Intervillous Histiocytes and Renal Tubular Dysgenesis-An Emerging Complex

We describe a case of a pregnancy complicated by early onset asymmetric growth restriction with anhydramnios with termination occurring at 21 weeks. Fetal autopsy showed demineralization of bones and renal tubular dysgenesis. Placental pathology showed features of massive perivillous fibrin deposition and chronic histiocytic intervillositis. We review prior documentation of this association and briefly discuss potential pathogenesis.

Placental pathologic lesions with a significant recurrence risk - what not to miss!

Here, we review three important placental pathologies with significant clinical implications and recurrence risks. They are, in order of most to least frequently seen, villitis of unknown etiology, chronic histiocytic intervillositis, and massive perivillous fibrin deposition (also known as maternal floor infarction). These entities occur in both preterm and term gestations and are observed more frequently with maternal and obstetric disorders including prior pregnancy loss, hypertension/preeclampsia, and autoimmune disease. They are associated with, and probably the cause of, significant perinatal morbidity and mortality including intrauterine growth restriction, fetal and neonatal demise, and fetal/neonatal neurocompromise (seizures and cerebral palsy). All three entities have high recurrence risks, with recurrence rates ranging from 34 to 100%. The histologic features of villitis of unknown etiology, chronic histiocytic intervillositis, and massive perivillous fibrin deposition are described herein. We discuss the clinical associations and suggest the subsequent clinical and pathological evaluation. Hypotheses as to the biology of these lesions are reviewed.

Follow-up and management of recurrent pregnancy losses due to massive perivillous fibrinoid deposition

Massive perivillous fibrinoid deposition is a rare placental pathology associated with significant adverse pregnancy outcome and can recur. We provide a detailed case review of a woman through 10 of her pregnancies, including 8 consecutive pregnancy losses and 2 live births. We also conducted a retrospective chart review of all massive perivillous fibrinoid deposition placenta specimens at our institution over an eight-year period. A total of 42 cases of massive perivillous fibrinoid deposition were identified from 2007 to 2015, yielding an incidence of 0.16%. Recurrence was seen in subsequent pregnancy in eight out of nine (88.9%) cases with more than one specimen. The clinical characteristics, perinatal outcomes and α-feto protein level of the 42 cases are presented. Also, presented is a review of the literature discussing placental pathology, pathogenetic mechanisms and management of this condition.

Inflammatory and vascular placental lesions are associated with neonatal amplitude integrated EEG recording in early premature neonates

INTRODUCTION

Placental histologic examination can assist in revealing the mechanism leading to preterm birth. Accumulating evidence suggests an association between intrauterine pathological processes, morbidity and mortality of premature infants, and their long term outcome. Neonatal brain activity is increasingly monitored in neonatal intensive care units by amplitude integrated EEG (aEEG) and indices of background activity and sleep cycling patterns were correlated with long term outcome. We hypothesized an association between types of placental lesions and abnormal neonatal aEEG patterns.

OBJECTIVE

To determine the association between the placental lesions observed in extreme preterm deliveries, and their neonatal aEEG patterns and survival.

PATIENTS AND METHODS

This prospective cohort study included extreme premature infants, who were born ≤ 28 weeks of gestation, their placentas were available for histologic examination, and had a continues aEEG, soon after birth)n = 34). Infants and maternal clinical data were collected. aEEG data was assessed for percentage of depressed daily activity in the first 3 days of life and for sleep cycling. Associations of placental histology with clinical findings and aEEG activity were explored using parametric and non-parametric statistics.

RESULTS

Twenty two out of the 34 newborns survived to discharge. Preterm prelabor rupture of membranes (PPROM) or chorioamnionitis were associated with placental lesions consistent with fetal amniotic fluid infection (AFI) or maternal under perfusion (MUP) (P < 0.05). Lesions consistent with fetal response to AFI were associated with absence of SWC pattern during the 1st day of life. Fetal-vascular-thrombo-occlusive lesions of inflammatory type were negatively associated with depressed cerebral activity during the 1st day of life, and with aEEG cycling during the 2nd day of life (P<0.05). Placental lesions associated with MUP were associated with depressed neonatal cerebral activity during the first 3 days of life (P = 0.007).

CONCLUSIONS

Depressed neonatal aEEG patterns are associated with placental lesions consistent with maternal under perfusion, and amniotic fluid infection of fetal type, but not with fetal thrombo-oclusive vascular disease of inflammatory type. Our findings highlight the association between the intrauterine mechanisms leading to preterm parturition and subsequent depressed neonatal cerebral function early after birth, which eventually may put premature infants at risk for abnormal neurodevelopmental outcome.

Placental massive perivillous fibrinoid deposition is associated with adverse pregnancy outcomes: a clinicopathological study of 12 cases

Introduction: Massive perivillous fibrinoid deposition (MPFD) is a very rare placental condition characterized by abnormally extensive fibrinoid deposition in the placental villous parenchyma. The aim of this study is to document clinical and pathological features with special focus on pregnancy outcomes of this condition in consecutive cases of MPFD in our local population.

Methods: This is a retrospective clinico-pathological study of cases affected by MPFD over the period January 2010–July 2014 in our hospital. We document clinical features (including perinatal outcome and subsequent pregnancies) and placental pathological characteristics.

Results: Twelve cases of MPFD were identified among 3640 placentas (0.33%). There was no identified recurrence. The affected infants had adverse outcomes, including intrauterine growth restriction (IUGR) (75%), preterm birth (58.3%), and fetal loss (25%). A high frequency of reduced PAPP-A in the first trimester (25%), and concurrent gestational hypertension or pre-eclampsia (25%) was noted.

Conclusion: MPFD is associated with adverse perinatal outcomes. Further research to better understand its pathogenesis and to improve clinical diagnosis and management is warranted.

Maternal Floor Infarction and Massive Perivillous Fibrin Deposition

Maternal floor infarction (MFI) and massive perivillous fibrin deposition (MPVFD) are pathologically overlapping placental disorders with characteristic gross and shared light microscopic features of excessive perivillous deposition of fibrinoid material. Although rare, they are associated with high rates of fetal growth restriction, perinatal morbidity and mortality, and risks of recurrence with fetal death. The cause of the extensive fibrinoid deposition is unknown, but evidence supports involvement of maternal alloimmune or autoimmune mechanisms. This article presents an updated discussion of features, placental histopathologic differential diagnosis, possible causes, clinical correlates, and adverse outcomes of the MFI/MPVFD spectrum.

Maternal Floor Infarction/Massive Perivillous Fibrin Deposition Associated with Hypercoiling of a Single-Artery Umbilical Cord: A Case Report

Maternal floor infarction is a rare and idiopathic placental disorder associated with adverse obstetric outcomes and a high rate of recurrence in subsequent pregnancies. The pathogenesis of maternal floor infarction is unclear but has been linked to diverse underlying maternal conditions, including gestational hypertension/preeclampsia, immune-mediated diseases, and thrombophilia. Few reports link maternal floor infarction to fetoplacental conditions. We report a 34-week, macerated, growth-restricted male fetus for which the placenta showed maternal floor infarction. The umbilical cord showed excessive coiling and a single umbilical artery. These cord changes are postulated to have resulted in increased placental villous resistance and decreased fetal blood flow, creating a hydrostatic pressure gradient between the villous stroma and the intervillous space. The pressure changes could then lead to trophoblast damage and fibrinoid deposition, contributing to the maternal floor infarction in this case.

Classification of placental lesions

Placental pathology can be useful in a variety of ways including immediate diagnosis of important conditions affecting the mother or infant, identifying conditions that are likely to recur in subsequent pregnancies, separating clinical syndromes into distinct pathological phenotypes for further investigation, and uncovering the underlying cause of unexpected adverse outcomes. Classification of placental lesions has evolved from being a purely descriptive exercise through a stage in which the major pathophysiological processes such as disorders of maternal implantation and the amniotic fluid infection syndrome were first described to a recently proposed comprehensive classification system that includes all of the major maternal and fetal vascular and infectious and idiopathic/immune inflammatory processes (Amsterdam Placental Workshop Group). Implementation of this unified system with reproducible grading and staging should help establish evidence-based recommendations for placental submission and facilitate progress in studying the pathogenesis, diagnosis, and treatment of obstetric disorders with an underlying placental etiology.

Association between cerebral palsy and microscopically verified placental infarction in extremely preterm infants

INTRODUCTION

Previously, cerebral palsy has been associated with placental infarctions diagnosed macroscopically by midwifes. However, the risk of misclassification of infarctionsis is high without a histological verification. Therefore, the objective of this study was to study placental histopathology in relation to developmental outcome at 2.5 years corrected age in a population born extremely preterm.

MATERIAL AND METHODS

A prospective cohort study was carried out at Karolinska University Hospital, Stockholm, Sweden on a population of 139 live born infants delivered <27 gestational weeks during 2004-2007. A senior perinatal pathologist, who was blinded to outcome data, evaluated all placental slides microscopically. Neuromotor and sensory functions of the children were evaluated. Bayley Scales of Infant and Toddler Development-III (Bayley-III) were used to assess development at corrected age 2.5 years. The outcome data were evaluated without reference to obstetrical and pathology data. The primary outcome measure was neurological and developmental status at 2.5 years of corrected age. This was measured as diagnosis of cerebral palsy, visual impairment, hearing impairment as well as performance on Bayley-III scales evaluating cognitive, language and motor functions.

RESULTS

Two out of seven children with placental infarction were diagnosed with cerebral palsy compared with one child of 51 without placental infarction (p = 0.036). For developmental outcome according to Bayley-III at 2.5 years no statistically significant associations with placental pathology were found.

CONCLUSION

A possible association between placental infarction, verified by microscopic examination, and cerebral palsy has been identified in this extremely preterm population.

The clinical implications of placental diagnoses

The clinical utility of placental pathology is both overestimated and underestimated, and the overall quality of placental pathology reporting, even at major medical centers, is highly variable. Clear benefits of examining placentas include the immediate diagnosis of treatable conditions in both the mother and the infant, clarification of the underlying etiology of adverse pregnancy outcomes, estimation of recurrence risk, and guidance for the management of future pregnancies. In order to realize these benefits and get the most out of their pathology departments, it is critical for clinicians to understand the range and implications of placental lesions. This article will review the nomenclature, diagnostic criteria and pitfalls, and clinical significance of seven common placental disease processes and a handful of other lesions.

Examination of the placenta: medico-legal implications

Formal examination of the placenta may provide valuable information to the clinicians, family, and court of law in cases of adverse pregnancy outcome when litigation is initiated. Placental examination contributes towards the identification of specific intrinsic or secondary placental lesions, and understanding the nature of the intrauterine environment. This article provides an update of important placental pathologies that may contribute towards neurologic injury of the newborn child, and describes the role of placental findings in the adjudication of cases of adverse neonatal outcome.

Placental pathology, perinatal death, neonatal outcome, and neurological development: a systematic review

BACKGROUND

The placenta plays a crucial role during pregnancy for growth and development of the fetus. Less than optimal placental performance may result in morbidity or even mortality of both mother and fetus. Awareness among pediatricians, however, of the benefit of placental findings for neonatal care, is limited.

OBJECTIVES

To provide a systematic overview of the relation between placental lesions and neonatal outcome.

DATA SOURCES

Pubmed database, reference lists of selected publications and important research groups in the field.

STUDY APPRAISAL AND SYNTHESIS METHODS

We systematically searched the Pubmed database for literature on the relation between placental lesions and fetal and neonatal mortality, neonatal morbidity and neurological outcome. We conducted three separate searches starting with a search for placental pathology and fetal and neonatal mortality, followed by placental pathology and neonatal morbidity, and finally placental pathology and neurological development. We limited our search to full-text articles published in English from January 1995 to October 2013. We refined our search results by selecting the appropriate articles from the ones found during the initial searches. The first selection was based on the title, the second on the abstract, and the third on the full article. The quality of the selected articles was determined by using the Newcastle-Ottawa Quality Assessment Scale.

RESULTS

Placental lesions are one of the main causes of fetal death, where placental lesions consistent with maternal vascular underperfusion are most important. Several neonatal problems are also associated with placental lesions, whereby ascending intrauterine infection (with a fetal component) and fetal thrombotic vasculopathy constitute the greatest problem.

CONCLUSIONS

The placenta plays a key role in fetal and neonatal mortality, morbidity, and outcome. Pediatricians should make an effort to obtain the results of placental examinations.

Recurrent massive perivillous fibrin deposition in the placenta associated with fetal renal tubular dysgenesis: case report and literature review

Massive perivillous fibrin deposition (MPVFD) of the placenta and renal tubular dysgenesis (RTD) are relatively rare diseases with potential recurrent risks that have not previously associated in the literature. Herein, we report the clinical course, autopsy findings, and placental pathologic features from 3 consecutive pregnancies delivered in 1 woman, all showing recurrent MPVFD in the placenta and RTD in the bilateral fetal kidneys.

Evidence of an imbalance of angiogenic/antiangiogenic factors in massive perivillous fibrin deposition (maternal floor infarction): a placental lesion associated with recurrent miscarriage and fetal death

OBJECTIVE

Massive perivillous fibrin deposition (MPFD) is associated with serious complications of pregnancy including recurrent spontaneous abortion, fetal growth restriction, and fetal demise. The aim of this study was to determine whether maternal plasma concentrations of angiogenic/antiangiogenic factors in MPFD differ from those of uncomplicated pregnancies.

STUDY DESIGN

This retrospective longitudinal case-control study included MPFD cases (n = 10) and control patients (n = 175) with uncomplicated pregnancies who were enrolled in a longitudinal study and delivered at term. Serial plasma concentrations of placental growth factor (PlGF), soluble endoglin (sEng), and soluble vascular endothelial growth factor receptor (sVEGFR)-1 and -2 were determined by an enzyme-linked immunosorbent assay (cases, n = 28 samples; controls, n = 723 samples). Individual analyte concentrations were averaged across gestational age at specimen collection intervals. Linear mixed models were used to test for differences in log-transformed mean analyte concentrations both overall and as a function of time.

RESULTS

The following results were found: (1) patients with MPFD had a lower mean plasma PlGF concentration (P = .03) and higher mean plasma concentrations of sVEGFR-1 and sEng (both P < .01) than controls, adjusted for potential confounders; (2) the mean plasma concentration of PlGF differed further among cases and controls as a function of gestational age interval (P < .0001); however, mean sVEGFR-1 and sEng group differences as a function of gestational age interval approached but did not reach significance (P = .09 and P = .11, respectively); (3) patients with MPFD had lower mean plasma concentrations of PlGF/sVEGFR-1 (P < .0001) and PlGF/sEng (P < .001): both of these relationships differed further as a function of gestational age interval (both P < .0001); and (4) differences in mean sVEGFR-1, sEng, and the ratios of PlGF to sVEGFR-1 and PlGF to sEng were observed before 20 weeks of gestation.

CONCLUSION

An imbalance of angiogenic/antiangiogenic factors is present in patients with MPFD prior to the diagnosis. We propose that these changes participate in the mechanisms responsible for adverse pregnancy outcomes in patients with MPFD.

Correlation of Placental Pathology with Perinatal Brain Injury

The purpose of placental pathology is to explain adverse clinical outcomes. One of the most tragic of these outcomes is perinatal brain injury with subsequent neurodisability. Findings in the placenta can play an important role in documenting sentinel events, uncovering clinically silent thromboinflammatory disease processes, revealing developmental alterations in functional reserve, and suggesting alterations in related maternal and fetal physiology. These findings, when integrated with clinical data, provide a plausible explanation for an otherwise unexpected outcome and can be helpful for treating physicians and family members.

Mutations in long-chain 3-hydroxyacyl coenzyme a dehydrogenase are associated with placental maternal floor infarction/massive perivillous fibrin deposition

Maternal floor infarction/massive perivillous fibrin deposition (MFI/MPVFD) of the placenta has an unclear etiology. The placenta of an 8-month-old child diagnosed with long-chain 3-hydroxyacyl coenzyme A dehydrogenase (LCHAD) deficiency reportedly showed MFI, but no further evidence of a direct association between MFI/MPVFD and LCHAD deficiency has been documented. Three cases of MFI/MPVFD were studied. Paraffin blocks of placental tissue were retrieved, tissue scrolls were harvested, and DNA was extracted. The alpha-subunit of the mitochondrial trifunctional protein containing the LCHAD coding region (HADHA) was subsequently amplified using specific primer sets and directly sequenced by the dideoxy chain termination method. All 3 placentas demonstrated heterozygous mutations in the HADHA gene. A sample from a 25-4/7 week gestation growth-restricted female infant revealed a heterozygous mutation in exon 11, 1072C>A (glutamine to lysine, Qln358Lys) with a heterozygous sequence difference in the intron following exon 6 (insertion of a T at position +9, +9insT). The 2nd sample from a 32-4/7 week gestation stillborn fetus revealed a heterozygous mutation (+3A>G after exon 3) and a clear homozygous sequence difference in exon 17. The 3rd sample from a 31 weeks gestation infant revealed heterozygosity for the+3A>G mutation after exon 3. All 3 placentas with MFI/MPVFD demonstrated heterozygous mutations in the HADHA gene, and 2 of the 3 placentas had 2 DNA changes. Given a background incidence of heterozygosity for LCHAD mutations of approximately 1 in 220, these findings lend support to the hypothesis that LCHAD mutations may be directly associated with and potentially causative of MFI/MPVFD.

Perinatal outcome and placental histological characteristics: a single-center study

OBJECTIVE

Placental pathology assists in characterizing the antenatal environment and may provide information about the baby's subsequent development. We aim to assess whether histological patterns of placenta are associated with an increased risk of perinatal diseases and to evaluate how different patterns of placental dysfunction can affect the neurodevelopmental outcome.

METHODS

We analyzed the histopathological characteristics of 105 singleton placentas from infants born between 23 and 31 weeks of gestation and we assessed pair-wise correlations with perinatal diseases. Estimated relative risks were calculated from odds ratios.

RESULTS

Histological chorioamnionitis (CA group) was detected on 51 of 100 placentas tested. Lesions of uteroplacental circulation (abruption, infarction or thrombosis, perivillous fibrin deposition, syncytial knots; vasculopathy group) were detected on 29. 25 normal placentas served as controls. The incidence of bronchopulmonary dysplasia (BPD) and patent ductus arteriosus (PDA) was higher in CA than in control group. The risk of developing retinopathy of prematurity (ROP), intraventricular hemorrhage (IVH) and PDA was higher in CA than in vasculopathy group.

CONCLUSIONS

At low gestational age CA, rather than placental lesions of vasculopathy, negatively impacts perinatal outcome. Clinical significance of histologic vasculopathy remains questionable. Other pathophysiological mechanisms than those associated with placental changes may occur following dysfunction of uteroplacental circulation.

[Cerebral palsy and perinatal asphyxia (II--Medicolegal implications and prevention)]

Obstetric litigation is a growing problem in developed countries and its escalating cost together with increasing medical insurance premiums is a major concern for maternity service providers, leading to obstetric practice cessation by many practitioners. Fifty-four to 74 % of claims are based on cardiotocographic (CTG) abnormalities and their interpretation followed by inappropriate or delayed reactions. A critical analysis is performed about the nine criteria identified by the American College of Obstetricians and Gynecologists and the American Academy of Pediatrics in their task force on Neonatal Encephalopathy and Cerebral Palsy: four essential criteria defining neonatal asphyxia and five other suggesting an acute intrapartum event sufficient to cause cerebral palsy in term newborns. The importance of placental histologic examination is emphasized in order to confirm sudden catastrophic events occurring before or during labor or to detect occult thrombotic processes affecting the fetal circulation, patterns of decreased placenta reserve and adaptative responses to chronic hypoxia. It may also exclude intrapartum hypoxia by revealing some histologic patterns typical of acute chorioamnionitis and fetal inflammatory response or compatible with metabolic diseases. Magnetic resonance imaging (MRI) of the infant's damaged brain is very contributive to elucidate the mechanism and timing of asphyxia in conjunction with the clinical picture, by locating cerebral injuries predominantly in white or grey matter. Intrapartum asphyxia is sometimes preventable by delivering weak fetuses by cesarean sections before birth, by avoiding some "sentinel" events, and essentially by responding appropriately to CTG anomalies and performing an efficient neonatal resuscitation. During litigation procedures, it is necessary to have access to a readable CTG, a well-documented partogram, a complete analysis of umbilical cord gases, a placental pathology and an extensive clinical work-up of the newborn infant including cerebral MRI. Malpractice litigation in obstetric care can be reduced by permanent CTG education, respect of national CTG guidelines, use of adjuncts such as fetal blood sampling for pH or lactates, regular review of adverse events in Clinical Risk Management (CRM) groups and periodic audits about low arterial cord pH in newborns, admission to neonatal unit, the need for assisted ventilation and the decision-to-delivery interval for emergency operative deliveries. Considering the fast occurrence of fetal cerebral hypoxic injuries, and thus despite an adequate management, many intrapartum asphyxias will not be preventable. Conversely, well-documented hypoxic-ischemic brain insults during the antenatal period do not automatically exclude intrapartum suboptimal obstetric care.

Maternal floor infarction associated with oligohydramnios and cystic renal dysplasia: report of 2 cases

Maternal floor infarction (MFI) is an unusual, idiopathic placental disorder characterized by deposition of amorphous fibrinoid material along the maternal aspect of the intervillous space. This condition is associated with poor perinatal outcome-in particular, spontaneous abortion-fetal growth restriction, and stillbirth, with a high recurrence rate in subsequent pregnancies. It is unknown whether MFI is a single entity or the common end point of different insults. Most studies have linked MFI to underlying maternal disorders including gestational hypertension, autoimmune disease, and thrombophilia. In contrast, there have been only a few case reports regarding the possibility of a fetal basis for MFI. We report 2 cases of MFI in fetuses who suffered from oligohydramnios as a result of bilateral cystic renal dysplasia. These 2 cases suggest the concept that fetoplacental factors may also play a role in MFI. It is speculated that the mechanism might involve changes in intrauterine hydrostatic pressure gradients.

Disorders of placental circulation and the fetal brain

Disorders of the placental circulation, including the release of deleterious mediators to the fetus, are important risk factors for central nervous system complications. These disorders result in discrete patterns of placental injury detectable by a thorough placental pathologic examination. Consideration of the location, severity, multiplicity, and timing of these lesions is critical to a full understanding of their significance. Less than 10% of placentas from term infants that later develop cerebral palsy lack any evidence of placental abnormalities potentially related to adverse outcome.

Placental pathology, a survival guide

Placental pathology continues to be an underutilized, undertaught, and inadequately handled surgical subspecialty. The requests for placental pathology are soaring, due partly to demands from obstetricians and to the litigious environment in which they practice, and to improved obstetrical care leading to pregnancies in medically challenging situations. Evaluation of the placenta requires a good understanding of the questions and issues concerning both the fetus/infant and the mother. Information from placental pathology can be critical in early neonatal care and in reproductive planning for the family, and it can provide risk assessment for neurologic outcome of the infant. A comfortable interaction among the obstetric staff, mothers, and pathologists often obviates need for legal intervention in unexpected pregnancy outcomes. Some critical pathologic features that involve maternal and fetal management are illustrated herein. A template for gross examination and a few critical histopathologic diagnostic features with clincopathologic correlation are included.

Decreased maternal protein S activity is associated with fetal growth restriction

INTRODUCTION

Protein S (PS) activity has been shown to decrease during normal pregnancy. The aim of this study was to determine any correlation between decreased maternal PS activity and fetal growth restriction (FGR).

METHODS

We carried out a retrospective study of maternal PS activity and complement 4b-binding protein (C4BP) concentration in 102 patients with FGR and 58 patients with fetuses that had normal growth. Among pregnancies affected by FGR, 14 diagnoses were made in the second trimester and 88 in the third trimester. Patients whose fetuses had normal growth were matched with FGR subjects for maternal age and gestational age at sampling (29 cases each in the second and third trimester).

RESULTS

Mean PS activity of the control group in the third trimester was significantly lower than in the second trimester (56.5+/-16.5% vs 35.8+/-13.8%). PS activity in women with FGR was significantly decreased in both the second trimester (36.6+/-13.2%) and third trimester (30.2+/-12.2%) compared with control group levels. Plasma concentrations of C4BP for the control group were significantly higher in the third trimester than in the second trimester (90.5+/-17.5% vs 81.1+/-13.6%). However, in women with FGR, plasma C4BP concentrations in both the second trimester (84.0+/-14.8%) and the third trimester (86.0+/-17.7%) were comparable with concentrations of the control group.

CONCLUSIONS

Maternal PS activity decreased as normal pregnancies progressed but decreased over time in cases with FGR. Excessive decreases in PS activity during pregnancy could contribute to development of FGR.

Infections and other inflammatory conditions

The etiology of cerebral palsy and other related perinatal brain injuries is poorly understood. Infections of the central nervous system are rare but important causes of neurodisability. Recent evidence suggests that infections and other inflammatory conditions apparently limited to the placenta are also associated with an increased risk of neurologic impairment. A major hypothesis to explain this connection is that cytokines, activated inflammatory cells, and other mediators of the innate immune response are released into the fetal circulation where they can directly or indirectly affect the development or integrity of the central nervous system. This review surveys the organisms, mediators, and placental lesions that have been associated with perinatal brain injury.

Placental pathology and cerebral palsy

Recent classification systems of cerebral palsy call for an assessment of the timing and etiology of brain injury. The placenta is an underused resource for addressing these important questions. An expert assessment of the placental pathology can provide temporally and mechanistically specific data not available from any other source. Key concepts for an understanding of the role of placental pathology are the "sentinel lesion," the high prevalence of thromboinflammatory lesions affecting large fetal placental vessels, the significance of underlying placental reserve, and the realization that placental findings can serve as markers for processes occurring in the mother or fetus.

Co-occurrence of massive perivillous fibrin deposition and chronic intervillositis: case report

Chronic intervillositis (CI) and massive perivillous fibrin deposition (MFD), together with its related entity, maternal floor infarction (MFI), are rare and poorly understood placental lesions. Both MFD/MFI and CI are associated with poor fetal outcome and high risk of recurrence. We report a patient who was found to have both MFD and CI in the same placenta, resulting in severe intrauterine fetal growth restriction and intrauterine fetal death at 37 weeks of gestation. Characteristic histological findings included both very extensive perivillous deposition of fibrinoid material and a heavy infiltrate of CD68-positive macrophages/monocytes in the maternal intervillous space. To our knowledge, this is the first time the co-occurrence of MFD and CI is reported in the literature.

Neonatal morbidity and placental pathology

OBJECTIVE

To investigate the association between gestational age, placental pathology and outcome among preterm births.

METHODS

Medical records and placental pathology results of 165 preterm infants (gestational age pound 34 weeks) were used to analyze the development of intraventricular hemorrhage (IVH), bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), patent ductus arteriosus (PDA) and sepsis, in association with placental findings in the gestational age categories of 22-27 (n=71) and 28-33 (n=93) weeks.

RESULTS

Significant differences were found in placental findings based on gestational age and neonatal morbidity. Lower gestational age was associated with increased infection-related lesions such as chorionic vasculitis (47.9%, P< 0.001) and acute chorioamnionitis (67.6%, P< 0.001). Placental lesions reflecting disturbances of fetal-placental blood flow (infarction, chorionic plate thrombi and basal perivillous fibrin) were predominantly seen in the 28-33 week gestational age category (P< 0.05-0.01). Despite the high prevalence of chorioamnionitis (38.8%), no significant association was found between this lesion and the tested preterm morbidity after controlling for gestational age. Only, villous edema and chorionic vasculitis were identified as independent predictors for the development of IVH (49.2%, ORA 2.57, 95% CI 1.01, 6.58 and 39.3%, ORA1.95, 95% CI 1.01, 4.21, respectively).

CONCLUSION

Villous edema and chorionic vasculitis are significant risk factors for the development of the IVH among neonates born at gestational age pound 34 weeks.

Discordancy for maternal floor infarction in dizygotic twin placentas

Maternal floor infarction (also known as massive perivillous fibrin/fibrinoid deposition) is a rare and devastating pregnancy disorder associated with prematurity, fetal growth restriction, spontaneous abortion, and long-term neurologic impairment. Recurrence in multiple pregnancies is common. Little is known regarding either the pathophysiology or the management and treatment of patients at risk for recurrence in subsequent pregnancies. Most authors have emphasized maternal risk factors believed to act in a dominant fashion irrespective of fetal genotype. We report on dizygotic twins discordant for the development of placental maternal floor infarction and fetal growth restriction. The mother was a poorly controlled class C diabetic, and the onset of disease was coincident with the clinical onset of preeclampsia. This case demonstrates that fetal genotype, or some other factor specific to an individual fetoplacental unit, can lead to the differential expression of maternal floor infarction in dizygotic twins gestating in the same intrauterine environment.