Placental histopathologic features in patients with thrombophilic mutations

Congenital Herpes Simplex Virus: A Histopathological View of the Placenta

Congenital Herpes simplex virus (HSV) infection is considered a common pregnancy pathology that is not always easy to diagnose. This study aimed to present the spectrum of placental histopathological lesions in pregnancies complicated by HSV infection. MEDLINE and Google Scholar databases were searched using the keywords "HSV" and "placental histopathology" up to June 20, 2022. Study inclusion required presenting placental histopathological anomalies in pregnant women diagnosed with HSV infection antenatally, during labor, or postnatally. Herein, we briefly present placental pathogenesis conditions, which have been correlated with congenital HSV infection, providing clinicians with a short review describing herpetic placental pathology.

Life After Amsterdam: Placental Pathology Consensus Recommendations and Beyond

The Amsterdam Placental Workshop Group Consensus Statement on Sampling and Definitions of Placental Lesions has become widely accepted and is increasingly used as the universal language to describe the most common pathologic lesions found in the placenta. This review summarizes the most salient aspects of this seminal publication and the subsequent emerging literature based on Amsterdam definitions and criteria, with emphasis on publications relating to diagnosis, grading, and staging of placental pathologic conditions. We also provide an overview of the recent expert recommendations on the pathologic grading of placenta accreta spectrum, with insights on their clinical context. Finally, we discuss the emerging entity of SARS-CoV2 placentitis.

Use of a Feed-Forward Back Propagation Network for the Prediction of Small for Gestational Age Newborns in a Cohort of Pregnant Patients with Thrombophilia

(1) Background: Fetal growth restriction is a relatively common disorder in pregnant patients with thrombophilia. New artificial intelligence algorithms are a promising option for the prediction of adverse obstetrical outcomes. The aim of this study was to evaluate the predictive performance of a Feed-Forward Back Propagation Network (FFBPN) for the prediction of small for gestational age (SGA) newborns in a cohort of pregnant patients with thrombophilia. (2) Methods: This observational retrospective study included all pregnancies in women with thrombophilia who attended two tertiary maternity hospitals in Romania between January 2013 and December 2020. Bivariate associations of SGA and each predictor variable were evaluated. Clinical and paraclinical predictors were further included in a FFBPN, and its predictive performance was assessed. (3) Results: The model had an area under the curve (AUC) of 0.95, with a true positive rate of 86.7%, and a false discovery rate of 10.5%. The overall accuracy of our model was 90%. (4) Conclusion: This is the first study in the literature that evaluated the performance of a FFBPN for the prediction of pregnant patients with thrombophilia at a high risk of giving birth to SGA newborns, and its promising results could lead to a tailored prenatal management.

Combined hereditary thrombophilias are responsible for poor placental vascularization development and low molecular weight heparins (LMWH) prevent adverse pregnancy outcomes in these patients

BACKGROUND

Even though thrombophilias are associated with negative pregnancy outcomes (PO), there is not a consensus of when thrombophilias should be screened for, or how they affect placental vascularization during pregnancy. Therefore, the main aim of this study was to discover inherited thrombophilias (IHT) in the first trimester in women with otherwise no indications for thrombophilia screening, based on their vascularization parameters. LMWH treatment in improvement of placental vascularization and PO was also assessed. Finally, the classification of thrombophilias based on observed obstetric risks was proposed.

METHODS

Women were included in study based on their poor gestational sac and later utero-placental juncture vascularization signal and screening for inherited thrombophilias. LMWH were then initiated and Resistance index of Uterine artery (RIAU) was followed alongside PO (preterm birth, preeclampsia, placental abruption, intrauterine growth reduction). Study group consisted of women with combined inherited thrombophilias. Control group consisted of patients with inherited thrombophilias who have received LMWH therapy since pregnancy beginning.

FINDINGS

Out of 219 women, 93 had IHT, and 43 had combined IHT. All pregnancies both in both groups ended up with live births. Vaginal birth was more present in the control group (p < .001), and all women in study group delivered by CS. Premature birth was present in 8.4% of patients in control group, and in 32.55% of the patients in the study (p < .001). PE wasn't noted, and only 1 case of PA in control group. In the control group, 6.5% patients had IUGR, and 32.55% in the study group (p < .05). Based on RIAU and PO, thrombophilia categories were established: S (severe), MO (moderate), MI (mild) and L (low). Higher risk thrombophilias had higher RIAU later in the pregnancy, earlier pregnancy termination and Intrauterine Growth Reduction (IUGR).

CONCLUSIONS

Thrombophilias should be considered and screened when poor vascularization is noted early in the pregnancy with Doppler sonography. Intervention with LMWH prevents adverse PO in these patients.

CD34 immunostain increases the sensitivity of placental diagnosis of fetal vascular malperfusion in stillbirth

INTRODUCTION

Postmortem regressive placental changes of stillbirth may obscure the pre-existing placental histomorphology. The objective is to find out whether the use of CD34 immunostain can increase the sensitivity of placental examination in the diagnosis of fetal vascular malperfusion (FVM).

METHODS

Twenty six independent clinical and 46 placental variables of 46 placentas from stillbirths were statistically compared to those of 92 placentas from livebirths. One histologically most unremarkable section per case was stained using double E-cadherin/CD34 immunostain (ECCD34). Clusters of avascular/hypovascular chorionic villi on hematoxylin and eosin (H&E) staining system and/or CD34 immunostaining, the latter also including endothelial CD34 positive debris in the villous stroma, were regarded as evidence of FVM.

RESULTS

The gestational age and cesarean section rate were statistically significantly lower and the induction of labor and mild erythroblastosis of fetal blood was higher, but the frequencies of clinical and placental features of umbilical cord compromise were not statistically significant between stillbirths and livebirths, respectively. By using H&E stain, 9 (19.6%) of stillbirths and 30 (32.6%) of livebirths showed clusters of avascular villi on H&E. By CD34, the rates of FVM increased to 23 (50%) and 34 (40%), respectively. The increase was statistically significant for stillbirths only (Chi square = 9.4, p = 0.002). By CD34, new clusters of hypovascular chorionic villi or villi with endothelial fragmentation were found in 23 stillbirth cases (50%) as opposed to livebirths (29 cases, 31.5%)(Chi square = 9.4, p = 0.002).

DISCUSSION

When compared with H&E stain, the CD34 increases sensitivity and/or upgrades FVM in placental examination in stillbirths but not in livebirths.

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.

Fetal Vascular Malperfusion

CONTEXT

- Fetal vascular malperfusion, also known as fetal thrombotic vasculopathy, remains an underrecognized pathologic finding and should be noted during placental evaluation.

OBJECTIVE

- To review histologic findings, gain familiarity with the updated terminology, and to recognize important clinical associations with this entity.

DATA SOURCES

- University of Michigan cases, PubMed search, multiple review articles including recent placental workshop group consensus statement, and selected book chapters.

CONCLUSIONS

- Multiple histologic patterns of fetal vascular malperfusion have been described including thrombosis, avascular villi, villous stromal-vascular karyorrhexis, intramural fibrin thrombi, and stem villous vascular obliteration. Various underlying etiologies can be involved in fetal vascular malperfusion. Cord lesions including abnormal insertion, length, and coiling are important causes. Maternal vascular malperfusion such as preeclampsia, hypercoagulable states, lupus anticoagulant, and sometimes diabetes have been associated with this condition. Fetal cardiac dysfunction/malformations and severe fetal inflammatory response in the setting of ascending intrauterine infection have also been attributed to this important finding. Fetal vascular malperfusion has been implicated in several significant and sometimes devastating clinical associations; these include intrauterine growth restriction, poor perinatal outcome, fetal demise, and neurodevelopmental sequelae. A diagnostic challenge may be encountered in cases with prior intrauterine fetal death, since degenerative changes post demise result in a similar histomorphologic picture. The diffuse versus the focal nature of the lesions may help in the distinction.

Decidual Vasculopathy: Placental Location and Association With Ischemic Lesions

Decidual vasculopathy (DV) is a general term for a number of lesions involving uteroplacental vessels. It is often seen in preeclamptic placentas and indicates a disorder of uteroplacental malperfusion and is associated with placental ischemia and infarction. Although some have advocated submitting special sections in order to better document DV, it is unclear which placental sections have the highest yield in demonstrating these abnormal vessels. Seventy-six consecutive cases of decidual vasculopathy were identified and evaluated for location of DV, as well as presence of other lesions of ischemic change, infarcts, and retroplacental hematomas. Sections reviewed were the membrane roll (MR), full thickness (FT) sections of the placental disc, and sections specifically of the basal plate (BP). DV was found in the MR in 67.1% of cases, in FT sections in 32.9%, and in the BP in 25.0% of cases ( P value = .004). DV was exclusive to the MR in 53.9%, the FT in 14.5%, and the BP in 9.2%. DV was present in 2 locations in 19.7% and in all 3 locations in 2.6%. The presence of DV in any location (MR, FT, and BP) was associated with placental ischemic change but not specifically with infarcts or retroplacental hematomas. The specific location of DV showed no difference in the presence of placental lesions. Our findings indicate DV is often present in 1 location and is associated with lesions of malperfusion. It is recommended that when clinically indicated, additional sections are submitted to demonstrate decidual vasculopathy.

Maternal extracellular vesicles and platelets promote preeclampsia via inflammasome activation in trophoblasts

Preeclampsia (PE) is a placenta-induced inflammatory disease associated with maternal and fetal morbidity and mortality. The mechanisms underlying PE remain enigmatic and delivery of the placenta is the only known remedy. PE is associated with coagulation and platelet activation and increased extracellular vesicle (EV) formation. However, thrombotic occlusion of the placental vascular bed is rarely observed and the mechanistic relevance of EV and platelet activation remains unknown. Here we show that EVs induce a thromboinflammatory response specifically in the placenta. Following EV injection, activated platelets accumulate particularly within the placental vascular bed. EVs cause adenosine triphosphate (ATP) release from platelets and inflammasome activation within trophoblast cells through purinergic signaling. Inflammasome activation in trophoblast cells triggers a PE-like phenotype, characterized by pregnancy failure, elevated blood pressure, increased plasma soluble fms-like tyrosine kinase 1, and renal dysfunction. Intriguingly, genetic inhibition of inflammasome activation specifically in the placenta, pharmacological inhibition of inflammasome or purinergic signaling, or genetic inhibition of maternal platelet activation abolishes the PE-like phenotype. Inflammasome activation in trophoblast cells of women with preeclampsia corroborates the translational relevance of these findings. These results strongly suggest that EVs cause placental sterile inflammation and PE through activation of maternal platelets and purinergic inflammasome activation in trophoblast cells, uncovering a novel thromboinflammatory mechanism at the maternal-embryonic interface.

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.

Fetal thrombotic vasculopathy is associated with thromboembolic events and adverse perinatal outcome but not with neurologic complications: a retrospective cohort study of 54 cases with a 3-year follow-up of children

OBJECTIVE

to test the hypothesis that placental fetal thrombotic vasculopathy (FTV) is associated with obstetric complications and predisposes the child to unfavorable outcomes.

METHODS

54 placentas with FTV lesions and 100 placentas without FTV lesions were collected over a 5-year period at the Croix-Rousse Pathology Department. Clinical findings including maternal, fetal, neonatal condition and pediatric outcome up to three years were collected for each case and control observation. The statistical analyses were assessed with Wald's chi-square derived from conditional logistic regression modeling.

RESULTS

FTV was associated with a significantly higher frequency of obstetric complications: (pregnancy-induced hypertension (OR 3.620, CI 1.563-8.385), preeclampsia (OR 3.674, CI 1.500-8.998), emergency delivery procedures (OR 3.727, CI 1.477-9.403), cesarean sections (OR 2.684, CI 1.016-7.088)), poor fetal condition (intrauterine growth restriction (IUGR) (OR 5.440, CI 2.007-14.748), nonreassuring fetal heart tracing (OR 6.062, CI 2.280-16.115), difficulties in immediate ex utero adaptation (OR 3.416, CI 1.087-10.732)) and perinatal or early childhood demise (OR 3.043, CI 1.327-6.978). On pathological examination, FTV was associated with marginal cord insertion (OR 3.492, CI 1.350-9.035), cord stricture and hypercoiled cord (OR 3.936, CI 1.209-12.813). Thromboembolic events were significantly more frequent in cases with FTV (OR 2.154, CI 1.032-5.622). Neurological complications within the first 3 years of life were also more frequent in the FTV group compared to the control group, but this association was not statistically significant.

CONCLUSIONS

FTV is associated with maternal complications, pathological findings in the placenta, especially gross cord abnormalities, IUGR, and poor perinatal or early childhood outcome. It may also predispose children to somatic thromboembolic events.

Clustering of maternal-fetal clinical conditions and outcomes and placental lesions

OBJECTIVE

To identify by an inductive statistical analysis mutually similar and clinically relevant clinicoplacental clusters.

STUDY DESIGN

Twenty-nine maternofetal and 49 placental variables have been retrospectively analyzed in a 3382 case clinicoplacental database using a hierarchical agglomerative Ward dendrogram and multidimensional scaling.

RESULTS

The exploratory cluster analysis identified 9 clinicoplacental (macerated stillbirth, fetal growth restriction, placenta creta, acute fetal distress, uterine hypoxia, severe ascending infection, placental abruption, and mixed etiology [2 clusters]), 5 purely placental (regressive placental changes, excessive extravillous trophoblasts, placental hydrops, fetal thrombotic vasculopathy, stem obliterative endarteritis), and 1 purely clinical (fetal congenital malformations) statistically significant clusters/subclusters. The clusters of such variables like clinical umbilical cord compromise, preuterine and postuterine hypoxia, gross umbilical cord or gross chorionic disk abnormalities did not reveal statistically significant stability.

CONCLUSION

Although clinical usefulness of several well-established placental lesions has been confirmed, claims about high predictability of others have not.

The effect of maternal thrombophilia on placental abruption: Histologic correlates

OBJECTIVE

To determine if the histology of placental abruption differs by maternal thrombophilia status.

STUDY DESIGN

This was a multicentre, case-control study of women with abruption and delivering at >or=20 weeks' gestation, collected as part of the ongoing New Jersey-placental abruption study. Women were identified by clinical criteria of abruption. Maternal blood was collected postpartum and tested for anticardiolipin antibodies, and mutations in the Factor V Leiden and prothrombin genes. Cases were comprised of women with an abruption and a positive thrombophilia screen. Controls were comprised of women with an abruption and a negative thrombophilia screen. All placental histology was systematically reviewed by two perinatal pathologists, blinded to the abruption status.

RESULTS

A total of 135 women with placental abruption were identified, of which 63.0% (n = 85) had at least one diagnosed maternal thrombophilia. There were increases in the rates of meconium-stained membranes (7.9%vs. 2.1%, p = 0.015) and decidual necrosis (4.5%vs. 2.1%, p = 0.023) when a maternal thrombophilia was diagnosed. Although there was no difference in the overall presence of infarcts between the two groups (27.0%vs. 38.3%, p = 0.064), the presence of an old infarct was more common among women with a positive thrombophilia screen (83.3%vs. 44.4%, p = 0.003).

CONCLUSION

Placental abruption with a positive maternal thrombophilia screen is associated with higher rates of old placental infarcts and decidual necrosis compared with abruption when thrombophilia is not diagnosed. These lesions suggest a chronic etiology of placental abruption in the presence of a maternal thrombophilia.

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.