Maternal thrombophilias are associated with specific placental lesions

Massive perivillous fibrin deposition: Diagnosis, obstetrical features, and treatment

MPVFD (Massive perivillous fibrin deposition) is placental lesion characterized by extensive massive deposits of fibrin in the intervillous space, extending over at least 25 % of the placental volume. Currently, this pathology can only be detected through histopathological examination of the placenta after a pregnancy has ended. The underlying mechanisms are poorly studied, there is no biomarker available for the diagnosis of MPVFD and treatment protocols are experimental and still lacking. The objective of this study is to systematically review the literature on the associated clinicopathologic features, treatment, and prognosis of MPVFD. We ended up with 17 studies, of these 12 studies were considered relevant for this article and included in the final analysis. All studies reporting MPVFD are retrospective. MPVFD is associated with recurrent miscarriage, intra uterine fetal death (IUFD), intra uterine growth restriction (IUGR) and preterm delivery. The prevalence in pregnancies with a delivery after 22 weeks of gestation was at 1.1 % and even higher to 2.7 % in recurrent early miscarriages. The reported risk of fetal death in MPVFD ranges mainly from 15 to 80 %. Preterm delivery is spontaneous in 50 to 70 % of cases and induced by of a severe intrauterine growth restriction (IUGR) in 30 to 50 % of cases depending on the study. Its causes and treatment are still poorly understood, although several avenues have been explored. This review summarizes current understanding of the prevalence, diagnostic features, clinical consequences, immune pathology, and potential prophylaxis against recurrence in this chronic inflammatory placental syndrome.

Pathophysiological, immunogenetic, anatomopathological profile of thrombophilia in pregnancy

Thrombophilic states have been associated with early and/or late pregnancy loss and possibly other severe obstetrical complications. Pregnancy-induced hypercoagulability, increased stasis, and the consequences of inherited and acquired thrombophilia are just a few of the factors that contribute to the development of thrombosis in pregnancy. In this review, we illustrate the impact that these factors have on the development of thrombophilia during pregnancy. We also explore how thrombophilia impact pregnancy outcomes. Next, we discuss how human leukocyte antigen G plays a part in thrombophilia during pregnancy by regulating cytokine release to prevent trophoblastic cell invasion and maintain local immunotolerance constant. Human leukocyte antigen class E is briefly explored with thrombophilia in pregnancy. Regarding the anatomopathologic aspect, we describe the different histopathological lesions of the placenta found in women with thrombophilia.

Value of Placental Examination in the Diagnostic Evaluation of Stillbirth

ObjectiveThe aim was to assess the contribution of placental examination in the etiologic investigation of stillbirth. Materials and Methods: A retrospective review of stillbirths that occurred after 14 weeks gestation was conducted for a one-year period. Twin pregnancies and fetuses without placentas were excluded. According to the fetoplacental examination, stillbirths were classified into etiologic groups. Results: A total of 147 stillbirths were selected. They were associated with placental, materno-fetal, fetal and multiple causes in 89 cases (61%), 23 cases (16%), 14 cases (9%) and 13 cases (9%), respectively. Unexplained stillbirths were observed in 8 cases (5%). Placental abnormalities were identified in 132/147 cases (90%). They were consistent with vascular, inflammatory and developmental lesions in 82/132 cases (61%), 28/132 cases (21%) and 18/132 cases (13%), respectively. Conclusion: Placental lesions were the main causes of stillbirth and were predominantly of vascular type including chronic villous hypoxia-ischemia and funicular anomalies.

Stillbirth due to SARS-CoV-2 placentitis without evidence of intrauterine transmission to fetus: association with maternal risk factors

OBJECTIVES

To describe the placental pathology, fetal autopsy findings and clinical characteristics of pregnancies that resulted in stillbirth owing to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) placentitis, and to identify potential risk factors.

METHODS

This was a prospective multicenter study of non-vaccinated pregnant women affected by coronavirus disease 2019 (COVID-19) in Greece from April 2020 to August 2021. A total of 165 placentas were examined histologically and six cases of stillbirth associated with SARS-CoV-2 placentitis were retrieved. Complete fetal autopsy was performed in three of these cases. Gross, histopathological, immunohistochemical, molecular and electron microscopy examinations were carried out in the stillbirth placentas and fetal organs. The histological findings of cases with SARS-CoV-2 placentitis were compared with those in 159 cases with maternal COVID-19 which resulted in a live birth. Regression analysis was used to identify predisposing risk factors for SARS-CoV-2 placentitis.

RESULTS

The placentas of all six stillborn cases showed severe and extensive histological changes typical of SARS-CoV-2 placentitis, characterized by a combination of marked intervillositis with a mixed inflammatory infiltrate and massive perivillous fibrinoid deposition with trophoblast damage, associated with intensely positive immunostaining for SARS-CoV-2 spike protein, the presence of virions on electron microscopy and positive reverse-transcription polymerase chain reaction test of placental tissues. The histological lesions obliterated over 75% of the maternal intervillous space, accounting for intrauterine fetal death. Similar histological lesions affecting less than 25% of the placenta were observed in seven liveborn neonates, while the remaining 152 placentas of COVID-19-affected pregnancies with a live birth did not show these findings. Complete fetal autopsy showed evidence of an asphyctic mode of death without evidence of viral transmission to the fetus. The mothers had mild clinical symptoms or were asymptomatic, and the interval between maternal COVID-19 diagnosis and fetal death ranged from 3 to 15 days. Statistically significant predisposing factors for SARS-CoV-2 placentitis included thrombophilia and prenatally diagnosed fetal growth restriction (FGR). Multiple sclerosis was seen in one case.

CONCLUSIONS

SARS-CoV-2 placentitis occurred uncommonly in COVID-19-affected pregnancies of non-vaccinated mothers and, when extensive, caused fetal demise, with no evidence of transplacental fetal infection. Thrombophilia and prenatally detected FGR emerged as independent predisposing factors for the potentially lethal SARS-CoV-2 placentitis. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

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.

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.

Chronic histiocytic intervillositis: A breakdown in immune tolerance comparable to allograft rejection?

Chronic histiocytic intervillositis (CHI) is a pregnancy disorder characterized by infiltration of maternal macrophages into the intervillous space of the human placenta, often with accompanying perivillous fibrin deposition. CHI is associated strongly with foetal growth restriction and increased risk of miscarriage and stillbirth. Although rare, affecting 6 in every 10 000 pregnancies beyond 12 weeks' gestation, the rate of recurrence is high at 25%-100%. To date, diagnosis of CHI can only be made post-delivery upon examination of the placenta due to a lack of diagnostic biomarkers, and criteria vary across publications. No treatment options have shown proven efficacy, and CHI remains a serious obstetric conundrum. Although its underlying aetiology is unclear, due to the presence of maternal macrophages and the reported increased incidence in women with autoimmune disease, CHI is hypothesized to be an inappropriate immune response to the semi-allogeneic foetus. Given this lack of understanding, treatment approaches remain experimental with limited rationale. However, there is recent evidence that immunosuppression and antithrombotic therapies may be effective in preventing recurrence of associated adverse pregnancy outcomes. With similarities noted between the pathological features of CHI and acute rejection of solid organ transplants, further investigation of this hypothesis may provide a basis for tackling CHI and other immune-related placental conditions. This review will explore parallels between CHI and allograft rejection and identify areas requiring further confirmation and exploitation of this comparison.

Massive Perivillous Fibrin Deposition Associated With Placental Syphilis: A Case Report

Massive perivillous fibrin deposition (MPFD) and the related entity of maternal floor infarction (MFI) are uncommon placental disorders of unknown etiology, associated with adverse obstetric outcome and a significant risk of recurrence. We describe a 19-year-old mother with untreated syphilis who delivered a male neonate with low birth weight, skin desquamation, and pneumonia. Placenta examination showed the expected changes for syphilis but unexpectedly, also showed MPFD. To our knowledge, this is the first report of MPFD associated with placental syphilis, thus expanding the list of etiologies that may be related to MPFD/MFI. It is postulated that the syphilis infection in our case led to a hypercoaguable state, eventually resulting in MPFD. In the right clinical setting, syphilis might be considered in the differential diagnosis when MPFD/MFI is observed on placental examination. The recurrence risk of MFPD/MFI associated with infections is believed to be lower than idiopathic cases and, by extrapolation, this lower risk should apply to syphilis as well.

Massive Perivillous Fibrin Deposition in Congenital Cytomegalovirus Infection: A Case Report

Cytomegalovirus (CMV) infection is one of the most common congenital viral infections. Classically associated placental findings include chronic villitis with plasma cells, stromal hemosiderin deposition, and identification of viral inclusions in villous endothelial and stromal cells. We present a case of confirmed congenital CMV infection that lacked these classical findings, but demonstrated massive perivillous fibrin deposition (MPVFD). This is the first report of CMV associated with MPVFD. MPVFD is an uncommon placental lesion associated with adverse fetal outcomes and a high risk of recurrence. However, the recurrence risk in patients with an infectious cause may be lower in than patients with other associated clinical conditions.

May the morphological findings in the first-trimester abortion materials be indicative of inherited thrombophilia?

PURPOSE

İnherited thrombophilia is associated with severe pregnancy complications including recurrent spontaneous abortion. In the light of this strong association, the impact of thrombophilic mutations on the placenta and their morphological reflections has aroused attention of both clinicians and pathologists. In the present study, we aimed to show the association between placental abnormalities with thrombophilia by examining the morphological findings in a wide range of first-trimester chorionic villi.

METHODS

We performed a histological examination on the abortion specimens obtained from 129 patients with recurrent pregnancy losses that were evaluated with respect to inherited thrombophilia based on the presence of Factor V Leiden (G1691A), Prothrombin G20210A and methylenetetrahydrofolate reductase (MTHFR) C677T gene mutations detected by genetic analysis. Abortion materials either with and without thrombophilia were evaluated in terms of the morphological parameters such as hydropic change, vascularity, fibrosis, fibrinoid degeneration, Hofbauer macrophage, syncytiotrophoblast knotting, villitis, calcification, villous contour and villous size, hemorrhage, thrombus, proliferation of trophoblasts, villous stromal or villous vascular karyorrhexis.

RESULTS

No statistically significant difference was found between the patient groups with and without thrombophilia in terms of morphological findings except vascularity of chorionic villi. The avascular chorionic villi (<3 vessels per villus) were found in 62.9% and 16.9% obtained from the women with and without thrombophilic mutation, respectively. This difference was statistically significant (P < 0.001).

CONCLUSION

As a conclusion, it could be stated that the analysis of morphological findings in the abortion specimen is not a time-wasting process. Particularly, data related with vascularity of chorionic villi would be precious and beneficial. We suggest that highlighting the presence of avascular villi in the pathology report as a parameter would be guiding for clinicians regarding the impact of the thrombophilic gene mutations.

Placental infarcts in the collaborative perinatal project: Variable associations infer variable constructs

PURPOSE

Reproducible diagnoses of placental infarcts may permit more accurate assessment of their clinical significance. Using data across the 12 study sites of the National Collaborative Perinatal Project, we investigated the consistency of associations between infarct features with birthweight, placental weight and measures of placental "efficiency."

METHODS

All delivered infants, live or stillborn, single or multiple, regardless of gestational age, were included. Pathologists scored infarcts by color (tan-white or "old" or pink-red "more recent"), size (cm), location (marginal or central), and total number.

RESULTS

Incidence of any infarcts and distributions of specific features such as size, color (indicating age), locations and total numbers of infarcts were highly variable across sites, as were their associations with birthweight and placental efficiency. The most stable associations (consistent results across sites) of placental infarct scores were with placental size and/or other placental shape variables and with birthweight, but the number of significant associations ranged from 13 to 1.

CONCLUSION

Given the extremes of infarct incidence within each site plus the variable correlations of infarct features with other placental and birth outcome measures, CPP infarct scores cannot be used as indicative of an underlying shared pathophysiologic construct. However, given the accumulating evidence that intrauterine stressors have the potential for lifelong impact on health, we propose that the infarct features and distinctions proposed are neither complex nor should they be jettisoned. Rather these measures should be clarified and refined. Only then can we understand the reported associations of placental infarcts with child and adult health outcomes.

Interaction of thrombophilic SNPs in patients with unexplained infertility-multifactor dimensionality reduction (MDR) model analysis

PURPOSE

Our aim was to evaluate the frequency and SNP-SNP interactions between factor V Leiden (FVL) G1691A, prothrombin G20210A mutation, and C677T MTHFR and PAI-1 4G/5G gene polymorphisms in female IVF patients with unexplained infertility (UI) by using a multifactor dimensionality reduction (MDR) model analysis.

METHODS

A total of 225 subjects were enrolled in the study. There were 105 females in UI group and 120 healthy controls. Designated SNPs were determined by using allele-specific PCR methods. The difference in thrombophilia prevalence was assessed by a chi-square test and logistic regression analysis. Four-locus SNP interaction model was tested using the MDR approach. A ten-fold cross-validation consistency (CVC) and permutation testing were performed.

RESULTS

There was a significant difference of MTHFR C677T polymorphism frequency between the groups. Significantly less UI patients had MTHFR CC genotype (p = 0.005), while the risk allele T was more frequent (OR = 1.83, p = 0.0018). Logistic regression determined a significant association only for MTHFR C677T in our patients (TT genotype OR = 2.99). The MDR analysis confirmed the significance of a single-locus model for MTHFR C677T polymorphism (p = 0.015; OR = 2.93). However, the best, significant predictive model was the two-locus model comprising MTHFR C677T and FVL (CVC = 10/10, testing accuracy = 60.95%, p = 0.013; OR = 3.02).

CONCLUSION

The MTHFR C677T polymorphism was significantly associated with UI, with minor allele T being more frequent. Additionally, there was a significantly increased presence of MTHFR C677T with FVL mutation in these patients. Therefore, MTHFR and its interaction with FVL should be recognized as contributing factors in the pathogenesis of infertility.

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.

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.

Of pregnancies complicated by small for gestational age babies at term, what proportions have placental findings with implications for future pregnancies or neonatal outcomes?

Background: Small for gestational age (SGA) is a term to define any baby born with birth weight <10th centile. SGA can be associated with a number of placental pathology findings, which may influence maternal outcomes, neonatal neurodevelopment, and future pregnancies.Aims: To identify the proportion of term pregnancies complicated by SGA with placental findings that may have implications for future pregnancies or neonatal outcomes.Method: A retrospective review between 2011 and 2015 of babies and placentas born at term with SGA histopathological findings were categorized as to whether they had a high recurrence rate and where the long-term neurodevelopmental outcome may affect the neonate.Results: Six hundred and ninety-eight babies were identified as SGA. Only 335 (47.8%) placentas were sent for histopathological assessment. Of these, 60 (17.9%) had histopathological findings associated with high recurrence rates and 68 (20.2%) had findings associated with potential adverse neonatal outcomes.Conclusions: Of those placentas sent for examination between 17.9% and 20.2% had findings associated with either high recurrence rates or findings that may benefit from neonatal follow-up. Under 50% of pregnancies complicated by SGA at term had a placental examination, resulting in a significant number of potential important clinical consequences being missed.

Can certain factors for recurrence of placenta-mediated pregnancy complications be identified after an initial small-for-gestational-age birth?

Introduction: After a small-for-gestational-age (SGA) birth, recurrence of placenta-mediated pregnancy complications (PMPCs) is a cause for anxiety when contemplating another pregnancy. We sought to identify factors potentially associated with this recurrence.Material and methods: This retrospective single-center observational study was conducted in a tertiary maternity unit between 1 January 2010 and 31 December 2017. We included all women having experienced a non-syndromic SGA birth and who were subsequently monitored for at least one other pregnancy in our institution. PMPCs were defined as recurrent SGA births, three consecutive first-trimester miscarriages, or preeclampsia.Results: Ninety-four women were included over a 7-year study period. Recurrent PMPCs were recorded in 30 (32%) cases, of which 29 featured recurrent SGA births. None of the following characteristics were significantly associated with recurrence: presence of preeclampsia during the initial pregnancy (six [20%] versus 25 [39%] cases in the recurrent PMPCs and non-recurrent PMPCs groups, respectively; p = .11), results of the histopathologic placental examination or thrombophilia screen, or implemented treatment during subsequent pregnancies.Conclusions: PMPCs recur frequently. No risk factor for recurrence was identified in our study. Results of etiologic assessments and treatments implemented after an initial SGA birth should therefore not modify level of clinical and ultrasound monitoring provided during subsequent pregnancies.Rationale: Recurrence of placenta-mediated pregnancy complications is a cause for anxiety when contemplating another pregnancy. We did not identify any risk factor after an initial small-for-gestational-age birth in our study; surveillance should therefore not be modified by the etiologic assessments' results.

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.

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.

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.

Contribution of fetal ANXA5 gene promoter polymorphisms to the onset of pre-eclampsia

OBJECTIVE

A common haplotype M2 consisting of minor SNP alleles located in the ANXA5 gene promoter region has been described as a risk factor for various obstetric complications such as recurrent pregnancy loss, pre-eclampsia and pregnancy-related thrombophilic disorder. However, the question of whether it is the maternal or fetal genotype that contributes to the onset of these disorders remains to be resolved.

METHODS

We analyzed ANXA5 gene variants in the blood and placental tissues from pre-eclampsia patients and normotensive controls. ANXA5 expression was examined by qRT-PCR, Western blotting and immunostaining. Results were compared between M2 and non-M2 carriers.

RESULTS

The M2 haplotype was found to be significantly frequent in placentas from pre-eclamptic patients relative to the controls (25.5% versus 10%, P = 0.044), In contrast, no significant differences were observed in maternal blood (13.0% versus 11.3%, P = 0.597). The placental expression of ANXA5 mRNA was found to be lower in M2 carriers. When examined by Western blot and immunostaining, the ANXA5 protein levels were found to be affected more by the placental than the maternal genotype. Histological examination of the placentas from the pre-eclamptic patients demonstrated that a placental M2 haplotype correlated more closely than maternal M2 with the severity of perivillous fibrin deposition.

CONCLUSIONS

Although preliminary, these results suggest that hypomorphic M2 alleles in the in placental ANXA5 promoter, whether transmitted maternally or paternally, might be an essential determinant of an increased risk of pre-eclampsia via local thrombophilia at the feto-maternal interface.

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.

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.

Placental fetal vascular thrombosis lesions and maternal thrombophilia

AIMS

Following intrauterine fetal death (IUFD), the placental fetal vessels undergo regressive changes. These changes are virtually indistinguishable from lesions that are the result of fetal vascular thrombosis (FVT). This study investigated the relation between these lesions and maternal thrombophilia.

METHODS

Placenta slides of 65 IUFDs with known maternal thrombophilia test results (compound MTHFR C677T and A1298C heterozygosity, n = 10; MTHFR 677TT homozygosity, n = 3; protein S deficiency, n = 0; factor V Leiden mutation, n = 2; prothrombin gene mutation G20210A, n = 1; lupus anticoagulant, n = 2; antiphospholipid syndrome, n = 1; MTHFR C677T heterozygosity, n = 5; MTHFR A1298C heterozygosity, n = 4; and MTHFR 1298CC homozygosity, n = 2) and of 30 livebirths with positive maternal thrombophilia test results (n = 5, 2, 0, 9, 2, 0, 2, 7, 2 and 1, respectively, for those thrombophilias) were microscopically examined for septation, fetal vessel thrombosis, intimal fibrin cushions, avascular villi, haemorrhagic endovasculitis and fibromuscular sclerosis.

RESULTS

Thirty of the 65 IUFDs had a positive maternal thrombophilia test; 22 of these 30 had FVT lesions. Thirty two of the 35 IUFDs with a negative maternal thrombophilia test had FVT lesions. Septation, defined as multiple lumens or 'recanalisation' in a placental vessel, was the lesion seen most often in IUFD (n = 41) whether by itself (n = 13) or in combination with other FVT lesions. Five of the 30 livebirths had FVT lesions but septation was not seen in any of the placentas from the 30 livebirths. FVT lesions did not have a significant relation with maternal thrombophilia.

CONCLUSIONS

The finding of fetal vascular thrombosis lesions in stillbirths does not imply thrombophilia as the cause of the fetal death. Factors other than thrombophilia may play a role in the cause of FVT lesions.

Antenatal suspicion of ischemic placental disease and coexistence of maternal and fetal placental disease: analysis of over 500 cases

OBJECTIVE

To investigate the antenatal suspicion of placental disease and the coexistence of maternal and fetal placental ischemic disease.

STUDY DESIGN

A prospective cohort study on normally formed singleton infants from 2000 to 2008 inclusive with placental ischemic disease.

RESULTS

Uteroplacental ischemia or fetoplacental thrombotic vasculopathy was identified in 511 of 74,857 births (7/1000 births). Four hundred fifty-nine cases met the inclusion criteria. Maternal and fetal placental vascular disease coexisted in 9.2% (n = 42) of cases. Placental ischemic disease was suspected antenatally in 70% (324/459). Maternal placental disease occurred in 40% (184/459) and 30% (140/459) had fetal pathology. The perinatal mortality rate was 12.7/1000. Antenatal suspicion of placental disease led to increased obstetric intervention and delivery of small-for-gestational age infants.

CONCLUSION

Maternal and fetoplacental vascular disease coexisted in 9.2%. Placental disease was suspected antenatally in 70% of cases and was associated with increased rates of obstetric intervention.

Thrombophilias and stillbirth

It is often postulated that both inherited and acquired thrombophilias increase the risk of stillbirth. In an attempt to reduce this theoretical risk, pregnant patients with prior fetal losses and thrombophilias are anticoagulated. However, there is no definitive proof that thrombophilias are causally linked to stillbirth. Prospective studies have failed to establish a definitive link between inherited thrombophilias and stillbirth. The extant literature suggests that only high concentrations of antiphospholipid antibodies are associated with stillbirth. Moreover, when pregnant women with prior fetal losses even in these cases are placed on anticoagulation, it is unclear that their recurrence risk of stillbirth decreases.

Avascular villi, increased syncytial knots, and hypervascular villi are associated with pregnancies complicated by factor V Leiden mutation

There is controversy about whether pathologic abnormalities are associated with pregnancies complicated by factor V Leiden (FVL) mutation. The purpose of this study was to evaluate 105 placentas delivered to mothers heterozygous for FVL mutation to determine if there are pathologic changes suggestive of hypoxia or thrombosis, which correlate with mutation status. We examined placentas obtained as part of a prospective study of 5188 pregnancies analyzed for the presence of FVL mutation in either the mother or the infant. One hundred five placentas from mothers heterozygous for the mutation were compared with 225 controls matched for maternal age, race, and geographic site. Of the 330 pregnancies, 50 infants were FVL mutation heterozygotes. Maternal FVL heterozygote status was associated with more frequent increased numbers of syncytial knots (13% vs 4%); the difference remained significant after controlling for hypertension, preeclampsia, small-for-gestational-age infants, and delivery prior to 35 weeks of gestation (odds ratio 3.6, 95% confidence interval 1.5-8.7, P  =  0.004). Maternal FVL heterozygotes had more hypervascular villi (10% vs 3%), with significance retained controlling for delivery route (odds ratio 3.4, 95% confidence ratio 1.2-9.4, P  =  0.018). Placentas from infants heterozygous for FVL mutation had more avascular villi than controls (odds ratio 2.9, 95% confidence interval 1.5-5.6, P  =  0.001). Fetal or maternal FVL heterozygosity was not associated with infarcts, small-for-gestational-age placentas, or fetal thrombotic vasculopathy. This analysis demonstrates that pathologic findings associated with placental hypoxia, specifically focal avascular villi, increased numbers of syncytial knots, and hypervascular villi, also correlate with FVL heterozygosity in infants or mothers.

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.