SARS-CoV-2 placentitis, stillbirth, and maternal COVID-19 vaccination: clinical-pathologic correlations.

Stillbirth is a recognized complication of COVID-19 in pregnant women that has recently been demonstrated to be caused by SARS-CoV-2 infection of the placenta. Multiple global studies have found that the placental pathology present in cases of stillbirth consists of a combination of concurrent destructive findings that include increased fibrin deposition that typically reaches the level of massive perivillous fibrin deposition, chronic histiocytic intervillositis, and trophoblast necrosis. These 3 pathologic lesions, collectively termed SARS-CoV-2 placentitis, can cause severe and diffuse placental parenchymal destruction that can affect >75% of the placenta, effectively rendering it incapable of performing its function of oxygenating the fetus and leading to stillbirth and neonatal death via malperfusion and placental insufficiency. Placental infection and destruction can occur in the absence of demonstrable fetal infection. Development of SARS-CoV-2 placentitis is a complex process that may have both an infectious and immunologic basis. An important observation is that in all reported cases of SARS-CoV-2 placentitis causing stillbirth and neonatal death, the mothers were unvaccinated. SARS-CoV-2 placentitis is likely the result of an episode of SARS-CoV-2 viremia at some time during the pregnancy. This article discusses clinical and pathologic aspects of the relationship between maternal COVID-19 vaccination, SARS-CoV-2 placentitis, and perinatal death.

Maternal COVID-19 causing intrauterine foetal demise with microthrombotic placental insufficiency: a case report.

BACKGROUND: Pregnant women have an increased risk of getting infected with SARS-CoV-2 and are more prone to severe illness. Data on foetal demise in affected pregnancies and its underlying aetiology is scarce and pathomechanisms remain largely unclear. CASE: Herein we present the case of a pregnant woman with COVID-19 and intrauterine foetal demise. She had no previous obstetric or gynaecological history, and presented with mild symptoms at 34 + 3 weeks and no signs of foetal distress. At 35 + 6 weeks intrauterine foetal death was diagnosed. In the placental histopathology evaluation, we found inter- and perivillous fibrin depositions including viral particles in areas of degraded placental anatomy without presence of viral entry receptors and SARS-CoV-2 infection of the placenta. CONCLUSION: This case demonstrates that maternal SARS-CoV-2 infection in the third trimester may lead to an unfavourable outcome for the foetus due to placental fibrin deposition in maternal COVID-19 disease possibly via a thrombogenic microenvironment, even when the foetus itself is not infected.

New onset MDA-5 positive dermatomyositis and massive perivillous fibrin deposition in third trimester of pregnancy: A case report.

We report a case of a 42-year-old woman (Gravida 1, Para 1) who presented in her third trimester of pregnancy with a photo distributed eruption and arthralgias and was subsequently diagnosed with dermatomyositis. She had an emergency Caesarean section at 34 weeks plus 6 days gestation due to decreased fetal movements and non-reassuring fetal heart rate. Her placenta was sent for histopathology and showed features of massive perivillous fibrin deposition. To our knowledge, this is the first case of MDA-5 positive dermatomyositis in pregnancy with a live delivery.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Placental Infection Is Associated With Massive Perivillous Fibrin Deposition at the Maternal-Fetal Interface: A Preliminary Study.

We observed an increased frequency of massive perivillous fibrin deposition (MPFD) during the second coronavirus disease 2019 (COVID-19) pandemic wave dominated by the Alpha variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). MPFD associated with 100% reverse transcription polymerase chain reaction (RT-PCR) positivity for SARS-CoV-2 and detection by immunohistochemistry. The Alpha variant was identified in all placentas with MPFD that could be sequenced.

Failure of placental detachment in accreta placentation is associated with excessive fibrinoid deposition at the utero-placental interface.

BACKGROUND: The main histopathologic diagnostic criteria for the diagnosis of placenta accreta for more than 80 years has been the finding of a direct attachment of the villous tissue to the superficial myometrium or adjacent to myometrial fibers without interposing decidua. There have been very few detailed histopathologic studies in pregnancies complicated by placenta accreta spectrum disorders and our understanding of the pathophysiology of the condition remains limited. OBJECTIVE: To prospectively evaluate the microscopic changes used in grading and to identify changes that might explain the abnormal placental tissue attachment. STUDY DESIGN: A total of 40 consecutive cesarean delivery hysterectomy specimens for placenta previa accreta at 32 to 37 weeks of gestation with at least 1 histologic slide showing deeply implanted villi were analyzed. Prenatal ultrasound examination included placental location, myometrial thickness, subplacental vascularity and lacunae. Macroscopic changes of the lower segment were recorded during surgery and areas of abnormal placental adherence were sampled for histology. In addition, 7 hysterectomy specimens with placenta in-situ from the Boyd Collection at 20.5 to 32.5 weeks were used as controls. RESULTS: All 40 patients had a history of at least 2 previous cesarean deliveries and presented with a mainly anterior placenta previa. Of note, 37 (92.5%) cases presented with increased subplacental vascularity, 31 (77.5%) cases with myometrial thinning and all with lacunae. Furthermore, 20 (50%) cases presented with subplacental hypervascularity, lacunae score of >3, and lacunae feeder vessels. Intraoperative findings included anterior lower segment wall increased vascularization in 36 (90.0%) cases and extended area of dehiscence in 18 (45.0%) cases. Immediate gross examination of hysterectomy specimens showed an abnormally attached areas involving up to 30% of the basal plate, starting at <2 cm from the dehiscence area in all cases. Histologic examination found deeply implanted villi in 86 (53.8%) samples with only 17 (10.6%) samples presenting with villous tissue reaching at least half the uterine wall thickness. There were no villi crossing the entire thickness of the uterine wall. There was microscopic evidence of myometrial scarification in all cases. Dense fibrinoid deposits, 0.5 to 2 mm thick, were found at the utero-placental interface in 119 (74.4%) of the 160 samples between the anchoring villi and the underlying uterine wall at the accreta areas and around all deeply implanted villi. In the control group, the Nitabuch stria and basal plate became discontinuous with advancing gestation and there was no evidence of fibrinoid deposition at these sites. CONCLUSION: Samples from accreta areas at delivery present with a thick fibrinoid deposition at the utero-placental interface on microscopic examination independently of deeply implanted villous tissue in the sample. These changes are associated with distortion of the Nitabuch membrane and might explain the loss of parts of the physiological site of detachment of the placenta from the uterine wall in placenta accreta spectrum. These findings indicate that accreta placentation is more than direct attachment of the villous tissue to the superficial myometrium and support the concept that accreta villous tissue is not truly invasive.

Excessive Subchorionic Fibrinoid Deposition as a Component of Massive Perivillous Fibrin Deposition: A Case With Maternal Immune Thrombocytopenia.

Maternal floor infarction (MFI) and massive perivillous fibrin deposition (MPFD) are overlapping placental disorders of unknown etiology, associated with adverse obstetric outcome, and a significant risk of recurrence. We describe a 31-year-old mother with asymptomatic thrombocytopenia throughout pregnancy and a positive lupus anticoagulant. She delivered a normal female neonate at term, whose weight was small for gestational age, with a placenta weighing less than the 10th percentile. Placental examination showed MPFD together with excessive subchorionic fibrinoid deposition. The placenta showed diffuse C4d deposition and an immune-mediated reaction was postulated for the pathogenesis of the placental changes. We suggest that excessive subchorionic fibrinoid deposition may be part of the morphologic spectrum of MFI/MPFD.

Combined Placental Maternal Floor Infarction and Cytomegalovirus Placentitis: A Case Report.

BackgroundMaternal floor infarction (MFI) and massive perivillous fibrin deposition (MPFD) are uncommon, related placental conditions secondary to trophoblastic cell damage. The etiology is unknown but MPFD/MFI is associated with adverse obstetric outcome and a significant risk of recurrence. Case report: We report a case of MPFD/MFI associated with cytomegalovirus (CMV) placentitis. A 27-year-old mother delivered a stillborn male fetus with a postmortem diagnosis of congenital CMV. The placenta showed a lymphohistiocytic villitis with isolated CMV inclusions, in combination with MFI. The villitis had features intermediate between CMV placentitis and villitis of unknown etiology (VUE). Conclusion: VUE is considered to be a maternal anti-fetal immune reaction resembling allograft rejection. We postulate that the viral infection in our case may have triggered this immune response, given that CMV antigens are known to cross react with some human antigens, in particular HLA. The subsequent trophoblastic cell damage could then lead to MFI/MFPD.

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.

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.

Pathoanatomical Lesions in Placentas With Excessively Hypercoiled Umbilical Cords: Frequent Detection of Massive Perivillous Fibrin Deposition.

This study focused to investigate a possible association of extensive umbilical hypercoiling (displaying an umbilical coiling index [UCI] of at least 1.0 coils/cm), clinical outcome, and associated pathoanatomical placental lesions. Of the 771 singleton placentas from the second and third trimesters submitted for pathoanatomical evaluation, 15 cases (2%) displayed extensive hypercoiling. There was an association of excessive hypercoiling with hypotrophy of fetuses and children (11 cases) and fetal demise (12 cases). Thin cord syndrome and umbilical stricture were observed in 9 cases and 4 cases, respectively. Seven of the 15 cases with excessive umbilical hypercoiling showed increased placental fibrin deposition (47% of the cases with hypercoiling), in 4 cases sufficient for rendering the diagnosis of massive perivillous fibrin deposition. Signs of maternal vascular malperfusion (n = 6) and chorangiosis (n = 2) were also detected in cases with hypercoiling. Recurrence of excessive umbilical hypercoiling was observed in 2 families, suggesting a genetic predisposition for the development of this lesion. Extensive hypercoiling could be a hitherto underrecognized pathogenetic factor for the development of massive perivillous fibrin deposition. A high UCI measured in the second trimester by ultrasound may be predictive of fetal hypotrophy, and intensified fetal monitoring is warranted, particularly if there is a history of hypercoiling and adverse fetal outcome.

Anti-clogging mechanisms of a motion-activated chest tube patency maintenance system: Histology and high-speed camera assessment.

The motion-activated system (MAS) employs vibration to prevent intraluminal chest tube clogging. We evaluated the intraluminal clot formation inside chest tubes using high-speed camera imaging and postexplant histology analysis of thrombus. The chest tube clogging was tested (MAS vs. control) in acute hemothorax porcine models (n = 5). The whole tubes with blood clots were fixed with formalin-acetic acid solution and cut into cross-sections, proceeded for H&E-stained paraffin-embedded tissue sections (MAS sections, n = 11; control sections, n = 11), and analyzed. As a separate effort, a high-speed camera (FASTCAM Mini AX200, 100-mm Zeiss lens) was used to visualize the whole blood clogging pattern inside the chest tube cross-sectional view. Histology revealed a thin string-like fibrin deposition, which showed spiral eddy or aggregate within the blood clots in most sections of Group MAS, but not in those of the control group. Histology findings were compatible with high-speed camera views. The high-speed camera images showed a device-specific intraluminal blood "swirling" pattern. Our findings suggest that a continuous spiral flow in blood within the chest tube (MAS vs. static control) contributes to the formation of a spiral string-like fibrin network during consumption of coagulation factors. As a result, the spiral flow may prevent formation of thick band-like fibrin deposits sticking to the inner tube surface and causing tube clogging, and thus may positively affect chest tube patency and drainage.

Massive Perivillous Fibrin Deposition of an Enterovirus A-Infected Placenta Associated With Stillbirth: A Case Report.

Massive perivillous fibrin deposition (MFD) is a morphologically defined severe placental lesion associated with perinatal morbidity and mortality. The etiology is unknown, and recurrence risk in subsequent pregnancies is assumed to be high. In most cases, a pathologic immune reaction is supposed to be responsible for the lesion. We report a case of a pregnant woman's suffering from hand, foot, and mouth disease in the 20th gestational week. Subsequently, MFD developed in the placenta and was followed by intrauterine growth restriction and stillbirth in the 29th gestational week. Enterovirus A with high homology to Coxsackievirus A16 was detected in the placenta by means of immunohistochemisty and reverse transcription polymerase chain reaction. This infection could be a rare cause of MFD and should be taken into consideration in the differential diagnosis of the individual etiology. Recurrence risk of virus-related MFD is expected to be lower than in MFD without infectious association.

Recurrent Chronic Intervillositis: The Diagnostic Challenge - A Case Report and Review of the Literature.

BACKGROUND: Chronic intervillositis (CI) is a rare placental condition involving diffuse infiltration of intervillous spaces by CD68- or CD45-positive maternal mononuclear inflammatory cells. Because no validated clinical or biochemical markers are specific to CI, the diagnosis is purely histopathological and is made postpartum. CASE: This report describes a case of recurrent CI associated with adverse complications in two successive pregnancies. Both pregnancies were complicated by intrauterine growth restriction. Coexistent massive perivillous fibrin deposition was present in the first placenta. This case highlights the importance of CI in explaining and predicting adverse perinatal outcomes. CONCLUSION: CI is associated with adverse pregnancy outcomes and a high risk of recurrence, and it can coexist with massive perivillous fibrin deposition. Pathologists must ensure that the significance of these diagnoses is adequately conveyed to clinicians, to optimize management of subsequent pregnancies.

Pathophysiology of placental-derived fetal growth restriction.

Placental-related fetal growth restriction arises primarily due to deficient remodeling of the uterine spiral arteries supplying the placenta during early pregnancy. The resultant malperfusion induces cell stress within the placental tissues, leading to selective suppression of protein synthesis and reduced cell proliferation. These effects are compounded in more severe cases by increased infarction and fibrin deposition. Consequently, there is a reduction in villous volume and surface area for maternal-fetal exchange. Extensive dysregulation of imprinted and nonimprinted gene expression occurs, affecting placental transport, endocrine, metabolic, and immune functions. Secondary changes involving dedifferentiation of smooth muscle cells surrounding the fetal arteries within placental stem villi correlate with absent or reversed end-diastolic umbilical artery blood flow, and with a reduction in birthweight. Many of the morphological changes, principally the intraplacental vascular lesions, can be imaged using ultrasound or magnetic resonance imaging scanning, enabling their development and progression to be followed in vivo. The changes are more severe in cases of growth restriction associated with preeclampsia compared to those with growth restriction alone, consistent with the greater degree of maternal vasculopathy reported in the former and more extensive macroscopic placental damage including infarcts, extensive fibrin deposition and microscopic villous developmental defects, atherosis of the spiral arteries, and noninfectious villitis. The higher level of stress may activate proinflammatory and apoptotic pathways within the syncytiotrophoblast, releasing factors that cause the maternal endothelial cell activation that distinguishes between the 2 conditions. Congenital anomalies of the umbilical cord and placental shape are the only placental-related conditions that are not associated with maldevelopment of the uteroplacental circulation, and their impact on fetal growth is limited.

Recurrent Massive Perivillous Fibrin Deposition and Chronic Intervillositis Treated With Heparin and Intravenous Immunoglobulin: A Case Report.

BACKGROUND: Massive perivillous fibrin deposition (MPVFD) and chronic intervillositis (CI) are related rare pathological correlates of severe intrauterine growth restriction (IUGR) and fetal loss with high recurrence rates. No standard management has been established. CASE: A patient underwent termination of pregnancy at 21 weeks for severe early onset IUGR. Placental histology showed mixed CI with MPVFD. Several months later, the patient became pregnant and was managed with prednisone and aspirin (ASA) but miscarried at 16 weeks. Placental pathology showed MPVFD and focal CI. For two subsequent pregnancies, she was treated with intravenous immunoglobulin (IVIG), heparin, and ASA. Both pregnancies resulted in healthy near-term deliveries with normal placentas. CONCLUSION: IVIG, heparin, and ASA can be an option in patients with recurrent pregnancy loss due to MPVFD and CI.

Chronic histiocytic intervillositis in three consecutive pregnancies in a single patient: Differing clinical results and pathology according to treatment used.

Chronic histiocytic intervillositis (CHI) is an extremely rare pathological condition but is strongly associated with severe obstetric complications and has a high recurrence rate. The management of this condition has not yet been established. We describe herein the occurrence of CHI in the late second-third trimester in each of three consecutive pregnancies in a single patient with four previous consecutive early miscarriages. In this patient, each of the three complicated pregnancies was managed with one of the following, respectively: low-dose aspirin; heparin plus low-dose aspirin; and prednisolone plus low-dose aspirin. CHI was histologically confirmed in all three pregnancies, but the clinical results and pathology (e.g. extent of histiocytic infiltration) in each pregnancy clearly differed with treatment. Both combination treatments eventuated in a live birth. Immunosuppressive therapy seemed to produce better clinical results by restricting the extent of the affected areas. The elevated alkaline phosphatase associated with the CHI was assumed to have no clinical prognostic value.

Massive perivillous fibrin deposition in the placenta and uterine metastasis of gastric adenocarcinoma during pregnancy.

The prognosis of gastric cancer during pregnancy is unfavorable because of delayed diagnosis and advanced stage. We present a case of gastric carcinoma metastasized to the placenta and uterus during pregnancy. Pathological examination revealed a poorly differentiated adenocarcinoma of the stomach with lymph node metastasis. After counseling, the patient decided to terminate the pregnancy and begin immediate treatment for gastric cancer. Hysterectomy and subtotal hysterectomy were performed because medical termination of the pregnancy was unsuccessful. Pathological examination of the placenta and uterus revealed metastases of gastric adenocarcinoma. All the uterine vessels were packed with tumor cells and the myometrium showed extensive coagulative necrosis. Moreover, microscopic findings of the placenta were consistent with massive perivillous fibrin deposition. Our case clearly suggests that massive perivillous fibrin deposition in the placenta can be associated with malignancy during pregnancy and that uterine metastasis of maternal malignancy may result in myometrial dysfunction unresponsive to uterotonics.

Maternal floor infarction: management of an underrecognized pathology.

Maternal floor infarction is a relatively rare condition characterized clinically by severe early onset fetal growth restriction with features of uteroplacental insufficiency. It has a very high recurrence rate and carries a significant risk or fetal demise. Pathological characteristics include massive and diffuse fibrin deposition along the decidua basalis and the perivillous space of the basal plate. We present a case of recurrent maternal floor infarction and propose diagnostic clues as well as potential therapeutic options.

MR imaging findings of massive perivillous fibrin deposition of the placenta: A case report.

Massive perivillous fibrin deposition (MPFD) of the placenta is characterized by the obliteration of the villous trophoblast with extensive deposition of fibrinoid material in the intervillous space. Here, we describe the MRI findings of a case of MPFD. The placenta demonstrates linear and geographical hypointensity on T2-weighted imaging, which is suggested to mainly reflect fibrin deposition. This finding should be noted, particularly in patients with miscarriage in their past history.

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.