Tissue Sentence Context

Table 1. Analysis of context sentence of placenta tissue in 97 abstracts.

PMID Senteces
32114744 Objective: To investigate the clinical characteristics and placental pathology of 2019-nCoV infection in pregnancy, and to evaluate intrauterine vertical transmission potential of 2019-nCoV infection. Methods: The placentas delivered from pregnant women with confirmed 2019-nCoV infection which were received in the Department of Pathology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology collected by February 4th, 2020 and retrospectively studied. […] Their clinical material including placental tissue and lung CT, and laboratory results were collected, meanwhile, nucleic acid detection of 2019-nCoV of the placentas were performed by RT-PCR. Results: Three placentas delivered from pregnant women with confirmed 2019-nCoV infection, who were all in their third trimester with emergency caesarean section. […] There were various degrees of fibrin deposition inside and around the villi with local syncytial nodule increases in all three placentas. […] One case of placenta showed the concomitant morphology of chorionic hemangioma and another one with massive placental infarction. […] All samples from three placentas were negative for the nucleic acid of 2019-nCoV. Conclusions: The clinical characteristics of pregnant women with 2019-nCoV infection in late pregnancy are similar to those of non-pregnant patients, and no severe adverse pregnancy outcome is found in the 3 cases of our observation. […] Pathological study suggests that there are no morphological changes related to infection in the three placentas.
32298273 Our results revealed that ACE2 was highly expressed in maternal-fetal interface cells including stromal cells and perivascular cells of decidua, and cytotrophoblast and syncytiotrophoblast in placenta. […] And thus, both the vertical transmission and the placenta dysfunction/abortion caused by SARS-CoV-2 need to be further carefully investigated in clinical practice.
32305459 The nucleic acid test from the mother’s amniotic fluid, vaginal secretions, cord blood, placenta, serum, anal swab, and breast milk were also negative.
32365180 The available evidence suggests that ACE2 is widely expressed in the ovary, uterus, vagina and placenta.
32376317 Sars-cov-2 could be recovered by real-time (RT) PCR from nasal and throat swabs, sputum and feces of symptomatic patients including neonates but not from vaginal swabs, amniotic fluid, placenta, cord blood, neonatal blood or breast milk.
32379909 However, mother-to-child SARS-CoV-2 transmission through the placenta probably does not occur, or likely occurs very rarely.2 All the studies conducted on COVID-19 pregnant women involved patients undergoing cesarean section, but the indications for such delivery modality were not clearly stated.
32385225 Questions arise concerning the continuation of pregnancy, how to terminate the pregnancy, the possibility of virus transmission through the placenta, isolation of the newborn after birth, and breastfeeding.
32391518 One recent review reported that in a small number of cases, two PCR swabs of the placenta were sent in additional to neonatal and cord blood testing, and both placental PCR swabs were negative.1 Other studies have demonstrated the finding of SARS-CoV2 IgM in neonates born to mothers diagnosed with COVID-19 during pregnancy,2,3 findings that may indicate vertical transmission of the virus in utero. […] We report our experience with placental/membrane SARS-CoV2 RNA PCR swab results after delivery to a series of symptomatic mothers with confirmed COVID-19 infection in pregnancy. […] Charts were reviewed for documentation of SARS-CoV-2 RNA RT-PCR testing sent from either the placenta or membranes within 30 minutes following delivery. […] Placental swabs were obtained from the amniotic surface after clearing the surface of maternal blood (placental PCR). […] Of 32 COVID-19 positive pregnant patients who gave birth in this timeframe, placental or membrane swabs were sent from 11 patients (Table). […] Of 11 placental or membrane swabs sent following delivery, 3 swabs were positive for SARS-CoV-2, all in women with moderate to severe COVID-19 illness at time of delivery. […] This is the first study to demonstrate the presence of SARS-CoV-2 RNA in placental or membrane samples. […] In summary, the presence of viral RNA by RT-PCR in placenta/membranes at the time of delivery suggests the need for further research into the possibility of vertical transmission.
32403141 However, without positive RT-PCR tests of amniotic fluid, placenta, or cord blood, there is a lack of virologic evidence for intrauterine vertical transmission. […] Additional RT-PCR tests on amniotic fluid, placenta, and cord blood are needed to ascertain the possibility of intrauterine vertical transmission. […] · More RT-PCR tests on amniotic fluid, placenta, and cord blood are recommended..
32441303 To describe histopathologic findings in the placentas of women with coronavirus disease 2019 (COVID-19) during pregnancy. […] Placentas were examined and compared to historical controls and women with placental evaluation for a history of melanoma. […] Sixteen placentas from patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were examined (15 with live birth in the third trimester, 1 delivered in the second trimester after intrauterine fetal demise). […] Compared to controls, third trimester placentas were significantly more likely to show at least one feature of maternal vascular malperfusion (MVM), particularly abnormal or injured maternal vessels, and intervillous thrombi. […] Rates of acute and chronic inflammation were not increased.The placenta from the patient with intrauterine fetal demise showed villous edema and a retroplacental hematoma. […] Relative to controls, COVID-19 placentas show increased prevalence of decidual arteriopathy and other features of MVM, a pattern of placental injury reflecting abnormalities in oxygenation within the intervillous space associated with adverse perinatal outcomes. […] These changes may reflect a systemic inflammatory or hypercoagulable state influencing placental physiology.
32454807 Five studies using data on umbilical cord blood, placenta, and/or amniotic fluid reported no positive results. […] En cinco estudios se analizó la sangre del cordón umbilical, la placenta o el líquido amniótico y no se informaron resultados positivos. […] O sangue do cordão umbilical, a placenta ou o líquido amniótico foram analisados em cinco estudos, não tendo sido relatados resultados positivos.
32474140 Centers for Disease Control to affect fetal development similarly to other common respiratory coronaviruses through effects of the maternal inflammatory response on the fetus and placenta.
32529643 Despite reports of neonatal COVID-19, SARS-CoV-2 has not been consistently isolated in perinatal samples thus, definitive proof of transplacental infection is still lacking. […] To address these questions, we assessed investigative tools used to confirm maternal-fetal infection and known protective mechanisms of the placental barrier that prevent transplacental pathogen migration. […] Histological examination demonstrated sparse viral particles, vascular malperfusion and inflammation in the placenta from pregnant women with COVID-19. […] The paucity of placental co-expression of ACE-2 and TMPRSS2, two receptors involved in cytoplasmic entry of SARS-CoV-2, may explain its relative insensitivity to transplacental infection. […] Further spatial-temporal studies are needed to determine the true potential for transplacental migration.
32542883 In March 2020, the World health organization reported coronavirus disease 2019 (COVID-19) as a pandemic.1 Khan et al., 2020, in their systemic review about positive COVID-19 pregnant women, showed a rate of 29.1% preterm birth and 16.4% low birth weight among their babies.2 This increases the interest that hyper-inflammatory state in COVID-19 may be associated with hypoxic injury in the placenta and developing pre-eclamptic state.
32570959 RT-PCR for SARS-CoV-2 yielded negative results on amniotic fluid, vaginal/cervical fluids, placenta tissue, and breast milk samples.
32573498 We present a case of second trimester pregnancy with symptomatic Covid-19 complicated by severe preeclampsia and placental abruption. […] We analyzed placenta for the presence of SARS-CoV-2 through molecular and immunohistochemical assays and by and electron microscopy, and we measured the maternal antibody response in blood to this infection. […] SARS-CoV-2 localized predominantly to syncytiotrophoblast cells at the maternal-fetal interface of the placenta. […] Histological examination of the placenta revealed a dense macrophage infiltrate, but no evidence for vasculopathy typically associated with preeclampsia. […] This case demonstrates SARS-CoV-2 invasion of the placenta, highlighting the potential for severe morbidity among pregnant women with Covid-19.
32574110 Reports of placental infection and vertical transmission are rare. […] Interestingly, despite lack of SARS-CoV-2 placenta productive infection there are several reports of significant abnormalities in placenta morphology.
32574285 The virus was not detected in the neonate nasopharyngeal swab samples at birth, in the placenta, in the umbilical cord, in the amniotic fluid, in the breast milk or in the maternal vaginal swab samples in any of these articles.
32620513 In addition, the placenta has been shown to possess ACE2 receptors on the villous cytotrophoblast and the syncytiotrophoblast and findings suggest that the coronavirus enters the host cells via these ACE2 receptors. […] Furthermore, the presence of the ACE2 receptors in the placenta may increase the risk of mother to baby transmission of the virus.
32647285 A total of eight autopsy lungs, one placenta, and ten kidney biopsies from COVID-19 patients were stained with a panel of commercially available antibodies for IHC and commercially available RNA probes for ISH. […] Similarly, autopsy lungs, placentas and renal biopsies from non-COVID-19 patients were stained with the same antibodies and probes. […] All eight lungs and the placenta from COVID-19 patients stained positive by IHC and ISH, while the kidney biopsies stained negative by both methodologies.
32658097 Placenta histopathology revealed SARS-CoV-2 infection by electron microscopy and immunohistochemistry.
32662421 Herein, building upon our previous single-cell study (Pique-Regi et al., 2019), another study, and new single-cell/nuclei RNA-sequencing data, we investigated the expression of ACE2 and TMPRSS2 throughout pregnancy in the placenta as well as in third-trimester chorioamniotic membranes. […] We report that co-transcription of ACE2 and TMPRSS2 is negligible in the placenta, thus not a likely path of vertical transmission for SARS-CoV-2. […] By contrast, receptors for Zika virus and cytomegalovirus, which cause congenital infections, are highly expressed by placental cell types. […] These data show that the placenta minimally expresses the canonical cell-entry mediators for SARS-CoV-2.
32669955 HIPED revealed enrichment of ACE2 protein in the placenta and ovary despite a low mRNA level.
32678975 Here, we review pathological findings in placentas from women who tested positive for SARS-CoV-2 as well as information on pregnancy outcomes associated with related and highly pathogenic coronaviruses (ie, severe acute respiratory syndrome (SARS-COV) and the Middle East respiratory syndrome, MERS). […] Greater understanding of the pathogenesis of SARS-CoV-2 in the placenta will yield important insight into potential therapeutic interventions for pregnant women with COVID-19.
32693656 Combination of the following keywords; COVID-19, SARS CoV-2, placenta, vertical transmission, intrauterine infection, breast milk were searched in databases. […] Eight placental tissues testing positive for the virus were reported. […] More RT-PCR tests on amniotic fluid, placenta, breast milk and cord blood are required.
32696426 Cells derived from the placenta and/or fetal membranes, in particular amniotic epithelial cells (AEC) and decidual stromal cells (DSC), have established, well-characterized, potent anti-inflammatory and immune-modulatory properties that make them attractive candidates for a cell-based therapy of COVID19 pneumonia. […] Placenta-derived cells are easy to procure from a perennial source and pose minimal ethical issues for their utilization.
32704477 SARS-Cov-2 was detected by RT-PCR in amniotic fluid in one case and in placental specimens in two cases. […] All five women had acute chorioamnionitis on placental histology, massive deposition of fibrin, mixed intervillitis/villitis, and intense neutrophil and lymphocyte infiltration. […] The intense placental inflammatory reaction in all five cases raises the possibility of a direct effect of SARS-CoV-2 on the placenta.
32711871 To conduct a systematic review of original peer-reviewed studies, containing data on the identification of SARS-CoV-2 in clinical samples of amniotic fluid, placenta or membranes, umbilical cord blood, and human milk, from women with a clinically or confirmed diagnosis of COVID-19. […] Seventeen studies were included, in which 143 clinical samples were identified (38 of amniotic fluid; 34 of placentas or membranes; 39 from umbilical cord blood and 32 from human milk). […] Among the 143 samples, nine were positive for SARS-CoV-2 RNA (one amniotic fluid sample obtained before rupturing the membranes; six samples of placenta or membranes, although authors indicate the possibility of contamination by maternal blood in three of these, and two samples of human milk). […] Following our search criteria, we found no studies that demonstrate the detection of SARS-CoV-2, in conjunction with viral isolation and the evaluation of the infective capacity of viral particles, in clinical samples of amniotic fluid, placenta or membranes, umbilical cord blood and human milk, from women with a confirmed or clinical diagnosis of COVID-19.
32712670 Lopinavir and darunavir were evaluated in clinically relevant combinations using an ex vivo human first-trimester placenta-decidua explant model, an in vitro human primary decidual cell culture system, and an in vivo mouse pregnancy model. […] The first-trimester (gestational age, 6-8 weeks) human placenta-decidua tissue was obtained from 11 to 15 healthy women undergoing elective termination of pregnancy. […] Human: Spiral artery remodeling was assessed by immunohistochemical analysis of first-trimester placenta-decidua explant co-culture system. […] Trophoblast migration was measured using a placental explant culture. […] Lopinavir-cART treatment was also associated with selective depletion of uNK cells, reduced trophoblast migration and defective placentation. […] Our results suggest that periconceptional initiation of lopinavir-cART, but not darunavir-cART, causes defective maturation of the uterine endometrium, leading to impairments in spiral artery remodeling and placentation, thus contributing to the poor birth outcomes. […] The human first-trimester placenta/decidua samples could only be obtained from healthy females undergoing elective termination of pregnancy. […] HIV infection is also associated with immune dysregulation, inflammation, alterations in angiogenic factors and complement activation, all of which could influence decidual and placental vascular remodeling and modify any cART effects.
32722449 In this review, we summarize studies regarding the potential evidence for transplacental transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), characterize the expression of its receptors and proteases, describe the placental pathology and analyze virus-host interactions at the maternal-fetal interface. […] We further discuss the potential molecular mechanisms, whereby the placenta serves as a defense front against pathogens by regulating the interferon type III signaling, microRNA-triggered autophagy and the nuclear factor-κB pathway. […] Based on these data, we conclude that vertical transmission may occur but rare, ascribed to the potent physical barrier, the fine-regulated placental immune defense and modulation strategies. […] Particularly, immunomodulatory mechanisms employed by the placenta may mitigate violent immune response, maybe soften cytokine storm tightly associated with severely ill COVID-19 patients, possibly minimizing cell and tissue damages, and potentially reducing SARS-CoV-2 transmission.
32739398 Severe acute respiratory syndrome coronavirus 2 viral RNA testing in neonatal cord blood was positive in 2.9% of samples (1/34), 7.7% of placenta samples (2/26), 0% of amniotic fluid (0/51), 0% of urine samples (0/17), and 9.7% of fecal or rectal swabs (3/31).
32741970 Robust proof of placental infection requires demonstration of viral localization within placental tissue. […] Only two of the few cases of possible vertical transmission have demonstrated placental infection. […] None have shown placental expression of the ACE2 or TMPRSS2 protein, both required for viral infection. […] We examined 19 COVID-19 exposed placentas for histopathologic findings, and for expression of ACE2, and TMPRSS2 by immunohistochemistry. […] Direct placental SARS-CoV-2 expression was studied by two methods-nucleocapsid protein expression by immunohistochemistry, and RNA expression by in situ hybridization. […] In 2 of 19 cases, SARS-CoV-2 RNA was present in the placenta focally in the ST and cytotrophoblast. […] There was no characteristic histopathology present in our cases including the two placental infections. […] We found that the placenta is capable of being infected but that this event is rare.
32743723 Molecular tests for SARS-CoV-2 on umbilical stump, placenta, and nasopharyngeal aspirate of the neonate, collected at birth were positive.
32744708 However, Reverse Transcription-Polymerase Chain Reaction tests of the breast milk, placenta, amniotic fluids, and cord blood and maternal vaginal secretions were all negative for SARS-CoV-2 in the reported cases.
32749712 Current literature suggests minimal maternal, fetal, and neonatal morbidity and mortality.1 COVID-19 manifestations appear similar between pregnant and non-pregnant women.2 OBJECTIVES/STUDY DESIGN: We present a case of placental SARS-CoV-2 virus in a woman with mild COVID-19 disease, then review the literature. […] To our knowledge, this is the first report of placental SARS-CoV-2 despite mild COVID-19 disease (no symptoms of COVID-19 aside from myalgias); patient had no fever, cough, or shortness of breath, but only myalgias and sick contacts. […] Despite her mild COVID-19 disease in pregnancy, we demonstrate placental vasculopathy and presence of SARS-CoV-2 virus across the placenta. […] Evidence of placental COVID-19 raises concern for placental vasculopathy (potentially leading to fetal growth restriction and other pregnancy complications) and possible vertical transmission - especially for pregnant women who may be exposed to COVID-19 in early pregnancy.
32757186 SARS-CoV-2, a RNA single-stranded virus, has been detected in the amniotic fluid, in the cord blood and in the placentas of the infected women. […] The extent of this putative risk might, however, vary during the different stages of pregnancy, owing to several variables (physiological modifications of the placenta, virus receptors’ expression, or delivery route).
32757366 For the placenta-related pathology, we will focus our discussion on the temporal expression of ACE2 throughout gestation for possible propagation of SARS-CoV-2 in the placenta in infected women and ensuing consequences.
32762171 ACE2 and CLEC4M are expressed in alimentary system, heart, kidney, lung and placenta.
32779810 Case reports indicate that vertical transmission is uncommon; however there is evidence that placental and fetal infection can occur.3-7 Placentas from infected patients show inflammatory, thrombotic and vascular changes that have been found in other inflammatory conditions.8,9 This suggests that the inflammatory nature of SARS-CoV-2 infection during pregnancy could cause adverse obstetric and neonatal events. […] Exposure to intrauterine inflammation and placental changes could also potentially result in long-term, multisystemic defects in exposed infants. […] This review will summarize the known literature on the placenta in SARS-CoV-2 infection, evidence of vertical transmission, and possible outcomes of prenatal exposure to the virus.
32798244 We hypothesized that the observed low incidence of perinatal infection could be related to a low expression of the membrane receptor for SARS-CoV2, ACE2, in the fetal-placental unit. […] We evaluated protein expression of ACE2 both in placentas and fetal organs from non-infected pregnancies across gestation. […] Immunocytochemistry analysis for ACE2 in organs and placentas were performed in May 2020, in samples from a registered biobank. […] Seven placentas including those of the 5 cases, 1 of a 7-week miscarriage and 1 of a symptomatic SARS-COV2 pregnancy at 34 weeks. […] Similar intensity and distribution of ACE2 staining were identified in the mother’s SARS-CoV2 placenta. […] Marked placental expression of ACE2 provides a rationale for vertical transmission at cellular level.
32798764 This work seeks to introduce placental extract-derived biologically active components as a therapeutic option and highlights their mechanism of action relevant to COVID-19 virus. […] Human placenta has been used in clinical practice for over a century and there is substantial experience in clinical applications of placental extract for different indications. […] Aqueous extract of human placentacontains growth factors, cytokines/chemokines, natural metabolic and other compounds, anti-oxidants, amino acids, vitamins, trace elements and biomolecules, which individually or in combination show accelerated cellular metabolism, immunomodulatory and anti-inflammatory effects, cellular proliferation and stimulation of tissue regeneration processes. […] Placental extract treatment is proposed as a suitable therapeutic approach consideringthe above properties which could protect against initial viral entry and acute inflammation of alveolar epithelial cells, reconstitute pulmonary microenvironment and regenerate the lung. […] We reviewed useful therapeutic information of placental biomolecules in relation to COVID-19 treatment. […] We propose the new approach of using placental growth factors, chemokines and cytokine which will execute antiviral activity in coordination with innate and humoral immunity and improve patient’s immunological responses to COVID-19. […] Executing a clinical trial using placental extract as preventive, protective and/or therapeutic approach for COVID-19treatment could advance the development of a most promising therapeutic candidate that can join the armamentaria against the COVID-19 virus.
32818801 The occurrence of trans-placental transmission of severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) infection remains highly debated. […] Placental positivity for SARS-CoV-2 has been reported in selected cases, but infection or virus-associated disease of fetal tissues or newborns remains to be demonstrated. […] We screened for SARS-CoV-2 spike (S) protein expression placentas from 101 women who delivered between February 7 and May 15, 2020, including 15 tested positive for SARS-CoV-2 RNA, 34 tested negative, and 52 not evaluated as they did not meet testing criteria (32), or delivered before COVID-19 pandemic declaration (20). […] Immunostain for SARS-CoV-2 nucleocapsid (N) was performed in the placentas of all COVID-19 positive women. […] One placenta resulted positive for the SARS-CoV-2 S and N proteins, which was further studied by RNA-in situ hybridization and RT-PCR for S transcripts, and by electron microscopy. […] A comprehensive immunohistochemical and immunofluorescence analysis of the placental inflammatory infiltrate completed the investigations. […] SARS-CoV-2 S and N proteins were strongly expressed in the placenta of a COVID-19 pregnant woman whose newborn tested positive for viral RNA and developed COVID-19 pneumonia soon after birth. […] The placenta intervillous inflammatory infiltrate consisted of neutrophils and monocyte-macrophages expressing activation markers. […] Placenta infection was associated with recruitment of maternal inflammatory cells in the intervillous space, without villitis. […] PD-L1 expression in syncytiotrophoblast and Hofbaeur cells, together with limited production of NETs, may have prevented immune cell-driven placental damage, ensuring sufficient maternal-fetus nutrient exchanges.
32825963 Herein, we thoroughly reviewed multiple organs including lung, gastrointestinal tract, liver, kidney, skin, heart, blood, spleen, lymph nodes, brain, blood vessels, and placenta in terms of COVID-19-related pathological alterations.
32838277 The impact of maternal SARS-CoV-2 infection on placental histopathology is not well known. […] To determine if significant placental histopathological changes occur after diagnosis of SARS-CoV-2 infection in pregnancy and whether these changes are correlated with the presence or absence of symptoms associated with infection. […] Retrospective cohort study of women diagnosed with SARS-CoV-2 infection who delivered at a single center from April 9th to April 27th, 2020, and had placental specimens reviewed by pathology. […] Histopathological characteristics were evaluated in each placenta and the incidence of these findings were compared between placentas after diagnosis of maternal SARS-CoV-2 infection and historical controls, as well as between placentas from patients with or without typical symptoms related to infection. […] A total of 50 placentas after diagnosis of maternal SARS-CoV-2 infection and 50 historical controls were analyzed. […] Among placentas from patients diagnosed with SARS-CoV-2 infection, 3 (6%) were preterm (33 3/7, 34 6/7 and 36 6/7 weeks of gestation), 16 (32%) were from patients with typical symptoms related to infection and 34 (68%) were from patients without typical symptoms related to the infection. […] Decidual vasculopathy was not visualized in any of the placentas from patients diagnosed with SARS-CoV-2 infection. […] There was no statistically significant difference in placental histopathological characteristics between the groups. […] Based on our data, there are no significant placental histopathological changes that occur after diagnosis of SARS-CoV-2 infection in the third trimester of pregnancy compared to a gestational age-matched historical control group. […] Similar incidences of histopathological findings were also discovered when comparing placentas from patients with SARS-CoV-2 infection with or without the presence of symptoms typically related to infection.
32842979 The highest sample yield was for placenta (96%), umbilical cord blood (93%), urine (99%), and maternal blood (91%).
32851697 The objective of this study was to examine the characteristics and distributions of possible SARS-CoV-2 target cells in the human TE and placenta. […] Single-cell transcriptomic datasets of the early TE as well as the first- and second-trimester placentas have been reported1,2 . […] Here, we conducted the transcriptomic analysis of 4198 early TE cells, 1260 first-trimester placental cells and 189 EVTs at 24-week placentas (EVT_24W) by SMART-Seq2 method. […] Immunohistochemical staining of the human first-, second- and third- trimester placentas was performed to confirm bioinformatic results. […] Via bioinformatic analysis, we identified the existence of ACE2 and TMPRSS2 expression in human TE as well as in the first- and second- trimester placentas. […] Amongst the placental cells, 20.4% of CTBs, 44.1% of STBs, 3.4% of EVT_8W and 63% of EVT_24W were ACE2 positive. […] Based on immunohistochemical results, expression level of ACE2 and TMPRSS2 in first- and second- and third-trimester placentas was observed. […] Our study has demonstrated the presence of ACE2 and TMPRSS2 positive cells in the human TE and placentas at different stages of pregnancy, which indicates the possibility that the SARS-CoV-2 could spread via the placenta and cause intrauterine fetal infection.
32853442 Cesarean delivery was performed because of a non-reassuring fetal heart rate; the placenta showed increased perivillous fibrin deposition and intervillositis. […] Moreover, placental infection with SARS-CoV-2 was demonstrated by placental immunostaining. […] The findings suggest a possible relationship between placental fibrin deposition and chronic and acute intervillositis, non-reassuring fetal heart rate and coagulopathy in pregnant women with COVID-19.
32853537 Although there is some evidence that severe acute respiratory syndrome coronavirus 2 can invade the human placenta, limited data exist on the gestational age-dependent expression profile of the severe acute respiratory syndrome coronavirus 2 cell entry mediators, angiotensin-converting enzyme 2 and transmembrane protease serine 2, at the human maternal-fetal interface. […] This is important because the expression of decidual and placental angiotensin-converting enzyme 2 and transmembrane protease serine 2 across gestation may affect the susceptibility of pregnancies to vertical transmission of severe acute respiratory syndrome coronavirus 2. […] This study aimed to investigate the expression pattern of specific severe acute respiratory syndrome coronavirus 2 cell entry genes, angiotensin-converting enzyme 2 and transmembrane protease serine 2, in the placenta across human pregnancy and in paired samples of decidua and placenta in pregnancies complicated by preterm birth or preeclampsia compared with those in term uncomplicated pregnancies. […] The first cohort was composed of placentae from first- (7-9 weeks), second- (16-18 weeks), and third-trimester preterm (26-31 weeks) and third-trimester term (38-41 weeks) pregnancies (n=5/group), whereas the second independent cohort included matched decidua and placentae from pregnancies from term uncomplicated pregnancies (37-41 weeks’ gestation; n=14) and pregnancies complicated by preterm birth (26-37 weeks’ gestation; n=11) or preeclampsia (25-37 weeks’ gestation; n=42). […] In the first cohort, angiotensin-converting enzyme 2 and transmembrane protease serine 2, exhibited a gestational age-dependent expression profile, that is, angiotensin-converting enzyme 2 and transmembrane protease serine 2 mRNA was higher (P<.05 in the first-trimester placenta than second-trimester preterm birth and term placentae exhibited a negative correlation with gestational age second cohort rna sequencing demonstrated very low or undetectable expression levels of angiotensin-converting enzyme preeclampsia decidua from late gestation. contrast transmembrane protease serine was expressed both decidual placental samples but did not change pregnancies complicated by either preeclampsia. increased these severe acute respiratory syndrome coronavirus cell entry-associated genes first trimester pregnancy compared those later stages suggests possibility differential susceptibility to entry across pregnancy.> </.05>
32859496 We report a case of pregnant woman in her third trimester with critical COVID-19, and amniotic fluid, umbilical cord blood, placenta, and neonatal gastric fluid were retained during cesarean section.
32862058 Parenchymal changes of placentas from COVID-19 infected mothers have been reported by several groups, but the localization and relative abundance of SARS-CoV-2 viral proteins and cellular entry machinery has not been fully characterized within larger placental tissue cohorts. […] An extended placental tissue cohort including samples from 15 COVID-19 positive maternal-fetal dyads (with n = 5 cases with evidence of fetal transmission) in comparison with 10 contemporary COVID-19 negative controls. […] CoV2 SP was present within the villous placenta in COVID-19 positive pregnancies with and without evidence of fetal transmission. […] Importantly, both CoV2 SP and ACE2 expression consistently localized primarily within the outer syncytiotrophoblast layer placental villi, a key physiologic interface between mother and fetus. […] Overall this study provides an important basis for the ongoing evaluation of SARS-CoV-2 physiology in pregnancy and highlights the importance of the placenta as a key source of primary human tissue for ongoing diagnostic and therapeutic research efforts to reduce the global burden of COVID-19.
32878840 We present a case of COVID-19 pneumonia in a 28-week pregnant woman with a known low lying placenta. […] The low lying placenta in this patient meant that we had to carefully consider the application of recommendations for thromboprophylaxis in pregnant COVID-19 patients.
32911234 Whether vertical transmission or placental pathology might occur following maternal infection during pregnancy remains unknown. […] This review aimed to summarise all studies that examined the placenta or neonates following infection with SARS-CoV-2, or closely related highly pathogenic coronavirus (SARS-CoV-1, or the Middle East respiratory syndrome coronavirus (MERS-CoV)). […] Twenty studies reported placental histopathology findings in third trimester placentas following maternal SARS-CoV-2 infection. […] Using the Amsterdam Consensus criteria to categorise the histopathology results, evidence of both fetal vascular malperfusion (35.3% of cases; 95% Confidence Interval (CI) 27.7-43.0%) and maternal vascular malperfusion (46% of cases; 95% CI 38.0-54.0%) were reported, along with evidence of inflammation in the placentas (villitis 8.7% cases, intervillositis 5.3% of cases, chorioamnionitis 6% of cases). […] The placental pathologies observed in SARS-CoV-2 were consistent with findings following maternal SARS-CoV-1 infection. […] Of those tested, a minority of neonates (2%) and placental samples tested positive for SARS-CoV-2 infection (21%). […] Limited conclusions can be drawn about the effect of maternal SARS-CoV-2 infection on placental pathology as most lack control groups and the majority of reports followed third trimester infection. […] A better understanding of the association between maternal SARS-CoV-2 infection and placental pathology will inform maternity care during the coronavirus pandemic.
32950981 Since the outbreak of coronavirus disease 2019 (COVID-19), there has been a debate whether pregnant women are at a specific risk for COVID-19 and whether it might be vertically transmittable through the placenta. […] We present a series of five placentas of SARS coronavirus 2 (SARS-CoV-2)-positive women who had been diagnosed with mild symptoms of COVID-19 or had been asymptomatic before birth. […] We provide a detailed histopathologic description of morphological changes accompanied by an analysis of presence of SARS-CoV-2 in the placental tissue. […] All placentas were term deliveries (40th and 41st gestational weeks). […] This placenta showed prominent lymphohistiocytic villitis and intervillositis and signs of maternal and foetal malperfusion. […] Viral RNA was present in both placenta tissue and the umbilical cord and could be visualized by in situ hybridization in the decidua. […] SARS-CoV-2 tests were negative at the time of delivery of 3/5 women, and their placentas did not show increased inflammatory infiltrates. […] There was no transplacental transmission to the infants. […] In acute COVID-19, prominent lymphohistiocytic villitis may occur and might potentially be attributable to SARS-CoV-2 infection of the placenta.
32965371 Few studies (3 out of 15) in our analysis have found positive results for SARS-CoV-2 in fetal membranes, placenta, and in newborns right after birth.
32969123 Biological plausibility for infection with SARS-CoV-2 exists in testis, ovaries, and placenta as they express ACE2 receptor activity. […] There is also evidence of significant placental pathology in SARS-CoV-2 infection, but it is unclear what effects there may be for early pregnancy, though available data suggest less severe effects compared to other respiratory virus outbreaks.
32974340 During pregnancy, the placental barrier protects the fetus from pathogens and ensures healthy development. […] To predict if the placenta is permissive to SARS-CoV-2, we utilized publicly available single-cell RNA-seq data to identify if the placental cells express the necessary factors required for infection. […] SARS-CoV-2 binding receptor ACE2 and the S protein priming protease TMPRSS2 are co-expressed by a subset of syncytiotrophoblasts (STB) in the first trimester and extravillous trophoblasts (EVT) in the second trimester human placenta. […] In addition, the non-canonical receptor BSG/CD147 and other proteases (CTSL, CTSB, and FURIN) are detected in most of the placental cells. […] Other coronavirus family receptors (ANPEP and DPP4) were also expressed in the first and second trimester placental cells. […] Additionally, the term placenta of multiple species including humans expressed ACE2, DPP4, and ANPEP along with the viral S protein proteases. […] The ACE2- and TMPRSS2-positive (ACE2 + TMPRSS2 +) placental subsets expressed mRNA for proteins involved in viral budding and replication. […] We carried out a systematic review and identified that in 12% of pregnant women with COVID-19, the placenta was infected with SARS-CoV-2, and the virus was detected in STBs. […] To conclude, herein we have uncovered the cellular targets for SARS-CoV-2 entry and have shown that these cells can potentially drive viremia in the developing human placenta.
33006691 COVID-19 increased the inflammatory responses of placenta, and fetuses and neonates had potential organ dysregulation and coagulation disorders. […] There was a potential intrauterine transmission while pregnant women had high titer of SARS-CoV-2, but it is necessary to detect SARS-CoV-2 in the blood cord, placenta, and amniotic fluid to further confirm intrauterine infection of fetuses.
33041350 Like other coronaviruses, CoV2 infection is anticipated to affect fetal development by maternal inflammatory response on the fetus and placenta.
33046695 Here, we analyse the viral genome on maternal and newborns nasopharyngeal swabs, vaginal swabs, maternal and umbilical cord plasma, placenta and umbilical cord biopsies, amniotic fluids and milk from 31 mothers with SARS-CoV-2 infection. […] In addition, we also test specific anti-SARS-CoV-2 antibodies and expression of genes involved in inflammatory responses in placentas, and in maternal and umbilical cord plasma. […] We detect SARS-CoV-2 genome in one umbilical cord blood and in two at-term placentas, in one vaginal mucosa and in one milk specimen.
33126048 We explored in silico, the potential interactions between SARS-CoV-2 proteins and proteins involved in the key functions of placenta. […] Genes crucial in placental functions thus identified were compared to the SARS-CoV-2 interactome for overlaps. […] The entry receptors for SARS-CoV-2 - ACE2 and TMPRSS2 are expressed in placenta. […] Other proteins that interact with SARS-CoV-2 like LOX, Fibulins-2 and 5, NUP98, GDF15, RBX1, CUL3, HMOX1, PLAT, MFGE8, and MRPs are vital in placental functions like trophoblast invasion and migration, syncytium formation, differentiation, and implantation. […] TLE3, expressed across first trimester placental tissues and cell lines, is involved in formation of placental vasculature, and is important in SARS-CoV (2003) budding and exit from the cells by COPI vesicles. […] SARS-CoV-2 can potentially interact with proteins having crucial roles in the placental function.
33183974 The angiotensin-converting enzyme 2 (ACE2), which acts as the SARS-CoV-2 receptor, is present in endothelial cells and has been noted within the human placenta. […] In this report, we highlight physiological and immune/inflammatory considerations that may explain the susceptibility and disease pathology in response to SARS CoV-2 during pregnancy, explore testing considerations in asymptomatic individuals, discuss the potential role and of placental ACE2 receptor in the pathogenesis of COVID-19 in pregnancy and in pregnancy outcomes, and finally share our perspective with respect to an urgently needed change concerning involvement of pregnant women in research addressing COVID-19.
33185524 We found chronic histiocytic intervillositis, maternal and fetal vascular malperfusion, microglial hyperplasia, and lymphocytic infiltrate in muscle in the placenta and fetal tissue. […] Placenta and umbilical cord blood tested positive for the virus by PCR, confirming transplacental transmission.
33203131 This communication summarizes the spectrum of pathology findings from pregnant women with COVID-19 based upon the infection status of their infants and addresses the potential interpretation of these results in terms of the effects of SARS-CoV-2 on the placenta and the pathophysiology of maternal-fetal infection. […] Placentas from pregnant women with COVID-19 and uninfected neonates show significant variability in the spectrum of pathology findings. […] In contrast, placentas from infected maternal-neonatal dyads are characterized by the finding of mononuclear cell inflammation of the intervillous space, termed chronic histiocytic intervillositis, together with syncytiotrophoblast necrosis. […] These placentas show prominent positivity of syncytiotrophoblast by SARS-CoV-2, fulfilling the published criteria for transplacental viral transmission as confirmed in fetal cells through identification of viral antigens by immunohistochemistry or viral nucleic acid using RNA in situ hybridization. […] The co-occurrence of chronic histiocytic intervillositis and trophoblast necrosis appears to be a risk factor for placental infection with SARS-CoV-2 as well as for maternal-fetal viral transmission, and suggests a potential mechanism by which the coronavirus can breach the maternal-fetal interface.
33209756 Concerning the vertical transmission, none of the positive mothers had a positive infant with COVID-19 except 1 case report that showed the infant had positive COVID-19 by the throat swab, yet negative cord blood, placenta, and mother’s breast milk.
33220455 SARS-CoV-2 was absent in breast milk, amniotic fluid, placenta or umbilical cord blood.
33228210 Microbiological analysis revealed absence of pathogenic bacteria whilst Real-time PCR identified the presence of RNA from Bovine Coronavirus (BCoV) in several organs: lungs, small intestine (jejunum), mediastinal lymph nodes, liver and placenta.
33233867 Samples from amniotic fluid, umbilical cord blood, placenta, cervical secretion, and breastmilk were collected and analyzed. […] A total of 15 placental swabs gave positive results for SARS-CoV-2 ribonucleic acid (RNA) on the fetal side of the placenta.
33237619 On the other hand, placenta-derived MSC express low levels of ACE2 but only in early passages of cultures.
33249229 Of them, the placental pathological characteristics of five participants were evaluated following the standard guidelines. […] For the neonate related biological samples, they all have negative results of RNA test, including nasopharyngeal swab, umbilical cord blood, amniotic fluid, vaginal fluid, placenta, or umbilical cord. […] Most of other pathological indicators of placental examination suggested no abnormal syndromes.
33249821 Placenta resulted negative for SARS-CoV-2; the umbilical cord blood sample was IgG positive and IgM negative as per maternal infection.
33258171 In this case, severe acute respiratory syndrome coronavirus 2 reverse transcription-polymerase chain reaction results were studied from samples obtained from the placenta, amniotic fluid, cord blood and postoperative breast milk - that were obtained while avoiding contamination and preserved appropriately - of a cesarean section performed under anesthesia on a woman with previous cesarean section and gestational diabetes mellitus history.
33321162 Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was demonstrated in the placenta; however, the data on the prevalence of placental infection and associated histopathology are limited. […] To identify the frequency and features of SARS-CoV-2 involvement, we performed a clinicopathologic analysis of 75 placental cases from women infected at the time of delivery and 75 uninfected controls. […] Placental samples were studied with anti-SARS-CoV-2 immunohistochemistry and/or in situ hybridization. […] Placental examination was normal in 12 of 75 infected and 3 of 75 uninfected subjects, respectively. […] In the remaining cases, placental pathology correlated with obstetric comorbidities without significant differences between SARS-CoV-2-positive and SARS-CoV-2-negative women. […] SARS-CoV-2 was identified in one placenta of an infected, but asymptomatic, parturient. […] SARS-CoV-2 is seldom identified in placentas of infected women. […] Placental involvement by the virus is characterized by STB damage disrupting the placental barrier and can be seen in asymptomatic mothers without evidence of vertical transmission.
33334687 Swabs from placenta, cord blood and vaginal secretion were negative.
33346816 Coronavirus disease 2019 (COVID-19) is caused by infection of the respiratory tract by SARS-CoV-2 which survives in the tissues during the clinical course of infection but there is limited evidence on placental infection and vertical transmission of SARS-CoV-2. […] Moreover, how long SARS-CoV-2 can survive in placenta is unknown. […] At 13 weeks of gestation, her throat swab tested negative for SARS-CoV-2 but viral RNA was detected in the placenta and the Spike (S) proteins (S1 and S2) were immunolocalized in cytotrophoblast and syncytiotrophoblast cells of the placental villi. […] The SARS-CoV-2 crossed the placental barrier, as the viral RNA was detected in the amniotic fluid and the S proteins were detected in the fetal membrane. […] This is the first study to provide concrete evidence of persistent placental infection of SARS-CoV-2 and its congenital transmission associated with hydrops fetalis and intrauterine fetal demise in early pregnancy.
33351086 Biological data are lacking with respect to risk of vertical transmission and mechanisms of fetoplacental protection in maternal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. […] To quantify SARS-CoV-2 viral load in maternal and neonatal biofluids, transplacental passage of anti-SARS-CoV-2 antibody, and incidence of fetoplacental infection. […] The main outcomes were SARS-CoV-2 viral load in maternal plasma or respiratory fluids and umbilical cord plasma, quantification of anti-SARS-CoV-2 antibodies in maternal and cord plasma, and presence of SARS-CoV-2 RNA in the placenta. […] Among 88 placentas tested, SARS-CoV-2 RNA was not detected in any. […] Nonoverlapping placental expression of SARS-CoV-2 receptors angiotensin-converting enzyme 2 and transmembrane serine protease 2 was noted. […] In this cohort study, there was no evidence of placental infection or definitive vertical transmission of SARS-CoV-2. […] Transplacental transfer of anti-SARS-CoV-2 antibodies was inefficient. […] Lack of viremia and reduced coexpression and colocalization of placental angiotensin-converting enzyme 2 and transmembrane serine protease 2 may serve as protective mechanisms against vertical transmission.
33367801 Multiple maternal, placental, and neonatal swabs were collected for the detection of SARS-CoV-2 using real-time quantitative polymerase chain reaction (RT-qPCR). […] Placental examination included immunohistochemical investigation against SARS-CoV-2 antigen expression, with SARS-CoV-2 ribonucleic acid (RNA) in situ hybridization and transmission electron microscopy. […] RT-qPCRs of the oropharynx, maternal blood, vagina, placenta, and urine were all positive over a period of 6 days, while breast milk, feces, and all neonatal samples tested negative. […] Placental findings showed the presence of SARS-CoV-2 particles with generalized inflammation characterized by histiocytic intervillositis with diffuse perivillous fibrin depositions with damage to the syncytiotrophoblasts. […] Placental infection by SARS-CoV-2 leads to fibrin depositions hampering fetal-maternal gas exchange with resulting fetal distress necessitating a premature emergency cesarean section.
33374593 The placenta is a temporary organ that is discarded after birth and is one of the most promising sources of various cells and tissues for use in regenerative medicine and tissue engineering, both in experimental and clinical settings. […] The placenta has unique, intrinsic features because it plays many roles during gestation: it is formed by cells from two individuals (mother and fetus), contributes to the development and growth of an allogeneic fetus, and has two independent and interacting circulatory systems.
33381779 RT-PCR of breast milk and maternal and neonatal samples taken at birth were negative; placenta and cord histology showed non-specific inflammation; and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific immunoglobulins were elevated in paired maternal and umbilical cord blood (n=5). […] Among the women who delivered, there was no definitive evidence of mother-to-child transmission via breast milk or placenta.
33384142 In this review, we examine key aspects of pregnancy that may be impacted by COVID-19 and summarize the current literature on SARS-CoV-2 infection of the placenta and in utero vertical transmission.
33387448 Low risk of vertical transmission is present, and SARS-CoV-2 can be detected in all conception products, particularly placenta and breast milk.
33393592 To characterize the placental pathology findings in a preselected cohort of neonates infected by transplacental transmission arising from maternal infection with SARS-CoV-2, and to identify pathology risk factors for placental and fetal infection. […] Case-based retrospective analysis by a multinational group of 19 perinatal specialists of the placental pathology findings from 2 cohorts of infants delivered to mothers testing positive for SARS-CoV-2 - liveborn neonates infected via transplacental transmission who tested positive for SARS-CoV-2 after delivery and had SARS-CoV-2 identified in cells of the placental fetal compartment by molecular pathology; and stillborn infants with syncytiotrophoblast positive for SARS-CoV-2. […] In placentas from all 6 liveborn neonates acquiring SARS-CoV-2 via transplacental transmission the syncytiotrophoblast was positive for coronavirus using immunohistochemistry, RNA in situ hybridization, or both. […] All 6 placentas had chronic histiocytic intervillositis and necrosis of the syncytiotrophoblast. […] The 5 stillborn/terminated infants had placental pathology findings that were similar including SARS-CoV-2 infection of the syncytiotrophoblast, chronic histiocytic intervillositis and syncytiotrophoblast necrosis. […] Their coexistence in all placentas from liveborn infants acquiring their infection prior to delivery indicates that that these findings constitute a pathology risk factor for transplacental fetal infection. […] Potential mechanisms of infection of the placenta and fetus with SARS-CoV-2, and potential future studies, are discussed.
33435547 Accumulating evidence supports that COVID-19 is not merely a respiratory illness per se, but potentially affects other organ systems including the placenta. […] The abundance of ACE-2 on the placental cell surface, especially the syncytiotrophoblasts, could potentially contribute to vertical transplacental transmission to the fetus following maternal COVID-19 infection. […] Intriguingly, despite the placentas being tested positive for SARS-CoV-2, there are very few newborns that manifest virus-induced diseases. […] The protective effects of the placental barrier to viral infection, limiting the spread of the virus to newborn infants, remain a mystery. […] In this review, we summarize the pathological features manifested in placenta due to COVID-19 maternal infection that have been previously reported, and relate them to the possible disease manifestation. […] The potential mechanistic pathways associated with transplacental viral transmission and adverse pregnancy outcomes are also discussed.
33441152 To explore the clinical characteristics and placental pathological changes of pregnant women with 2019 novel coronavirus (CoV) disease (COVID-19) in the third trimester, and to assess the possibility of vertical transmission. […] The placenta tissues were evaluated by using immunohistochemistry for inflammatory cells and Hofbauer cells, and using severe acute respiratory syndrome (SARS) CoV-2 RNA Fluorescence In-Situ Hybridization (FISH) and SARS-CoV-2 spike protein immunofluorescence (IF) double staining. […] All eight placentas from the third trimester pregnancy women were studied. […] No significate chronic histiocytic intervillositis was noted in the placenta. […] The number of macrophages and inflammatory cells such as T cells, B cells and plasma cells in the placental villous was not significantly increased in all cases. […] We found no evidence of vertical transmission and adverse maternal-fetal outcomes in the placentas of third trimester COVID-19 pregnancy women, which provided further information for the clinical management of those women in the third trimester.
33453449 The results of her nasopharyngeal swab for SARS-CoV-2, tested the same day, were negative, but the placenta was infected by SARS-CoV-2 and serology was positive 11 days later.
33462908 The pathological changes of COVID-19 on the placenta is evaluated by hematoxylin-eosin staining. […] There were two placentas found with acute chorioamnionitis, one showed normal placenta morphology.
33465727 We present a case of third trimester pregnancy complicated by SARS-CoV-2 infection and subsequent reduced fetal movements, resulting in emergency Caesarean delivery with demonstrable placental SARS-CoV-2 placentitis. […] We show through illustration of this case and literature review that SARS-Co-V-2 placentitis is an uncommon but readily recognisable complication of maternal SARS-CoV-2 infection that may be a marker of potential vertical transmission and that may have the capacity to cause fetal compromise through a direct injurious effect on the placenta.
33469663 Further investigation showed the presence of similar signalling events in the kidney, placenta, pancreas, testis, stomach, small intestine and adrenal gland suggesting the possible the mechanistic lineage of viral infection in other tissue.
33472696 The placental changes found in pregnant women have a definite impact on the foetus. […] Microscopic examination of the foetal appendages revealed thrombotic vasculopathy in the placenta and in the umbilical cord vessels.
33476549 Maternal infections have previously been associated with compromised placental antibody transfer, but the mechanism underlying this compromised transfer is not established. […] Here, we used systems serology to characterize the Fc profile of influenza-, pertussis-, and SARS-CoV-2-specific antibodies transferred across the placenta. […] SARS-CoV-2-specific transfer was linked to altered SARS-CoV-2-antibody glycosylation profiles and was partially rescued by infection-induced increases in IgG and increased FCGR3A placental expression.
33482757 The presence of SARS-CoV-2 has been demonstrated in biological samples during pregnancy (placenta, umbilical cord or amniotic fluid); however, maternal and fetal effects of the virus are not well known. […] Other samples (faeces, urine, serum, amniotic fluid, cord and peripheral blood, placenta and breastmilk) will be collected in order to analyse whether or not there is a risk of vertical transmission and to describe the behaviour of the virus in other fluids.
33497369 The effect of SARS-CoV-2 infection on the pathophysiology of the placenta and its impact on pregnancy outcome has not yet been fully elucidated. […] Here, we present a comprehensive clinical, morphological, and molecular analysis of placental tissues from pregnant women with and without SARS-CoV-2 infection. […] SARS-CoV-2 could be detected in half of placental tissues from SARS-CoV-2-positive women. […] SARS-CoV-2 tissue load was low in all but one patient which exhibited severe placental damage leading to neonatal neurological manifestations. […] The placental transcriptional response induced by high viral load of SARS-CoV-2 showed an immunopathology phenotype similar to autopsy lung tissues from patients with severe COVID-19. […] This finding contrasted with the lack of inflammatory response in placental tissues from SARS-CoV-2-positive women with low viral tissue load and from SARS-CoV-2-negative women. […] Importantly, no evidence of vertical transmission of SARS-CoV-2 was found in any newborns, suggesting that the placenta may be an effective maternal-neonatal barrier against the virus even in the presence of severe infection. […] Our observations suggest that severe placental damage induced by the virus may be detrimental for the neonate independently of vertical transmission.
33497931 Recent reports suggest SARS-CoV-2, the virus causing COVID-19, may be transmittable from pregnant mother to placenta and fetus, albeit rarely. […] The efficacy of vertical transmission of SARS-CoV-2 critically depends on the availability of its receptor, ACE2, in the placenta. […] In the present study, we tested the hypothesis that placental ACE2 expression is oxygenation-dependent by studying the expression of ACE2 and associated cell entry regulators in the monochorionic twin anemia-polycythemia (TAPS) placenta, a model of discordant placental oxygenation. […] We performed a retrospective comparative immunohistochemical, immunofluorescence and Western blot analysis of ACE2, TMPRSS2 and Cathepsin B expression in anemic and polycythemic territories of TAPS placentas (N = 14). […] Placental hypoxia is associated with upregulation of ACE2 expression, concomitant with increased expression of its key cell entry proteases. […] ACE2-regulated placental functions, both infection- and non-infection related, may be highly oxygenation-dependent.
33512440 Understanding the dynamics of maternal antibody responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy and subsequent transplacental antibody transfer can inform neonatal management as well as maternal vaccination strategies. […] Antibody concentrations and transplacental transfer ratios were analyzed in combination with demographic and clinical data. […] Placental transfer ratios more than 1.0 were observed among women with asymptomatic SARS-CoV-2 infections as well as those with mild, moderate, and severe coronavirus disease 2019. […] In this cohort study, maternal IgG antibodies to SARS-CoV-2 were transferred across the placenta after asymptomatic as well as symptomatic infection during pregnancy.
33514427 In this phase 1 clinical trial, we present the safety, feasibility, and tolerability of the multiple infusions of high dose MSCs, which originated from the placenta and umbilical cord, in critically ill COVID-19-induced ARDS patients. human umbilical cord MSCs (UC-MSCs; 6 cases) or placental MSCs (PL-MSCs; 5 cases).
33527073 This report presents a case of stillbirth with associated placental pathology during week 35 in an otherwise healthy pregnant woman with SARS-CoV-2 infection. […] Placental findings in this case showed patchy acute chorionitis and diffuse infarction/villous necrosis of the placental parenchyma resulting in extensive vascular malperfusion. […] Fetal autopsy was most significant for placental findings and no congenital malformations were discovered. […] The findings in this case are consistent with reports in the literature of pathological placental changes associated with COVID-19. […] This outcome was supported by the histopathological findings in the placenta.
33556768 The present study was done to find the histopathological alterations in the placenta of SARS-CoV-2 positive pregnancies with either no symptoms or mild coronavirus disease (COVID)-19 related symptoms and its association with neonatal outcomes. […] After delivery the histopathological examination of the placenta of these women was done and the findings recorded on a predesigned proforma based on the Amsterdam consensus criteria for evidence of maternal and fetal vascular malperfusion changes. […] The following features of maternal vascular malperfusion (MVM) were significantly higher in the placentae of COVID-19 positive pregnancies: retroplacental hematomas (RPH), accelerated villous maturation (AVM), distal villous hyperplasia (DVH), atherosis, fibrinoid necrosis, mural hypertrophy of membrane arterioles (MHMA), vessel ectasia and persistence of intramural endovascular trophoblast (PIEVT). […] Additionally, perivillous fibrin deposition was also significantly higher in the placentae of cases. […] Asymptomatic or mildly symptomatic SARS-CoV-2 positive pregnant women, with otherwise uncomplicated pregnancies, show evidence of placental injury at a microscopic level. […] This placental injury apparently does not lead to poor pregnancy outcomes.
33559937 ACE2 and TMPRSS2, which play a critical role in the entrance of SARS-COV-2 into the cell, are coexpressed in placental development stages, so the placenta also carries a risk for this virus. […] Many studies have shown that this virus causes some histopathological changes in the placenta. […] This article focuses on revealing the effects of the virus on the placenta in all aspects.