The placental pathology in Coronavirus disease 2019 infected mothers and its impact on pregnancy outcome

Severe Acute Respiratory Syndrome Coronavirus 2, the Human Placenta, and Adverse Perinatal Outcomes

The relationship among timing and severity of coronavirus disease 2019 (COVID-19) during pregnancy, placental pathology, and adverse pregnancy outcomes is not well understood. A prospective cohort study of 497 pregnant patients with COVID-19 whose placentas underwent systematic pathologic examination was conducted. The main exposure was timing of COVID-19 during pregnancy (first/second versus third trimester). The primary outcome was composite placental pathology that included high-grade maternal vascular malperfusion or >25% perivillous fibrin deposition. There were 63 patients who had the composite placental pathology outcome. In adjusted analyses that controlled for maternal age, parity, active infection at delivery, interval from time of diagnosis to delivery, and COVID-19 variant, timing of COVID-19 during pregnancy was not associated with risk of the composite placental pathology outcome. Among secondary COVID-19-related exposures that were investigated, severity of disease and treatment for COVID-19 were associated with risk of the composite placental pathology outcome. In addition, patients with COVID-19 in the first 9 months of the pandemic had the highest rate of the composite placental pathology outcome. In this large cohort, placental vascular pathology was common among COVID-19 cases but was unrelated to timing of COVID-19 during pregnancy or adverse pregnancy outcomes. These findings suggest that uncomplicated COVID-19 during pregnancy does not require intensive fetal surveillance or detailed pathologic examination of the placenta after delivery.

Long COVID clinical evaluation, research and impact on society: a global expert consensus

BACKGROUND

Long COVID is a complex, heterogeneous syndrome affecting over four hundred million people globally. There are few recommendations, and no formal training exists for medical professionals to assist with clinical evaluation and management of patients with Long COVID. More research into the pathology, cellular, and molecular mechanisms of Long COVID, and treatments is needed. The goal of this work is to disseminate essential information about Long COVID and recommendations about definition, diagnosis, treatment, research and social issues to physicians, researchers, and policy makers to address this escalating global health crisis.

METHODS

A 3-round modified Delphi consensus methodology was distributed internationally to 179 healthcare professionals, researchers, and persons with lived experience of Long COVID in 28 countries. Statements were combined into specific areas: definition, diagnosis, treatment, research, and society.

RESULTS

The survey resulted in 187 comprehensive statements reaching consensus with the strongest areas being diagnosis and clinical assessment, and general research. We establish conditions for diagnosis of different subgroups within the Long COVID umbrella. Clear consensus was reached that the impacts of COVID-19 infection on children should be a research priority, and additionally on the need to determine the effects of Long COVID on societies and economies. The consensus on COVID and Long COVID is that it affects the nervous system and other organs and is not likely to be observed with initial symptoms. We note, biomarkers are critically needed to address these issues.

CONCLUSIONS

This work forms initial guidance to address the spectrum of Long COVID as a disease and reinforces the need for translational research and large-scale treatment trials for treatment protocols.

Extracellular Vesicles Alter Trophoblast Function in Pregnancies Complicated by COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and resulting coronavirus disease (COVID-19) cause placental dysfunction, which increases the risk of adverse pregnancy outcomes. While abnormal placental pathology resulting from COVID-19 is common, direct infection of the placenta is rare. This suggests that pathophysiology associated with maternal COVID-19, rather than direct placental infection, is responsible for placental dysfunction. We hypothesized that maternal circulating extracellular vesicles (EVs), altered by COVID-19 during pregnancy, contribute to placental dysfunction. To examine this hypothesis, we characterized circulating EVs from pregnancies complicated by COVID-19 and tested their effects on trophoblast cell physiology in vitro. Trophoblast exposure to EVs isolated from patients with an active infection (AI), but not controls, altered key trophoblast functions including hormone production and invasion. Thus, circulating EVs from participants with an AI, both symptomatic and asymptomatic cases, can disrupt vital trophoblast functions. EV cargo differed between participants with COVID-19, depending on the gestational timing of infection, and Controls, which may contribute to the disruption of the placental transcriptome and morphology. Our findings show that COVID-19 can have effects throughout pregnancy on circulating EVs, and circulating EVs are likely to participate in placental dysfunction induced by COVID-19.

Review of organ damage from COVID and Long COVID: a disease with a spectrum of pathology

Long COVID, as currently defined by the World Health Organization (WHO) and other authorities, is a symptomatic condition that has been shown to affect an estimated 10 %-30 % of non-hospitalized patients after one infection. However, COVID-19 can also cause organ damage in individuals without symptoms, who would not fall under the current definition of Long COVID. This organ damage, whether symptomatic or not, can lead to various health impacts such as heart attacks and strokes. Given these observations, it is necessary to either expand the definition of Long COVID to include organ damage or recognize COVID-19-induced organ damage as a distinct condition affecting many symptomatic and asymptomatic individuals after COVID-19 infections. It is important to consider that many known adverse health outcomes, including heart conditions and cancers, can be asymptomatic until harm thresholds are reached. Many more medical conditions can be identified by testing than those that are recognized through reported symptoms. It is therefore important to similarly recognize that while Long COVID symptoms are associated with organ damage, there are many individuals that have organ damage without displaying recognized symptoms and to include this harm in the characterization of COVID-19 and in the monitoring of individuals after COVID-19 infections.

Placental lesions in stillbirth following the Amsterdam consensus: A systematic review and meta-analysis

Placental disorders remain one of the main causes of stillbirth. However, the lack of standardised nomenclature has significantly limited the clinical utility of placental histology. Following the Amsterdam consensus classification, which now allows proper comparisons of placenta histology across the world, we conducted the first systematic review and meta-analysis (Prospero CRD42023410469) to assess the commonest stillbirth-associated placental lesions worldwide. Eighteen studies with 3082 placentas were included. Maternal vascular malperfusion and fetal vascular malperfusion were the most prevalent placental lesions in stillbirth, and significantly more frequent in stillbirths than livebirths [OR 3.0 (95 % CI 2.0-4.5), p < 0.001 and OR 5.12 (95 % CI 3.09-8.47), p < 0.001, respectively]. However, when adjusting for gestational age, only maternal vascular malperfusion remained significant at term. Better understanding of the pathophysiology underlying placental lesions is needed to inform timely risk assessment and therapeutic interventions capable of reducing placental-related stillbirths.

Evaluation of the effect of SARS-CoV-2 infection on Doppler ultrasound and placental findings of pregnant women: a systematic review and meta-analysis

PURPOSE

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can infect the human placenta and has been shown to have an adverse effect on Doppler ultrasound parameters and placental features. However, the specific effects of the SAS-CoV-2 infection on the fetal-placental unit in pregnant women remain unclear. The aim of this systematic review and meta-analysis was to evaluate the impact of SARS-CoV-2 infection on Doppler ultrasound and placental findings in pregnant women.

METHODS

A systematic search was conducted using four electronic databases (PubMed, Embase, Scopus, and Cochrane Library) to select publications published in peer-reviewed journals written in English. Odds ratios (ORs) were calculated, along with their 95% confidence intervals (CIs). Heterogeneity was assessed using Cochrane Q and I2 statistics and the appropriate P-value. The analysis used RevMan 5.3.

RESULTS

This meta-analysis included 1,210 pregnant women from 10 case-control studies. SARS-CoV-2-infected pregnant women exhibited higher likelihoods of placental abnormalities (OR, 2.62; 95% CI, 1.66 to 4.13), aberrant Doppler values (OR, 1.95; 95% CI, 1.16 to 3.27), an abnormal cerebroplacental ratio (OR, 2.68; 95% CI, 1.52 to 4.75), altered fetoplacental circulation (OR, 1.56; 95% CI, 1.07 to 2.28), and increased placental thickness and placental venous lakes (OR, 1.85; 95% CI, 1.25 to 2.72).

CONCLUSION

According to this meta-analysis, pregnant women infected with SARS-CoV-2 are more likely to experience altered Doppler ultrasonography parameters and placental abnormalities, including increased placental thickness, placental venous lakes, altered fetoplacental circulation, and cerebroplacental ratio. However, the limited number of case-control studies requires larger sample sizes to validate and enhance the evidence.

Vitamin D Receptor-Interplay in COVID-19-Negative, -Infected, and -Vaccinated Women during Pregnancy

Background: The trophoblast is a significant source of vitamin D synthesis during pregnancy, with the literature suggesting its role in fetal growth. We aim to underline a possible mechanism that would explain negative fetal outcomes in COVID-19-positive mothers by examining the relationship between altered placental structure and function and throphoblast cells' vitamin D receptor levels. Methods: The study included 170 placental samples collected from women who gave birth at term without complications, divided into three groups: COVID-19-positive and unvaccinated, COVID-19-negative and vaccinated, and COVID-19-negative and unvaccinated, with exclusion criteria for any other medical complications. Immunohistochemistry (IHC) was performed to detect vitamin D receptor (VDR) expression, and immediate fetal outcomes (weight and Apgar score) were assessed. Results: We found lower gestational age at birth, lower birth weight, and reduced placental VDR (vitamin D receptor) levels in COVID-19-positive women compared to COVID-19-vaccinated and COVID-19-negative women. Conclusions: The presence of the vitamin D receptor in the placenta is related to fetal and placental growth. Its deficiency may contribute to negative fetal outcomes in COVID-19-positive cases.

Association between maternal and perinatal outcomes and histological changes in the placenta of patients with Covid-19: A cohort study

Although studies evaluated placental involvement in Covid-19 patients, few have assessed its association with clinical repercussions. The study aimed to determine the association between the clinical status and maternal and perinatal outcomes of patients with Covid-19 at delivery and changes in placental histology. It is so far the largest cohort evaluating placentas of patients infected by the SARS-CoV-2. A secondary analysis was conducted of a database from which a cohort of 226 patients, who tested real-time polymerase chain reaction-positive for Covid-19 at delivery and whose placentas were collected and submitted to pathology, was selected for inclusion. One or more types of histological changes were detected in 44.7% of the 226 placentas evaluated. The most common abnormalities were maternal vascular malperfusion (38%), evidence of inflammation/infection (9.3%), fetal vascular malperfusion (0.8%), fibrinoid changes and intervillous thrombi (0.4%). Oxygen use (P = .01) and need for admission to an intensive care unit (ICU) (P = .04) were less common in patients with placental findings, and hospital stay was shorter in these patients (P = .04). There were more fetal deaths among patients with evidence of inflammation/infection (P = .02). Fetal death, albeit uncommon, is associated with findings of inflammation/infection. Oxygen use and need for admission to an ICU were less common among patients with placental findings, probably due to the pregnancy being interrupted early. None of the other findings was associated with maternal clinical status or with adverse perinatal outcome.

Extracellular vesicles alter trophoblast function in pregnancies complicated by COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and resulting coronavirus disease (COVID-19) causes placental dysfunction, which increases the risk of adverse pregnancy outcomes. While abnormal placental pathology resulting from COVID-19 is common, direct infection of the placenta is rare. This suggests that pathophysiology associated with maternal COVID-19, rather than direct placental infection, is responsible for placental dysfunction and alteration of the placental transcriptome. We hypothesized that maternal circulating extracellular vesicles (EVs), altered by COVID-19 during pregnancy, contribute to placental dysfunction. To examine this hypothesis, we characterized maternal circulating EVs from pregnancies complicated by COVID-19 and tested their effects on trophoblast cell physiology in vitro . We found that the gestational timing of COVID-19 is a major determinant of circulating EV function and cargo. In vitro trophoblast exposure to EVs isolated from patients with an active infection at the time of delivery, but not EVs isolated from Controls, altered key trophoblast functions including hormone production and invasion. Thus, circulating EVs from participants with an active infection, both symptomatic and asymptomatic cases, can disrupt vital trophoblast functions. EV cargo differed between participants with COVID-19 and Controls, which may contribute to the disruption of the placental transcriptome and morphology. Our findings show that COVID-19 can have effects throughout pregnancy on circulating EVs and circulating EVs are likely to participate in placental dysfunction induced by COVID-19.

COVID-19 Vaccination and Reproductive Health: a Comprehensive Review for Healthcare Providers

With all the current misinformation on social media platforms about the COVID-19 vaccine and its potential effects on fertility, it is essential for healthcare providers to have evidenced-based research to educate their patients, especially those who are trying to conceive, of the risks to mothers and fetuses of being unvaccinated. It is well known that COVID-19 infection puts pregnant women at higher risk of complications, including ICU admission, placentitis, stillbirth, and death. In February of 2021, the American College of Obstetricians and Gynecologists (ACOG), the American Society for Reproductive Medicine (ASRM), and the Society for Maternal-Fetal Medicine (SMFM) released a statement denying any link between COVID vaccination and infertility. ASRM later confirmed and stated that "everyone, including pregnant women and those seeking to become pregnant, should get a COVID-19 vaccine". In this review, we aim to provide a compilation of data that denies any link between vaccination and infertility for healthcare providers to be able to educate their patients based on evidence-based medicine. We also reviewed the effect of COVID-19 virus and vaccination on various parameters and processes that are essential to obtaining a successful pregnancy.

Evidence of Placental Villous Inflammation and Apoptosis in Third-Trimester Symptomatic SARS-CoV-2 Maternal Infection

PURPOSE

In view of conflicting reports on the ability of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) to infect placental tissue, this study aimed to further evaluate the impact of inflammation and placental damage from symptomatic third-trimester maternal COVID-19 infection.

MATERIALS AND METHODS

This case-control study included 32 placenta samples each from symptomatic COVID-19 pregnancy and normal non-COVID-19 pregnancy. The villous placental area's inflammatory expression [angiotensin converting enzyme-2 (ACE-2), transmembrane protease serine-2 (TMPRSS2), interferon-γ (IFN-γ), interleukin-6 (IL-6), and SARS-CoV-2 spike protein] and apoptotic rate were examined using immunohistochemistry and Terminal deoxynucleotidyl transferase dUTP Nick-End Labeling (TUNEL) assay. Comparison and correlation analysis were used based on COVID-19 infection, placental SARS-CoV-2 spike protein evidence, and maternal severity status.

RESULTS

Higher expressions of TMPRSS2, IFN-γ, and trophoblast apoptotic rate were observed in the COVID-19 group (p<0.001), whereas ACE-2 and IL-6 expressions were not significantly different from the control group (p>0.05). Additionally, SARS-CoV-2 spike protein was detected in 8 (25%) placental samples of COVID-19 pregnancy. COVID-19 subgroup analysis revealed increased IFN-γ, trophoblast, and stromal apoptosis (p<0.01). Moreover, the results of the current study revealed no correlation between maternal COVID-19 severity and placental inflammation as well as the apoptotic process.

CONCLUSION

The presence of SARS-CoV-2 spike protein as well as altered inflammatory and apoptotic processes may indicate the presence of placental disturbance in third-trimester maternal COVID-19 infection. The lack of correlation between placental disruption and maternal severity status suggests the need for more research to understand the infection process and any potential long-term impacts on all offsprings born to COVID-19-infected pregnant women.

COVID-19 in pregnant women: a systematic review and meta-analysis on the risk and prevalence of pregnancy loss

BACKGROUND

Pregnant women infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are more likely to experience preterm birth and their neonates are more likely to be stillborn or admitted to a neonatal unit. The World Health Organization declared in May 2023 an end to the coronavirus disease 2019 (COVID-19) pandemic as a global health emergency. However, pregnant women are still becoming infected with SARS-CoV-2 and there is limited information available regarding the effect of SARS-CoV-2 infection in early pregnancy on pregnancy outcomes.

OBJECTIVE AND RATIONALE

We conducted this systematic review to determine the prevalence of early pregnancy loss in women with SARS-Cov-2 infection and compare the risk to pregnant women without SARS-CoV-2 infection.

SEARCH METHODS

Our systematic review is based on a prospectively registered protocol. The search of PregCov19 consortium was supplemented with an extra electronic search specifically on pregnancy loss in pregnant women infected with SARS-CoV-2 up to 10 March 2023 in PubMed, Google Scholar, and LitCovid. We included retrospective and prospective studies of pregnant women with SARS-CoV-2 infection, provided that they contained information on pregnancy losses in the first and/or second trimester. Primary outcome was miscarriage defined as a pregnancy loss before 20 weeks of gestation, however, studies that reported loss up to 22 or 24 weeks were also included. Additionally, we report on studies that defined the pregnancy loss to occur at the first and/or second trimester of pregnancy without specifying gestational age, and for second trimester miscarriage only when the study presented stillbirths and/or foetal losses separately from miscarriages. Data were stratified into first and second trimester. Secondary outcomes were ectopic pregnancy (any extra-uterine pregnancy), and termination of pregnancy. At least three researchers independently extracted the data and assessed study quality. We calculated odds ratios (OR) and risk differences (RDs) with corresponding 95% CI and pooled the data using random effects meta-analysis. To estimate risk prevalence, we performed meta-analysis on proportions. Heterogeneity was assessed by I2.

OUTCOMES

We included 120 studies comprising a total of 168 444 pregnant women with SARS-CoV-2 infection; of which 18 233 women were in their first or second trimester of pregnancy. Evidence level was considered to be of low to moderate certainty, mostly owing to selection bias. We did not find evidence of an association between SARS-CoV-2 infection and miscarriage (OR 1.10, 95% CI 0.81-1.48; I2 = 0.0%; RD 0.0012, 95% CI -0.0103 to 0.0127; I2 = 0%; 9 studies, 4439 women). Miscarriage occurred in 9.9% (95% CI 6.2-14.0%; I2 = 68%; 46 studies, 1797 women) of the women with SARS CoV-2 infection in their first trimester and in 1.2% (95% CI 0.3-2.4%; I2 = 34%; 33 studies; 3159 women) in the second trimester. The proportion of ectopic pregnancies in women with SARS-CoV-2 infection was 1.4% (95% CI 0.02-4.2%; I2 = 66%; 14 studies, 950 women). Termination of pregnancy occurred in 0.6% of the women (95% CI 0.01-1.6%; I2 = 79%; 39 studies; 1166 women).

WIDER IMPLICATIONS

Our study found no indication that SARS-CoV-2 infection in the first or second trimester increases the risk of miscarriages. To provide better risk estimates, well-designed studies are needed that include pregnant women with and without SARS-CoV-2 infection at conception and early pregnancy and consider the association of clinical manifestation and severity of SARS-CoV-2 infection with pregnancy loss, as well as potential confounding factors such as previous pregnancy loss. For clinical practice, pregnant women should still be advised to take precautions to avoid risk of SARS-CoV-2 exposure and receive SARS-CoV-2 vaccination.

COVID-19 in the Netherlands: lessons from a nationwide query of dutch autopsy, histology, and cytology pathological reports

Since the onset of the COVID-19 pandemic, autopsies have played a valuable role in understanding the pathophysiology of COVID-19. In this study, we have analyzed COVID-19-related pathology reports from autopsies, histology, and cytology on a nationwide level. Pathology reports from all 43 pathology laboratories in the Netherlands stating "COVID," "Corona," and/or "SARS" were queried from the Dutch Nationwide Pathology Database (Palga). Consecutive reports of the included patients were also retrieved. Out of 5065 entries, a total of 1833 eligible COVID-19-related pathology reports between January 2020 and June 2021 were included in this collection of reports. Lung histopathology reports reflected differences in the severity of abnormalities (acute diffuse alveolar damage, alveolar histiocytes, and thrombi during the first three pandemic waves (Wuhan variant) versus the fourth wave (alpha variant)). Autopsy reports from 2020 state significantly shorter disease duration and younger age of death compared to autopsy reports from 2021. All reports together reflected a more granular pathology with comorbidities such as chronic histiocytic intervillositis, perniosis, and thrombi found in a variety of organs (lungs, kidneys, and small and large intestines). This nationwide overview of pathology reports provides data related to deaths as well as comorbidities in a clinical setting of COVID-19. Certain findings reported in SARS-CoV-infected lungs and placentas were also reported in post-COVID-19 tissue of the same kind. Consecutive reports after the earliest reports with COVID-19 allowed for follow-up reports. These follow-up reports can help with post-viral studies regarding long-term effects of COVID-19 as well as identifying the effects of different SARS-CoV-2 variants.

An Update on COVID-19-Associated Placental Pathologies

COVID-19 pregnancies are associated with increased rates of premature delivery and stillbirths. It is still a matter of debate whether there is a COVID-19-associated pattern of placenta pathology. We updated our previously published results on a systematic literature review and meta-analysis of COVID-19 pregnancies. In total, 38 reports on 3677 placentas were evaluated regarding histopathological changes. Maternal vascular malperfusion (32%), fetal vascular malperfusion (19%), acute and chronic inflammation (20% and 22%) were frequent pathologies. In non-COVID-19 pregnancies, placentas show similar histologic patterns and mainly similar frequencies of manifestation. It has to be taken into account that there might be an observation bias, because some findings are diagnosed as a "pathology" that might have been classified as minor or unspecific findings in non-COVID-19 placentas. COVID-19 placentitis occurs in 1-2% of cases at the most. In conclusion, this updated meta-analysis indicates that COVID-19 infection during pregnancy does not result in an increased rate of a specific placenta pathology and COVID-19 placentitis is rare.

SARS-CoV-2 infection during pregnancy and perinatal outcomes in Estonia in 2020 and 2021: A register-based study

INTRODUCTION

Data from different countries show partly controversial impact of SARS-CoV-2 infection on pregnancy outcomes. A nationwide register-based study was conducted in Estonia to assess the impact of SARS-CoV-2 infection at any time during pregnancy on stillbirth, perinatal mortality, Apgar score at 5 minutes, cesarean section rates, rates of preterm birth and preeclampsia.

MATERIAL AND METHODS

Data on all newborns and their mothers were obtained from the Estonian Medical Birth Registry, and data on SARS-CoV-2 testing dates, test results and vaccination dates against SARS-CoV-2 from the Estonian Health Information System. Altogether, 26 211 births in 2020 and 2021 in Estonia were included. All analyses were performed per newborn. Odds ratios with 95% confidence intervals (CI) were analyzed for all outcomes, adjusted for mother's place of residence, body mass index, age of mother at delivery and hypertension and for all the aforementioned variables together with mother's vaccination status using data from 2021 when vaccinations against SARS-CoV-2 became available. For studying the effect of a positive SARS-CoV-2 test during pregnancy on preeclampsia, hypertension was omitted from the models to avoid overadjustment.

RESULTS

SARS-CoV-2 infection during pregnancy was associated with an increased risk of stillbirth (adjusted odds ratio [aOR] 2.81; 95% CI 1.37-5.74) and perinatal mortality (aOR 2.34; 95% CI 1.20-4.56) but not with a lower Apgar score at 5 minutes, higher risk of cesarean section, preeclampsia or preterm birth. Vaccination slightly decreased the impact of SARS-CoV-2 infection during pregnancy on perinatal mortality.

CONCLUSIONS

A positive SARS-CoV-2 test during pregnancy was associated with higher rates of stillbirth and perinatal mortality in Estonia but was not associated with change in preeclampsia, cesarean section or preterm birth rates.

Placental pathology in a large (Swedish) cohort of SARS-CoV-2 infected mothers

INTRODUCTION

SARS-CoV-2 placentitis is associated with placental destruction and insufficiency and can affect perinatal outcome. The aim of the current study was to contribute with increased knowledge regarding placental histology in maternal SARS-CoV-2 infection during the pregnancy, as well as the correlation to the severity of maternal SARS-CoV-2 infection.

MATERIAL AND METHODS

This retrospective observational study included 116 women who had a verified SARS-CoV-2 infection during pregnancy and gave birth between April 2020 and February 2022 in the Stockholm region, Sweden. Placental tissue was evaluated regarding several histopathological parameters, amongst them detection of the triad of characteristics of placental SARS-CoV-2 infection: chronic histiocytic intervillositis, fibrin deposition and villous trophoblast necrosis, and immunohistochemistry for ORF-3 protein expression was used for confirmation. Medical records were reviewed for maternal characteristics and neonatal outcome.

RESULTS

SARS-CoV-2 placentitis was present in one-fifth of the examined placentas admitted to the institute due to maternal SARS-CoV-2 infection, out of which 86,4 % were delivered by acute caesarian section (ACS), all on fetal indication, and one pregnancy ended in stillbirth. Half of the cases without placentitis were delivered by ACS, out of which 50 % were on fetal indication. There was a clear tendency of a shorter time gap between confirmed maternal SARS-CoV-2 infection and delivery in the placentitis group.

DISCUSSION

The presence of SARS-CoV-2 placentitis does not seem to correlate with maternal factors or the severity of infection. It does correlate with development of placental dysfunction of acute/subacute onset and is often manifested as reduced fetal movements.

Hypoxia modifies levels of the SARS-CoV-2 cell entry proteins, angiotensin-converting enzyme 2, and furin in fetal human brain endothelial cells

BACKGROUND

It is not known whether human fetal brain endothelial cells that form the blood-brain barrier express angiotensin-converting enzyme 2, transmembrane serine protease 2, and furin, which are SARS-CoV-2 cell entry proteins. Moreover, it is unclear whether hypoxia, commonly observed during severe maternal COVID-19, can modify their level of expression. We hypothesized that human fetal brain endothelial cells isolated from early- and midpregnancy brain microvessels express angiotensin-converting enzyme 2, transmembrane serine protease 2, and furin. Furthermore, we hypothesized that hypoxia modifies their expression levels in a gestational age- and time-of-exposure-dependent manner.

OBJECTIVE

This study aimed to investigate whether early- and midpregnancy human fetal brain endothelial cells express angiotensin-converting enzyme 2, transmembrane serine protease 2, and furin SARS-CoV-2-associated cell entry proteins and to determine the effects of hypoxia on angiotensin-converting enzyme 2, transmembrane serine protease 2, and furin expression levels in human fetal brain endothelial cells.

STUDY DESIGN

This was a prospective study where human fetal brain endothelial cells isolated from early-pregnancy (12.4±0.7 weeks of gestation) and midpregnancy (17.9±0.5 weeks of gestation) fetal brain microvessels (6 per group) were exposed to different oxygen tensions (20%, 5%, and 1% oxygen) for 6, 24, and 48 hours. Angiotensin-converting enzyme 2, transmembrane serine protease 2, and furin messenger RNA and protein levels and localization were assessed using quantitative polymerase chain reaction, Western blot testing, and immunofluorescence.

RESULTS

Angiotensin-converting enzyme 2, transmembrane serine protease 2, and furin co-localize with the endothelial cell marker von Willebrand factor in human fetal brain endothelial cells isolated from early pregnancy and midpregnancy. In early pregnancy, TMPRSS2 messenger RNA expression was decreased by 5% oxygen compared with 20% oxygen after 6 hours of exposure (P<.05). In midpregnancy, 5% oxygen down-regulated ACE2 messenger RNA compared with 20% oxygen after 24 hours (P<.05). Furin messenger RNA expression was decreased under 5% and 1% oxygen compared with 20% oxygen (P<.05) after 24 hours. In midpregnancy, angiotensin-converting enzyme 2 protein levels were decreased under 5% and 1% oxygen (P<.001) after 24 hours. In contrast, furin protein levels were increased under 1% oxygen compared with 20% oxygen after 24 hours (P<.05). At 48 hours, 1% oxygen increased angiotensin-converting enzyme 2 protein levels compared with 20% oxygen (P<.01).

CONCLUSION

Hypoxia modifies the expression of selected SARS-CoV-2 cell entry proteins in human fetal brain endothelial cells in a gestational age- and time-of-exposure-dependent manner. As severe COVID-19 may lead to maternal hypoxia, an altered expression of these proteins in the developing human blood-brain barrier could potentially lead to altered SARS-CoV-2 brain invasion and neurologic sequelae in neonates born to pregnancies complicated by SARS-CoV-2 infection.

SARS-CoV-2 Infection in Unvaccinated High-Risk Pregnant Women in the Bronx, NY, USA Is Associated with Decreased Apgar Scores and Placental Villous Infarcts

Babies born to severe acute respiratory syndrome corona virus-2 (SARS-CoV-2)-infected mothers are at greater risk for perinatal morbidity and more likely to receive a neurodevelopmental diagnosis in the first year of life. However, the effect of maternal infection on placental function and neonatal outcomes varies depending upon the patient population. We set out to test our hypothesis that maternal SARS-CoV-2 infection in our underserved, socioeconomically disadvantaged, mostly unvaccinated, predominantly African American and Latina population in the Bronx, NY would have effects evident at birth. Under IRB approval, 56 SARS-CoV-2-positive patients infected during the "first wave" of the pandemic with alpha and beta strains of the virus, 48 patients infected during the "second wave" of the pandemic with delta and omicron strains and 61 negative third-trimester high-risk patients were randomly selected from Montefiore Medical Center (MMC), Bronx, NY. In addition, two positive cases from Yale New Haven Hospital, CT were included as controls. All 104 placentas delivered by SARS-CoV-2-positive mothers were uninfected by the virus, based on immunohistochemistry, in situ hybridization, and qPCR analysis. However, placental villous infarcts were significantly increased in first-wave cases compared to second-wave cases or negative controls. Significantly lower Apgar scores at 1 min and 5 min were observed in neonates born to infected mothers with severe symptoms. These findings suggest that even without entering the placenta, SARS-CoV-2 can affect various systemic pathways, culminating in altered placental development and function, which may adversely affect the fetus, especially in a high-risk patient population such as ours. These results underline the importance of vaccination among pregnant women, particularly in low-resource areas.

A spectrum of pathological changes induced by SARS-COV-2: An observational study in a cohort of pregnant women from Mizoram, India

Background

Maternal infection by SARS-CoV-2 may lead to adverse pregnancy outcomes and causes pathological changes in the placenta. However, consensus regarding characteristic pathological features is lacking. Researchof the placental histopathology in a cohort of women from Mizoram, India, was conducted to relate the SARS-CoV-2 infection's effectswith pregnancy and its outcome.

Materials and methods

The characteristics of 72 pregnant women diagnosed positive for SARS-CoV-2 who eventually delivered at Zoram Medical College Hospital, Mizoram, neonates' well-being, and histopathological features of placentas were studied.

Results

Of 72 women in this study, 59 (81.9%) gave birth at full term. Among these births, 5 were normal vaginal deliveries, while the remaining 67 (93.1%) were delivered via cesarean section. The reasons for cesarean delivery were either related to SARS-CoV-2 infection (n ​= ​49), existing obstetric problems (n ​= ​15) or fetal-distress (n ​= ​5). All deliveries resulted in live births of COVID-negative babies, with 80.6% (n ​= ​58) of the newborns having a birth weight of over 2.5 ​kg. APGAR scores ranged from 4 to 6 in 61 (84.7%) of the babies, and 10 neonates required resuscitation, of which 8 were managed in the neonatal intensive care unit (NICU). The placental histopathology showed increased fibrin thrombi in 8 cases (11.1%), while 20 cases (28%) showed focal infarction, microcalcification levels were elevated in 16 cases (22.2%), and a small percentage of cases (1.4%) exhibited small fibrotic villi and inter-villus agglutination. Placental chorioangiosis was detected in 28 (38.9%) of the cases, while avascular villi were seen in 6 cases. Meconium-stained liquor was observed in a single case. Intervillous hemorrhage was found in 42 cases, whileintervillous inflammation and increased syncytial knots were present in 14 and 5 cases, respectively. The placenta pathology of 10 neonates who required resuscitation/NICU admission was not significantly different from that of the 62 neonates who did not require it. However, a higher proportion of placenta from the asymptomatic group showed no abnormality compared to the symptomatic group (p ​= ​0.046).

Conclusion

SARS-CoV-2 infection causes a range of morphological changes and lesions in the placenta, including chorangiosis, villositis, chorioamnionitis, fetal vascular malperfusion/thrombosis, fibrin-deposition, increased syncytial-knotting, increased microcalcification, increased villous agglutination, focal infarct, intervilloushemorrhage as well as inflammation. Placental histopathological findings from this study can provide additional information to the existing literature on the subject.

Congenital SARS-CoV-2 Infection in Two Neonates with Confirmation by Viral Culture of the Placenta in One Case

Congenital infections with SARS-CoV-2 are uncommon. We describe two confirmed congenital SARS-CoV-2 infections using descriptive, epidemiologic and standard laboratory methods and in one case, viral culture. Clinical data were obtained from health records. Nasopharyngeal (NP) specimens, cord blood and placentas when available were tested by reverse transcriptase real-time PCR (RT-PCR). Electron microscopy and histopathological examination with immunostaining for SARS-CoV-2 was conducted on the placentas. For Case 1, placenta, umbilical cord, and cord blood were cultured for SARS-CoV-2 on Vero cells. This neonate was born at 30 weeks, 2 days gestation by vaginal delivery. RT-PCR tests were positive for SARS-CoV-2 from NP swabs and cord blood; NP swab from the mother and placental tissue were positive for SARS-CoV-2. Placental tissue yielded viral plaques with typical morphology for SARS-CoV-2 at 2.8 × 10² pfu/mL confirmed by anti-spike protein immunostaining. Placental examination revealed chronic histiocytic intervillositis with trophoblast necrosis and perivillous fibrin deposition in a subchorionic distribution. Case 2 was born at 36 weeks, 4 days gestation. RT-PCR tests from the mother and infant were all positive for SARS-CoV-2, but placental pathology was normal. Case 1 may be the first described congenital case with SARS-CoV-2 cultivated directly from placental tissue.

Fetal brain biometry and cortical development after maternal SARS-CoV-2 infection in pregnancy: A prospective case-control study

OBJECTIVES

To assess cerebral growth and the development of fetal cortex using neurosonography in fetuses from pregnancies experiencing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) according to infection timing.

METHODS

Pregnancies with by SARS-CoV-2 during first and second trimesters were prospectively studied and matched with unaffected controls. Enclosed women underwent neurosonography at 30-34 weeks of gestation and corpus callosum (CC) and cerebellar vermis (CV) lengths measured. Further Sylvian fissure (SF), insula. Parieto-occipital fissure (POF), and calcarine sulci fissures (CSF) depths were obtained. The ultrasonographic variables considered were normalized with fetal head size.

RESULTS

One hundred and seventy four consecutive pregnancies experiencing SARS COV 2 infection (81 before 14 weeks and 93 later) and 131 not affected pregnancies were considered. General and pregnancy characteristics were similar between the three groups of women. No significant differences existed in CC and CV lengths across groups. Similarly, insula, SF, POF And CSF depth did not result changed in fetuses of affected mothers.

CONCLUSIONS

SARS-CoV-2 infection does nor resulted associate with differential fetal cortical development or brain growth in mildly symptomatic pregnant women. This information may be useful to reassure infected mothers on the health of their fetuses.