Maternal immune responses and obstetrical outcomes of pregnant women with COVID-19 and possible health risks of offspring

SARS-CoV-2 infection, inflammation and birth outcomes in a prospective NYC pregnancy cohort

Associations between antenatal SARS-CoV-2 infection and pregnancy outcomes have been conflicting and the role of the immune system is currently unclear. This prospective cohort study investigated the interaction of antenatal SARS-CoV-2 infection, changes in cytokine and HS-CRP levels, birthweight and gestational age at birth. 2352 pregnant participants from New York City (2020-2022) were included. Plasma levels of interleukin (IL)-1β, IL-6, IL-17A and high-sensitivity C-reactive protein (HS-CRP) were quantified in blood specimens obtained across pregnancy. Quantile and linear regression models were conducted to 1) assess the impact of antenatal SARS-CoV-2 infection, overall and by timing of detection of SARS-CoV-2 positivity (< 20 weeks versus ≥ 20 weeks), on birthweight and gestational age at delivery; 2) examine the relationship between SARS-CoV-2 infection and maternal immune changes during pregnancy. All models were adjusted for maternal demographic and obstetric factors and pandemic timing. Birthweight models were additionally adjusted for gestational age at delivery and fetal sex. Immune marker models were also adjusted for gestational age at specimen collection and multiplex assay batch. 371 (15.8%) participants were infected with SARS-CoV-2 during pregnancy, of which 98 (26.4%) were infected at < 20 weeks gestation. Neither SARS-CoV-2 infection in general nor in early or late pregnancy was associated with lower birthweight nor earlier gestational age at delivery. Further, we did not observe cytokine or HS-CRP changes in response to SARS-CoV-2 infection and thus found no evidence to support a potential association between immune dysregulation and the diversity in pregnancy outcomes following infection.

The COVID-19 Pandemic Period, SARS-CoV-2 Infection, and Perinatal Health

This cohort study assesses population-level associations of COVID-19 with birth parent and infant health, distinguishing the COVID-19 pandemic period from individual SARS-CoV-2 infection.

COVID-19 and Pregnancy: Interrelationships With Asthma and Allergy

Pregnant individuals are at higher risk of complications from respiratory viruses such as coronavirus-19 disease (COVID-19). Altered lung function, vaccine hesitancy, and resistance to taking necessary medications because of a lack of safety data in pregnancy make this population especially vulnerable to the effects of COVID-19. Like many medical conditions, the treatment of allergic conditions, including asthma and allergic rhinitis, were affected during the pandemic, with decreased numbers of in-person visits and interruptions in medical treatment. There were initially no data to allow pregnant women with asthma know whether the condition put them at higher risk of complications from COVID-19. There are now increasing data for the efficacy and safety of vaccines for COVID-19 in at-risk populations, including pregnant women. Vaccine studies show no increased risk for spontaneous abortion, congenital anomalies, or pregnancy complications. Furthermore, infants of individuals vaccinated during pregnancy have been shown to obtain protective antibodies via the placenta, providing protection against COVID-19 after birth. Although overall risks are low, pregnant women who become infected with COVID-19 are at higher risk for maternal and pregnancy complications. Antiviral treatment is available for pregnant women with mild to moderate symptoms of COVID-19, with reassuring safety data to date. Dexamethasone is the mainstay of inpatient therapy.

Screening for coronavirus disease 2019 in pregnant women admitted for delivery: an observational study

OBJECTIVE

The aim of this study was to examine the impact of symptom-based screening on the prevalence and outcomes of neonatal coronavirus disease 2019 in pregnant women admitted for delivery.

METHODS

A retrospective observational study was conducted from June to August 2020 at Gonzaga Mota of Messejana Hospital, Fortaleza, CE, Brazil. All pregnant women were screened for coronavirus disease 2019 based on symptoms. Reverse transcription-polymerase chain reaction or immunology assays for severe acute respiratory syndrome coronavirus 2 were performed when a patient reported a symptom. All newborns of symptomatic patients were submitted for Reverse transcription-polymerase chain reaction. Newborns were divided into groups according to the Reverse transcription-polymerase chain reaction results to identify the relationship between maternal symptoms and neonatal coronavirus disease 2019.

RESULTS

A total of 55 (55/1,026, 5.4%) and 50 (50/1,026, 4.8%) pregnant women reported symptoms and had a positive confirmatory test, respectively. The most common symptom of coronavirus disease 2019 among the pregnant women with positive confirmatory test was cough (n=23, 46%). Seven newborns (7/50, 14%) of symptomatic mothers had positive Reverse transcription-polymerase chain reaction. Upon birth, no newborn had serious complications.

CONCLUSION

Universal screening of pregnant women admitted for delivery can reduce the perinatal transmission of coronavirus disease 2019. Symptom-based screening can be an alternative for regions with a low prevalence of the disease where a better allocation of financial resources is necessary.

The Impact of COVID-19 on Preterm Birth Among Pregnant Women in Al-Qassim, Saudi Arabia

BACKGROUND

Pregnant women are regarded as a unique group due to the distinct immunological condition that pregnancy produces, which makes pregnant women more susceptible to respiratory infections like coronavirus disease 2019 (COVID-19) and its consequences. During pregnancy, many viral infections have been recognized to increase the risk of adverse obstetrical outcomes such as preterm delivery. The purpose of this study was to investigate the effects of COVID-19 infection on preterm birth in pregnant women in the Al-Qassim region of Saudi Arabia.

METHODS

 This retrospective cohort study was conducted in Saudi Arabia between December 2019 to October 2021. The target subjects were pregnant women with live singleton gestations who underwent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction (PCR) testing for COVID-19 infection during their delivery hospitalization. Data gathered included patient demographic information, clinical characteristics, and pregnancy outcomes. Data were analyzed using R version 4.1.1 (R Core Team (2021); R Foundation for Statistical Computing, Vienna, Austria).

RESULTS

 A total of 381 pregnant women were included. The median maternal age of women was 31.0 years (IQR: 27.0, 35.0) and the median BMI value was 30.5 kg/m² (IQR: 26.9, 34.8). The most common comorbidities were diabetes (7.1%) and asthma (4.5%). A known history of preterm birth was prevalent among 2.9%. Of the participants, 13.6% had a prenatal COVID-19 infection, of whom 57.7% had their infections resolved. The prevalence of positive PCR testing was 13.6%. Preterm birth occurred in 46 women (12.1%, 95%CI 9.1-15.9). Preterm birth was significantly associated with having a maternal age of ≥35 years, having high frequencies of parity, and having a past history of preterm birth, as well as having a history of hypertension and diabetes. Preterm birth was not significantly associated with having a confirmed COVID-19 infection at delivery.

CONCLUSION

It was shown that preterm birth is evident among women with COVID-19 infection. Preterm birth is significantly associated with old age, multiparity, and a history of preterm delivery. Preterm birth is not significantly associated with having a confirmed COVID-19 infection at delivery. More research regarding infection-related adverse effects is advised and should be highlighted.

The effects of COVID-19 on placental morphology

The impact of the COVID-19 infection, caused by Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), during the pandemic has been considerably more severe in pregnant women than non-pregnant women. Therefore, a review detailing the morphological alterations and physiological changes associated with COVID-19 during pregnancy and the effect that these changes have on the feto-placental unit is of high priority. This knowledge is crucial for these mothers, their babies and clinicians to ensure a healthy life post-pandemic. Hence, we review the placental morphological changes due to COVID-19 to enhance the general understanding of how pregnant mothers, their placentas and unborn children may have been affected by this pandemic. Based on current literature, we deduced that COVID-19 pregnancies were oxygen deficient, which could further result in other pregnancy-related complications like preeclampsia and IUGR. Therefore, we present an up-to-date review of the COVID-19 pathophysiological implications on the placenta, covering the function of the placenta in COVID-19, the effects of this virus on the placenta, its functions and its link to other gestational complications. Furthermore, we highlight the possible effects of COVID-19 therapeutic interventions on pregnant mothers and their unborn children. Based on the literature, we strongly suggest that consistent surveillance for the mothers and infants from COVID-19 pregnancies be prioritised in the future. Though the pandemic is now in the past, its effects are long-term, necessitating the monitoring of clinical manifestations in the near future.

Exploring the impact of COVID-19 on newborn neurodevelopment: a pilot study

The COVID-19 pandemic can seize the opportunity to explore the hypothesis of prenatal exposure to viral infections increases the risk for neurodevelopmental disorders. Advancing our knowledge in this regard would improve primary prevention of mental disorders in children. For this pilot study, six-week-old infants born to mothers exposed (n = 21) or unexposed (n = 21) to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were assessed in Santander-Cantabria (Spain) using the Neonatal Behavioral Assessment Scale (NBAS). Groups comparisons were performed to explore the effects that infection and timing of exposure (in terms of the three trimesters of pregnancy). The infants' competencies and performances on the NBAS were generally similar in the exposed and unexposed to SARS-CoV-2 groups. The most significant difference found was a less optimally response to cuddliness (item on the state regulation domain) particularly in infants born to mothers exposed in the third trimester of pregnancy, and in pull-to-sit (item on the motor system domain). Although our interpretations must be careful, these preliminary results highlight the possible association between prenatal SARS-CoV-2 exposure and poorer development in motor skills and infant interactive behavior. Further longitudinal studies are needed to explore these relationships and disentangle the biological mechanisms implicated.

Panoramic snapshot of serum soluble mediator interplay in pregnant women with convalescent COVID-19: an exploratory study

Introduction

SARS-CoV-2 infection during pregnancy can induce changes in the maternal immune response, with effects on pregnancy outcome and offspring. This is a cross-sectional observational study designed to characterize the immunological status of pregnant women with convalescent COVID-19 at distinct pregnancy trimesters. The study focused on providing a clear snapshot of the interplay among serum soluble mediators.

Methods

A sample of 141 pregnant women from all prenatal periods (1^st, 2^nd and 3^rd trimesters) comprised patients with convalescent SARS-CoV-2 infection at 3-20 weeks after symptoms onset (COVID, n=89) and a control group of pre-pandemic non-infected pregnant women (HC, n=52). Chemokine, pro-inflammatory/regulatory cytokine and growth factor levels were quantified by a high-throughput microbeads array.

Results

In the HC group, most serum soluble mediators progressively decreased towards the 2^nd and 3^rd trimesters of pregnancy, while higher chemokine, cytokine and growth factor levels were observed in the COVID patient group. Serum soluble mediator signatures and heatmap analysis pointed out that the major increase observed in the COVID group related to pro-inflammatory cytokines (IL-6, TNF-α, IL-12, IFN-γ and IL-17). A larger set of biomarkers displayed an increased COVID/HC ratio towards the 2^nd (3x increase) and the 3^rd (3x to 15x increase) trimesters. Integrative network analysis demonstrated that HC pregnancy evolves with decreasing connectivity between pairs of serum soluble mediators towards the 3^rd trimester. Although the COVID group exhibited a similar profile, the number of connections was remarkably lower throughout the pregnancy. Meanwhile, IL-1Ra, IL-10 and GM-CSF presented a preserved number of correlations (≥5 strong correlations in HC and COVID), IL-17, FGF-basic and VEGF lost connectivity throughout the pregnancy. IL-6 and CXCL8 were included in a set of acquired attributes, named COVID-selective (≥5 strong correlations in COVID and <5 in HC) observed at the 3^rd pregnancy trimester.

Discussion and conclusion

From an overall perspective, a pronounced increase in serum levels of soluble mediators with decreased network interplay between them demonstrated an imbalanced immune response in convalescent COVID-19 infection during pregnancy that may contribute to the management of, or indeed recovery from, late complications in the post-symptomatic phase of the SARS-CoV-2 infection in pregnant women.

The Impact of Coronavirus Disease 2019 on Maternal and Fetal Wellbeing in New Mexico

Coronavirus disease 2019 (COVID-19) has been shown to affect the vasculature, including placental changes. Insults to the placenta, especially in the first and second trimester, can affect placental functionality with a resultant impact on fetal growth and wellbeing. Thus, we explored the relationship between antenatally acquired maternal COVID-19 infection and neonatal birth characteristics. A retrospective chart review was completed using the University of New Mexico electronic medical record system. ICD-10 codes were used to identify individuals that had a positive pregnancy test and positive COVID-19 screening test between 1 March 2020 to 24 March 2021. Chi-square and nonparametric Wilcoxon analyses were used, with p < 0.05 considered significant. A total of 487 dyad charts was analyzed, with 76 (16%) individuals identified as being COVID-19-positive (CovPos) during pregnancy. CovPos mothers were significantly more likely to deliver via a cesarean section compared to CovNeg mothers (33% vs. 20%, p < 0.01). There was a significant difference in gestational age at delivery, with infants born to CovPos individuals born at an earlier gestational age than those born to CovNeg individuals (37.6 vs. 38.5 weeks; p < 0.01). Our findings showed differences in maternal and infant characteristics following COVID-19 infection during pregnancy. Additional investigations are required to further delineate these relationships with a focus on potential long-term impacts on the neonate.

COVID-19 in Pregnant Women, Maternal-Fetal Involvement, and Vertical Mother-to-Child Transmission: A Systematic Review

Pregnant women are included in the COVID-19 risk groups even if they do not have any pathology. This requires an analysis of research focused on pregnant women to understand the impact of SARS-CoV-2 on their condition. There is also a need to know whether there is vertical mother-to-child transmission, as well as other consequences in case the pregnant woman is infected and COVID-19 positive. A systematic review was carried out to analyze the existing information on the complications of a pregnant woman infected with the SARS-CoV-2 coronavirus and the possibility of vertical transmission from mother to child, registered in the PROSPERO website and searched in the PubMed, Scopus, CINAHL, and Cochrane Library databases. Finally, 22 articles were included in the review. The review suggests that vertical transmission from mother to child could be exceptionally possible at the time of delivery or breastfeeding, but not through the placenta. It is interesting to point out the good acceptance of vaccination by pregnant women, which may be the reason for the low infectivity. Further research on pregnant women should be carried out to provide evidence on vertical mother-to-child transmission and the role of breast milk in relation to SARS-CoV-2.

Cytokine Imbalance as a Biomarker of Treatment-Resistant Schizophrenia

Treatment-resistant schizophrenia (TRS) is an important and unresolved problem in biological and clinical psychiatry. Approximately 30% of cases of schizophrenia (Sch) are TRS, which may be due to the fact that some patients with TRS may suffer from pathogenetically “non-dopamine” Sch, in the development of which neuroinflammation is supposed to play an important role. The purpose of this narrative review is an attempt to summarize the data characterizing the patterns of production of pro-inflammatory and anti-inflammatory cytokines during the development of therapeutic resistance to APs and their pathogenetic and prognostic significance of cytokine imbalance as TRS biomarkers. This narrative review demonstrates that the problem of evaluating the contribution of pro-inflammatory and anti-inflammatory cytokines to maintaining or changing the cytokine balance can become a new key in unlocking the mystery of “non-dopamine” Sch and developing new therapeutic strategies for the treatment of TRS and psychosis in the setting of acute and chronic neuroinflammation. In addition, the inconsistency of the results of previous studies on the role of pro-inflammatory and anti-inflammatory cytokines indicates that the TRS biomarker, most likely, is not the serum level of one or more cytokines, but the cytokine balance. We have confirmed the hypothesis that cytokine imbalance is one of the most important TRS biomarkers. This hypothesis is partially supported by the variable response to immunomodulators in patients with TRS, which were prescribed without taking into account the cytokine balance of the relation between serum levels of the most important pro-inflammatory and anti-inflammatory cytokines for TRS.

SARS-CoV-2, COVID-19, and Reproduction: Effects on Fertility, Pregnancy, and Neonatal Life

Since its discovery in Wuhan, China, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread over the world, having a huge impact on people’s lives and health. The respiratory system is often targeted in people with the coronavirus disease 2019 (COVID-19). The virus can also infect many organs and tissues in the body, including the reproductive system. The consequences of the SARS-CoV-2 infection on fertility and pregnancy in hosts are poorly documented. Available data on other coronaviruses, such as severe acute respiratory syndrome (SARS-CoV) and Middle Eastern Respiratory Syndrome (MERS-CoV) coronaviruses, identified pregnant women as a vulnerable group with increased pregnancy-related complications. COVID-19 was also shown to impact pregnancy, which can be seen in either the mother or the fetus. Pregnant women more likely require COVID-19 intensive care treatment than non-pregnant women, and they are susceptible to giving birth prematurely and having their newborns admitted to the neonatal intensive care unit. Angiotensin converting enzyme 2 (ACE2), a key player of the ubiquitous renin-angiotensin system (RAS), is the principal host cellular receptor for SARS-CoV-2 spike protein. ACE2 is involved in the regulation of both male and female reproductive systems, suggesting that SARS-CoV-2 infection and associated RAS dysfunction could affect reproduction. Herein, we review the current knowledge about COVID-19 consequences on male and female fertility, pregnant women, and their fetuses. Furthermore, we describe the effects of COVID-19 vaccination on reproduction.

Subjective social status, COVID-19 health worries, and mental health symptoms in perinatal women

Pregnant women and those who have recently given birth are considered an at-risk population during the COVID-19 pandemic with regards to the impact of both general stress and pandemic-related stressors. The extent to which subjective social status (SSS), one's perception of relative standing compared to others in a social hierarchy, might mitigate the effects of COVID-19-related health worries on mental health has not yet been reported, despite SSS often outperforming socioeconomic status as a predictor of various health outcomes including depression. This cross-sectional survey study tested the moderating effect of SSS on association between COVID-19- related health worries and mental health symptoms (depressive and generalized anxiety) among a sample of 1,637 perinatal women from the United States who took part in the Perinatal Experiences and COVID-19 Effects (PEACE) Study between May 2020 and June 2021. We found that high subjective social status was protective against depressive symptoms when self-reported COVID-19-related worry was low. When COVID-19-related worry was high, subjective social status was no longer influential. Higher levels of COVID-19-related health worries were associated with more anxiety symptoms, and higher subjective social status did not moderate anxiety symptomatology at either level of COVID-19-related worry. Although higher SSS has historically been protective against mental health decline, in the context of the COVID-19 pandemic it may not be sufficiently protective against anxiety, or against depression for those who experience high levels of worry regarding the effects of COVID-19 on health.

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We assessed perinatal women for mental health symptoms and subjective social status.

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High subjective social status protected against depression when COVID worry was low.

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When COVID worry was high, subjective social status didn't protect against depression.

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COVID-19-related health worries were associated with more anxiety symptoms.

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High subjective social status was not protective against anxiety symptoms.

COVID-19 in pregnancy: implications for fetal brain development

The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy on the developing fetal brain is poorly understood. Other antenatal infections such as influenza have been associated with adverse neurodevelopmental outcomes in offspring. Although vertical transmission has been rarely observed in SARS-CoV-2 to date, given the potential for profound maternal immune activation (MIA), impact on the developing fetal brain is likely. Here we review evidence that SARS-CoV-2 and other viral infections during pregnancy can result in maternal, placental, and fetal immune activation, and ultimately in offspring neurodevelopmental morbidity. Finally, we highlight the need for cellular models of fetal brain development to better understand potential short- and long-term impacts of maternal SARS-CoV-2 infection on the next generation.

Differential effects of early or late exposure to prenatal maternal immune activation on mouse embryonic neurodevelopment

Prenatal exposure to maternal infection increases the risk of developing mental health disorders, such as schizophrenia and autism spectrum disorder. Exposure to maternal immune activation has been associated with a number of neuroanatomical deficits in adolescent and adult offspring, with differing effects based on the gestational timing of infection. However, little is known about how the embryo brain is affected. We show, using whole-brain MRI, that maternal immune activation significantly affects brain anatomy. When the exposure occurs early in pregnancy, volume reductions are mainly observed, while the opposite is true for exposure later in pregnancy. Furthermore, we identify alterations to the density of certain classes of neurons and glia, which have been associated with stress and inflammation in the brain.

Exposure to maternal immune activation (MIA) in utero is a risk factor for neurodevelopmental and psychiatric disorders. MIA-induced deficits in adolescent and adult offspring have been well characterized; however, less is known about the effects of MIA exposure on embryo development. To address this gap, we performed high-resolution ex vivo MRI to investigate the effects of early (gestational day [GD]9) and late (GD17) MIA exposure on embryo (GD18) brain structure. We identify striking neuroanatomical changes in the embryo brain, particularly in the late-exposed offspring. We further examined the putative neuroanatomical underpinnings of MIA timing in the hippocampus using electron microscopy and identified differential effects due to MIA timing. An increase in apoptotic cell density was observed in the GD9-exposed offspring, while an increase in the density of neurons and glia with ultrastructural features reflective of increased neuroinflammation and oxidative stress was observed in GD17-exposed offspring, particularly in females. Overall, our findings integrate imaging techniques across different scales to identify differential impact of MIA timing on the earliest stages of neurodevelopment.

Treatment with anti-SARS-CoV-2 monoclonal antibodies in pregnant and postpartum women: first experiences in Florence, Italy

Purpose

Pregnant and postpartum women are at increased risk of developing severe COVID-19. Monoclonal antibodies (mAbs) are now widely used in high-income countries to treat mild to moderate COVID-19 outpatients at risk for developing severe disease. Very few data are available on the use of mAbs in special populations, including pregnant and postpartum women. Here we present our early experience with mAbs in these two populations.

Methods

Electronic records of pregnant and postpartum women treated with mAbs at Careggi University Hospital, Florence, were retrieved. Relevant data were extracted (age, presence of risk factors for COVID-19, oxygen support, mAb type, gestational age, and pregnancy status). When available, outcomes at 28 days after administration were also included.

Results

From March 1st to September 30th 2021, eight pregnant and two postpartum women have been treated with mAbs at our center. The median age was 31 years (IQR 30–33.5, range 29–38), median gestational age was 24 weeks. Seven patients had additional risk factors. According to the Italian disposition, all patients received casirivimab/imdevimab, with five receiving a 2.4 mg dose and five receiving a 8 g dose. Eight patients improved. One developed myocarditis, considered a COVID-19 complication. Another required a transient increase of low flow oxygen support before improving and being discharged. At a 28 days follow-up, all patients were clinically recovered. We did not observe mAbs related adverse events.

Conclusion

Although preliminary data should be interpreted with caution, it is remarkable how mAbs were well tolerated by pregnant women with COVID-19. Further data on mAbs in this special population should be collected but the use of mAbs in pregnant and postpartum patients should be considered. Even thus oral antivirals are becoming available, they are not recommended in pregnant and postpartum women. This population may specifically benefit from treatment with last generation mAbs.

Emerging Knowledge of the Neurobiology of COVID-19

Many patients with COVID-19 will experience acute or longer-term neuropsychiatric complications. The neurobiological mechanisms behind these are beginning to emerge; however, the neurotropic hypothesis is not strongly supported by clinical data. The inflammatory response to SARS-CoV-2 is likely to be responsible for delirium and other common acute neuropsychiatric manifestations. Vascular abnormalities such as endotheliopathies contribute to stroke and cerebral microbleeds, with their attendant neuropsychiatric sequelae. Longer-term neuropsychiatric syndromes fall into 2 broad categories: neuropsychiatric deficits occurring after severe (hospitalized) COVID-19 and "long COVID," which occurs in many patients with a milder acute COVID-19 illness.

Syncytin, envelope protein of human endogenous retrovirus (HERV): no longer 'fossil' in human genome

Human endogenous retroviruses (HERVs) are 'fossil viruses' that resulted from stable integrations of exogenous retroviruses throughout evolution. HERVs are defective and do not produce infectious viral particles. However, some HERVs retain a limited coding capacity and produce retroviral transcripts and proteins, which function in human developmental process and various pathologies, including many cancers and neurological diseases. Recently, it has been reported that HERVs are differently expressed in COVID-19 disease caused by infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this review, we discuss the molecular structure and function of HERV ENV proteins, particularly syncytins, and their conventional roles in human development and diseases, and potential involvement in COVID-19 regarding the newly reported mental symptoms. We also address COVID-19 vaccine-related infertility concerns arising from the similarity of syncytin with the spike protein of SARS-CoV-2, which have been proved invalid.

Single-cell immunophenotyping of the fetal immune response to maternal SARS-CoV-2 infection in late gestation

BACKGROUND

During the COVID-19 pandemic, thousands of pregnant women have been infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The implications of maternal SARS-CoV-2 infection on fetal and childhood well-being need to be characterized. We aimed to characterize the fetal immune response to maternal SARS-CoV-2 infection.

METHODS

We performed single-cell RNA-sequencing and T cell receptor sequencing on cord blood mononuclear cells (CBMCs) from newborns of mothers infected with SARS-CoV-2 in the third trimester (cases) or without SARS-CoV-2 infection (controls).

RESULTS

We identified widespread gene expression changes in CBMCs from cases, including upregulation of interferon-stimulated genes and major histocompatibility complex genes in CD14⁺ monocytes, transcriptional changes suggestive of activation of plasmacytoid dendritic cells, and activation and exhaustion of natural killer cells. Lastly, we observed fetal T cell clonal expansion in cases compared to controls.

CONCLUSIONS

As none of the infants were infected with SARS-CoV-2, our results suggest that maternal SARS-CoV-2 infection might modulate the fetal immune system in the absence of vertical transmission.

IMPACT

The implications of maternal SARS-CoV-2 infection in the absence of vertical transmission on fetal and childhood well-being are poorly understood. Maternal SARS-CoV-2 infection might modulate the fetal immune system in the absence of vertical transmission. This study raises important questions about the untoward effects of maternal SARS-CoV-2 on the fetus, even in the absence of vertical transmission.

Covid-19 vaccine and its consequences in pregnancy: Brief review

Pregnancy is linked to a higher incidence of severe Covid-19. It's critical to find safe vaccinations that elicit protective pregnant and fetal immune responses. This review summarises the rate of COVID-19 infection, maternal antibodies responsiveness, placenta antibody transmission, and adverse events after COVID-19 vaccination in pregnancy studied in epidemiological studies evaluating mRNA vaccines. Potential COVID-19 infection in pregnant women can be prevented using mRNA-based vaccinations. Gestation, childbirth, and perinatal mortality were proven unaffected by COVID-19 vaccination. Injection-site discomfort, tiredness, and migraine are the most prevalent side effects, but these are temporary. After the first dosage of vaccinations, fast antibody responses were demonstrated. The adaptive immunity is found to be more significant after booster vaccination, and is linked to improved placental antigen transmission. Two vaccination doses are associated with more robust maternal and fetal antibody levels. Longer delays between the first immunization dosage and birth are linked to greater fetal IgG antibody levels with reduction in antigen transmission proportion. The mRNA vacciness are effective in reducing the severity of COVID-19 infection and these vaccinations are regarded to be safe options for pregnant women and their unborn fetus.

COVID-19 in pregnant women and children: Insights on clinical manifestations, complexities, and pathogenesis

Pregnancy changes the body's immune system to counteract the spectrum of infections, including COVID-19, which can pose complications. Pregnant women are less likely to contract COVID-19 infections than the general public. However, pregnant women are at slightly increased risk of becoming severely unwell if they do catch COVID-19, and congenital conditions in pregnant women may worsen the state of infection and lead to critical stages and even mortality. The possibility of vertical transmission has been reported in only a few cases of COVID-19; however, it was not noted in cases of SARS and MERS. Vaccination coverage in pregnant women remains a challenge. Children are the next suspected and vulnerable population to acquire infection after the first and second waves. Children are disproportionately infected compared with older populations, but the severity of infection is less compared to adults. This review highlights the complexities of COVID-19 in pregnant women and the underlying reasons why children tend to be comparatively less severely affected. Ethnicity, nutrition, lifestyle, and therapeutics influence the severity of infection in children. Low expression of angiotensin-converting enzyme 2 receptors, indigenous virus competence, and maternal immunity is the first-line defense for children against COVID-19. Habituating herbal medicines from childhood may help support a robust and defensive immune system to counteract novel antigens and encourage healthy generations.

Maternal immune activation as a risk factor for psychiatric illness in the context of the SARS-CoV-2 pandemic

Inflammation, due to infectious pathogens or other non-infectious stimuli, during pregnancy is associated with elevated risk for neurodevelopmental disorders such as schizophrenia and autism in the offspring. Although historically identified through retrospective epidemiologic studies, the relationship between maternal immune activation and offspring neurodevelopmental disease risk is now well established because of clinical studies which utilized prospective birth cohorts, serologically confirmed infection records, and subsequent long-term offspring follow-up. These efforts have been corroborated by preclinical research which demonstrates anatomical, biochemical, and behavioural alterations that resemble the clinical features of psychiatric illnesses. Intervention studies further demonstrate causal roles of inflammatory mediators, such as cytokines, in these long-lasting changes in behaviour and brain. This review summarizes a selection of maternal immune activation literature that explores the relationship between these inflammatory mediators and the neuropsychiatric-like effects later observed in the offspring. This literature is presented alongside emerging information regarding SARS-CoV-2 infection in pregnancy, with discussion of how these data may inform future research regarding the effects of the present coronavirus pandemic on emerging birth cohorts.

Meta-analysis of the frequency of intrauterine growth restriction and preterm premature rupture of the membranes in pregnant women with COVID-19

The impact of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in pregnancy has yet to be determined. Some studies indicate that SARSCoV- 2 infection may be associated with a higher risk of adverse outcomes in pregnant women. Here, we performed a meta-analysis to estimate the frequency of intrauterine growth restriction (IUGR) and preterm premature rupture of the membranes (PPROM) in pregnant women with Coronavirus disease-2019 (COVID-19). A comprehensive search was performed in various databases, such as PubMed, Scopus, SciELO, MedRxiv, and Web of Science, to find all relevant studies published before 10 February 2021. Cross-sectional and consecutive case series reporting the pregnancy outcomes of COVID-19 were included. A total of 24 studies, including 8 studies on IUGR and 16 studies on PPROM, were selected. Pooled data showed that the frequencies of IUGR and PPROM in pregnant women with COVID-19 were 2.6% and 9.9%, respectively. Analyses stratified by ethnicity showed that the frequencies of IUGR in Asian and Caucasian COVID-19-infected pregnant women were 2.9% and 2.0%, respectively. Moreover, the frequencies of PPROM in Asian and Caucasian COVID-19-infected pregnant women were 10.2% and 5.8%, respectively. This meta-analysis showed that the frequencies of IUGR and PPROM in COVID-19-infected pregnant women were 2.6% and 9.9%, respectively. However, well-designed, large-scale and multicenter clinical studies are required to improve and validate these results.

SARS-CoV-2 in pregnancy and possible transfer of immunity: assessment of peripartal maternal and neonatal antibody levels and a longitudinal follow-up

OBJECTIVES

In the current Severe Acute Respiratory Distress Coronavirus 2 (SARS-CoV-2) pandemic there is still great uncertainty about the effects of an infection in pregnancy especially regarding a possible fetal transmission of antibodies to SARS-CoV-2 and the longevity of this immunity.

METHODS

Sixteen women who were infected with SARS-CoV-2 during pregnancy and their offspring were included. The antibody response to SARS-CoV-2 was measured in mother and umbilical cord blood peripartum and in a follow-up examination 6-11 weeks after birth. Medical history, symptoms regarding SARS-CoV-2, obstetric and neonatal information were queried following recommendations by the WHO.

RESULTS

A total of 73% of the women and one third of the infants developed antibodies to SARS-CoV-2 spike (S) protein receptor binding domain (RBD), with a long interval between infection and birth proving favorable for a transplacentar transfer of antibodies to the neonates. All infants showed declining or vanishing antibody-titers in the follow-up examination, while the titers of their mothers were stable or even increased.

CONCLUSIONS

Our results demonstrate that transplacental transfer of SARS-CoV-2-specific antibodies is possible, but also indicate that the immunity that may be gained as a result might decrease in newborns postpartum. This provides important evidence that could be useful for further studies covering vaccination during pregnancy.

ACE2 Is Expressed in Immune Cells That Infiltrate the Placenta in Infection-Associated Preterm Birth

COVID-19 is associated with increased incidence of preterm birth (PTB). We assessed pathways by which SARS-CoV-2 could access the placenta. Placentae, from PTB with or without chorioamnionitis (ChA), or from term pregnancies (n = 12/13/group) were collected. Peripheral blood was collected from healthy pregnant women (n = 6). Second trimester placental explants (16–20 weeks, n = 5/group) were treated with lipopolysaccharide (LPS, to mimic bacterial infection) and ACE2, CCL2, IL-6/8 and TNFα mRNA was assessed. ChA-placentae exhibited increased ACE2 and CCL2 mRNA expression (p < 0.05). LPS increased cytokine and ACE2 mRNA in placental explants. Placental ACE2 protein localized to syncytiotrophoblast, fetal endothelium, extravillous trophoblast and in immune cells-subsets (M1/M2 macrophage and neutrophils) within the villous stroma. Significantly increased numbers of M1 macrophage and neutrophils were present in the ChA-placenta (p < 0.001). Subsets of peripheral immune cells from pregnant women express the ACE2 mRNA and protein. A greater fraction of granulocytes was positive for ACE2 protein expression compared to lymphocytes or monocytes. These data suggest that in pregnancies complicated by ChA, ACE2 positive immune cells in the maternal circulation have the potential to traffic SARS-CoV-2 virus to the placenta and increase the risk of vertical transmission to the placenta/fetus.

Poly (I:C)-induced maternal immune activation modifies ventral hippocampal regulation of stress reactivity: prevention by environmental enrichment

Environmental enrichment (EE) has been successfully implemented in human rehabilitation settings. However, the mechanisms underlying its success are not understood. Incorporating components of EE protocols into our animal models allows for the exploration of these mechanisms and their role in mitigation. Using a mouse model of maternal immune activation (MIA), the present study explored disruptions in social behavior and associated hypothalamic pituitary adrenal (HPA) axis functioning, and whether a supportive environment could prevent these effects. We show that prenatal immune activation of toll-like receptor 3, by the viral mimetic polyinosinic-polycytidylic acid (poly(I:C)), led to disrupted maternal care in that dams built poorer quality nests, an effect corrected by EE housing. Standard housed male and female MIA mice engaged in higher rates of repetitive rearing and had lower levels of social interaction, alongside sex-specific expression of several ventral hippocampal neural stress markers. Moreover, MIA males had delayed recovery of plasma corticosterone in response to a novel social encounter. Enrichment housing, likely mediated by improved maternal care, protected against these MIA-induced effects. We also evaluated c-Fos immunoreactivity associated with the novel social experience and found MIA to decrease neural activation in the dentate gyrus. Activation in the hypothalamus was blunted in EE housed animals, suggesting that the putative circuits modulating social behaviors may be different between standard and complex housing environments. These data demonstrate that augmentation of the environment supports parental care and offspring safety/security, which can offset effects of early health adversity by buffering HPA axis dysregulation. Our findings provide further evidence for the viability of EE interventions in maternal and pediatric settings.