SARS-CoV-2 positivity in offspring and timing of mother-to-child transmission: living systematic review and meta-analysis

COVID-19 in pregnancy: Perinatal outcomes and complications

BACKGROUND

The risk of severe coronavirus disease 2019 (COVID-19) in pregnant women is elevated.

AIM

To examine the outcomes of pregnant women with COVID-19 and report perinatal outcomes and complications, while providing a brief review of current literature.

METHODS

The study included pregnant women presenting from April 2020 to February 2022 to the emergency department (ED) of a tertiary hospital. We retrospectively recorded the maternal and perinatal files, including patient epidemiological and clinical characteristics, laboratory values, outcomes, treatment modalities and associations were explored.

RESULTS

Among the 60 pregnant women, 25% required hospitalization, all of whom were symptomatic. Preterm delivery occurred in 30% of cases. Ten percent of neonates required admission to the neonatal intensive care unit, and 5% were classified as small for their gestational age. All mothers survived COVID-19 and pregnancy, with 6.6% requiring invasive mechanical ventilation. Preterm delivery rates did not differ between hospitalized and non-hospitalized pregnant women; composite unfavorable perinatal outcomes, including stillbirth, small for gestational age, or neonatal intensive care unit (ICU) admission, did not significantly increase in the cases hospitalized for COVID-19 (P = 0.09). The odds of hospitalization increased 2.3-fold for each day of delayed ED presentation [adj. OR (95%CI: 1.46-3.624), P < 0.001]. Comorbidity status was an independent predictor of hospitalization, albeit with marginal significance [adj. OR = 16.13 (95%CI: 1.021-255.146), P = 0.048]. No independent predictors of adverse fetal outcome (composite) were identified, and eventual hospitalization failed to reach statistical significance by a slight margin (P = 0.054).

CONCLUSION

Delayed ED presentation and comorbidities increase hospitalization odds. This study highlights the importance of continuous and specific guidance for managing pregnant COVID-19 patients, including timely and appropriate interventions to minimize maternal and perinatal morbidity and mortality.

Maternal COVID-19 infection associated with offspring neurodevelopmental disorders

Maternal COVID-19 infection increases the incidence of neurodevelopmental disorders (NDDs) in offspring, although the underlying mechanisms have not been elucidated. This study demonstrated that COVID-19 infection during pregnancy disrupted the balance of maternal and fetal immune environments, driving alterations in astrocytes, endothelial cells, and excitatory neurons. A risk score was established using 47 unique genes in the single-cell transcriptome of gestational mothers. The high risk score in CD4 proliferating T cell level served as an indicator for increased risk of offspring NDDs. Summary-based Mendelian randomization and phenome-wide association study analyses were conducted to identify the causal association of the transcriptional changes with the increased risk of offspring NDDs. Additionally, 10 drugs were identified as potential therapeutic candidates. Our findings support a model where the maternal COVID-19 infection changed the levels of CD4 proliferating T cells, leading to the alterations of astrocytes, endothelial cells, and excitatory neurons in offspring, contributing to the increased risk of NDDs in these individuals.

Impact of Infections During Pregnancy on Transplacental Antibody Transfer

Vaccination in pregnancy is important to protect the mother and fetus from infectious diseases. The transfer of maternal antibodies across the placenta during pregnancy can continue to protect the neonate for several months after birth while the neonatal adaptive immune system develops. Several pathogens have been shown to impair the transplacental transfer of maternal antibodies, including human immunodeficiency virus, malaria, the severe acute respiratory syndrome coronavirus 2, and cytomegalovirus. This review discusses the mechanisms contributing to decreased transplacental antibody transfer in the setting of maternal infections, such as changes in antibody glycosylation profile, maternal hypergammaglobulinemia, and placental injury. The frequency of epidemics is increasing, and pregnant people are more likely to become exposed to novel pathogens now than they were in the past. Understanding the mechanisms by which infectious diseases impair maternal-fetal antibody transfer is important for pandemic preparedness to maximize the impact of maternal vaccination for child health.

SARS-CoV-2 seroprevalence and preeclampsia markers in Mozambican pregnant women with perinatal loss

BACKGROUND

SARS-CoV-2 infection during pregnancy is known to be associated with poor pregnancy outcomes, including pre-eclampsia (PE), prematurity, perinatal and maternal mortality. Data on the burden of SARS-CoV-2 infection among pregnant women and their offspring in Sub-Saharan Africa is limited. We aimed to estimate SARS-CoV-2 seroprevalence and determine PE biomarkers in Mozambican pregnant women with perinatal loss.

METHODS

A cross-sectional study was conducted among women who had a fetal or an early neonatal death at the Maputo Central Hospital (MCH), Mozambique. Anti-SARS-CoV-2 IgG/IgM were determined in maternal and umbilical cord blood and PE biomarkers (sFlt-1 and PIGF) in maternal blood. SARS-CoV-2 RT-PCR was performed in placenta and fetal lung biopsies from participants found to be SARS-CoV-2 seropositive.

RESULTS

A total of 100 COVID-19 unvaccinated women were included in the study from March 2021 to April 2022. Total SARS-CoV-2 antibodies were detected in 68 [68%; 95CI (58 - 76)] maternal and 55 [55%; 95CI (54 - 74)] cord blood samples. SARS-CoV-2 IgM was detected in 18 cord blood samples and a positive placental RT-PCR in three of these participants. The proportion of women with moderate to high sFlt-1/PIGF ratio was higher in SARS-CoV-2 seropositive women than in those seronegative (71.2% vs 28.8%, p = 0.339), although the difference was not statistically significant.

CONCLUSIONS

SARS-CoV-2 seroprevalence among Mozambican women with perinatal loss was high during the second pandemic year, and there was evidence of vertical transmission in stillbirths. Findings also suggest that maternal SARS-CoV-2 infection may increase the risk of developing PE.

Serological Outcome in the First Months of Life of Children Born to Mothers with SARS-CoV-2 Infection during Pregnancy

BACKGROUND

The objective of this study is to analyze the transplacental transmission of SARS-CoV-2 antibodies, their persistence in newborns, the factors that may influence this transmission, and the protection these antibodies confer over time.

METHODS

This prospective cohort was conducted in a tertiary pediatric hospital in the Barcelona Metropolitan Region, Spain. It included neonates born to mothers who had SARS-CoV-2 infection during pregnancy or delivery between August 2020 and January 2022. We followed the recruited children for at least six months, and blood tests were performed to determine the presence of SARS-CoV-2 antibodies.

RESULTS

A total of 101 children were recruited. Among the serologies performed on children under three months of age, 44/82 were positive (53.7%). Newborns whose mothers presented more severe disease exhibited higher seropositivity odds (coefficient 9.747; p = 0.002). There were increased preterm deliveries when maternal infection occurred closer to the time of delivery. No severe SARS-CoV-2 infections were detected in children during the follow-up.

CONCLUSIONS

Slightly more than half of the SARS-CoV-2 serologies performed in the first three months were positive. This appears to confer protection during early childhood. The severity of maternal infection is the most significant factor influencing the transmission of antibodies in children born to unvaccinated mothers.

Maternal Immunization with Adjuvanted Recombinant Receptor-Binding Domain Protein Provides Immune Protection against SARS-CoV-2 in Infant Monkeys

Maternal vaccinations administered prior to conception or during pregnancy enhance the immune protection of newborn infants against many pathogens. A feasibility experiment was conducted to determine if monkeys can be used to model the placental transfer of maternal antibody against SARS-CoV-2. Six adult rhesus monkeys were immunized with adjuvanted recombinant-protein antigens comprised of receptor-binding domain human IgG1-Fc fusion proteins (RBD-Fc) containing protein sequences from the ancestral-Wuhan or Gamma variants. The female monkeys mounted robust and sustained anti-SARS-CoV-2 antibody responses. Blood samples collected from their infants after delivery verified prenatal transfer of high levels of spike-specific IgG, which were positively correlated with maternal IgG titers at term. In addition, an in vitro test of ACE2 neutralization indicated that the infants' IgG demonstrated antigen specificity, reflecting prior maternal immunization with either Wuhan or Gamma-variant antigens. All sera showed stronger ACE2-RBD binding inhibition when variants in the assay more closely resembled the vaccine RBD sequence than with more distantly related variants (i.e., Delta and Omicron). Monkeys are a valuable animal model for evaluating new vaccines that can promote maternal and infant health. Further, the findings highlight the enduring nature and safety of the immune protection elicited by an adjuvanted recombinant RBD-Fc vaccine.

SARS-CoV-2 infection during pregnancy: clinical characteristics and vertical transmission in a referral hospital in Peru

Motivation for the study. There is a gap in knowledge about vertical transmission of SARS- CoV-2 and its implications for maternal and neonatal health, despite evidence of multisystem involvement in pregnant women with COVID-19. Main findings. The study results suggest low incidence of vertical transmission during pregnancy, with only one PCR-positive case in the placenta and one asymptomatic neonate. Implications. Our results can inform strategies for prevention and management of COVID-19 in pregnant women, as well as guide the development of health policies aimed at protecting maternal and neonatal health during the pandemic. The aim of this study was to analyze the vertical transmission of SARS-CoV-2 in pregnant women with COVID-19 in the Gynecology and Obstetrics Department of the Edgardo Rebagliati Martins National Hospital (HNERM). Twelve pregnant women who met the inclusion criteria were included. Real-time PCR (RT-PCR) tests for SARS-CoV-2 were performed when each woman was admitted to the hospital, placenta samples were collected for pathological evaluation as well. The results showed that vertical transmission of the virus was rare, with an overall low positivity rate in newborns. Although the study has limitations, such as the small number of cases and the lack of electron microscope analysis, it is the first attempt to evaluate vertical transmission in Peru. It is concluded that more research is needed to better understand the relationship between COVID-19 infection and complications during pregnancy.

Impacts of COVID-19 on mothers' and newborns' health outcomes in regional Canada: A cross-sectional analysis

Background

COVID-19 infection and pandemic-related stressors (e.g., socioeconomic challenges, isolation) resulted in significant concerns for the health of mothers and their newborns during the perinatal period. Therefore, the primary objective of this study was to compare the health outcomes of pregnant mothers and their newborns one year prior to and one year into the pandemic period in Alberta, Canada. Secondary objectives included investigating: 1) predictors of admission to neonatal intensive care units (NICU) and to compare NICU-admitted newborn health outcomes between the two time periods; 2) hospital utilization between the two time periods; and 3) the health outcomes of mothers and their newborns following infection with COVID-19.

Methods

This analytical cross-sectional study used a large administrative dataset (n = 32,107) obtained from provincial regional hospitals and homebirths in Alberta, Canada, from April 15, 2019, to April 14, 2021. Descriptive statistics characterized the samples. Chi-squares and two-sample t-tests statistically compared samples. Multivariable logistic regression identified predictor variables.

Results

General characteristics, pregnancy and labor complications, and infant outcomes were similar for the two time periods. Preterm birth and low birthweight predicted NICU admission. During the pandemic, prevalence of hospital visits and rehospitalization after discharge decreased for all infants and hospital visits after discharge decreased for NICU-admitted neonates. The odds of hospital revisits and rehospitalization after discharge were higher among newborns with COVID-19 at birth.

Conclusions

Most of the findings are contextualized on pandemic-related stressors (rather than COVID-19 infection) and are briefly compared with other countries. Hospitals in Alberta appeared to adapt well to COVID-19 since health conditions were comparable between the two time periods and COVID-19 infection among mothers or newborns resulted in few observable impacts. Further investigation is required to determine causal reasons for changes in hospital utilization during the pandemic and greater birthweight among pandemic-born infants.

Pregnancy and perinatal outcomes of women with SARS-CoV-2 infection during pregnancy

INTRODUCTION

This study aimed to compare the pregnancy and perinatal outcomes of women with and without severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy.

METHODS

Women who delivered in an obstetric unit from March 2022 to October 2022 were recruited. The history of vaccination and SARS-CoV-2 infection during pregnancy was recorded. The pregnancy and perinatal outcomes of women with and without SARS-CoV-2 infection were compared.

RESULTS

A total of 1015 women were recruited - 41.5% had SARS-CoV-2 infection during pregnancy and 25.2% were unvaccinated. The incidences of preeclampsia, gestational diabetes mellitus and caesarean section were similar between the two groups. There were more preterm deliveries (9.0% vs 5.1%, P = 0.01) and more late preterm deliveries of between 33 and 36 + 6 weeks (6.2% vs. 3.7%, P = 0.03) in the SARS-CoV-2 infection group. There were no statistically significant differences between the two groups in perinatal outcomes, including birthweight, incidence of small for gestational age, low Apgar scores, and neonatal intensive care or special care baby unit admissions. There were no differences in pregnancy and perinatal outcomes between women infected in the first/second trimester and those infected in the third trimester, except for lower mean birthweight (3180 g vs. 3292 g, P = 0.04). There were no major differences in pregnancy outcome between vaccinated and unvaccinated women.

CONCLUSION

The pregnancy and perinatal outcomes of women who were infected with SARS-CoV-2 during gestation appear favourable.

SARS-CoV-2 Infection Among Newborn Infants: A Scoping Review

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection of mothers may increase the risk of complications and adverse birth outcomes among newborn infants born more than 37 weeks' gestation.

PURPOSE

The aim of this scoping review is to identify the research gaps in the literature on SARS-CoV-2 positive newborn infants born at more than 37 weeks' gestation in United States (U.S.).

DATA SOURCES

A search for relevant articles was conducted using multiple resources including three databases CINAHL, Ovid MEDLINE, and Web of Science. This scoping review included case reports, case series, cohort, and retrospective studies focusing on newborn infants born more than 37 weeks of gestation with SARS-CoV-2 infection.

STUDY SELECTION

A total of 4262 citations were screened, and 12 articles met the eligibility criteria.

DATA EXTRACTION

Two authors independently screened the articles using a multi-step approach.

RESULTS

This review identified the gaps in literature on newborn infants up to one month of age. Few studies have focused on SARS-CoV-2 positive newborn infants born more than 37 gestational weeks. This review demonstrates a higher prevalence of community-acquired SARS-CoV-2 infections among infants following discharge.

IMPLICATIONS OF PRACTICE AND RESEARCH

Few U.S. based studies have focused on newborn infants born more than 37 weeks' gestation with SARS-CoV-2 infection. Future follow-up studies are essential on these infants especially during the first 30 days of life. Discharge teaching on SARS-CoV-2 infection is vital in reducing community transmission, admissions, and emergency department visits.

Seroprevalence and placental transfer of SARS-CoV-2 antibodies in unvaccinated pregnant women

PURPOSE

Pregnant women are at risk of severe SARS-CoV-2 infection, potentially leading to obstetric and neonatal complications. Placental transfer of antibodies directed to SARS-CoV-2 may be protective against neonatal COVID-19, but this remains to be studied. We aimed to determine the seroprevalence of SARS-CoV-2 antibodies in a population of unvaccinated pregnant women and to determine the placental transfer of these antibodies.

METHODOLOGY

A total of 1197 unvaccinated women with mostly unknown pre-study SARS-CoV-2 infection status, were tested at delivery for SARS-CoV-2 spike protein IgG antibodies during the first year of the pandemic. Umbilical cord samples were collected and assessed for seropositivity if the mother was seropositive. Maternal characteristics, pregnancy and neonatal outcomes and data on SARS-CoV-2 infection were extracted from medical records.

RESULTS

Specific IgG were detected in 258 women (21.6%). A significant placental transfer to the newborn was observed in 81.3% of cases. The earlier in the 2nd and 3rd trimesters that the mother had contracted the disease and the more symptomatic she was, the greater the likelihood of transplacental transfer of IgG to her newborn.

CONCLUSION

Approximately one in five women had detectable anti-SARS-CoV-2 spike protein IgG antibodies at delivery during the first year of the pandemic, and these antibodies were significantly transferred to their fetuses. This research provides further evidence to better understand the dynamics of the placental transfer of SARS-CoV-2 IgG antibodies from mothers to their newborns, which is necessary to improve vaccination strategies.

Nationwide Analysis of the Outcomes and Mortality of Hospitalized Infants with Concomitant Diagnosis of COVID-19

OBJECTIVE

Coronavirus disease 2019 (COVID-19) generally causes milder illness in the pediatric population. However, infants represent a higher-risk population with evolving symptomatology and severity. There is a paucity of large population-based data on the impact of COVID-19 on hospitalized infants.

STUDY DESIGN

In this large cohort study, the National Inpatient Sample database was queried for all infant hospital admissions between January and December 2020 in the United States, with and without a diagnosis of COVID-19 based on ICD-10-CM U07. The mortality and morbidity of infants with and without COVID-19 were evaluated. Parent-reported race and outcomes were also analyzed.

RESULTS

A weighted total of 3,754,236 infants who were hospitalized were identified, of which 4,265 patients (0.11%) had a concomitant diagnosis of COVID-19. Infants with COVID-19 had similar mortality and extracorporeal membrane oxygenation utilization. Infants with concomitant COVID-19 had a higher rate of respiratory failure, congestive heart failure, acute kidney injury, and coagulopathy. Compared with Caucasian infants and Asian infants, Hispanic and African American infants were more likely to have COVID-19 hospital admissions than hospitalizations without COVID-19 diagnosis. Patients with lower median household income represented the majority of the COVID-19 hospitalization. The infants with COVID-19 were more likely to have Medicaid or Medicare insurance and less likely to have private insurance.

CONCLUSION

In this large cohort of hospitalized infants with COVID-19, the infection was associated with complications, including respiratory failure and endotracheal intubations but not associated with a higher risk for mortality. Infants from racial minorities and lower socioeconomic strata carry the highest burden of COVID-19 infection.

KEY POINTS

· Infants with COVID-19 represent a higher-risk group with evolving symptomatology and severity.. · Infants with COVID-19 had similar mortality rates and extracorporeal membrane oxygenation utilization as those without COVID-19.. · Racial minorities and lower socioeconomic strata carry the highest burden of COVID-19 infection..

Maternal COVID-19 Infection Associated with Fetal Systemic Inflammatory Complications in COVID-19-Negative Neonates: A Case-Series

OBJECTIVE

This study aimed to examine fetal and neonatal inflammatory and neurologic complications associated with maternal coronavirus disease 2019 (COVID-19) infection.

STUDY DESIGN

Case-series using a convenience sample of neonates cared for in a large referral-based children's hospital neonatal intensive care unit between September 2021 and May 2022.

RESULTS

We identified seven neonates with exposure to maternal severe acute respiratory syndrome related coronavirus 2 (SARS-CoV-2) and a presentation consistent with inflammatory complications. All had some degree of neurologic injury with neuroimaging findings including restricted diffusion indicating injury in the white matter, cortex, deep gray structures, and splenium of the corpus callosum as well as intracranial hemorrhage. In addition, many infants had cytopenia and abnormal coagulation studies. Placental pathology, when available, revealed inflammation, clot with calcifications, and hematomas with associated infarcts.

CONCLUSION

Neonates born to mothers with SARS-CoV-2, even when negative for the virus themselves, may have complications consistent with a systemic inflammatory syndrome. Placental pathology as well as neurologic imaging in infants with neurologic findings may help to support this diagnosis.

KEY POINTS

· A systemic inflammatory response may cause illness in babies born to mothers with a history of COVID-19.. · Inflammatory markers and placental pathology are helpful in supporting this diagnosis.. · Consider neuroimaging in infants of mothers with a history of COVID-19 with neurologic findings..

Prevalence of SARS-CoV-2 in newborns born to SARS-CoV-2-positive mothers at 2 weeks of life

Introduction

Limited evidence exists on management recommendations for neonates born to SARS-CoV-2-positive mothers. This study looked at transmission risk of neonates presenting for primary care in a large regional health system within New York during the early months of the COVID-19 pandemic.

Methods

This was a prospective, observational study of newborns born to SARS-CoV-2-positive mothers presenting at any of the 19 Northwell Health-Cohen Children's Medical Center primary care practices who underwent another oropharyngeal/nasopharyngeal swab for detection of SARS-CoV-2 by day of life (DOL) 14.

Results

Among 293 newborns born to SARS-CoV-2-positive mothers who were negative at birth, 222 were retested at DOL 14, corresponding to times with different predominant strains. Of these, seven tested positive but had no symptoms.

Conclusion

The overall low transmission rates and absence of symptomatic infection support the safety of direct breastfeeding after hospital discharge with appropriate hand and breast hygiene.

Characteristics and outcomes of neonates hospitalised with SARS-CoV-2 infection in the UK by variant: a prospective national cohort study

OBJECTIVE

Neonatal infection with wildtype SARS-CoV-2 is rare and good outcomes predominate. We investigated neonatal outcomes using national population-level data to describe the impact of different SARS-CoV-2 variants.

DESIGN

Prospective population-based cohort study.

SETTING

Neonatal, paediatric and paediatric intensive care inpatient care settings in the UK.

PATIENTS

Neonates (first 28 days after birth) with confirmed SARS-CoV-2 infection who received inpatient care, March 2020 to April 2022. Neonates were identified through active national surveillance with linkage to national SARS-CoV-2 testing data, routinely recorded neonatal data, paediatric intensive care data and obstetric and perinatal mortality surveillance data.

OUTCOMES

Presenting signs, clinical course, severe disease requiring respiratory support are presented by the dominant SARS-CoV-2 variant in circulation at the time.

RESULTS

344 neonates with SARS-CoV-2 infection received inpatient care; breakdown by dominant variant: 146 wildtype, 123 alpha, 57 delta and 18 omicron. Overall, 44.7% (153/342) neonates required respiratory support; short-term outcomes were good with 93.6% (322/344) of neonates discharged home. Eleven neonates died: seven unrelated to SARS-CoV-2 infection, four were attributed to neonatal SARS-CoV-2 infection (case fatality 4/344, 1.2% 95% CI 0.3% to 3.0%) of which three were born preterm due to maternal COVID-19. More neonates were born very preterm (23/54) and required invasive ventilation (27/57) when delta variant was predominant, and all four SARS-CoV-2-related deaths occurred in this period.

CONCLUSIONS

Inpatient care for neonates with SARS-CoV-2 was uncommon. Although rare, severe neonatal illness was more common during the delta variant period, potentially reflecting more severe maternal disease and associated preterm birth.

TRIAL REGISTRATION NUMBER

ISRCTN60033461.

Possibility of intrauterine transmission from mother to fetus/newborn: Systematic review and meta-analysis of diagnostic methods to detect SARS-CoV-2 infection

Several studies have reported vertical transmission of SARS-CoV-2; however, information regarding intrauterine transmission based on diagnostic methods to detect SARS-CoV-2 infection is scarce. A systematic review and meta-analysis was conducted to identify and explore the studies that attempt to ascertain the possibility of intrauterine transmission of SARS-CoV-2 infection according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA 2020) statement. The results demonstrate that SARS-CoV-2 can be transmitted intrauterine, as detected by clinical manifestations (1.00, 95 % CI: 1.00 - 1.00, 0.51, 95 % CI: 0.22 - 0.80), imaging (0.50, 95 % CI: 0.24 - 0.76, 0.03, 95 % CI: 0.00 - 0.17), molecular (1. 00, 95 % CI: 1.00 - 1.00, 0.92, 95 % CI: 0.77 - 1.00), immunological (0.32, 95 % CI: 0.10 - 0.57, 0.34, 95 % CI: 0.11 - 0.61), and histological approaches (0.79, 95 % CI: 0.52 - 0.98) in maternal and fetal/neonatal specimens, respectively. The possibility of intrauterine transmission of SARS-CoV-2 from mother to fetus/newborn was 41 % (95 % CI 0.37 - 0.45). We might confirm/verify the intrauterine transmission of SARS-CoCV-2 from mother to fetus/newborn.

Burden of Respiratory Syncytial Virus-Associated Acute Respiratory Infections During Pregnancy

BACKGROUND

With the licensure of maternal respiratory syncytial virus (RSV) vaccines in Europe and the United States, data are needed to better characterize the burden of RSV-associated acute respiratory infections (ARI) in pregnancy. The current study aimed to determine among pregnant individuals the proportion of ARI testing positive for RSV and the RSV incidence rate, RSV-associated hospitalizations, deaths, and perinatal outcomes.

METHODS

We conducted a systematic review, following PRISMA 2020 guidelines, using 5 databases (Medline, Embase, Global Health, Web of Science, and Global Index Medicus), and including additional unpublished data. Pregnant individuals with ARI who had respiratory samples tested for RSV were included. We used a random-effects meta-analysis to generate overall proportions and rate estimates across studies.

RESULTS

Eleven studies with pregnant individuals recruited between 2010 and 2022 were identified, most of which recruited pregnant individuals in community, inpatient and outpatient settings. Among 8126 pregnant individuals, the proportion with ARI that tested positive for RSV ranged from 0.9% to 10.7%, with a meta-estimate of 3.4% (95% confidence interval [CI], 1.9%-54%). The pooled incidence rate of RSV among pregnant individuals was 26.0 (95% CI, 15.8-36.2) per 1000 person-years. RSV hospitalization rates reported in 2 studies were 2.4 and 3.0 per 1000 person-years. In 5 studies that ascertained RSV-associated deaths among 4708 pregnant individuals, no deaths were reported. Three studies comparing RSV-positive and RSV-negative pregnant individuals found no difference in the odds of miscarriage, stillbirth, low birth weight, and small size for gestational age. RSV-positive pregnant individuals had higher odds of preterm delivery (odds ratio, 3.6 [95% CI, 1.3-10.3]).

CONCLUSIONS

Data on RSV-associated hospitalization rates are limited, but available estimates are lower than those reported in older adults and young children. As countries debate whether to include RSV vaccines in maternal vaccination programs, which are primarily intended to protect infants, this information could be useful in shaping vaccine policy decisions.

Vertical transmission of SARS-CoV-2 - data from the German COVID-19 related obstetric and neonatal outcome study (CRONOS)

OBJECTIVES

We aimed to determine the frequency of SARS-CoV-2 positivity in newborns born to mothers with peripartum SARS-CoV-2 infection in a German cohort, to identify potential risk factors associated with neonatal SARS-CoV-2 infection, and to present short-term outcomes of newborns with vertical transmission of SARS-CoV-2.

METHODS

Data on women with SARS-CoV-2 infection occurring anytime during their pregnancy was gathered prospectively within the CRONOS registry. From April 2020 to February 2023 a total of 8,540 women had been registered. The timing and the probability of mother-to-child transmission in neonates born to women with perinatal SARS-CoV-2 infection were classified using the WHO classification system. The severity of maternal infection, maternal vaccination status, type of dominant virus, and perinatal outcome parameters were analyzed as potential risk factors for neonatal SARS-CoV-2 infection.

RESULTS

6.3 % resp. 42.9 % of tested newborns and stillbirths were SARS-CoV-2 positive. 2.1 % of newborns with confirmed and possible SARS-CoV-2 infection were identified. Severe maternal COVID-19 (odds ratio 4.4, 95 % confidence interval 1.8-11.1) and maternal infection with the Delta virus (OR 3.2, 1.4-7.7) were associated with neonatal SARS-CoV-2 infection. Newborns with a confirmed or possible infection were significantly more often admitted to the NICU (65.2 % neonatal infection vs. 27.5 % non, p<0.001).

CONCLUSIONS

The rate of neonatal SARS-CoV-2 positivity was higher in our cohort than previously reported, neonatal SARS-CoV-2 infections were rare. Our data emphasizes confirmative testing should be performed in newborns of SARS-CoV-2 infected mothers to identify neonatal SARS-CoV-2 infection as an underlying pathology leading to NICU admission.

Newborn Hospitalizations Before and During COVID-19 Pandemic in Poland: A Comparative Study Based on a National Hospital Registry

Objectives: There are limited data on the impact of the COVID-19 outbreak in Poland on newborn health. The aim of the study is to show recent information on hospitalizations of newborns in Poland in the pre-pandemic and COVID-19 pandemic era. Methods: A retrospective, population-based study was conducted using data from hospital discharge records of patients hospitalized in 2017-2021. Results: The data on which the study was based consisted of a substantial number of 104,450 hospitalization records. Annual hospitalization rate was estimated to be 50.3-51.9 per 1,000 in 2017-2019, 56 per 1,000 in 2020 and it rose to 77.7 per 1,000 in 2021. In comparison to the pre-pandemic period, in the COVID-19 era, we observed significantly more hospitalization cases of newborns affected by maternal renal and urinary tract diseases (p < 0.001), syndrome of infant of mother with gestational diabetes (p < 0.001), maternal complications of pregnancy (p < 0.001). In the COVID-19 era, the prevalence of COVID-19 among newborns was 4.5 cases per 1,000 newborn hospitalizations. Conclusion: The COVID-19 pandemic outbreak could significantly contribute to qualitative and quantitative changes in hospitalizations among newborns.

Assessment of severity and feto-maternal outcomes among COVID-19 infected pregnant females hospitalized at tertiary care center in western Nepal

Objective

There is a paucity of data assessing the severity of coronavirus disease 2019 (COVID-19) infection and feto-maternal outcomes in pregnant women in Nepal, especially during the third wave of the pandemic with the Delta variant. This study aimed to severity as well as maternal-fetal outcomes among pregnant women with COVID-19 infection.

Methods

In this cross-sectional study carried out amongst COVID-19 positive pregnant women visiting our institution for 6 months from January through June 2022, data surrounding COVID-19 severity and fetal outcomes were collected in a structured questionnaire. Disease severity was categorized based on the NIH (National Institutes of Health) severity classification. Descriptive statistics were used to describe the outcomes.

Results

A total of 105 pregnant females infected with COVID-19 during the third wave were included in our study. The participants ranged from 16 through 40 years, mean gestational age being 36.6 weeks. Most of the women (40.55%) belonged to Brahmin and Chhetri ethnic backgrounds. About half (48.55%) of females were asymptomatic and four patients had severe disease requiring intensive care management. Only 13 pregnant females underwent vaccination. Of the 91 females that underwent delivery at our center, 77 (84.62%) were term. The rate of cesarean delivery was slightly higher (51.65%) than normal delivery. None of the babies born to COVID-positive pregnant females tested positive for COVID-19 and there were no stillbirths or any congenital anomalies. The majority of babies (68.14%) had normal fetal weight.

Conclusion

Severe COVID-19 infection and adverse maternal-fetal outcomes during the third wave of COVID-19 infection with the Delta variant in Nepal were less than in other regions of the world despite low rates of vaccination.

Adverse perinatal outcomes in gestational diabetes mellitus with and without SARS-CoV-2 infection during pregnancy: results from two nationwide registries in Germany

INTRODUCTION

Pregnancy is a known independent risk factor for a severe course of COVID-19. The relationship of SARS-CoV-2 infection and gestational diabetes mellitus (GDM) on neonatal outcomes is unclear. Our aim was to determine if SARS-CoV-2 infection represents an independent risk factor for adverse perinatal outcomes in pregnancy with GDM.

RESEARCH DESIGN AND METHODS

We compared data from two German registries including pregnant women with GDM, established during the SARS-CoV-2 pandemic (COVID-19-Related Obstetric and Neonatal Outcome Study (CRONOS), a multicenter prospective observational study) and already existing before the pandemic (German registry of pregnant women with GDM; GestDiab). In total, 409 participants with GDM and SARS-CoV-2 infection and 4598 participants with GDM, registered 2018-2019, were eligible for analyses. The primary fetal and neonatal outcomes were defined as: (1) combined: admission to neonatal intensive care unit, stillbirth, and/or neonatal death, and (2) preterm birth before 37+0 weeks of gestation. Large and small for gestational age, maternal insulin therapy, birth weight >4500 g and cesarean delivery were considered as secondary outcomes.

RESULTS

Women with SARS-CoV-2 infection were younger (32 vs 33 years) and had a higher median body mass index (28 vs 27 kg/m²). In CRONOS, more neonates developed the primary outcome (adjusted OR (aOR) 1.48, 95% CI 1.11 to 1.97) and were born preterm (aOR 1.50, 95% CI 1.07 to 2.10). Fasting glucose was higher in women in CRONOS versus GestDiab (5.4 vs 5.3 mmol/L) considering each 0.1 mmol/L increase was independently associated with a 5% higher risk of preterm birth among women in CRONOS only (aOR 1.05, 95% CI 1.01 to 1.09).

CONCLUSIONS

GDM with SARS-CoV-2 infection in pregnancy is associated with an increased risk of adverse fetal and neonatal outcomes as compared with GDM without SARS-CoV-2 infection.

Impact on the first year of life of newborns with gestational infection by SARS-COV-2. Analysis of auditory effects

Introduction

One of the causes of congenital hearing loss are infections suffered by the mother during pregnancy. The objective of this study was to investigate the effects on hearing in newborns to SARS-CoV-2 seropositive mothers during pregnancy. We also studied the hearing impact in the first year of life of the newborns to investigate whether neonatal infection produced a risk of infantile sensorineural hearing loss.

Material and methods

All children born in our center whose mother had been infected with SARS-CoV-2 positive COVID were included and were audiologically studied at two and a half months and at one year of life. All infants were evaluated by brainstem evoked response audiometry (BERA) and auditory steady-state responses (ASSR).

Results

The range of the latencies for BERA founded were inside the desired ranges of normality both at two and a half months and at one year of life No significant differences by sex and ears were found in the BERA performed (p > 0,05). The mean ASSR values were found to be significantly below 30 dB in all frequencies studied both at two and a half months, and at one year of life (p < 0,05).

Conclusion

There is no association between COVID-19 infection during pregnancy and neonatal hearing loss. Further studies are needed to clarify this field since it is still unclear whether pregnant women infected with SARS-CoV-2 can produce hearing alterations in their newborns according to the current evidence in the literature.

Neonatal outcomes of maternal prenatal coronavirus infection

The coronavirus disease 2019 (COVID-19) pandemic has led to significant changes in life and healthcare all over the world. Pregnant women and their newborns require extra attention due to the increased risk of adverse outcomes. Adverse pregnancy outcomes include intensive care unit (ICU) admission, pulmonary, cardiac, and renal impairment leading to mortality. Immaturity and variations of the neonatal immune system may be advantageous in responding to the virus. Neonates are at risk of vertical transmission and in-utero infection. Impaired intrauterine growth, prematurity, vertical transmission, and neonatal ICU admission are the most concerning issues. Data on maternal and neonatal outcomes should be interpreted cautiously due to study designs, patient characteristics, clinical variables, the effects of variants, and vaccination beyond the pandemic. Cesarean section, immediate separation of mother-infant dyads, isolation of neonates, and avoidance of breast milk were performed to reduce transmission risk at the beginning of the pandemic in the era of insufficient knowledge. Vertical transmission was found to be low with favorable short-term outcomes. Serious fetal and neonatal outcomes are not expected, according to growing evidence. Long-term effects may be associated with fetal programming. Knowledge and lessons from COVID-19 will be helpful for the next pandemic if it occurs. IMPACT: Prenatal infection with SARS-CoV-2 is associated with adverse maternal and neonatal outcomes. Our review includes the effects of COVID-19 on the fetus and neonates, transmission routes, placental effects, fetal and neonatal outcomes, and long-term effects on neonates. There is a growing body of data and evidence about the COVID-19 pandemic. Knowledge and lessons from the pandemic will be helpful for the next pandemic if it happens.

Is SARS-CoV-2 vertical transmission still a current problem? A case report on a diagnosed SARS-CoV-2 infection with a positive sample of urines

BACKGROUND AND AIM

Current data suggest little to no possibility of original COVID-19 transmission in pregnant women to the fetus during pregnancy or childbirth. Warning with Omicron new variants has decreased.

CASE REPORT

A clinical case of a SARS-CoV-2 virus transplacental infection of a newborn, born at the end of 2022, from a mother who tested positive for Sars-covid-2 and positive IgM SARS-CoV-2 anti-virus. The newborn tested positive for SARS-CoV-2 12 hours after birth, and was clinically symptomatic after three days, an increase in IgM antibodies was not found, although the virus was identified in the urine samples through molecular tests. The insufficient time to determine the presence of antibodies and the immune system's state of immaturity can explain the lack of IgM in the newborn's blood at 14 days after birth.

CONCLUSIONS

The Omicron SARS-CoV-2 keeps provoking infections among newborns, especially if the mother contracts it during the third trimester. The host response is most likely influenced by the newborn's peculiar state of immune immaturity. Just before birth, a positive nasal swab and the presence of a positive urine examination confirmed the diagnosis of intraplacental exposure. Research on the virus through molecular tests of urines can represent an additional technique when an aetiological framework of the infection is necessary and a distinction between congenital and post-natal forms.

Preeclampsia to COVID-19: A journey towards improved placental and vascular function using sulforaphane

Excess inflammation and oxidative stress are common themes in many pathologies of pregnancy including preeclampsia and more recently severe COVID-19. The risk of preeclampsia increases following maternal infection with COVID-19, potentially relating to significant overlap in pathophysiology with endothelial, vascular and immunological dysfunction common to both. Identifying a therapy which addresses these injurious processes and stabilises the endothelial and vascular maternal system would help address the significant global burden of maternal and neonatal morbidity and mortality they cause. Sulforaphane is a naturally occurring phytonutrient found most densely within cruciferous vegetables. It has anti-inflammatory, antioxidant and immune modulating properties via upregulation of phase-II detoxification enzymes. This review will cover the common pathways shared by COVID-19 and preeclampsia and offer a potential therapeutic target via nuclear factor erythroid 2-related factor upregulation in the form of sulforaphane.

Histological Alterations in Placentas of Pregnant Women with SARS-CoV-2 Infection: A Single-Center Case Series

This study aimed to investigate the histopathological changes associated with SARS-CoV-2 infection in placentas. A case series of anatomopathological analysis was conducted on the placentas of pregnant women with SARS-CoV-2 who delivered between March and December 2020 at Santo Amaro Hospital (HSA) in Salvador, Brazil. Out of the 29 placentas examined, the median weight was 423.0 (IQR: 385.0-521.0) g. Among them, 58.3% (n = 14) had inadequate weight relative to the newborn's weight. The histopathological findings revealed that 86.2% (n = 25) of the placentas had poorly defined lobes, and the fetal and maternal surface color was normal in 89.7% (n = 26) and 93.1% (n = 27), respectively. Additionally, 51.7% (n = 15) of the umbilical cords displayed hypercoiling. The most frequent microscopic finding was infarction, present in 35.3% (n = 6) of the cases, followed by 11.8% (n = 2) for each of chorioamnionitis, chronic villitis, focal perivillositis, and laminar necrosis. Analysis of the umbilical cords identified 23.5% (n = 4) cases of intervillous thrombosis, while amnion analysis showed 13.8% (n = 4) cases of squamous metaplasia. Extraplacental membrane examination revealed fibrin deposition in 93.1% (n = 27) of the cases, necrosis in 62.0% (n = 18), calcifications in 51.7% (n = 15), cysts in 37.9% (n = 11), neutrophilic exudate in 17.2% (n = 5), thrombosis in 13.7% (n = 4), and delayed placental maturation in 6.9% (n = 2). All analyzed placentas exhibited histopathological changes, primarily vascular and inflammatory, which indicate SARS-CoV-2 infection in term pregnancies. These alterations could be associated with impaired placental function, fetal growth restriction, preeclampsia, and prematurity. However, further prospective studies are required to validate the type, prevalence, and prognosis of each of these changes.

Developing and testing a protocol using a common data model for federated collection and analysis of national perinatal health indicators in Europe

Context: International comparisons of the health of mothers and babies provide essential benchmarks for guiding health practice and policy, but statistics are not routinely compiled in a comparable way. These data are especially critical during health emergencies, such as the coronavirus disease (COVID-19) pandemic. The Population Health Information Research Infrastructure (PHIRI) project aimed to promote the exchange of population data in Europe and included a Use Case on perinatal health. Objective: To develop and test a protocol for federated analysis of population birth data in Europe. Methods: The Euro-Peristat network with participants from 31 countries developed a Common Data Model (CDM) and R scripts to exchange and analyse aggregated data on perinatal indicators. Building on recommended Euro-Peristat indicators, complemented by a three-round consensus process, the network specified variables for a CDM and common outputs. The protocol was tested using routine birth data for 2015 to 2020; a survey was conducted assessing data provider experiences and opinions. Results: The CDM included 17 core data items for the testing phase and 18 for a future expanded phase. 28 countries and the four UK nations created individual person-level databases and ran R scripts to produce anonymous aggregate tables. Seven had all core items, 17 had 13-16, while eight had ≤12. Limitations were not having all items in the same database, required for this protocol. Infant death and mode of birth were most frequently missing. Countries took from under a day to several weeks to set up the CDM, after which the protocol was easy and quick to use. Conclusion: This open-source protocol enables rapid production and analysis of perinatal indicators and constitutes a roadmap for a sustainable European information system. It also provides minimum standards for improving national data systems and can be used in other countries to facilitate comparison of perinatal indicators.

Impact of COVID-19 on pregnant women's health: Consequences in obstetrics two years after the pandemic

The pandemic linked to SARS-CoV-2 has profoundly disrupted the health systems and many studies have led to a better understanding of this virus, which is responsible for severe disease, particularly during pregnancy. Pregnancy is a risk factor for severe COVID-19. Term of pregnancy and vaccination status is the main risk factor in addition to classic comorbidities like general population. COVID-19 during pregnancy is responsible for more maternal death, stillbirth, pre-eclampsia spontaneous and induced prematurity. Vaccination is therefore strongly recommended for pregnant patients. In addition, the COVID-19 pandemic has highlighted a psychological and social dimension that should not be neglected in the management of a pregnant patient. Correlation between immunological changes and clinical impact are described in this review. Many conclusions can now be made and are summarized in this article in order to discuss possible future research.

Transplacental transfer of anti-SARS-CoV-2 neutralizing antibodies in comparison to other pathogens total antibodies

BACKGROUNDS

Due to immaturity of their immune system, passive maternal immunization is essential for newborns during their first months of life. Therefore, in the current context of intense circulation of SARS-CoV-2, identifying factors influencing the transfer ratio (TR) of neutralizing antibodies against SARS-CoV-2 (NAb) appears important.

METHODS

Our study nested in the COVIPREG cohort (NCT04355234), included mothers who had a SARS-CoV-2 PCR positive during their pregnancy and their newborns. Maternal and neonatal NAb levels were measured with the automated iFlash system.

RESULTS

For the 173 mother-infant pairs included in our study, the median gestational age (GA) at delivery was 39.4 weeks of gestation (WG), and 29.7 WG at maternal SARS-CoV-2 infection. Using a multivariate logistic model, having a NAb TR above 1 was positively associated with a longer delay from maternal positive SARS-CoV-2 PCR to delivery (aOR 1.09, 95% CI: 1.03 - 1.17) and with a later GA at delivery (aOR = 1.58, 95% CI: 1.09 - 2.52). It was negatively associated with being a male newborn (aOR 0.21, 95% CI: 0.07 - 0.59). In 3rd trimester SARS-CoV-2 infected mothers, NAb TR was inferior to VZV, toxoplasmosis, CMV, measle and rubella's TR. However, in 1st or 2nd trimester infected mothers, only measle TR was different from NAb TR.

CONCLUSION

Male newborn of mothers infected by SARS-CoV-2 during their pregnancy appear to have less protection against SARS-CoV-2 in their first months of life than female newborns. Measle TR was superior to NAb TR even in case of 1st or 2nd trimester maternal SARS-CoV-2 infection. Future studies are needed to investigate possible differences in transmission of NAb following infection vs vaccination and its impact on TR.

Sustained and Boosted Antibody Responses in Breast Milk After Maternal SARS-CoV-2 Vaccination

Background: Pregnant and lactating women were not included in the initial large vaccine clinical trials for SARS-CoV-2 (COVID) infection. Delineating the antibody titers in serum and breast milk of lactating women is important to determine the safety and benefits of vaccination in this special population. Objective: To investigate COVID vaccinations in breastfeeding dyads and effects on lactation, the Antibody Detection of Vaccine-Induced Secretory Effects trial (ADVISE) prospectively evaluated anti-COVID antibodies in serum and breast milk after initial paired and booster vaccines. Methods: This is a prospective longitudinal surveillance cohort study of lactating women. Eligibility criteria included ≥18 years of age, currently lactating, and at enrollment either received COVID vaccination within the past 60 days or planning vaccination within 60 days. Results: Among 63 lactating mothers, COVID vaccination led to breast milk secretory IgA (sIgA) and IgG antibodies with consistent viral neutralizing activity. Milk sIgA titers increased further after second vaccination and were prolonged after a third booster dose, including women with extended breastfeeding beyond 12 months. Milk IgG antibody titers were higher and more sustained than sIgA. Antibody titers were not associated with individual dyad characteristics or vaccine manufacturer. Vaccine-induced antibodies from milk were not detected in infant circulation. Conclusions and Relevance: Maternal COVID vaccination during lactation is well tolerated and generates sustained and boosted antibody responses in breast milk. COVID-specific sIgA and IgG antibodies with neutralizing activity are found in breast milk, including boosted mothers who continue breastfeeding beyond 12 months. These data support universal COVID vaccinations for all lactating mothers, including booster immunizations during extended breastfeeding (NCT04895475).

Methodological quality and reporting quality of COVID-19 living systematic review: a cross-sectional study

OBJECTIVES

The main objective of this study is to evaluate the methodological quality and reporting quality of living systematic reviews (LSRs) on Coronavirus disease 2019 (COVID-19), while the secondary objective is to investigate potential factors that may influence the overall quality of COVID-19 LSRs.

METHODS

Six representative databases, including Medline, Excerpta Medica Database (Embase), Cochrane Library, China national knowledge infrastructure (CNKI), Wanfang Database, and China Science, Technology Journal Database (VIP) were systematically searched for COVID-19 LSRs. Two authors independently screened articles, extracted data, and then assessed the methodological and reporting quality of COVID-19 LSRs using the "A Measurement Tool to Assess systematic Reviews-2" (AMSTAR-2) tool and "Preferred Reporting Items for Systematic reviews and Meta-Analyses" (PRISMA) 2020 statement, respectively. Univariate linear regression and multivariate linear regression were used to explore eight potential factors that might affect the methodological quality and reporting quality of COVID-19 LSRs.

RESULTS

A total of 64 COVID-19 LSRs were included. The AMSTAR-2 evaluation results revealed that the number of "yes" responses for each COVID-19 LSR was 13 ± 2.68 (mean ± standard deviation). Among them, 21.9% COVID-19 LSRs were rated as "high", 4.7% as "moderate", 23.4% as "low", and 50% as "critically low". The evaluation results of the PRISMA 2020 statement showed that the sections with poor adherence were methods, results and other information. The number of "yes" responses for each COVID-19 LSR was 21 ± 4.18 (mean ± standard deviation). The number of included studies and registration are associated with better methodological quality; the number of included studies and funding are associated with better reporting quality.

CONCLUSIONS

Improvement is needed in the methodological and reporting quality of COVID-19 LSRs. Researchers conducting COVID-19 LSRs should take note of the quality-related factors identified in this study to generate evidence-based evidence of higher quality.

Use of Monoclonal Antibodies in Pregnant Women Infected by COVID-19: A Case Series

BACKGROUND

Monoclonal antibodies are designed to target specific proteins of COVID-19 and can be used as a treatment for people with mild to moderate infection and at a high risk of severe disease. Casirivimab/imdevimab, sotrovimab, and Bamlanivimab/etesevimab have been authorized for emergency use in the treatment of COVID-19. However, during pregnancy, these drugs have not been extensively studied.

METHODS

A total of 22 pregnant women with mild to moderate infection were treated with three different monoclonal antibodies, and efficacy and safety were evaluated in the first period and until six months of follow-up.

RESULTS

No infusion/allergic reactions occurred. No fatal or adverse events were observed in the pregnant women or fetus. The time of negativization with sotrovimab was shorter in comparison to Imdevimav/casirivimab (p = 0.0187) and Bamlanivimab/etesevimab (p < 0.00001). The time of negativization with sotrovimab was earlier in comparison to Imdevimav/casirivimab (t-value: 2.92; p = 0.0052) in vaccinated patients and similar in comparison to Imdevimav/casirivimab (t-value: 1.48; p = 0.08). In unvaccinated patients, sotrovimab was faster to achieve negativization in comparison to Bamlanivimab/etesevimab (t-value: 10.75; p < 0.0005).

CONCLUSIONS

Pregnant COVID-19 patients receiving sotrovimab obtained better clinical outcomes. Pregnancy or neonatal complications were not observed after monoclonal treatment, confirming the safety and tolerability of these drugs in pregnant women.

Maternal Fever and Reduced Fetal Movement as Predictive Risk Factors for Adverse Neonatal Outcome in Cases of Congenital SARS-CoV-2 Infection: A Meta-Analysis of Individual Participant Data from Case Reports and Case Series

OBJECTIVES

To determine risk factors for primary and secondary adverse neonatal outcomes in newborns with congenital SARS-CoV-2 infection.

DATA SOURCES

PubMed/MEDLINE and Google Scholar from January 2020 to January 2022.

STUDY ELIGIBILITY CRITERIA

newborns delivered after 24 weeks of gestation with confirmed/possible congenital SARS-CoV-2 infection, according to standard classification criteria.

METHODS

Execution of the IPD analyses followed the PRISMA-IPD statement. Univariate non-parametric tests compared numerical data distributions. Fisher's exact or Chi-square test determined categorical variables' statistical significance. Multivariate logistic regression revealed risk factors for adverse neonatal outcome.

RESULTS

Maternal fever was associated with symptomatic congenital infection (OR: 4.55, 95% CI: 1.33-15.57). Two-thirds of women that reported decreased fetal movements were diagnosed with IUFD (p-value = 0.001). Reduced fetal movement increased the risk of intrauterine fetal death by 7.84 times (p-value = 0.016, 95% CI: 2.23-27.5). The risk of stillbirth decreased with gestational age at the time of maternal infection (p-value < 0.05, OR: 0.87, 95% CI: 0.79-0.97).

CONCLUSIONS

Maternal fever and perception of reduced fetal movement may be predictive risk factors for adverse pregnancy outcome in cases with congenital SARS-CoV-2 infection.

[Clinical characteristics of neonates infected with the Omicron variant of SARS-CoV-2: a multicenter cross-sectional survey]

OBJECTIVES

To investigate the clinical characteristics of neonates infected with the Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

METHODS

A cross-sectional survey was conducted on 542 hospitalized neonates with confirmed coronavirus disease 2019 (COVID-19) in 27 hospitals in Shenzhen from December 7, 2022, to January 12, 2023 (during the Omicron variant epidemic period). The neonates were divided into two groups: asymptomatic infection and symptomatic infection. The clinical characteristics, results of laboratory examination, chest X-ray findings, and outcome were compared between the two groups.

RESULTS

Among the 542 neonates, there were 285 males and 257 females. Among them, 515 (95.0%) were full-term infants, and 27 (5.0%) were preterm infants. The asymptomatic infection group had 60 cases, and the symptomatic infection group had 482 cases. Among them, 336 cases (69.7%) were mild, 125 cases (25.9%) were moderate, 15 cases (3.1%) were severe, and 6 cases (1.2%) were critical. Fever was the most common symptom (434 cases, 90.0%), followed by cough and/or spitting (183 cases, 38.0%), nasal congestion and/or runny nose (131 cases, 27.2%), shortness of breath (36 cases, 7.5%), and feeding intolerance (30 cases, 6.2%). Among the 325 cases who underwent chest X-ray examination, 136 cases (41.8%) had patchy or consolidative shadows in the lungs, 2 cases (0.6%) had pneumothorax, 2 cases (0.6%) had decreased lung transparency, and 185 cases (57.0%) showed no abnormality. Among the 396 cases (73.1%) who received treatment, 341 cases (86.1%) received symptomatic treatment, 137 cases (34.6%) received antibiotic treatment, 4 cases (1.0%) received immunoglobulin treatment, and 23 cases (5.8%) received respiratory support treatment. All 542 neonates were discharged from the hospital after their clinical symptoms were relieved, and the median hospital stay was 5 days. The white blood cell count, neutrophil count, hemoglobin, and procalcitonin were lower in the symptomatic infection group than those in the asymptomatic infection group (P<0.05), while the platelet count and blood glucose levels were higher in the symptomatic infection group than those in the asymptomatic infection group (P<0.05). The proportions of neonates with decreased neutrophil count, increased platelet count, and decreased hemoglobin concentration were higher in the symptomatic infection group than those in the asymptomatic group (P<0.05).

CONCLUSIONS

Most neonates with COVID-19 caused by the Omicron variant of SARS-CoV-2 are mild, with fever as the predominant symptom. Symptomatic neonates with COVID-19 are often accompanied by decreased neutrophil count, increased platelet count, and decreased hemoglobin level. Symptomatic treatment is the main treatment, and the prognosis is good.

Confirmed SARS-CoV-2 infection in Scottish neonates 2020-2022: a national, population-based cohort study

OBJECTIVES

To examine neonates in Scotland aged 0-27 days with SARS-CoV-2 infection confirmed by viral testing; the risk of confirmed neonatal infection by maternal and infant characteristics; and hospital admissions associated with confirmed neonatal infections.

DESIGN

Population-based cohort study.

SETTING AND POPULATION

All live births in Scotland, 1 March 2020-31 January 2022.

RESULTS

There were 141 neonates with confirmed SARS-CoV-2 infection over the study period, giving an overall infection rate of 153 per 100 000 live births (141/92 009, 0.15%). Among infants born to women with confirmed infection around the time of birth, the confirmed neonatal infection rate was 1812 per 100 000 live births (15/828, 1.8%). Two-thirds (92/141, 65.2%) of neonates with confirmed infection had an associated admission to neonatal or (more commonly) paediatric care. Six of these babies (6/92, 6.5%) were admitted to neonatal and/or paediatric intensive care; however, none of these six had COVID-19 recorded as their main diagnosis. There were no neonatal deaths among babies with confirmed infection.

IMPLICATIONS AND RELEVANCE

Confirmed neonatal SARS-CoV-2 infection was uncommon over the first 23 months of the pandemic in Scotland. Secular trends in the neonatal confirmed infection rate broadly followed those seen in the general population, although at a lower level. Maternal confirmed infection at birth was associated with an increased risk of neonatal confirmed infection. Two-thirds of neonates with confirmed infection had an associated admission to hospital, with resulting implications for the baby, family and services, although their outcomes were generally good. Ascertainment of confirmed infection depends on the extent of testing, and this is likely to have varied over time and between groups: the extent of unconfirmed infection is inevitably unknown.

SARS-CoV-2 infection in patients with or at risk for venereal infections: Incidence and associated factors in a sexual health clinic

BACKGROUND AND OBJECTIVE

SARS-CoV-2 is more easily spread by close contact, which is inherent to sexual intercourse. People with, or at risk for, sexually transmitted infections (STIs) may therefore have higher rates of COVID-19. The aim of this study was to estimate SARS-CoV-2 antibody seroprevalence in people seen at a dedicated STI clinic, compare our findings to the estimated seroprevalence in the local general population, and study factors associated with SARS-CoV-2 infection in this setting.

MATERIAL AND METHODS

Cross-sectional observational study including consecutive patients older than 18 years of age who had not yet been vaccinated against COVID-19 and who underwent examination or screening at a dedicated municipal STI clinic in March and April 2021. We ordered rapid SARS-CoV-2 serology and collected information on demographic, social, and sexual variables, STI diagnoses, and history of symptoms compatible with SARS-CoV-2 infection.

RESULTS

We studied 512 patients (37% women). Fourteen (24.2%) had a positive SARS-CoV-2 test. Variables associated with positivity were use of FFP2 masks (odds ratio 0.50) and a higher-than-average number of sexual partners (odds ratio 1.80). Use of FFP2 masks was not randomly distributed in this sample.

CONCLUSIONS

Sexually active members of the population in this study had a higher incidence of SARS-CoV-2 infection than the general population. The main route of infection in this group appears to be respiratory, linked to close contact during sexual encounters; sexual transmission of the virus is probably limited.

COVID-19 in third trimester of pregnancy

The COVID-19 pandemic disease, which affects the respiratory system and produces flu-like symptoms, is caused by the SARS-CoV-2 virus. It is transmitted by close contact, oronasal secretions, or droplets. In general, pregnant individuals are at increased risk than nonpregnant individuals for developing serious SARS-CoV-2 virus-related illnesses, particularly during the third trimester. Despite the lack of research on COVID-19-infected pregnant mothers, this review article has discussed the clinical and laboratory characteristics and impact of COVID-19 on delivery, management, and vaccination of pregnant individuals with COVID-19 infection.

A critical review of COVID-19 course and vaccination in dermatology patients on immunomodulatory/biologic therapy: recommendations should not differ between non-pregnant and pregnant individuals

COVID-19 can have detrimental effects on immunosuppressed patients. Here, we evaluate the evidence regarding continuing immunomodulatory/biologic (IMBI) therapy in pregnant dermatology patients during the COVID-19 pandemic. Also, we discuss the risks of COVID-19 vaccination in pregnant dermatology patients on IMBI therapy. As indicated in this review, regarding continuing IMBI therapy in pregnant dermatology patients during the pandemic, there is no compelling reason for treating them differently than non-pregnant. The body of evidence indicates that mRNA COVID-19 vaccines are safe during pregnancy. Studies on rheumatology patients, a group that overlaps significantly with the dermatology group, provided essential findings. IMBI in a non-pregnant rheumatology patient was not associated with COVID-19 mortality (except for rituximab), and vaccination of the rheumatology patient during pregnancy improved the obstetric outcomes compared to the unvaccinated patient. Based on this data, it can be stated that after weighing the benefit-risk profile of the available COVID-19 vaccines, the recommendation for the pregnant dermatology patient speaks in favor of the COVID-19 vaccination. COVID-19 vaccine recommendations in pregnant dermatology patients on IMBI should not differ from those for their non-pregnant counterparts.

Mother-to-child transmission of SARS-CoV-2 infection in high-income countries: a systematic review and meta-analysis of prospective observational studies

Mother-to-child transmission of SARS-CoV-2 has been reported since the onset of the COVID-19 pandemic. We conducted a study to summarize evidence on the risk of mother-to-child transmission in the first 30 days after birth in high-income countries and to evaluate the association between preventive measures and the risk of infection for the neonate. A systematic review and meta-analysis were undertaken following PRISMA guidelines. The National Library of Medicine, Web of Science, and Excerpta Medica databases were screened on February 26, 2022. All prospective observational studies addressing the frequency of infection in infants born to mothers SARS-CoV-2 positive were included. Twenty-six studies were included, reporting data of 2653 mothers with SARS-CoV-2 and 2677 neonates. The proportion meta-analysis pointed out an overall estimate of SARS-CoV-2 infection among infants of 2.3% (95% CI: 1.4-3.2%). Data from studies with (1.4%, 95% CI: 0.8-2) and without (1.3%, 95% CI: 0.0-2.7%) rooming-in provided similar risk of infection. Adopting at least two prevention measures during rooming-in resulted in a rate of mother-to-child infection of 1.0% (95%CI: 0.3-1.7%). The results of this study show a low rate of perinatal infection, support the rooming-in and confirm the effectiveness of preventive measures in reducing the risk of mother-to-child viral transmission.

Neuroimaging assessment of pediatric cerebral changes associated with SARS-CoV-2 infection during pregnancy

Background

SARS-CoV-2 infection and perinatal neurologic outcomes are still not fully understood. However, there is recent evidence of white matter disease and impaired neurodevelopment in newborns following maternal SARS-CoV-2 infection. These appear to occur as a consequence of both direct viral effects and a systemic inflammatory response, with glial cell/myelin involvement and regional hypoxia/microvascular dysfunction. We sought to characterize the consequences of maternal and fetal inflammatory states in the central nervous system of newborns following maternal SARS-CoV-2 infection.

Methods

We conducted a longitudinal prospective cohort study from June 2020 to December 2021, with follow-up of newborns born to mothers exposed or not exposed to SARS-CoV-2 infection during pregnancy. Brain analysis included data from cranial ultrasound scans (CUS) with grayscale, Doppler studies (color and spectral), and ultrasound-based brain elastography (shear-wave mode) in specific regions of interest (ROIs): deep white matter, superficial white matter, corpus callosum, basal ganglia, and cortical gray matter. Brain elastography was used to estimate brain parenchymal stiffness, which is an indirect quantifier of cerebral myelin tissue content.

Results

A total of 219 single-pregnancy children were enrolled, including 201 born to mothers exposed to SARS-CoV-2 infection and 18 from unexposed controls. A neuroimaging evaluation was performed at 6 months of adjusted chronological age and revealed 18 grayscale and 21 Doppler abnormalities. Predominant findings were hyperechogenicity of deep brain white matter and basal ganglia (caudate nuclei/thalamus) and a reduction in the resistance and pulsatility indices of intracranial arterial flow. The anterior brain circulation (middle cerebral and pericallosal arteries) displayed a wider range of flow variation than the posterior circulation (basilar artery). Shear-wave US elastography analysis showed a reduction in stiffness values in the SARS-CoV-2 exposed group in all analyzed regions of interest, especially in the deep white matter elasticity coefficients (3.98 ± 0.62) compared to the control group (7.76 ± 0.77); p-value < 0.001.

Conclusion

This study further characterizes pediatric structural encephalic changes associated with SARS-CoV-2 infection during pregnancy. The maternal infection has been shown to be related to cerebral deep white matter predominant involvement, with regional hyperechogenicity and reduction of elasticity coefficients, suggesting zonal impairment of myelin content. Morphologic findings may be subtle, and functional studies such as Doppler and elastography may be valuable tools to more accurately identify infants at risk of neurologic damage.

Case report: Fatal lung hyperinflammation in a preterm newborn with SARS-CoV-2 infection

Vertical transmission of SARS-CoV-2 from mother to fetus is widely accepted. Whereas most infected neonates present with mild symptoms or are asymptomatic, respiratory distress syndrome (RDS) and abnormal lung images are significantly more frequent in COVID-19 positive neonates than in non-infected newborns. Fatality is rare and discordant meta-analyses of case reports and series relating perinatal maternal COVID-19 status to neonatal disease severity complicate their extrapolation as prognostic indicators. A larger database of detailed case reports from more extreme cases will be required to establish therapeutic guidelines and allow informed decision making. Here we report an unusual case of a 28 weeks' gestation infant with perinatally acquired SARS-CoV-2, who developed severe protracted respiratory failure. Despite intensive care from birth with first line anti-viral and anti-inflammatory therapy, respiratory failure persisted, and death ensued at 5 months. Lung histopathology showed severe diffuse bronchopneumonia, and heart and lung immunohistochemistry confirmed macrophage infiltration, platelet activation and neutrophil extracellular trap formation consistent with late multisystem inflammation. To our knowledge, this is the first report of SARS CoV-2 pulmonary hyperinflammation in a preterm newborn with fatal outcome.

Effect of COVID-19 on Pregnancy and Neonate's Vital Parameters: A Systematic Review

Background

COVID-19 is a new pandemic, which was declared by the World Health Organization in 2019 as a threat to public health. According to numerous reports, it can have negative consequences for pregnant women, labour, and neonates born to infected mothers. The aim of this paper was to gather the evidence and to present a summary of the results of studies concerning COVID-19 in pregnant women and their neonates.

Methods

Articles from prestigious journals covering the period from 2020 to February 2023, relevant review papers, and original research articles from PubMed were analysed. In order to analyse the available research literature, the Web of Science, Scopus, and PubMed databases were used, in which the search for articles was conducted using terms ("pregnancy," "coronavirus," "SARS-CoV-2," and "newborn") and using PRISMA (Preferred Reporting Items for Systemic Reviews and Meta-Analysis) guidelines for clinical trials. Meta-analyses and systematic reviews (2022-2023) on symptoms, neonatal course, and risk of COVID-19 infection have been summarized. Summary of meta-analyses and systematic reviews (2022-2023) on the effect and adverse reaction of the COVID-19 vaccination is presented.

Results

As a result of the research conducted, it was confirmed that in most pregnant women, no serious signs of the infection were observed, although isolated cases of death related to COVID-19 in pregnant women were reported. Several authors called attention to the more severe course of the infection in pregnant women with obesity. It seemed that no vertical transmission from mother to child was occurring. Nevertheless, the information was not clinching. The condition of the neonates born to mothers with COVID-19 was in most cases described as normal; however, some papers reported deaths of infected neonates.

Conclusions

Due to insufficient data, further research is necessary. Further studies and follow-up are recommended, which would make possible an assessment of remote effects of COVID-19 on pregnancy and vital parameters of the newborn.

Maternal SARS-CoV-2, Placental Changes and Brain Injury in 2 Neonates

Long-term neurodevelopmental sequelae are a potential concern in neonates following in utero exposure to severe acute respiratory syndrome coronavirus disease 2 (SARS-CoV-2). We report 2 neonates born to SARS-CoV-2 positive mothers, who displayed early-onset (day 1) seizures, acquired microcephaly, and significant developmental delay over time. Sequential MRI showed severe parenchymal atrophy and cystic encephalomalacia. At birth, neither infant was SARS-CoV-2 positive (nasopharyngeal swab, reverse transcription polymerase chain reaction), but both had detectable SARS-CoV-2 antibodies and increased blood inflammatory markers. Placentas from both mothers showed SARS-CoV-2-nucleocapsid protein and spike glycoprotein 1 in the syncytiotrophoblast, fetal vascular malperfusion, and significantly increased inflammatory and oxidative stress markers pyrin domain containing 1 protein, macrophage inflammatory protein 1 βη, stromal cell-derived factor 1, interleukin 13, and interleukin 10, whereas human chorionic gonadotropin was markedly decreased. One infant (case 1) experienced sudden unexpected infant death at 13 months of age. The deceased infant's brain showed evidence of SARS-CoV-2 by immunofluorescence, with colocalization of the nucleocapsid protein and spike glycoprotein around the nucleus as well as within the cytoplasm. The constellation of clinical findings, placental pathology, and immunohistochemical changes strongly suggests that second-trimester maternal SARS-CoV-2 infection with placentitis triggered an inflammatory response and oxidative stress injury to the fetoplacental unit that affected the fetal brain. The demonstration of SARS-CoV-2 in the deceased infant's brain also raises the possibility that SARS-CoV-2 infection of the fetal brain directly contributed to ongoing brain injury. In both infants, the neurologic findings at birth mimicked the presentation of hypoxic-ischemic encephalopathy of newborn and neurologic sequelae progressed well beyond the neonatal period.

Persistent Tachypnoea in Early Infancy: A Clinical Perspective

Tachypnoea in the newborn is common. It may arise from the many causes of the respiratory distress syndrome such as hyaline membrane disease, transient tachypnoea of the newborn, meconium aspiration etc. Congenital heart disease rarely presents with early tachypnoea on day one or two, in contrast to the early presentation of cyanosis, unless there is "pump" (ventricular) failure such as may occur in a cardiomyopathy/myocarditis, or as a result of severe obstruction to either ventricle. Space-occupying lesions within the chest, for example from a diaphragmatic hernia or a congenital cystic adenomatoid malformation, may present with early tachypnoea, as can a metabolic cause resulting in acidosis. The aim of this paper, however, is to focus on infants where the tachypnoea persists or develops beyond the newborn period, at times with minimal signs but occasionally with serious underlying pathology. They include causes that may have originated in the newborn but then persist; for example, arising from pulmonary hypoplasia or polycythemia. Many congenital cardiac abnormalities, particularly those causing left sided obstructive lesions, or those due to an increasing left to right shunt from large communications between the systemic and pulmonary circulations, need be considered. Respiratory causes, for example arising from aspiration, primary ciliary dyskinesia, cystic fibrosis, or interstitial lung disease, may lead to ongoing tachypnoea. Infective causes such as bronchiolitis or infantile wheeze generally are readily recognisable. Finally, there are a few infants who present with persistent tachypnoea over the first few weeks/months of their life who remain well and have normal investigations with the tachypnoea gradually resolving. How should one approach infants with persistent tachypnoea?

Severe Acute Respiratory Syndrome Coronavirus 2 Infection Symptoms in Pregnancy and Maternal and Neonatal Complications Due to COVID-19: A Systematic Review

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in pregnant women is associated with severe maternal and neonatal complications including maternal and newborn death.

Aims

This review aimed to assess the SARS-CoV-2 infection symptoms during pregnancy as well as maternal and neonatal complications in Iran.

Settings and Design

A developing and low-income country and a systematic review.

Materials and Methods

International scientific databases including PubMed, Web of Science, Scopus and Google Scholar were searched in a systematic review manner. Two independent researchers were checked and identified articles from September 2019 to September 2022 based on eligibility criteria and quality appraisal. The results of review were reported in two sections including maternal and neonatal outcomes.

Statistical Analysis Used

Descriptive statistics was used for statistical analysis.

Results

Seventeen studies including 870 pregnant mothers with COVID-19 met the eligibility criteria and were reviewed. The main maternal consequences of COVID-19 were intensive care unit (ICU) admission, pre-term delivery, maternal death, pre-mature rupture of membranes, pre-eclampsia, intrauterine growth retardation and stillbirth. Neonatal ICU admission, newborn death, neonatal sepsis, low birth weight and respiratory distress syndrome, tachypnoea, asphyxia and pneumothorax were the most common outcomes of COVID-19 infection in offspring of pregnant subjects.

Conclusion

Pregnant mothers with COVID-19 infection are at higher risk of being admitted to the ICU and mechanical ventilation and consequently maternal and neonatal death. Comparing the maternal and foetal consequences in different ethnicities, regions and countries may be related to the socioeconomic status of people and should be considered with respect to different determines. Moreover, the maternal and neonatal complications due to COVID-19 infection in Iran and other developing countries seem to be higher than other countries.

Severe COVID-19 during pregnancy in Sweden, Norway, and Denmark

INTRODUCTION

Pregnancy is a risk factor for severe coronavirus disease 2019 (COVID-19) and adverse pregnancy outcomes. We aimed to explore maternal characteristics, pregnancy outcomes, vaccination status, and virus variants among pregnant women admitted to intensive care units (ICU) with severe COVID-19.

MATERIAL AND METHODS

We identified pregnant women admitted to ICU in Sweden (n = 96), Norway (n = 31), and Denmark (n = 16) because of severe COVID-19, from national registers and clinical databases between March 2020 and February 2022 (Denmark), August 2022 (Sweden), or December 2022 (Norway). Their background characteristics, pregnancy outcome, and vaccination status were compared with all birthing women and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test-positive pregnant women during the same time period. We calculated the number admitted to ICU per 10 000 birthing and per 1000 SARS-CoV-2 test-positive women during the Index, Alpha, Delta, and Omicron periods.

RESULTS

Women admitted to ICU had a higher mean body mass index, were more often of non-Scandinavian origin, had on average lower education and income levels, had a higher proportion of chronic and pregnancy-related conditions, delivered preterm, had neonates with low Apgar scores, and had more infants admitted to neonatal care, compared with all birthing and test-positive pregnant women. Of those admitted to ICU, only 7% had been vaccinated before admission. Overall, the highest proportion of women admitted to ICU per birthing was during the Delta period (4.1 per 10 000 birthing women). In Norway, the highest proportion admitted to ICU per test-positive pregnant women was during the Delta period (17.8 per 1000 test-positive), whereas the highest proportion of admitted per test-positive in Sweden and Denmark was seen during the Index period (15.4 and 8.9 per 1000 test-positive, respectively).

CONCLUSIONS

Admission to ICU because of COVID-19 in pregnancy was a rare event in the Scandinavian countries, but women who were unvaccinated, of non-Scandinavian origin, and with lower socio-economic status were at higher risk of admission to ICU. In addition, women admitted to ICU for COVID-19 had higher risk of adverse pregnancy outcomes.

COVID-19 Disease in Under-5 Children: Current Status and Strategies for Prevention including Vaccination

Since the coronavirus disease (COVID-19) pandemic hit the globe in early 2020, we have steadily gained insight into its pathogenesis; thereby improving surveillance and preventive measures. In contrast to other respiratory viruses, neonates and young children infected with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) have a milder clinical presentation, with only a small proportion needing hospitalization and intensive care support. With the emergence of novel variants and improved testing services, there has been a higher incidence of COVID-19 disease reported among children and neonates. Despite this, the proportion of young children with severe disease has not increased. Key mechanisms that protect young children from severe COVID-19 disease include the placental barrier, differential expression of angiotensin-converting enzyme 2 (ACE-2) receptors, immature immune response, and passive transfer of antibodies via placenta and human milk. Implementing mass vaccination programs has been a major milestone in reducing the global disease burden. However, considering the lower risk of severe COVID-19 illness in young children and the limited evidence about long-term vaccine safety, the risk-benefit balance in children under five years of age is more complex. In this review, we do not support or undermine vaccination of young children but outline current evidence and guidelines, and highlight controversies, knowledge gaps, and ethical issues related to COVID-19 vaccination in young children. Regulatory bodies should consider the individual and community benefits of vaccinating younger children in their local epidemiological setting while planning regional immunization policies.

Maternal and neonatal outcomes following SARS-CoV-2 infection

Infection with SARS-CoV-2 causing COVID-19 in pregnancy is known to confer risks to both the pregnant patient and fetus. A review of the current literature demonstrates that pregnant individuals with SARS-CoV-2 infection are at risk for higher composite morbidity, intensive care unit admission, ventilatory support, pre-eclampsia, preterm birth, and neonatal intensive care unit admissions compared to pregnant individuals without SARS-CoV-2. Worse obstetric morbidity and mortality generally correlate with the severity of COVID-19. Comorbidities such as diabetes increase the risk of severe COVID-19. An increased risk of stillbirth appears to be predominantly confined to pregnancies affected in the Delta variant time period. Further, vaccination against SARS-CoV-2 has been demonstrated to be safe and effective in pregnancy and while breastfeeding. Therefore, continued counseling encouraging vaccination remains imperative. The long-term maternal and neonatal consequences of pregnancies affected by SARS-CoV-2 remain unknown, and therefore continued research in this regard is warranted.