Vertical transmission of SARS CoV-2: a systematic review

Placenta a potential gateway of prenatal SARS-CoV-2 infection: A review

SARS-CoV-2, the causative agent of COVID-19, can infect various tissues in the body apart from the lungs. Although placental infection remains controversial, COVID-19-associated placental abnormalities have been reported worldwide. Therefore, COVID-19 poses a significant risk for fetal distress as well. Scientists are currently debating whether such distress results from direct viral induced assault or placental damage caused by the mother's immune response. The placenta develops different histopathological lesions in response to maternal SARS-CoV-2 infection. While some studies support both theories, the transmission rate through the placenta remains low. Therefore, a more in-depth study is necessary to determine the primary cause of maternal SARS-CoV-2-induced fetal distress. This comprehensive review is aimed to shed light on the possible reasons towards fetal distress among mothers with COVID-19. This review describes the various mechanisms of viral entry along with the mechanisms by which the virus could affect the placenta. Reported cases of placental abnormalities and fetal distress symptoms have been collated to provide an overview of the current state of knowledge on vertical transmission of COVID-19.

Transplacental Transmission of SARS-CoV-2: A Narrative Review

Background and Objectives: The study aims to explore the potential for transplacental transmission of SARS-CoV-2, focusing on its pathophysiology, placental defense mechanisms, and the clinical implications for maternal and neonatal health. Materials and Methods: A comprehensive review of the current literature was conducted, analyzing studies on SARS-CoV-2 infection in pregnancy, the expression of key viral receptors (ACE2 and TMPRSS2) in placental cells, and the immune responses involved in placental defense. The review also examined the clinical outcomes related to maternal and neonatal health, including adverse pregnancy outcomes and neonatal infection. Results: The expression of ACE2 and TMPRSS2 in the placenta supports the biological plausibility of SARS-CoV-2 transplacental transmission. Histopathological findings from the infected placentas reveal inflammation, vascular changes, and the evidence of viral particles in placental tissues. Clinical reports indicate an increased risk of preterm birth, intrauterine growth restriction, and neonatal infection in pregnancies affected by COVID-19. However, the frequency and mechanisms of vertical transmission remain variable across studies, highlighting the need for standardized research protocols. Conclusions: SARS-CoV-2 can potentially infect placental cells, leading to adverse pregnancy outcomes and neonatal infection. While evidence of transplacental transmission has been documented, the risk and mechanisms are not fully understood. Ongoing research is essential to clarify these aspects and inform obstetric care practices to improve maternal and neonatal outcomes during the COVID-19 pandemic.

Impact of SARS-CoV-2 infection during pregnancy on the placenta and fetus

Pregnant people and their fetuses are vulnerable to adverse health outcomes from coronavirus 2019 disease (COVID-19) due to infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). COVID-19 has been associated with higher rates of maternal mortality, preterm birth, and stillbirth. While SARS-CoV-2 infection of the placenta and vertical transmission is rare, this may be due to the typically longer time interval between maternal infection and testing of the placenta and neonate. Placental injury is evident in cases of SARS-CoV-2-associated stillbirth with massive perivillous fibrin deposition, chronic histiocytic intervillositis, and trophoblast necrosis. Maternal COVID-19 can also polarize fetal immunity, which may have long-term effects on neurodevelopment. Although the COVID-19 pandemic continues to evolve, the impact of emerging SARS-CoV-2 variants on placental and perinatal injury/mortality remains concerning for maternal and perinatal health. Here, we highlight the impact of COVID-19 on the placenta and fetus and remaining knowledge gaps.

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.

Vertical transmission and maternal passive immunity post-SARS-CoV-2

Since 2020, the highly contagious nature and various transmission routes of SARS-CoV-2 have rendered the pandemic interminable. Vertical transmission (VT) through the placenta and breast milk, which is frequent for certain virus types, is thought to exist for SARS-CoV-2 and is hypothesized by many researchers. Conversely, antibodies are produced to counteract the effect of viruses. Since newborns' immunologic system cannot produce proper antibodies, maternal antibodies are usually transferred from mother to infant/fetus to meet the need. This theory leads to the hypothesis of transmission of antibodies through the placenta and breast milk following SARS-CoV-2 infection or vaccination. This paper further discusses these hypotheses, considering consequences of fetus/infant harm versus benefit.

Risk of Testing Positive for COVID-19 among Healthcare and Healthcare-Related Workers

Understanding the risk factors associated with COVID-19 infection among healthcare workers is crucial for infection prevention and control. The aim of this study was to examine the risk of testing positive for COVID-19 among a multicenter cohort of workers, taking into account their occupational roles (medical professionals, staff in operational and administrative roles, or laboratory personnel) in healthcare settings. The data analyzed in this study included 2163 individuals with suggestive COVID-19 symptoms who underwent laboratory testing. The incidence rate in the study sample was calculated to be 15.3 cases per 10,000 person-days. The results from the multiple regression model indicated that job roles were not significantly associated with the risk of testing positive. However, age and the duration of the pandemic were identified as significant risk factors, with increasing age and longer pandemic duration being associated with a higher risk of testing positive. Additionally, vaccination was found to reduce the risk of testing positive. These findings provide valuable insights into COVID-19 transmission among indoor healthcare workers, highlighting the influence of age, pandemic duration, and vaccination on infection risk. Further research is needed to develop evidence-based strategies aimed at protecting healthcare workers and preventing virus spread in healthcare settings.

Associations of stress, anxiety, and partner satisfaction with maternal-fetal attachment in women pregnant during the COVID-19 pandemic: an online study

BACKGROUND

The COVID-19 pandemic has led to exceptional stress in pregnant women. The aim of the present study was to investigate associations of maternal stress (pandemic-related and -unrelated), anxiety, and relationship satisfaction experienced during the COVID-19 pandemic with prenatal mother-infant attachment.

METHODS

An online study was conducted evaluating pandemic-related stress, pregnancy-specific stress (unrelated to the pandemic), anxiety, partnership satisfaction, and maternal-fetal attachment in German-speaking women during the second COVID-19 lockdown between January and March 2021. In total, 431 pregnant women (349 lived in Germany and 82 in Switzerland) filled in the questionnaires and gave information on demographic and pregnancy-related variables (i.e. age, gestational age, parity). Bivariate correlations were calculated in order to investigate associations between the different variables and additionally, a hierarchical regression model was conducted in order to evaluate the influence of the independent variables on prenatal attachment.

RESULTS

The hierarchical regression analysis revealed that after controlling for age, gestational age, and parity higher pandemic-related stress, namely stress associated with feeling unprepared for birth, higher partnership satisfaction as well as higher positive appraisal (considered as a way of coping with pandemic-related stress) was associated with stronger maternal-fetal attachment, whereas associations of anxiety and other forms of stress were non-significant.

CONCLUSIONS

The study highlights interesting associations between maternal pandemic-related preparedness stress and positive appraisal of the pregnancy as well as partnership satisfaction and prenatal attachment in women pregnant during the COVID-19 pandemic.

Tunable nanochannel resistive pulse sensing device using a novel multi-module self-assembly

Nanochannel-based resistive pulse sensing (nano-RPS) system is widely used for the high-sensitive measurement and characterization of nanoscale biological particles and biomolecules due to its high surface to volume ratio. However, the geometric dimensions and surface properties of nanochannel are usually fixed, which limit the detections within particular ranges or types of nanoparticles. In order to improve the flexibility of nano-RPS system, it is of great significance to develop nanochannels with tunable dimensions and surface properties. In this work, we proposed a novel multi-module self-assembly (MS) strategy which allows to shrink the geometric dimensions and tune surface properties of the nanochannels simultaneously. The MS-tuned nano-RPS device exhibits an enhanced signal-to-noise ratio (SNR) for nanoparticle detections after shrunk the geometric dimensions by MS strategy. Meanwhile, by tuning the surface charge, an enhanced resolution for viral particles detection was achieved with the MS-tuned nano-RPS devices by analyzing the variation of pulse width due the tuned surface charge. The proposed MS strategy is versatile for various types of surface materials and can be potentially applied for nanoscale surface reconfiguration in various nanofluidic devices.

Outcome of Newborns with Confirmed or Possible SARS-CoV-2 Vertical Infection-A Scoping Review

Severe acute respiratory syndrome virus 2 (SARS-CoV-2), the virus that causes 2019 coronavirus disease (COVID-19), has been isolated from various tissues and body fluids, including the placenta, amniotic fluid, and umbilical cord of newborns. In the last few years, much scientific effort has been directed toward studying SARS-CoV-2, focusing on the different features of the virus, such as its structure and mechanisms of action. Moreover, much focus has been on developing accurate diagnostic tools and various drugs or vaccines to treat COVID-19. However, the available evidence is still scarce and consistent criteria should be used for diagnosing vertical transmission. Applying the PRISMA ScR guidelines, we conducted a scoping review with the primary objective of identifying the types, and examining the range, of available evidence of vertical transmission of SARS-CoV-2 from mother to newborn. We also aimed to clarify the key concepts and criteria for diagnosis of SARS-CoV-2 vertical infection in neonates and summarize the existing evidence and advance the awareness of SARS-CoV-2 vertical infection in pregnancy. Most studies we identified were case reports or case series (about 30% of poor quality and inconsistent reporting of the findings). Summarizing the existing classification criteria, we propose an algorithm for consistent diagnosis. Registration: INPLASY2022120093.

Is respiratory syncytial virus infection more dangerous than COVID 19 in the neonatal period?

OBJECTIVE

We aimed to compare the clinical features, laboratory findings and primary outcomes of the neonates with RSV and neonates with SARS-CoV-2 infections.

MATERIALS AND METHODS

This nested case-control study included the neonates who were administered in the neonatal intensive care unit (NICU) of the University of Health Sciences, Dr Behçet Uz Children's Hospital during the period of 01 March-30 April 2020. Respiratory PCR samples and COVID-19 samples were taken simultaneously. Only RSV positive and COVID-19 positive infants were compared. Demographic, epidemiological and clinical data were obtained from hospital electronic information system medical records. The chest radiographs at the admission were evaluated by using standard definitions for normal chest X-ray, atelectasis, bronchopenumonia, peribronchial thickening and hyperinflation in various lung volumes.

RESULTS

A total of 30 infants were enrolled in the study and RSV was identified in 20/30 infants (66%). No significant differences were observed between the two groups in terms of general characteristics. Comparing to the infants with Covid-19 infections, infants with RSV infections had significantly higher rates of having oxygen support (p = .03). Total NICU duration time was 6.7 ± 1.6 days in COVID positive group and 11.1 ± 5.1 days in the RSV group (p = .01). Infants with COVID-19 had more normal chest X-rays. Infants with RSV-positive had a significantly higher proportion of atelectasis than those with COVID-19 infants (p = .04).

DISCUSSION

This is the first study that compares RSV infection and COVID-19 infection. RSV infection can be more serious in the neonatal period. In cases with suspected COVID-19 infection, it should be kept in mind if atelectasis is seen on chest radiography. Respiratory failure may be more serious in RSV positive infants and RSV infection may be more dangerous for the neonatal period.

Epidemiology of Neonatal COVID-19 in the United States

OBJECTIVES

Data on coronavirus disease 2019 (COVID-19) infections in neonates are limited. We aimed to identify and describe the incidence, presentation, and clinical outcomes of neonatal COVID-19.

METHODS

Over 1 million neonatal encounters at 109 United States health systems, from March 2020 to February 2021, were extracted from the Cerner Real World Database. COVID-19 diagnosis was assessed using severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) laboratory tests and diagnosis codes. Incidence of COVID-19 per 100 000 encounters was estimated.

RESULTS

COVID-19 was diagnosed in 918 (0.1%) neonates (91.1 per 100 000 encounters [95% confidence interval 85.3-97.2]). Of these, 71 (7.7%) had severe infection (7 per 100 000 [95% confidence interval 5.5-8.9]). Median time to diagnosis was 14.5 days from birth (interquartile range 3.1-24.2). Common signs of infection were tachypnea and fever. Those with severe infection were more likely to receive respiratory support (50.7% vs 5.2%, P < .001). Severely ill neonates received analgesia (38%), antibiotics (33.8%), anticoagulants (32.4%), corticosteroids (26.8%), remdesivir (2.8%), and COVID-19 convalescent plasma (1.4%). A total of 93.6% neonates were discharged home after care, 1.1% were transferred to another hospital, and discharge disposition was unknown for 5.2%. One neonate (0.1%) with presentation suggestive of multisystem inflammatory syndrome in children died after 11 days of hospitalization.

CONCLUSIONS

Most neonates infected with SARS-CoV-2 were asymptomatic or developed mild illness without need for respiratory support. Some had severe illness requiring treatment of COVID-19 with remdesivir and COVID-19 convalescent plasma. SARS-CoV-2 infection in neonates, though rare, may result in severe disease.

SARS-CoV-2 Is Persistent in Placenta and Causes Macroscopic, Histopathological, and Ultrastructural Changes

SARS-CoV-2 is a virus that belongs to the Betacoronavirus genus of the Coronaviridae family. Other coronaviruses, such as SARS-CoV and MERS-CoV, were associated with complications in pregnant women. Therefore, this study aimed to report the clinical history of five pregnant women infected with SARS-CoV-2 (four symptomatic and one asymptomatic who gave birth to a stillborn child) during the COVID-19 pandemic. They gave birth between August 2020 to January 2021, a period in which there was still no vaccination for COVID-19 in Brazil. In addition, their placental alterations were later investigated, focusing on macroscopic, histopathological, and ultrastructural aspects compared to a prepandemic sample. Three of five placentas presented SARS-CoV-2 RNA detected by RT-PCRq at least two to twenty weeks after primary pregnancy infection symptoms, and SARS-CoV-2 spike protein was detected in all placentas by immunoperoxidase assay. The macroscopic evaluation of the placentas presented congested vascular trunks, massive deposition of fibrin, areas of infarctions, and calcifications. Histopathological analysis showed fibrin deposition, inflammatory infiltrate, necrosis, and blood vessel thrombosis. Ultrastructural aspects of the infected placentas showed a similar pattern of alterations between the samples, with predominant characteristics of apoptosis and detection of virus-like particles. These findings contribute to a better understanding of the consequences of SARS-CoV-2 infection in placental tissue, vertical transmission.

Pregnant and breastfeeding women's attitudes and fears regarding the COVID-19 vaccination

PURPOSE

The COVID-19 vaccination is probably the most important source to fight the COVID-19 pandemic. However, recommendations and possibilities for vaccination for pregnant and breastfeeding women are inconsistent and dynamically changing.

METHODS

An anonymous, online, cross-sectional survey was conducted among pregnant and breastfeeding women in Germany between 30th March and 19th April 2021 addressing COVID-19 vaccination attitudes including the underlying reasons for their decision. Additionally, anxiety regarding a SARS-CoV-2 infection and a symptomatic course of the infection were evaluated.

RESULTS

In total, 2339 women (n = 1043 pregnant and n = 1296 breastfeeding) completed the survey. During pregnancy the majority (57.4%) are not in favour of receiving the vaccine, 28.8% are unsure and only 13.8% would get vaccinated at the time of the survey. In contrast, 47.2% would be in favour to receive the vaccine, if more scientific evidence on the safety of the vaccination during pregnancy would be available. Breastfeeding women show higher vaccination willingness (39.5% are in favour, 28.1% are unsure and 32.5% not in favour). The willingness to be vaccinated is significantly related to the women's anxiety levels of getting infected and to develop disease symptoms. Main reasons for vaccination hesitancy are the women's perception of limited vaccination-specific information, limited scientific evidence on vaccination safety and the fear to harm the fetus or infant.

CONCLUSIONS

The results provide important implications for obstetrical care during the pandemic as well as for official recommendations und information strategies regarding the COVID-19 vaccination.

Detection of SARS-CoV-2 contamination in the operating room and birthing room setting: a cross-sectional study

BACKGROUND

The exposure risks to front-line health care workers caring for patients with SARS-CoV-2 infection undergoing surgery or obstetric delivery are unclear, and an understanding of sample types that may harbour virus is important for evaluating risk. We sought to determine whether SARS-CoV-2 viral RNA from patients with SARS-CoV-2 infection undergoing surgery or obstetric delivery was present in the peritoneal cavity of male and female patients, in the female reproductive tract, in the environment of the surgery or delivery suite (surgical instruments or equipment used, air or floors), and inside the masks of the attending health care workers.

METHODS

We conducted a cross-sectional study from November 2020 to May 2021 at 2 tertiary academic Toronto hospitals, during urgent surgeries or obstetric deliveries for patients with SARS-CoV-2 infection. The presence of SARS-CoV-2 viral RNA in patient, environmental and air samples was identified by real-time reverse transcription polymerase chain reaction (RT-PCR). Air samples were collected using both active and passive sampling techniques. The primary outcome was the proportion of health care workers' masks positive for SARS-CoV-2 RNA. We included adult patients with positive RT-PCR nasal swab undergoing obstetric delivery or urgent surgery (from across all surgical specialties).

RESULTS

A total of 32 patients (age 20-88 yr) were included. Nine patients had obstetric deliveries (6 cesarean deliveries), and 23 patients (14 male) required urgent surgery from the orthopedic or trauma, general surgery, burn, plastic surgery, cardiac surgery, neurosurgery, vascular surgery, gastroenterology and gynecologic oncology divisions. SARS-CoV-2 RNA was detected in 20 of 332 (6%) patient and environmental samples collected: 4 of 24 (17%) patient samples, 5 of 60 (8%) floor samples, 1 of 54 (2%) air samples, 10 of 23 (43%) surgical instrument or equipment samples, 0 of 24 cautery filter samples and 0 of 143 (95% confidence interval 0-0.026) inner surface of mask samples.

INTERPRETATION

During the study period of November 2020 to May 2021, we found evidence of SARS-CoV-2 RNA in a small but important number of samples obtained in the surgical and obstetric operative environment. The finding of no detectable virus inside the masks worn by the health care teams would suggest a low risk of infection for health care workers using appropriate personal protective equipment.

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

OBJECTIVES

To assess the rates of SARS-CoV-2 positivity in babies born to mothers with SARS-CoV-2 infection, the timing of mother-to-child transmission and perinatal outcomes, and factors associated with SARS-CoV-2 status in offspring.

DESIGN

Living systematic review and meta-analysis.

DATA SOURCES

Major databases between 1 December 2019 and 3 August 2021.

STUDY SELECTION

Cohort studies of pregnant and recently pregnant women (including after abortion or miscarriage) who sought hospital care for any reason and had a diagnosis of SARS-CoV-2 infection, and also provided data on offspring SARS-CoV-2 status and risk factors for positivity. Case series and case reports were also included to assess the timing and likelihood of mother-to-child transmission in SARS-CoV-2 positive babies.

DATA EXTRACTION

Two reviewers independently extracted data and assessed study quality. A random effects model was used to synthesise data for rates, with associations reported using odds ratios and 95% confidence intervals. Narrative syntheses were performed when meta-analysis was inappropriate. The World Health Organization classification was used to categorise the timing of mother-to-child transmission (in utero, intrapartum, early postnatal).

RESULTS

472 studies (206 cohort studies, 266 case series and case reports; 28 952 mothers, 18 237 babies) were included. Overall, 1.8% (95% confidence interval 1.2% to 2.5%; 140 studies) of the 14 271 babies born to mothers with SARS-CoV-2 infection tested positive for the virus with reverse transcriptase polymerase chain reaction (RT-PCR). Of the 592 SARS-CoV-2 positive babies with data on the timing of exposure and type and timing of tests, 14 had confirmed mother-to-child transmission: seven in utero (448 assessed), two intrapartum (18 assessed), and five during the early postnatal period (70 assessed). Of the 800 SARS-CoV-2 positive babies with outcome data, 20 were stillbirths, 23 were neonatal deaths, and eight were early pregnancy losses; 749 babies were alive at the end of follow-up. Severe maternal covid-19 (odds ratio 2.4, 95% confidence interval 1.3 to 4.4), maternal death (14.1, 4.1 to 48.0), maternal admission to an intensive care unit (3.5, 1.7 to 6.9), and maternal postnatal infection (5.0, 1.2 to 20.1) were associated with SARS-CoV-2 positivity in offspring. Positivity rates using RT-PCR varied between regions, ranging from 0.1% (95% confidence interval 0.0% to 0.3%) in studies from North America to 5.7% (3.2% to 8.7%) in studies from Latin America and the Caribbean.

CONCLUSION

SARS-CoV-2 positivity rates were found to be low in babies born to mothers with SARS-CoV-2 infection. Evidence suggests confirmed vertical transmission of SARS-CoV-2, although this is likely to be rare. Severity of maternal covid-19 appears to be associated with SARS-CoV-2 positivity in offspring.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020178076.

READERS' NOTE

This article is a living systematic review that will be updated to reflect emerging evidence. Updates may occur for up to two years from the date of original publication.

Possible vertical transmission of corona virus disease 19 (COVID-19) from infected pregnant mothers to neonates: a multicenter study

INTRODUCTION

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is highly contagious with various possible routes of transmission, resulting in high mortality globally. Controversy exists regarding the vertical transmission of the SARS-CoV-2 infection to fetuses of COVID-19-infected women. The aim of this study was to investigate the possibility of the vertical transmission of SARS-CoV-2 from COVID-19-infected mothers to their neonates.

MATERIALS AND METHODS

We prospectively collected demographical and clinical characteristics of 31 COVID-19 positive pregnant women and their neonates. All mothers and neonates were tested for SARS-CoV-2 infection using the real-time polymerase chain reaction on nasopharyngeal swabs and breast milk samples. Antenatal and placental abnormalities were ultrasonically and histopathologically examined. In cord blood samples, the immunoglobins (Ig) M and IgG were estimated qualitatively.

RESULTS

The women's mean age and gestational age were 31 years and 38 weeks, respectively, with 58% undergoing an elective cesarean section. Gestational diabetes was reported in 29% of cases, 64.5% of women were medically free and only 16.12% were symptomatic. A normal antenatal ultrasound was observed in 77.42% of cases. Nine cord blood samples were positive for IgG. Villous infarction (24%), villous agglutination, and chorangiosis (51%), accelerated villous maturation (21%) and reduced and hypercoiling were reported for 6.97% of the umbilical cords. Three newborns had possible vertical transmission of SARS-CoV-2 infection, of which, two were preterm and IUFD. The third neonate was born full-term, admitted to NICU and later discharged in good health.

CONCLUSION

Our findings support the possibility of the direct vertical transmission of the SARS-CoV-2 infection to neonates from infected mothers. Further studies with a larger sample size are required to validate the current findings.

Study of perinatal transmission of SARS-CoV-2 in a Mexican public hospital

OBJECTIVES

COVID-19 is a viral transmissible disease and there is limited evidence on vertical transmission and prevalence of SARS-CoV-2 during pregnancy, birth, and the postnatal period. This descriptive cross-sectional study aimed to evaluate the possible perinatal transmission of SARS-CoV-2 in mothers and neonates in a Mexican population.

METHODS

A total of 133 nasopharyngeal swab samples from mothers, 131 swab samples from neonates, and 140 colostrum samples were obtained, and the presence of SARS-CoV-2 was determined by qPCR.

RESULTS

One in eight asymptomatic 38-39 weeks' pregnant women were positive for the presence of SARS-CoV-2 in nasopharyngeal swabs taken just before delivery; and one in 12 nasopharyngeal swabs collected from neonates immediately after delivery without breast feeding were also positive. It was also determined that one in 47 colostrum/milk samples were positive for the test. In addition, there was no association between positive results and any collected metadata of mothers or newborns.

CONCLUSIONS

Asymptomatic women carried the SARS-CoV-2 virus during delivery, with perinatal transmission of SARS-CoV-2 to newborns. Since neonates were sampled immediately after birth, the detection of positive cases might be due to infection by the virus in utero.

Susceptibility to COVID-19 in Pregnancy, Labor, and Postpartum Period: Immune System, Vertical Transmission, and Breastfeeding

The new coronavirus (SARS-Cov-2) was first identified in late 2019 as the new RNA virus in the coronaviridae family responsible for causing COVID-19 in the residents of China's Hubei province. In mid-March 2020 WHO declared the pandemic caused by this virus as a result of thousands of people infected all over the world. Epidemiological evidence obtained from other pandemics, such as influenza and ebola, suggest that pregnant women are more susceptible to serious complications and death from viral infection. Physiological changes in the anatomical structure of the respiratory system as well as in the immune system during the pregnancy-puerperal period seem to contribute to this greater risk. Thus, pregnant women are more susceptible to be infected by the SARS-COV-2 or other viruses and to have serious COVID-19 disease. In fact, COVID-19 can alter immune responses at the maternal-fetal interface, affecting the well-being of both mother and her fetus. There is still no sufficient evidence in the literature to support the occurrence of vertical transmission and through breastfeeding, but the prevalence of prematurity was high among pregnant women infected by SARS-Cov-2. In this review, the changes in the immune system that may increase susceptibility to SARS-Cov-2 are discussed as well as the possible mechanisms involved in the transmission of the virus to the fetus by vertical transmission and during breastfeeding.

Vertical Transmission of SARS-CoV-2: A Systematic Review of Systematic Reviews

The COVID-19 pandemic has hugely impacted global public health and economy. The COVID-19 has also shown potential impacts on maternal perinatal and neonatal outcomes. This systematic review aimed to summarize the evidence from existing systematic reviews about the effects of SARS-CoV-2 infections on maternal perinatal and neonatal outcomes. We searched PubMed, MEDLINE, Embase, and Web of Science in accordance with PRISMA guidelines, from 1 December 2019 to 7 July 2021, for published review studies that included case reports, primary studies, clinical practice guidelines, overviews, case-control studies, and observational studies. Systematic reviews that reported the plausibility of mother-to-child transmission of COVID-19 (also known as vertical transmission), maternal perinatal and neonatal outcomes, and review studies that addressed the effect of SARS-CoV-2 infection during pregnancy were also included. We identified 947 citations, of which 69 studies were included for further analysis. Most (>70%) of the mother-to-child infection was likely due to environmental exposure, although a significant proportion (about 20%) was attributable to potential vertical transmission of SARS-CoV-2. Further results of the review indicated that the mode of delivery of pregnant women infected with SARS-CoV-2 could not increase or decrease the risk of infection for the newborns (outcomes), thereby emphasizing the significance of breastfeeding. The issue of maternal perinatal and neonatal outcomes with SARS-CoV-2 infection continues to worsen during the ongoing COVID-19 pandemic, increasing maternal and neonatal mortality, stillbirth, ruptured ectopic pregnancies, and maternal depression. Based on this study, we observed increasing rates of cesarean delivery from mothers with SARS-CoV-2 infection. We also found that SARS-CoV-2 could be potentially transmitted vertically during the gestation period. However, more data are needed to further investigate and follow-up, especially with reports of newborns infected with SARS-CoV-2, in order to examine a possible long-term adverse effect.

The Effects of COVID-19 on the Placenta During Pregnancy

Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic. The virus primarily affects the lungs where it induces respiratory distress syndrome ranging from mild to acute, however, there is a growing body of evidence supporting its negative effects on other system organs that also carry the ACE2 receptor, such as the placenta. The majority of newborns delivered from SARS-CoV-2 positive mothers test negative following delivery, suggesting that there are protective mechanisms within the placenta. There appears to be a higher incidence of pregnancy-related complications in SARS-CoV-2 positive mothers, such as miscarriage, restricted fetal growth, or still-birth. In this review, we discuss the pathobiology of COVID-19 maternal infection and the potential adverse effects associated with viral infection, and the possibility of transplacental transmission.

Neonatal outcomes of pregnant women with COVID-19 in a developing country setup

BACKGROUND

Current evidence on vertical transmission of severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) and neonatal outcome among exposed newborns is emerging and posing a challenge for preventive interventions. Perinatal transmission to the neonates especially during breastfeeding and rooming in is also relatively unknown.

METHODS

This prospective observational study was conducted in Kalinga Institute of Medical Science (KIMS), Odisha state from 1st May to 20th October 2020. A total of 165 neonates born to SARS-CoV-2 infected mothers were enrolled. Real time polymerase chain reaction (RT PCR) testing was done in first 32 neonates in initial 24 h of life.

RESULTS

The clinical characteristics of 162 mothers & 165 neonates were analyzed. Mode of delivery was by caesarian section in most (n = 103, 60%) cases. Three (3/32, 9.4%) inborn and 6 outborn neonates were SARS-CoV-2 positive. Thirty-eight (23%) babies needed neonatal intensive care. Clinical characteristics of neonates were meconium-stained amniotic fluid (MSAF [23.63%]), prematurity (16.9%), respiratory distress (10.5%), moderate to severe hypoxic ischemic encephalopathy (3.6%), sepsis (7%) and hyperbilirubinemia (8.7%). Out of 138 stable babies kept on mother side and initiated breast feeding, none of them developed any signs and symptoms attributable to SARS-CoV-2. Five (3%) neonates died in COVID hospital of which one baby was SARS-CoV-2 positive.

CONCLUSION

There was an increased rate of incidences of hypoxic ischemic encephalopathy, meconium stained liquor and cesarean section delivery in COVID hospital. We found a possible vertical transmission in 9.4% cases. None of the neonates developed sign and symptoms of SARS-CoV-2 infection during rooming in and breast feeding.

Immunological and physiopathological approach of COVID-19 in pregnancy

Coronavirus disease-2019 (COVID-19) related to Coronavirus-2 (SARS-CoV-2) is a worldwide health concern. Despite the majority of patients will evolve asymptomatic or mild-moderate upper respiratory tract infections, 20% will develop severe disease. Based on current pathogenetic knowledge, a severe COVID-19 form is mainly a hyperinflammatory, immune-mediated disorder, triggered by a viral infection. Due to their particular immunological features, pregnant women are supposed to be particularly susceptible to complicate by intracellular infections as well as immunological disturbances. As an example, immune-thrombosis has been identified as a common immune-mediated and pathogenic phenomenon both in COVID-19, in obstetric diseases and in COVID-19 pregnant women. According to extensive published clinical data, is rationale to expect an interference with the normal development of pregnancy in selected SARS-CoV-2-infected cases, mainly during third trimester.This manuscript provides insights of research to elucidate the potential harmful responses to SARS-CoV-2 and /or other coronavirus infections, as well as bidirectional interactions between COVID-19 and pregnancy to improve their respective management.

COVID-19 and pregnancy: An umbrella review of clinical presentation, vertical transmission, and maternal and perinatal outcomes

BACKGROUND

We conducted an overview of systematic reviews (SRs) summarizing the best evidence regarding the effect of COVID-19 on maternal and child health following Cochrane methods and PRISMA statement for reporting (PROSPERO-CRD42020208783).

METHODS

We searched literature databases and COVID-19 research websites from January to October 2020. We selected relevant SRs reporting adequate search strategy, data synthesis, risk of bias assessment, and/or individual description of included studies describing COVID-19 and pregnancy outcomes. Pair of reviewers independently selected studies through COVIDENCE web-software, performed the data extraction, and assessed its quality through the AMSTAR-2 tool. Discrepancies were resolved by consensus. Each SR's results were synthesized and for the most recent, relevant, comprehensive, and with the highest quality, by predefined criteria, we presented GRADE evidence tables.

RESULTS

We included 66 SRs of observational studies out of 608 references retrieved and most (61/66) had "critically low" overall quality. We found a relatively low degree of primary study overlap across SRs. The most frequent COVID-19 clinical findings during pregnancy were fever (28-100%), mild respiratory symptoms (20-79%), raised C-reactive protein (28-96%), lymphopenia (34-80%), and pneumonia signs in diagnostic imaging (7-99%). The most frequent maternal outcomes were C-section (23-96%) and preterm delivery (14-64%). Most of their babies were asymptomatic (16-93%) or presented fever (0-50%), low birth weight (5-43%) or preterm delivery (2-69%). The odds ratio (OR) of receiving invasive ventilation for COVID-19 versus non-COVID-19 pregnant women was 1.88 (95% Confidence Interval [CI] 1.36-2.60) and the OR that their babies were admitted to neonatal intensive care unit was 3.13 (95%CI 2.05-4.78). The risk of congenital transmission or via breast milk was estimated to be low, but close contacts may carry risks.

CONCLUSION

This comprehensive overview supports that pregnant women with COVID-19 may be at increased risk of adverse pregnancy and birth outcomes and low risk of congenital transmission.

SARS-CoV-2 Genetic Variability and Non-Specific Immunity Associated with the Use of Different BCG Strains-A Molecular and Clinical Approach

The effect of BCG vaccination against tuberculosis on the reduction in COVID-19 infection is related to the effect of the BCG vaccine on the immunomodulation of non-specific immunity. In the early stages of the pandemic, countries with universal BCG vaccination programs registered a low number of new cases of COVID-19, with the situation now reversed, as exemplified by India. The high genetic variability of SARS-CoV-2, a known characteristic of RNA viruses, causing the occurrence of SARS-CoV-2 variants may have led to the virus adapting to overcome the initial immune protection. The strains from the United Kingdom (B1.1.7), Brazil (B1.1.28 and B1.1.33), South Africa (B.1.351), and India (B.1.617) are characterized by a greater ability to spread in the environment, in comparison with the original infectious agent of SARS-CoV-2. It should be remembered that the large variation in the genetic makeup of SARS-CoV-2 may result in future changes in its pathogenicity, immunogenicity and antigenicity, and therefore it is necessary to carefully study the mutations occurring within the virus to determine whether the current vaccines will remain effective. However, most studies show that monoclonal antibodies produced after vaccination against COVID-19 are effective against the newly developed variants.

Consequences of Early Separation of Maternal-Newborn Dyad in Neonates Born to SARS-CoV-2 Positive Mothers: An Observational Study

As the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection continues its spread all over the world, data on perinatal management of the maternal-infant dyad are urgent. We performed an observational study to describe the effects of the early separation of the maternal-infant dyad, in case of maternal SARS-CoV-2 infection. We reported the medical records for 37 neonates born to 37 SARS-CoV-2 positive mothers in a setting of separation of the dyad after birth. Data on neonatal infection, clinical condition, and breastfeeding rate were recorded until the first month of life. No maternal deaths were recorded; 37.8% of women had at least one pregnancy-related complication. We reported a high adherence to recommended safety measures after discharged with 84.8% of the mothers using at least one personal protective device and 51.5% using all the protective devices. We reported one case of vertical transmission and no cases of horizontal transmission. However, the separation of the dyad had a negative impact on breastfeeding because only 23.5% of the newborns received exclusively human milk during the first month of life. Despite early separation of the dyad protecting the newborns from possible horizontal transmission of SARS-CoV-2, it negatively affects breastfeeding during the first months of life.

Chronic Histiocytic Intervillositis With Trophoblast Necrosis Is a Risk Factor Associated With Placental Infection From Coronavirus Disease 2019 (COVID-19) and Intrauterine Maternal-Fetal Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Transmission in Live-Born and Stillborn Infants

CONTEXT.—

The number of neonates with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is increasing, and in a few there are reports of intrauterine infection.

OBJECTIVE.—

To characterize the placental pathology findings in a preselected cohort of neonates infected by transplacental transmission arising from maternal infection with SARS-CoV-2, and to identify pathology risk factors for placental and fetal infection.

DESIGN.—

Case-based retrospective analysis by a multinational group of 19 perinatal specialists of the placental pathology findings from 2 cohorts of infants delivered to mothers testing positive for SARS-CoV-2: live-born neonates infected via transplacental transmission who tested positive for SARS-CoV-2 after delivery and had SARS-CoV-2 identified in cells of the placental fetal compartment by molecular pathology, and stillborn infants with syncytiotrophoblast positive for SARS-CoV-2.

RESULTS.—

In placentas from all 6 live-born neonates acquiring SARS-CoV-2 via transplacental transmission, the syncytiotrophoblast was positive for coronavirus using immunohistochemistry, RNA in situ hybridization, or both. All 6 placentas had chronic histiocytic intervillositis and necrosis of the syncytiotrophoblast. The 5 stillborn/terminated infants had placental pathology findings that were similar, including SARS-CoV-2 infection of the syncytiotrophoblast, chronic histiocytic intervillositis, and syncytiotrophoblast necrosis.

CONCLUSIONS.—

Chronic histiocytic intervillositis together with syncytiotrophoblast necrosis accompanies SARS-CoV-2 infection of syncytiotrophoblast in live-born and stillborn infants. The coexistence of these 2 findings in all placentas from live-born infants acquiring their infection prior to delivery indicates that they constitute a pathology risk factor for transplacental fetal infection. Potential mechanisms of infection of the placenta and fetus with SARS-CoV-2, and potential future studies, are discussed.

High Levels of Interferon-Alpha Expressing Macrophages in Human Breast Milk During SARS-CoV-2 Infection: A Case Report

Introduction: In addition to hand washing and wearing masks, social distancing and reducing exposure time to <15 minutes are the most effective measures against the spread of COVID-19. Unfortunately, three of these guidelines are very difficult, if not impossible, for nursing babies: they cannot wear masks, stay six feet away from the lactating breasts, nor consistently finish within 15 minutes while nursing. We report a case of a nursing mother with SARS-CoV-2 infection, documenting changes of immune cells and cytokines in breast milk with and without the infection. Case Description: With Institutional Review Board (IRB) approval, we obtained expressed breast milk samples from a lactating mother before and during SARS-CoV-2 infection as documented by reverse transcription-PCR. Using flow cytometry analysis, we measured the immune cell profiles and expression of cytokines such as interferon alpha (IFNα) in milk leukocytes before and during infection. Results: There was an eightfold increase in IFNα+ milk leukocytes, from 1% before SARS-CoV-2 infection to 8% when actively infected. The milk macrophages showed the highest increase in IFNα expression. Both T and B lymphocytes showed mild increase. Innate lymphoid cells, neutrophils, and natural killer cells showed no increase in IFNα expression and the dendritic cells actually showed a reduction. Conclusion: We document the presence and high expression of IFNα in the breast milk macrophages of a lactating mother with confirmed COVID-19, compared with her milk before the infection.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2): a Systemic Infection

To date, seven identified coronaviruses (CoVs) have been found to infect humans; of these, three highly pathogenic variants have emerged in the 21st century. The newest member of this group, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was first detected at the end of 2019 in Hubei province, China. Since then, this novel coronavirus has spread worldwide, causing a pandemic; the respiratory disease caused by the virus is called coronavirus disease 2019 (COVID-19). The clinical presentation ranges from asymptomatic to mild respiratory tract infections and influenza-like illness to severe disease with accompanying lung injury, multiorgan failure, and death. Although the lungs are believed to be the site at which SARS-CoV-2 replicates, infected patients often report other symptoms, suggesting the involvement of the gastrointestinal tract, heart, cardiovascular system, kidneys, and other organs; therefore, the following question arises: is COVID-19 a respiratory or systemic disease? This review aims to summarize existing data on the replication of SARS-CoV-2 in different tissues in both patients and ex vivo models.

Maternal and fetal effects of COVID-19 virus on a complicated triplet pregnancy: a case report

BACKGROUND

Coronavirus disease 2019 (COVID-19), the global pandemic that has spread throughout the world, is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Given the limited scientific evidence on the manifestations and potential impact of this virus on pregnancy, we decided to report this case.

CASE PRESENTATION

The patient was a 38 year-old Iranian woman with a triplet pregnancy and a history of primary infertility, as well as hypothyroidism and gestational diabetes. She was hospitalized at 29 weeks and 2 days gestational age due to elevated liver enzymes, and finally, based on a probable diagnosis of gestational cholestasis, she was treated with ursodeoxycholic acid. On the first day of hospitalization, sonography was performed, which showed that biophysical scores and amniotic fluid were normal in all three fetuses, with normal Doppler findings in two fetuses and increased umbilical artery resistance (pulsatility index [PI] > 95%) in one fetus. On day 4 of hospitalization, she developed fever, cough and myalgia, and her COVID-19 test was positive. Despite mild maternal symptoms, exacerbated placental insufficiency occurred in two of the fetuses leading to the rapid development of absent umbilical artery end-diastolic flow. Finally, 6 days later, the patient underwent cesarean section due to rapid exacerbation of placental insufficiency and declining biophysical score in two of the fetuses. Nasopharyngeal swab COVID-19 tests were negative for the first and third babies and positive for the second baby. The first and third babies died 3 and 13 days after birth, respectively, due to collapsed white lung and sepsis. The second baby was discharged in good general condition. The mother was discharged 3 days after cesarean section. She had no fever at the time of discharge and was also in good general condition.

CONCLUSIONS

This was a complicated triplet pregnancy, in which, after maternal infection with COVID-19, despite mild maternal symptoms, exacerbated placental insufficiency occurred in two of the fetuses, and the third fetus had a positive COVID-19 test after birth. Therefore, in cases of pregnancy with COVID-19 infection, in addition to managing the mother, it seems that physicians would be wise to also give special attention to the possibility of acute placental insufficiency and subsequent fetal hypoxia, and also the probability of vertical transmission.

COVID in obstetrics: labor analgesia and cesarean section

PURPOSE OF REVIEW

This review is based on the latest evidence to provide a good standard of care for COVID-19 parturients and protection to healthcare givers.

RECENT FINDINGS

COVID-19 by itself is not an indication for cesarean section. Different publications demonstrated the efficacy of neuraxial analgesia/anesthesia for delivery. Although SARS-CoV-2 was associated with a certain neurotropism, neuraxial block was not associated with neurological damage in COVID-19 parturients, and seems as safe and effective as in normal situations. It permits to avoid a general anesthesia in case of intrapartum cesarean section. Epidural failure is a concern: it may lead to a general anesthesia in case of emergency cesarean section. Local protocols and well-trained anesthesiologists will be helpful. COVID-19 patients require special circuits and every step (transfer to and from theatre, recovery, analgesia, and so on) should be planned in advance. For cesarean section under general anesthesia, personal protection equipment must be enhanced. Postoperative analgesia with neuraxial opioids, NSAIDs, or regional blocks are recommended. COVID-19 and pregnancy increase the risk of thrombosis, so thromboprophylaxis has to be considered and protocolized.

SUMMARY

Anesthetic care for delivery in COVID-19 parturients should include neuraxial blocks. Special attention should be paid on the risk of thrombosis.

The calm after the storm: re-starting ART treatments safely in the wake of the COVID-19 pandemic

The coronavirus disease 2019 (COVID-19) pandemic created a significant impact on medically assisted reproduction (MAR) services. ESHRE decided to mobilize resources in order to collect, analyse, monitor, prepare and disseminate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) knowledge specifically related to ART and early pregnancy. This article presents the impact of the SARS-CoV-2 pandemic focusing on reproductive healthcare. It details the rationale behind the guidance prepared to support MAR services in organizing and managing the re-start of treatments or in case of any future wave of COVID-19 disease. The guidance includes information on patient selection and informed consent, staff and patient triage and testing, adaptation of ART services, treatment planning and code of conduct. The initiatives detailed in this article are not necessarily COVID-specific and such action plans could be applied effectively to manage similar emergency situations in different areas of medicine, in the future.

SARS-CoV-2: Structure, Biology, and Structure-Based Therapeutics Development

The pandemic of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been posing great threats to the world in many aspects. Effective therapeutic and preventive approaches including drugs and vaccines are still unavailable although they are in development. Comprehensive understandings on the life logic of SARS-CoV-2 and the interaction of the virus with hosts are fundamentally important in the fight against SARS-CoV-2. In this review, we briefly summarized the current advances in SARS-CoV-2 research, including the epidemic situation and epidemiological characteristics of the caused disease COVID-19. We further discussed the biology of SARS-CoV-2, including the origin, evolution, and receptor recognition mechanism of SARS-CoV-2. And particularly, we introduced the protein structures of SARS-CoV-2 and structure-based therapeutics development including antibodies, antiviral compounds, and vaccines, and indicated the limitations and perspectives of SARS-CoV-2 research. We wish the information provided by this review may be helpful to the global battle against SARS-CoV-2 infection.

Problems with Early Systematic Reviews: The Case of Coronavirus Disease 2019 (COVID-19) in Pregnancy

Introduction

Rapid dissemination of findings regarding the Coronavirus Disease 2019 (COVID-19) and its potential effects on pregnancy is crucial to support understanding and development of recommendations for optimization of obstetrics care. However, much of the current studies published are in the form of case reports or case series which can be prone to biases. Other factors also further complicate attempts to analyze data accurately. Hence, this evaluation hopes to highlight some of these problems and provide suggestions to help clinicians mitigate and make reasonable conclusions when reading the abundant yet limited body of evidence when furthering their research efforts.

Methods

Studies regarding COVID-19 and pregnancy were searched on databases such as PubMed, EMBASE, Scopus, the Cochrane Library. Manual search of references of select articles were also undertaken. Apart from summarizing study limitations identified by authors, the characteristics of current literature and systematic reviews were also evaluated to identify potential factors affecting accuracy of subsequent analysis.

Results

Factors such as innate biasness in study design of current literature, duplicate reporting, differing inclusion criteria of systematic reviews, scarce data, inadequate follow-up period and limitations of systematic reviews have been shown to hinder the ability for accurate data extrapolation.

Discussion

Unless additional studies are conducted in identified areas of data scarcity and a common list of factors affecting accuracy of data analysis are taken into account when developing recommendations, discrepancies will continue to arise and accurate data analysis and valid systematic reviews will be precluded.