COVID-19 and Pregnancy: Vertical Transmission and Inflammation Impact on Newborns

Review of short-term and long-term adverse effects of covid-19 vaccination during pregnancy

BACKGROUND

The covid-19 pandemic sparked a debate about the safety of vaccines during pregnancy. However, pregnant women were excluded from the Pfizer-BioNTech vaccine phase 3 trials. As two years have passed since the first Covid-19 vaccine and more studies have been conducted, we want to evaluate the scientific literature to determine any actual risks in taking the vaccine during pregnancy.

METHODS

We conducted literature research using PubMed and Google Scholar databases from January to April 2023. As the review considers short- and long-term adverse effects it was divided into two parts. The first part was conducted as a systematic review. The second concerning long-term negative effects due to lack of research is a literature review. The inclusion criteria for the systematic review part were singleton pregnancies, women vaccinated during pregnancy, and studies from 2020 and later. The most common short-term pregnancy adverse effects were included in the search: preterm delivery, small gestation age, intrauterine death, congenital defects, stillborn, fetal growth retardation, spontaneous abortion. Maternal immune activation was the primary concern for the long-term adverse effects and whether vaccination could cause it. The search terms included maternal immune activation, fetal neurodevelopment, neuropsychiatric disorders and the studies used were from 2019.

RESULTS

Most studies showed no significant difference in short-term adverse effects between vaccinated and non-vaccinated women and their fetuses. However, the literature is insufficient to evaluate possible long-term adverse effects.

CONCLUSION

Available evidence supports the safety of administering SARS-CoV-2 vaccines to pregnant women, but further systematic reviews and meta-analyses are essential. Maternal immune activation caused by vaccination may impact a child's neurodevelopment and should be a concern for future studies.

SARS-CoV-2 Infection during Pregnancy Followed by Thalamic Neonatal Stroke-Case Report

A neonatal stroke is a cerebrovascular process caused by interruption of cerebral blood flow that occurs with an incidence between 1 per 1600 and 1 per 2660 live births. Relative higher incidence in the neonatal period compared to later childhood is favored by the hypercoagulability state of the mother, mechanical stress during delivery, transient right to left intracardiac shunt, high hematocrit, blood viscosity, and risk of dehydration during the first few days of life. The exact cause of a neonatal stroke remains unclear in many cases. About 80% of neonatal strokes are due to arterial ischemic events involving the middle cerebral artery. Typical clinical manifestations in a neonatal stroke are usually seizures that appear immediately after birth or after several days of life, but many of the cases may remain asymptomatic. We present the case of a late preterm infant diagnosed with a thalamic stroke on the fifth day of life with no clinical signs except for repeated episodes of apnea. The anamnesis and clinical context, in this case, revealed a SARS-CoV-2 infection in late pregnancy and early bacterial neonatal sepsis. Early identification of a perinatal stroke and increasing awareness of physicians about this condition in the neonatal period have paramount importance to reduce developmental postischemic damage.

Nasopharyngeal SARS-CoV-2 load and perinatal outcomes after maternal infection diagnosed close to delivery

BACKGROUND

The occurrence of COVID-19 during the pregnancy can cause several negative maternal and neonatal outcomes. Nasopharyngeal viral load is associated with inflammatory markers and might influence the disease severity in non-pregnant patients, but there are no data about the relationship between viral load and perinatal outcomes in pregnant patients.

OBJECTIVE

To investigate the hypothesis that nasopharyngeal SARS-CoV-2 load (estimated with real-time polymerase chain reaction delta cycle (ΔCt), measured in hospital clinical laboratories) is associated with perinatal outcomes, when COVID-19 is diagnosed in the third trimester of pregnancy.

STUDY DESIGN

International, retrospective, observational, multi-center, cohort study enrolling 390 women (393 neonates, three pairs of twins), analyzed with multivariate generalized linear models with skewed distributions (gamma) and identity link. The analyses were conducted for the whole population and then followed by a subgroup analysis according to the clinical severity of maternal COVID-19.

RESULTS

The estimated viral load in maternal nasopharynx is not significantly associated with gestational age at birth (adjusted B: -0.008 (95%CI: -0.04; 0.02); p = 0.889), birth weight (adjusted B: 4.29 (95%CI: -25; 35); p = 0.889), weight Z-score (adjusted B: -0.01 (95%CI: -0.03; 1); p = 0.336), 5' Apgar scores (adjusted B: -0. -9.8e^-4 (95%CI: -0.01; 0.01); p = 0.889), prematurity (adjusted OR: -0.97 (95%CI: 0.93; 1.03); p = 0.766) and the small for gestational age status (adjusted OR: 1.03 (95%CI: 0.99; 1.07); p = 0.351). Similar results were obtained in subgroup analyses according to COVID-19 clinical severity.

CONCLUSIONS

The estimated maternal nasopharyngeal viral load in pregnant women affected by COVID-19 during the third trimester is not associated with main perinatal outcomes.

Hearing screening test in neonates born to COVID-19-positive mothers

SARS-CoV-2, the responsible virus for the COVID-19 pandemic, has demonstrated neurotropic properties indicated by cases presenting with auditory and vestibular system insults. The expression of ACE-2 receptors in the placenta and the detection of IgM antibodies against the virus in the fetuses of pregnant women suffering from COVID-19 render vertical transmission of the infection to the fetus possible. Thus, our study aims to examine whether, similar to other viruses like CMV, SARS-CoV-2 is responsible for congenital hearing loss. This is a retrospective study in a regional pediatric hospital. The medical records of newborns (n = 111) born by mothers positive for COVID-19 during pregnancy who underwent screening hearing tests with Transient Evoked Otoacoustic Emissions (TEOAE) and Automatic Auditory Brainstem Response (AABR) from February 2020 to June 2022 were reviewed. Neonates with additional aggravating factors for congenital hearing loss were excluded from the study. For the study period, nine mothers were found positive during the first trimester, twenty mothers in the second trimester, and eighty-three mothers in the third trimester. TEOAEs test and AABR test scored PASS bilaterally in all neonates tested.

CONCLUSION

Infection with COVID-19 during pregnancy was not a risk factor for hearing loss, similar to other studies.

WHAT IS KNOWN

• The pathogenetic mechanism of the viral-induced impairment of the organ of Corti includes direct damage to the hair cells and indirect damage due to the induction of the innate inflammatory response. • Early data suggested that the SARS-CoV-2 virus also has neurotropic properties with manifestations from the sensory epithelia.

WHAT IS NEW

• Although the intrauterine infection remains controversial, the expression of the ACE-2 receptor on the placenta and the detection of IgM antibodies, as well as the covid-19 genome in fetuses, make the vertical transmission tenable. • In our study, the newborn hearing screening results indicate that COVID-19 infection during pregnancy is not a risk factor for hearing loss.

Perinatal Cerebral Ischemic Lesion and SARS-CoV-2 Infection during Pregnancy: A Case Report and a Review of the Literature

Perinatal stroke is related to possible differences in predisposing factors and outcomes between acutely and retrospectively diagnosed cases. In most cases, there are different risk factors and infections that could play an important role. Thus far, different clinical manifestations have been reported in children presenting with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), ranging from asymptomatic status to severe disease sustained by an immune-mediated inflammatory response. SARS-CoV-2 has been associated with severe neurological diseases including seizures and encephalitis in both adults and children. However, there are still few reports regarding the possible relation between SARS-CoV-2 infection of mothers during pregnancy and the neurologic outcome of the newborns. We described the case of a newborn diagnosed with a perinatal stroke, born at 35 weeks of gestation from a mother presenting with SARS- CoV-2 infection during the last months of pregnancy. We also added a brief review of the literature with similar cases. Close monitoring and early intervention in young children born to infected mothers would be highly recommended for the potential neurodevelopmental risk.

Maternal COVID-19 Infection and Possible Associated Adverse Neurological Fetal Outcomes, Two Case Reports

INTRODUCTION

The long-term effects of prenatal coronavirus disease 2019 (COVID-19) infection on the fetal brain are mostly unknown at this time; however, there is increasing evidence being published.

CASE REPORT

Two cases of severe ventriculomegaly, neurological dysfunction, and seizures were found in neonates with prenatal exposure to COVID-19 infection during the first and third trimesters of pregnancy.

CONCLUSION

Inflammation during the prenatal and neonatal periods may be associated with neurological disorders or injury. Despite the presumed lack of vertical transmission, post-COVID-19 syndrome and its associated inflammation may have an impact on the unborn fetus. Hyper-vigilance and dissemination of adverse findings are of significant importance as we navigate through this evolving pandemic and its effects.

KEY POINTS

· Prenatal exposure to COVID-19 may affect the fetal brain.. · There is a possibility of neonatal neurological sequelae from maternal COVID-19.. · Does maternal COVID-19 infection cause infantile seizures?.

Unexpected Vertical Transmission of SARS-CoV-2: Discordant Clinical Course and Transmission from Mother to Newborn

Mother-to-newborn COVID-19 transmission is mainly postnatal, but single-case reports and small case series have also described SARS-CoV-2 transplacental transmission. Unfortunately, studies regarding vertical transmission of SARS-CoV-2 lack systematic approaches to diagnosis and classification. So far, scientific evidence seems to suggest that the severity of maternal infection increases the risk of vertical transmission. We report two neonates born from COVID-19-positive mothers, of which one of the newborns had a vertical infection. The placental involvement, and consequent intrauterine transmission of SARS-CoV-2, were inversely related to the severity of the maternal disease. The description of cases divergent from current evidence on this topic could provide new insights to better understand SARS-CoV-2 vertical transmission.

Neurological effects of COVID-19 in infants and children

Neurological manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in children are becoming increasingly apparent as the coronavirus disease (COVID-19) pandemic continues. While children manifest relatively milder features of the disease, accumulating evidence warrants concern that COVID-19 exacts both acute- and long-term effects on the developing central and peripheral nervous systems. This review focuses on the relatively underinvestigated topic of the effects of SARS-CoV-2 on the brain in infancy and childhood, concluding that clinicians should be attentive to both the acute effects and long-term consequences of COVID-19 from a neurological perspective.

Molecular and Physiological Aspects of SARS-CoV-2 Infection in Women and Pregnancy

Whilst scientific knowledge about SARS-CoV-2 and COVID-19 is rapidly increasing, much of the effects on pregnant women is still unknown. To accommodate pregnancy, the human endometrium must undergo a physiological transformation called decidualization. These changes encompass the remodeling of endometrial immune cells leading to immunotolerance of the semi-allogenic conceptus as well as defense against pathogens. The angiotensin converting enzyme 2 (ACE2) plays an important regulatory role in the renin-angiotensin-system (RAS) and has been shown to be protective against comorbidities known to worsen COVID-19 outcomes. Furthermore, ACE2 is also crucial for decidualization and thus for early gestation. An astounding gender difference has been found in COVID-19 with male patients presenting with more severe cases and higher mortality rates. This could be attributed to differences in sex chromosomes, hormone levels and behavior patterns. Despite profound changes in the female body during pregnancy, expectant mothers do not face worse outcomes compared with non-pregnant women. Whereas mother-to-child transmission through respiratory droplets during labor or in the postnatal period is known, another question of in utero transmission remains unanswered. Evidence of placental SARS-CoV-2 infection and expression of viral entry receptors at the maternal-fetal interface suggests the possibility of in utero transmission. SARS-CoV-2 can cause further harm through placental damage, maternal systemic inflammation, and hindered access to health care during the pandemic. More research on the effects of COVID-19 during early pregnancy as well as vaccination and treatment options for gravid patients is urgently needed.

Viral Infections During Pregnancy: The Big Challenge Threatening Maternal and Fetal Health

Viral infections during pregnancy are associated with adverse pregnancy outcomes, including maternal and fetal mortality, pregnancy loss, premature labor, and congenital anomalies. Mammalian gestation encounters an immunological paradox wherein the placenta balances the tolerance of an allogeneic fetus with protection against pathogens. Viruses cannot easily transmit from mother to fetus due to physical and immunological barriers at the maternal-fetal interface posing a restricted threat to the fetus and newborns. Despite this, the unknown strategies utilized by certain viruses could weaken the placental barrier to trigger severe maternal and fetal health issues especially through vertical transmission, which was not fully understood until now. In this review, we summarize diverse aspects of the major viral infections relevant to pregnancy, including the characteristics of pathogenesis, related maternal-fetal complications, and the underlying molecular and cellular mechanisms of vertical transmission. We highlight the fundamental signatures of complex placental defense mechanisms, which will prepare us to fight the next emerging and re-emerging infectious disease in the pregnancy population.

Maternal and Adult Interleukin-17A Exposure and Autism Spectrum Disorder

Epidemiological evidence in humans has suggested that maternal infections and maternal autoimmune diseases are involved in the pathogenesis of autism spectrum disorder. Animal studies supporting human results have shown that maternal immune activation causes brain and behavioral alterations in offspring. Several underlying mechanisms, including interleukin-17A imbalance, have been identified. Apart from the pro-inflammatory effects of interleukin-17A, there is also evidence to support the idea that it activates neuronal function and defines cognitive behavior. In this review, we examined the signaling pathways in both immunological and neurological contexts that may contribute to the improvement of autism spectrum disorder symptoms associated with maternal blocking of interleukin-17A and adult exposure to interleukin-17A. We first describe the epidemiology of maternal immune activation then focus on molecular signaling of the interleukin-17 family regarding its physiological and pathological roles in the embryonic and adult brain. In the future, it may be possible to use interleukin-17 antibodies to prevent autism spectrum disorder.

Plasma Lipidomic and Metabolomic Profiling after Birth in Neonates Born to SARS-CoV-19 Infected and Non-Infected Mothers at Delivery: Preliminary Results

Pregnant women are among the high-risk populations for COVID-19, whereas the risk of vertical transmission to the fetus is very low. Nevertheless, metabolic alternations described in COVID-19 patients may also occur in pregnant women and their offspring. We prospectively evaluated the plasma lipidomic and metabolomic profiles, soon after birth, in neonates born to infected mothers (cases, n = 10) and in the offspring of uninfected ones at delivery (controls, n = 10). All cases had two negative tests for SARS-CoV-2 (nasopharyngeal swabs) performed 72 h apart. Blood samples were obtained within the first hours after birth. Liquid chromatography-high resolution mass spectrometry (UHPLC-TOF/MS) and gas chromatography-mass spectrometry (GC-MS) were applied for the analyses. Multivariate statistical analysis was performed for data evaluation. Changes in several plasma lipid species-classes (long-chain fatty acids phosphatidylcholines, triglycerides), and amino-acids were identified that allowed for clear discrimination between the study groups. The results of this preliminary investigation suggest that neonates born to Sars-Cov-19 positive mothers, without evidence of viral infection at birth, have a distinct plasma lipidomic and metabolomic profile compared to those of uninfected mothers. Whether these findings are reflective of maternal metabolic alternations due to the virus or a metabolic response following an unidentified neonatal infection warrants further investigation.

Special Issue "Immune Ontogeny and Vaccination in Early Life: How the Non-Human Primate Model Can Help Expand the Current Knowledge in Pediatric Immunology and Infectious Diseases Research"

The development of the immune system requires a number of changes that occur during the first months of life [...].