Vertical transmission of coronavirus disease 2019: a systematic review and meta-analysis

Comparing the immunogenicity of COVID-19 infection and vaccination in pregnant women as measured by anti-S IgG

BACKGROUND

Pregnancy is a critical time for women, making them more susceptible to infectious diseases like COVID-19. This study aims to determine the immunogenicity of COVID-19 in pregnant women who have been infected compared to those who have received the inactive COVID-19 vaccine.

MATERIALS AND METHODS

In this retrospective cohort study, pregnant women who received the inactivated COVID-19 vaccine (Sinopharm) and those with a history of COVID-19 infection during pregnancy were studied. Participants who had experienced stillbirth, received different COVID-19 vaccines, or had intrauterine fetal death were excluded from the study. Overall, the study included 140 participants. The participants were divided into two groups of 70 participants - pregnant women who received the Sinopharm vaccine and pregnant women who had COVID-19 infection during pregnancy. Before delivery, blood samples were collected from all mothers to evaluate the maternal immunoglobulin G (IgG) level. Blood samples were also taken from the baby's umbilical cord during delivery to measure the newborn's IgG level. Additionally, blood samples were collected from babies whose mothers showed signs of acute infection to measure their IgM levels and evaluate vertical transmission.

FINDINGS

The study found a significant relationship between the mean level of maternal IgG and umbilical cord IgG within the groups (P < 0.001). The highest levels of maternal IgG (2.50 ± 2.17) and umbilical cord IgG (2.43 ± 2.09) were observed in pregnant women with a previous COVID-19 infection and no history of vaccination (P < 0.001). Only one baby was born with a positive IgM, and this baby was born to a mother who showed signs of COVID-19 infection in the last five days of pregnancy. The mother was 28 years old, with a BMI of 33; it was her first pregnancy, and she gave birth to a male newborn at term.

CONCLUSION

Administering an inactivated vaccine during pregnancy can generate immunity in both the mother and the child. However, the vaccine's immunity level may not be as potent as that conferred by COVID-19 infection during pregnancy. Nonetheless, the risk of vertical transmission of COVID-19 is considered minimal and can be classified as negligible.

Preserved prenatal lung growth assessed by fetal MRI in the omicron-dominated phase of the SARS-CoV-2 pandemic

OBJECTIVES

With SARS-CoV-2 evolving, disease severity and presentation have changed due to changes in mechanisms of entry and effector site as well as due to effects of vaccination- and/or infection-acquired immunity. We re-assessed fetal lung pathology in pregnancies with uncomplicated SARS-CoV-2 infections during the late, omicron-dominated pandemic phase to inform disease understanding and pregnancy consultation.

METHODS

In this case-control study, fetal lung volumes were assessed by fetal MRI in 24 pregnancies affected by mild maternal SARS-CoV-2 infection during the omicron-dominated pandemic phase with prevailing immunity through vaccination and/or prior SARS-CoV-2 infection.

RESULTS

Fetal lung volumes (normalized to estimated fetal weight) in 24 pregnancies (GA 33.3 ± 3.8, 12 female fetuses) following mild, uncomplicated SARS-CoV-2 infection did not differ significantly from both, published reference values (96.3% ± 22.5% of 50th percentile reference values, p = 0.43), or fetal lung volumes of a site-specific, non-COVID control group (n = 15, 94.2% ± 18.5%, p = 0.76). Placental assessment revealed no group differences in thrombotic changes or placental heterogeneity (p > 0.05, respectively), and fetal lung volume did not correlate with placental heterogeneity when adjusting for gestational age at scan (p > 0.05).

CONCLUSION

Assessment of fetal lung volume by MRI revealed unaffected lung growth in pregnancies affected by uncomplicated SARS-CoV-2 infection in the omicron-dominated pandemic phase in the presence of prevailing hybrid immunity. This finding contrasts sharply with the observed reduction in fetal lung volume following maternal alpha-variant infection in the pre-vaccination era and might reflect tropism- as well as immunity-related effects.

KEY POINTS

Question: Is fetal lung development affected by mild maternal SARS-CoV-2 infection during the omicron-dominated phase of the pandemic?

FINDINGS

Fetal lung volume in 24 affected pregnancies did not differ significantly from published reference values or fetal lung volumes in 15 site-specific, non-COVID-affected control pregnancies.

CLINICAL RELEVANCE

Preserved fetal lung volume following mild maternal SARS-CoV-2 infection during the omicron-dominated phase contrasts with previous findings of reduced volume in unvaccinated pregnancies during the alpha-dominated pandemic phase. These observations might reflect tropism- as well as immunity-related effects.

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.

Association between situs inversus and maternal SARS-CoV-2 infection at gestational age 4-6 weeks

BACKGROUND

A dramatic increase in fetal situs inversus diagnoses by ultrasound in the months following the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) surge of December 2022 in China led us to investigate whether maternal SARS-CoV-2 exposure could be associated with elevated risk of fetal situs inversus.

METHODS

In this multi-institutional, hospital-based, matched case-control study, we investigated pregnant women who underwent ultrasonographic fetal biometric assessment at gestational weeks 20-24 at our hospitals. Each pregnant woman carrying a situs inversus fetus was randomly matched with four controls based on the date of confinement. Relevant information, including SARS-CoV-2 infection, and other potential risk factors were collected. Conditional logistic regression was used to test possible associations between fetal situs inversus and SARS-CoV-2 infection at different gestational weeks as well as individual risk factors.

FINDINGS

A total of 52 pregnant women diagnosed with fetal situs inversus between January 1 and October 31, 2023 and 208 matched controls with normal fetuses were enrolled. We found no association between an increased risk of fetal situs inversus with gestational SARS-CoV-2 infection or with other risk factors. However, fetal situs inversus was significantly associated with SARS-CoV-2 infection specifically in gestational weeks 4-6 (adjusted odds ratio [aOR] 6.54 [95% confidence interval 1.76-24.34]), but not with infection at other gestational ages, after adjusting for covariates.

CONCLUSIONS

Increased risk of fetal situs inversus is significantly associated with maternal SARS-CoV-2 infection at gestational weeks 4-6, corresponding to the fetal developmental window for visceral lateralization in humans.

FUNDING

National Key R&D Program of China, etc.

The effect of long-term COVID-19 infection on maternal and fetal complications: a retrospective cohort study conducted at a single center in China

Investigate the effect of long-term COVID-19 on maternal and fetal complications. A retrospective cohort study was conducted. A total of 623 pregnant women who delivered in Kunming First People's Hospital from November 1, 2022 to July 31, 2023 were selected. By employing statistical methods, we compared the associations between maternal and fetal complications in pregnant women with acute COVID-19 during pregnancy, long-term COVID-19, and non-COVID-19 pregnant women. In the final 623 samples, there were 209 pregnant women with acute COVID-19, 72 pregnant women with long-term COVID-19, and 342 pregnant women without COVID-19. The epidemiological and clinical characteristics of all subjects were similar. Pregnant individuals who developed long-term COVID-19 during their pregnancy had an increased risk of experiencing gestational hypertension (OR 3.344, 95% CI 1.544-7.243), gestational diabetes mellitus (OR 2.301, 95% CI 1.290-4.102), and fetal intrauterine growth restriction (OR 2.817, 95% CI 1.385-5.952). Multivariate binary logistic regression analysis showed that this association remained consistent even after adjusting for confounders and performing subgroup analyses. Other maternal and fetal complications, such as premature rupture of membranes, preterm delivery, neonatal asphyxia, and transfer of neonates to NICU, did not exhibit statistically significant associations. After linear regression analysis, the platelet count (β: - 0.127, 95% CI - 0.001-0.000) of pregnant women with long-term COVID-19 was slightly lower than that of non-COVID-19 pregnant women, and the other coagulation parameters were not statistically significant. The incidence of gestational hypertension, gestational diabetes mellitus and fetal intrauterine growth restriction in pregnant women with long-term COVID-19 is significantly increased, but it does not further increase the coagulation status.

Prenatal mental health and emotional experiences during the pandemic: associations with infant neurodevelopment screening results

BACKGROUND

This study determined whether parental mental health and emotional experiences during the prenatal period were linked to infant developmental outcomes through the Ages and Stages Questionnaire (ASQ-3) at 8-10 months.

METHODS

Participants included 133 individuals who were living in the US and were pregnant or had given birth within 6 months prior to enrollment. Respondents were majority White with high education and income levels. Online surveys were administered from May 2020 to September 2021; follow-up surveys were administered from November 2020 to August 2022.

RESULTS

Parent generalized anxiety symptoms were positively associated with infant communication (β = 0.34, 95% CI [0.15, 1.76], p < 0.05), while parent-fetal bonding was positively associated with infant communication (β = 0.20, 95% CI [0.05, 0.76], p < 0.05) and personal-social performance (β = 0.20, 95% CI [0.04, 0.74], p < 0.05). COVID-19-related worry was negatively associated with infant communication (β = -0.30, 95% CI [-0.75, -0.12], p < 0.05) and fine motor performance (β = -0.25, 95% CI [-0.66, -0.03], p < 0.05).

CONCLUSION

Parent mental health and emotional experiences may contribute to infant developmental outcomes in high risk conditions such as a pandemic.

IMPACT STATEMENT

Maternal SARS-CoV-2 infection has been evaluated in relation to child outcomes, however, parent psychosocial experiences should not be overlooked when considering pandemic risks to child development. Specific prenatal mental health and pandemic-related emotional experiences are associated with infant developmental performance, as assessed by the Ages and Stages. Questionnaire (ASQ-3) at 8 to 10 months old. Findings indicate that parental prenatal anxiety and emotional experiences from the pandemic should be assessed when evaluating child developmental delays.

Interplay of Dyadic Consensus, Reflective Functioning, and Perinatal Affective Difficulties in Modulating Fear of COVID-19 among First-Time Mothers: A Mediation Analysis

BACKGROUND

The COVID-19 pandemic has exacerbated fears and anxieties, potentially influencing maternal perinatal mental health. This study addresses a gap in the literature on fear of COVID-19 in pregnant women, aiming to identify contributing factors.

METHOD

Participants were 401 primiparous women with an average age of 34 years (SD = 4.56) who were recruited through the National Health System during birth support courses. They completed a series of self-reported instruments via an online survey, providing information on their levels of reflective functioning, dyadic consensus, perinatal maternal affectivity, and fear of COVID-19. Pearson's correlation and mediation analysis via a generalized linear model were implemented to analyze the collected data.

RESULTS

The relationship between dyadic consensus and fear of COVID-19 was significant and negative. Furthermore, a significant parallel mediation involving perinatal maternal affectivity and reflective functioning was found to the extent that, when these factors were inserted into the model, the direct association between dyadic consensus and fear of COVID-19 became non-significant (total mediation).

CONCLUSIONS

The results highlight the importance of dyadic adjustment in alleviating maternal COVID-19 fear, emphasizing interventions promoting couple functioning, mentalization, and addressing affective difficulties. Such approaches are vital for supporting expecting mothers during challenging times like the COVID-19 pandemic.

Endocytosis at the maternal-fetal interface: balancing nutrient transport and pathogen defense

Endocytosis represents a category of regulated active transport mechanisms. These encompass clathrin-dependent and -independent mechanisms, as well as fluid phase micropinocytosis and macropinocytosis, each demonstrating varying degrees of specificity and capacity. Collectively, these mechanisms facilitate the internalization of cargo into cellular vesicles. Pregnancy is one such physiological state during which endocytosis may play critical roles. A successful pregnancy necessitates ongoing communication between maternal and fetal cells at the maternal-fetal interface to ensure immunologic tolerance for the semi-allogenic fetus whilst providing adequate protection against infection from pathogens, such as viruses and bacteria. It also requires transport of nutrients across the maternal-fetal interface, but restriction of potentially harmful chemicals and drugs to allow fetal development. In this context, trogocytosis, a specific form of endocytosis, plays a crucial role in immunological tolerance and infection prevention. Endocytosis is also thought to play a significant role in nutrient and toxin handling at the maternal-fetal interface, though its mechanisms remain less understood. A comprehensive understanding of endocytosis and its mechanisms not only enhances our knowledge of maternal-fetal interactions but is also essential for identifying the pathogenesis of pregnancy pathologies and providing new avenues for therapeutic intervention.

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.

Vertical Transmission of SARS-CoV-2 during Pregnancy: A Prospective Italian Cohort Study

OBJECTIVE

The extent of vertical transmission (VT) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from mothers their fetuses or neonates is still uncertain. We aimed to determine the incidence of VT.

STUDY DESIGN

In this prospective cohort study. All mother diagnosed with SARS-CoV-2 infection at the time of delivery or up to 1 week prior and their neonates, managed in a tertiary referral hospital for pregnancy complicated by coronavirus disease 2019 (COVID-19) in Rome, from April 2 to December 22, 2020, were included. Maternal infection was defined as nasopharyngeal swab test results positive for SARS-CoV-2 reverse transcription-polymerase chain reaction (RT-PCR). Biological samples were collected before, at, and after delivery to test positivity for SARS-CoV-2 RT-PCR and anti-SARS-CoV-2-specific antibodies.

RESULTS

The cohort included 95 women and 96 neonates with documented SARS-CoV-2 test results. Four neonates (4.2%) tested positive. The incidence of VT, according to the guidance criteria for diagnosing perinatal SARS-CoV-2 infection, was 5.2%. Neonatal symptoms were due to prematurity or fetal distress: symptomatic infants had lower median (min-max) gestational age, 38.1 (29.3-40.6) versus 39.3 (33.9-41.9) weeks (p = 0.036), and 1-minute and 5-minute Apgar scores, 9 (3-9) versus 9 (7-10) (p = 0.036) and 10 (6-10) versus 10 (8-10) (p = 0.012), respectively, than asymptomatic infants and needed more frequent assistance in the delivery room (22.2 vs 2.5%; p = 0.008). Only six (7.1%) neonates had anti-SARS-CoV-2-specific antibodies, despite the ongoing maternal infection.

CONCLUSION

The incidence of VT is low as is the detection of specific anti-SARS-CoV-2 antibodies in cord blood when infection is contracted late in pregnancy. This would suggest poor protection of infants against horizontal transmission of the virus.

KEY POINTS

· VT of SARS-CoV-2 from pregnant mothers to fetuses or neonates can be possible.. · In this prospective cohort study, the incidence of VT is found to be 5.2%.. · VT is low but exists..

Prenatal SARS-CoV-2 infection results in neurodevelopmental and behavioral outcomes in mice

Prenatal exposure to viral pathogens has been known to cause the development of neuropsychiatric disorders in adulthood. Furthermore, COVID-19 has been associated with a variety of neurological manifestations, raising the question of whether in utero SARS-CoV-2 exposure can affect neurodevelopment, resulting in long-lasting behavioral and cognitive deficits. Using a human ACE2-knock-in mouse model, we have previously shown that prenatal exposure to SARS-CoV-2 at later stages of development leads to fetal brain infection and gliosis in the hippocampus and cortex. In this study, we aimed to determine whether infection of the fetal brain results in long-term neuroanatomical alterations of the cortex and hippocampus or in any cognitive deficits in adulthood. Here, we show that infected mice developed slower and weighed less in adulthood. We also found altered hippocampal and amygdala volume and aberrant newborn neuron morphology in the hippocampus of adult mice infected in utero. Furthermore, we observed sex-dependent alterations in anxiety-like behavior and locomotion, as well as hippocampal-dependent spatial memory. Taken together, our study reveals long-lasting neurological and cognitive changes as a result of prenatal SARS-CoV-2 infection, identifying a window for early intervention and highlighting the importance of immunization and antiviral intervention in pregnant women.

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..

Post-discharge Care Practices, Challenges, and Outcomes in Newborn Infants of Mothers With SARS-CoV-2 Infection: Insights From Public Hospitals

Background The data regarding the care at home and outcomes in infants of mothers infected with SARS-CoV-2 continue to evolve. There is a paucity of studies beyond the immediate newborn period. Our research aims to improve the understanding in these areas by studying the newborn population discharged from public hospitals in several boroughs of New York City (NYC) through the first year of the COVID-19 pandemic. Objective The objective of this study is to assess parental perspective and describe post-discharge care practices, patterns of healthcare utilization, challenges in obtaining care, and outcomes in infants between six and 12 months of age born to mothers infected with SARS-CoV-2 at the time of delivery. Methods We conducted an institutional review board (IRB)-approved multi-center retrospective cohort study of infants born to SARS-CoV-2-positive mothers at five NYC public hospitals between March and December of 2020. Clinical and demographic data were collected from electronic medical records. A phone interview of the caregivers using a standard questionnaire was conducted to collect data about care at home, healthcare utilization patterns, and challenges with access to healthcare. Results Our study cohort included 216 infants born to SARS-CoV-2-positive mothers with 16 (7.4%) mothers being symptomatic at discharge. Ten infants tested positive, and two showed symptoms before discharge. Two hundred seven (95.8%) infants were discharged home to their parents, and eight (3.7%) were transferred to other facilities. One hundred thirty-eight (66%) infants had at least one visit to the emergency room (ER) for various complaints where two were found to have COVID-19 with one needing hospitalization. One hundred seventy-two (79.6%) families responded to the phone interview. Most mothers (78%) cohabitated with their infants at home, and 70.3% elected to breastfeed. However, only 56.3% of mothers reported using all the recommended infection prevention practices at home. More than half (57%) of the families reported financial hardship related to the pandemic. Although 46.2% of patients missed their in-person health maintenance visits, telemedicine was highly utilized for follow-up with most being phone visits (70.3%). The majority of the infants (95.5%) remained up-to-date with their routine immunizations. Conclusions Our results suggest that infants born to SARS-CoV-2-infected mothers showed increased utilization of medical care and telemedicine between six and 12 months of age. Mothers reported low adherence to infection prevention practices at home; however, infants rarely showed clinically significant SARS-CoV-2 infection while maintaining high breastfeeding rates after discharge.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

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.

SARS-CoV-2 perinatal transmission and neonatal outcomes across four different waves of COVID-19 pandemic: A nationwide prospective cohort study from the Italian Society of Neonatology

OBJECTIVES

To describe how SARS-CoV-2 infection at the time of delivery affected maternal and neonatal outcomes across four major waves of the COVID-19 pandemic in Italy.

METHODS

This is a large, prospective, nationwide cohort study collecting maternal and neonatal data in case of maternal peripartum SARS-CoV-2 infection between February 2020 and March 2022. Data were stratified across the four observed pandemic waves.

RESULTS

Among 5201 COVID-19-positive mothers, the risk of being symptomatic at delivery was significantly higher in the first and third waves (20.8-20.8%) than in the second and fourth (13.2-12.2%). Among their 5284 neonates, the risk of prematurity (gestational age <37 weeks) was significantly higher in the first and third waves (15.6-12.5%). The risk of intrauterine transmission was always very low, while the risk of postnatal transmission during rooming-in was higher and peaked at 4.5% during the fourth wave. A total of 80% of positive neonates were asymptomatic.

CONCLUSION

The risk of adverse maternal and neonatal outcomes was significantly higher during the first and third waves, dominated by unsequenced variants and the Delta variant, respectively. Postnatal transmission accounted for most neonatal infections and was more frequent during the Omicron period. However, the paucity of symptoms in infected neonates should lead us not to separate the dyad.

Tiny Lungs, Big Differences: Navigating the Varied COVID-19 Landscape in Neonates vs. Infants via Biomarkers and Lung Ultrasound

Due to their susceptibilities, neonates and infants face unique SARS-CoV-2 challenges. This retrospective study will compare the illness course, symptoms, biomarkers, and lung damage in neonates and infants with SARS-CoV-2 infection from February 2020 to October 2023. This study was conducted at two hospitals in Timisoara, Romania, using real-time multiplex PCR to diagnose and lung ultrasonography (LUS) to assess lung involvement. Neonates had a more severe clinical presentation, an increased immune response, and greater lung involvement. Neonates had more PCR-positive tests (p = 0.0089) and longer hospital stays (p = 0.0002). In neonates, LDH, CRP, and ferritin levels were higher, indicating a stronger inflammatory response. Reduced oxygen saturation in neonates indicates respiratory dysfunction. The symptoms were varied. Infants had fever, cough, and rhinorrhea, while neonates had psychomotor agitation, acute dehydration syndrome, and candidiasis. This study emphasizes individualized care and close monitoring for neonatal SARS-CoV-2 infections. Newborn lung ultrasonography showed different variances and severity levels, emphasizing the need for targeted surveillance and therapy. Newborns have high lung ultrasound scores (LUSS), indicating significant lung involvement. Both groups had initial lung involvement, but understanding these modest differences is crucial to improving care for these vulnerable populations.

Analysis of the transplacental transmission of SARS CoV-2 virus and antibody transfer according to the gestational age at maternal infection

To quantify transplacental transmission of SARS-CoV-2 virus and antibody transfer in pregnant women and their newborns according to the gestational age at maternal infection. A prospective observational multicenter study including pregnant women with a positive RT-PCR or a positive serology for SARS-CoV-2 and compatible symptoms, from April to December 2020, in 11 French maternities. The study was designed to obtain a systematic collection of mother-infant dyad's samples at birth. SARS-CoV-2 viral load was measured by RT-PCR. IgG and IgM antibodies against the SARS-CoV-2 spike protein were measured by enzyme-linked immunosorbent assay. Antibody concentrations and transplacental transfer ratios were analyzed according to the gestational age at maternal infection. The primary outcome was the rate of SARS CoV-2 materno-fetal transmission at birth. The secondary outcome was the quantification of materno-fetal antibody transfer. Maternal and neonatal outcomes at birth were additionally assessed. Among 165 dyads enrolled, one congenital infection was confirmed {n = 1 (0.63%) IC95% [0.02%; 3.48%]}. The average placental IgG antibody transfer ratio was 1.27 (IC 95% [0.69-2.89]). The transfer ratio increased with increasing time between the onset of maternal infection and delivery (P Value = 0.0001). Maternal and neonatal outcomes were reassuring. We confirmed the very low rate of SARS-CoV-2 transplacental transmission (< 1%). Maternal antibody transfer to the fetus was more efficient when the infection occurred during the first and second trimester of pregnancy.

Safety of COVID-19 Vaccination During Pregnancy and Lactation: A VigiBase Analysis

BACKGROUND

There is limited evidence on the safety of coronavirus disease 2019 (COVID-19) vaccination during pregnancy and lactation. Thus, we aimed to evaluate the association between COVID-19 vaccination during pregnancy and lactation and reporting risk of adverse pregnancy or lactation outcomes.

METHODS

Using VigiBase, we performed a disproportionality analysis with case/non case design. Cases were defined based on the Standardized MedDRA Queries (SMQs) of "pregnancy and neonatal topics" and non-cases were defined as all other adverse events. We included all reports with COVID-19 vaccines as the suspected cause. Using the full database as the comparators, reporting odds ratios (RORs) with 95% confidence intervals (CIs) were estimated by logistic regression while adjusting for maternal age. Infants' age and sex were additionally adjusted in analyzing the risk of COVID-19 vaccination during lactation.

RESULTS

We identified 10,266 and 6,474 reports with the SMQ of "pregnancy and neonatal topics" associated with COVID-19 vaccines during pregnancy and lactation, respectively. No significant RORs of adverse pregnancy outcomes associated with COVID-19 vaccines during pregnancy were observed; however, "functional lactation disorders" showed significant disproportionality during lactation with adjusted ROR of 1.48 (95% CI, 1.21-1.79). Further analysis that analyzed "functional lactation disorders" at a preferred term level, showed higher ROR in mastitis (2.76 [95% CI, 1.45-5.27]).

CONCLUSION

Overall, we did not observe a positive association between COVID-19 vaccination during pregnancy and risk of reporting adverse pregnancy outcomes. However, we found a significant disproportionate reporting association between COVID-19 vaccination during lactation and "functional lactation disorders", specifically mastitis. Continuous surveillance is warranted to confirm the safety of COVID-19 vaccine during pregnancy and lactation.

Study of the Vertical Transmission of COVID-19 by Using the World Health Organisation Protocol in a Tertiary Care Hospital in Eastern India

BACKGROUND

The World Health Organisation (WHO) has established criteria to diagnose vertical transmission in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This study aimed to determine the incidence of vertical transmission of SARS-CoV-2 using WHO criteria in a tertiary care centre in eastern India.

METHODS

A hospital-based prospective observational study was conducted from June 2021 to February 2022 on women admitted for delivery with a positive nasopharyngeal (NP) swab and a SARS-CoV-2 real-time reverse-transcriptase polymerase chain reaction (RT-PCR) test. Following the delivery, the amniotic fluid (AF) and swab from the placenta were tested for SARS-CoV-2 by the Truenat test. The umbilical cord and maternal blood were analyzed to detect immunoglobulin M (IgM) and immunoglobulin G (IgG). The nasopharyngeal swabs of the newborns were tested for SARS-CoV-2 by RT-PCR.

RESULTS

Forty-eight SARS-CoV-2-positive asymptomatic women were included in the study. Twenty-eight (58.3%) were delivered via cesarean section. Preterm delivery occurred in 13 (27.1%) cases. In only one case, vertical transmission was confirmed as the neonate had a positive nasopharyngeal SARS-CoV-2 RT-PCR test and the cord blood was IgM positive (suggesting an immune response in the neonate). The placenta was positive in three cases, and amniotic fluid was positive in two. However, vertical transmission was deemed unlikely in these cases as there was no evidence of immune response or viral persistence according to the WHO criteria. There was one stillbirth, and it tested negative for SARS-CoV-2.

CONCLUSION

This study strengthens the evidence of vertical transmission in COVID-19-positive asymptomatic mothers. The data suggest a low transmission rate.

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

INTRODUCTION

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

MATERIAL AND METHODS

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

RESULTS

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

DISCUSSION

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

Covid-19 infection in pregnant women: Auditory evaluation in infants

 Recent studies showed that COVID-19 infection can affect cochleo-vestibular system. The possibility of a vertical transmission is controversial. Some studies suggested that it is possible but unlikely, others find no evidence of vertical transmission. The objective of this study was to investigate whether exposure to COVID-19 during pregnancy or at birth has an impact on the hearing of the offspring. As part of the national hearing screening program, we performed in all newborns between January 2022 and February 2023, TEOAEs (Transient Evoked Otoacoustic Emissions) at birth and at 3 months. For those "REFER" at the third month test, we performed aABR (Automatic Auditory Brainstem Response) at 6 months. We analysed separately result between infants born to COVID-positive mothers during pregnancy and those born to COVID-negative mothers. To statistical verify differences we performed "Chi-square test". We enrolled a total of 157 infants, of whom 16 were born to mothers who had a molecular PCR test positive for COVID-19. In the latter we tested a total of 32 ears and only 1 ear (3,1%) resulted "REFER". On the other hand, in the control group we tested a total of 282 ears and 22 (7,8%) were found to be "REFER". Our study showed no significant differences in audiological assessment between newborns exposed to COVID-19 infection during pregnancy or at birth compared to the unexposed group. However, further studies with a larger patient's sample will be necessary for a more comprehensive evaluation.

Mechanisms of SARS-CoV-2 Placental Transmission

The widespread occurrence of SARS-CoV-2 infections and the diverse range of symptoms have placed significant strain on healthcare systems worldwide. Pregnancy has also been affected by COVID-19, with an increased risk of complications and unfavorable outcomes for expectant mothers. Multiple studies indicate that SARS-CoV-2 can infiltrate the placenta, breach its protective barrier, and infect the fetus. Although the precise mechanisms of intrauterine transmission remain unclear, factors such as perinatal infection, macrophages, sexual intercourse, and the virus' interaction with host angiotensin-converting enzyme 2 (ACE2) and neuropilin-1 (NRP-1) proteins appear to play a role in this process. The integrity of the placental barrier fluctuates throughout pregnancy and appears to influence the likelihood of fetal transmission. The expression of placental cell receptors, like ACE2, changes during pregnancy and in response to placental damage. However, due to the consistent presence of others, such as NRP-1, SARS-CoV-2 may potentially enter the fetus at different stages of pregnancy. NRP-1 is also found in macrophages, implicating maternal macrophages and Hofbauer cells as potential routes for viral transmission. Our current understanding of SARS-CoV-2's vertical transmission pathways remains limited. Some researchers question the ACE2-associated transmission model due to the relatively low expression of ACE2 in the placenta. Existing studies investigating perinatal transmission and the impact of sexual intercourse have either involved small sample sizes or lacked statistical significance. This review aims to explore the current state of knowledge regarding the potential mechanisms of COVID-19 vertical transmission, identifying areas where further research is needed to fill the gaps in our understanding.

Maternal and neonatal outcomes associated with illness severity of maternal COVID-19

BACKGROUND

Several reports demonstrated that perinatal SARS-CoV-2 has significant impact on maternal and neonatal health outcomes. However, the relationship between severity of maternal illness with outcomes remains less clear.

METHODS

This is a single-center retrospective cohort study of mother/infant dyads with positive maternal test for SARS-CoV-2 between 14 days prior and 3 days after delivery from 3/30/2020 to 12/28/2021.

RESULTS

Among 538 mothers, those with moderate/severe/critical illness were more likely to undergo induction, receive oxygen, mechanical ventilation or ECMO. Mortality was significantly higher among the mothers with severe illness than asymptomatic and those with mild illness (6% vs 0% and 0%, respectively, P < 0.05). Neonates born to mothers with moderate/severe/critical illness were more likely to be preterm with lower birth weight, and to be admitted to the NICU (P < 0.05) but not to be small for gestational age. Mild maternal illness was only associated with NICU admission for isolation precaution and decreased rate of breastfeeding.

CONCLUSIONS

Maternal illness severity was significantly associated with prematurity and several adverse maternal and neonatal outcomes.

Maternal SARS-CoV-2 impacts fetal placental macrophage programs and placenta-derived microglial models of neurodevelopment

The SARS-CoV-2 virus activates maternal and placental immune responses, which in the setting of other infections occurring during pregnancy are known to impact fetal brain development. The effects of maternal immune activation on neurodevelopment are mediated at least in part by fetal brain microglia. However, microglia are inaccessible for direct analysis, and there are no validated non-invasive surrogate models to evaluate in utero microglial priming and function. We have previously demonstrated shared transcriptional programs between microglia and Hofbauer cells (HBCs, or fetal placental macrophages) in mouse models. Here, we assessed the impact of maternal SARS-CoV-2 on HBCs isolated from term placentas using single-cell RNA-sequencing. We demonstrated that HBC subpopulations exhibit distinct cellular programs, with specific subpopulations differentially impacted by SARS-CoV-2. Assessment of differentially expressed genes implied impaired phagocytosis, a key function of both HBCs and microglia, in some subclusters. Leveraging previously validated models of microglial synaptic pruning, we showed that HBCs isolated from placentas of SARS-CoV-2 positive pregnancies can be transdifferentiated into microglia-like cells, with altered morphology and impaired synaptic pruning behavior compared to HBC models from negative controls. These findings suggest that HBCs isolated at birth can be used to create personalized cellular models of offspring microglial programming.

Non-Viral RNA Delivery During Pregnancy: Opportunities and Challenges

During pregnancy, the risk of maternal and fetal adversities increases due to physiological changes, genetic predispositions, environmental factors, and infections. Unfortunately, treatment options are severely limited because many essential interventions are unsafe, inaccessible, or lacking in sufficient scientific data to support their use. One potential solution to this challenge may lie in emerging RNA therapeutics for gene therapy, protein replacement, maternal vaccination, fetal gene editing, and other prenatal treatment applications. In this review, the current landscape of RNA platforms and non-viral RNA delivery technologies that are under active development for administration during pregnancy is explored. Advancements of pregnancy-specific RNA drugs against SARS-CoV-2, Zika, influenza, preeclampsia, and for in-utero gene editing are discussed. Finally, this study highlights bottlenecks that are impeding translation efforts of RNA therapies, including the lack of accurate cell-based and animal models of human pregnancy and concerns related to toxicity and immunogenicity during pregnancy. Overcoming these challenges will facilitate the rapid development of this new class of pregnancy-safe drugs.

Effects of novel coronavirus Omicron variant infection on pregnancy outcomes: a retrospective cohort study from Guangzhou

Objective

Since 2022, Omicron has been circulating in China as a major variant of the novel coronavirus, but the effects of infection with Omicron variants on pregnant women and newborns are unknown. The purpose of this study was to determine the clinical characteristics of Omicron infection during pregnancy and its effect on pregnancy outcomes.

Methods

This study retrospectively analyzed the data of 93 confirmed cases of novel coronavirus infection and 109 non-infected patients admitted to the isolation ward of Guangdong Maternal and Child Health Hospital from December 1, 2022 to January 31, 2023, and statistically analyzed the clinical features of Omicron variant infection during pregnancy and its impact on pregnancy outcomes. Further effects of underlying diseases on Omicron infection in pregnant women were analyzed.

Results

The incubation period of COVID-19 infection was 0.99±0.86 days, 94.38% of patients had fever or other respiratory symptoms, the lymphocyte count in the infected group was lower than that in the uninfected group, and the lymphocyte count was further reduced in the patients with pregnancy complications or complications. Compared with the uninfected group, APTT and PT were prolonged, platelet count and fibrinogen were decreased in the infected group, all of which had statistical significance. COVID-19 infection during pregnancy increased the rate of cesarean section compared to uninfected pregnant patients, and COVID-19 infection in gestational diabetes resulted in a 4.19-fold increase in cesarean section rate. There was no statistically significant difference in gestational age between the two groups. The incidence of intrauterine distress, turbidity of amniotic fluid and neonatal respiratory distress were higher in the infection group. No positive cases of neonatal COVID-19 infection have been found.

Conclusion

The patients infected with omicron during pregnancy often have febrile respiratory symptoms with lymphocyopenia, but the incidence of severe disease is low. Both Omicron infection and gestational diabetes further increase the incidence of cesarean section, and this study found no evidence of vertical transmission of Omicron.

A retrospective observational study on maternal and neonatal outcomes of COVID-19: Does the mild SARS-CoV-2 infection affect the outcome?

Background

Currently, several SARS-CoV-2 variants, including Omicron, are still circulating globally. This underscores the necessity for a comprehensive understanding of their impact on obstetric and neonatal outcomes in pregnant women, even in cases of mild infection.

Methods

We conducted a retrospective, single-center observational study to investigate the association between gestational SARS-CoV-2 infection and maternal-fetal outcomes in the Chinese population. The study enrolled 311 pregnant patients with SARS-CoV-2 infection (exposure group) and 205 uninfected pregnant patients (control group). We scrutinized the hospital records to collect data on demographics, clinical characteristics, and maternal and neonatal outcomes for subsequently comparison.

Results

Similar characteristics were observed in both groups, including maternal age, height, BMI, gravidity, parity, and comorbidities (p > 0.05). A majority (97.4%) of pregnant women in the exposure group with COVID-19 experienced mild clinical symptoms, with fever (86.5%) and cough (74.3%) as the primary symptoms. The exposure group exhibited significantly higher incidences of cesarean section and fetal distress compared to the control group (p < 0.05). Furthermore, pregnant women in the exposure group showed reduced levels of hemoglobin and high-sensitivity C-reactive protein, while experiencing significantly increased levels of lymphocytes, prothrombin time, alanine aminotransferase, and aspartate aminotransferase (p < 0.05). Notably, recent SARS-CoV-2 infection prior to delivery appeared to have an adverse impact on liver function, blood and coagulation levels in pregnant women. When comparing the two groups, there were no significant differences in the postpartum hemorrhage rate, premature birth rate, birth weight, neonatal asphyxia rate, neonatal department transfer rate, and neonatal pneumonia incidence.

Conclusions

Our study suggests that mild COVID-19 infection during pregnancy does not have detrimental effects on maternal and neonatal outcomes. However, the increased risks of events such as fetal distress and cesarean section, coupled with potential alterations in physical function, reveal the consequences of SARS-CoV-2 infection during pregnancy, even in mild cases. These findings emphasize the importance of proactive management and monitoring of pregnant individuals with COVID-19.

Evaluation of pregnancy outcomes in mothers with COVID-19 infection: a systematic review and meta-analysis

Pregnant women are one of the endangered groups who need special attention in the COVID-19 epidemic. We conducted a systematic review and summarised the studies that reported adverse pregnancy outcomes in pregnant women with COVID-19 infection. A literature search was performed in PubMed and Scopus up to 1 September 2022, for retrieving original articles published in the English language assessing the association between COVID-19 infection and adverse pregnancy outcomes. Finally, in this review study, of 1790 articles obtained in the initial search, 141 eligible studies including 1,843,278 pregnant women were reviewed. We also performed a meta-analysis of a total of 74 cohort and case-control studies. In this meta-analysis, both fixed and random effect models were used. Publication bias was also assessed by Egger's test and the trim and fill method was conducted in case of a significant result, to adjust the bias. The result of the meta-analysis showed that the pooled prevalence of preterm delivery, maternal mortality, NICU admission and neonatal death in the group with COVID-19 infection was significantly more than those without COVID-19 infection (p<.01). A meta-regression was conducted using the income level of countries. COVID-19 infection during pregnancy may cause adverse pregnancy outcomes including of preterm delivery, maternal mortality, NICU admission and neonatal death. Pregnancy loss and SARS-CoV2 positive neonates in Lower middle income are higher than in High income. Vertical transmission from mother to foetus may occur, but its immediate and long-term effects on the newborn are unclear.

SARS-CoV-2 infection as cause of in-utero fetal death: regional multicenter cohort study

OBJECTIVE

Placental infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can lead to placental insufficiency and in-utero fetal death (IUFD). The objective of this study was to confirm and quantify the extent to which fetoplacental infection with SARS-CoV-2 is a cause of fetal death.

METHODS

This was a multicenter retrospective cohort study of fetal deaths that underwent postmortem examination between January 2020 and January 2022 in three fetal pathology units in Paris, France. All cases of IUFD and termination of pregnancy (TOP) occurring in 31 maternity hospitals in the Paris region undergo detailed placental pathological examination in these units. Databases were searched for cases of IUFD and TOP. Cases with fetal malformation or cytogenetic abnormality were excluded to avoid bias. We included cases of IUFD with a placental or undetermined cause and cases of TOP in the context of severe intrauterine growth restriction (IUGR). Placentas were sent to a single virology unit for reverse-transcription polymerase chain reaction (RT-PCR) testing by a single laboratory technician blinded to the initial postmortem examination report. Our primary endpoint was the proportion of positive placental SARS-CoV-2 RT-PCR tests in the cohort.

RESULTS

Among 147 722 deliveries occurring over 2 years, 788 postmortem examinations for IUFD and TOP for severe IUGR were recorded, of which 462 (58.6%) were included. A total of 13/462 (2.8%) placentas tested positive for SARS-CoV-2 by RT-PCR. Wild-type virus and alpha and delta variants were identified. All positive cases had histological lesions consistent with placental dysfunction. There was a strong correlation between SARS-CoV-2 placentitis and the presence of chronic intervillositis and/or massive fibrin deposits in the placenta. When both lesion types were present, the specificity and negative predictive value for the diagnosis of placental SARS-CoV-2 infection were 0.99 (95% CI, 0.98-1.00) and 0.96 (95% CI, 0.94-0.98), respectively.

CONCLUSIONS

At the height of the SARS-CoV-2 pandemic, the cause of more than half of fetal deaths in the Paris area was determined by postmortem analysis to be of placental or undetermined origin. Of these cases, 2.8% were due to placental SARS-CoV-2 infection with a specific pattern of histological involvement. This study highlights the need for SARS-CoV-2 screening in stillbirth assessment. The impact of vaccination coverage remains to be established. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Navigation of Knowledge: the Impact of COVID-19 on Pregnancy-a Bibliometric Analysis

Since the outbreak of COVID-19, countries around the world have faced huge economic and social burdens. SARS-COV-2 may exist in nature for a long time due to the diversity of its different variants. Pregnant women and newborns as vulnerable groups will suffer serious health threats. Bibliometrics as a method of summarizing publications can be used to extract important achievements and hot topics in this field. We search the target publications from the Web of Science Core collection database, and then use Microsoft Office Excel, CiteSpace, R, Scimago, and VOSviewer for visual analysis. Finally, we included 1709 publications from 2998 institutions in 104 countries. The number of publications has exploded since the COVID-19 pandemic in 2019. Among them, the USA, China, Britain, and Italy have higher quantity and quality. We identified important journals, authors, keywords, and references in this field. Anxiety, stress, risk of pregnancy complications, and vaccine safety and acceptance have received extensive attention from scholars during the COVID-19 pandemic and will continue to be urgent issues to be addressed in the future. Most of the current studies fall into the category of case reports and clinical data analysis. COVID-19 has been linked to serious pregnancy complications and mental illness, and vaccination during pregnancy is recommended to protect both mother and fetus. Further large-scale cohort studies and discovery of molecular mechanisms are needed in this field.

Comparative clinical and placental pathologic characteristics in pregnancies with and without SARS-CoV-2 infection

OBJECTIVES

To compare the clinical and morphological characteristics of the "mother-placenta-fetus" system in high risk pregnant women of three groups: no SARS-CoV-2 infection, mild SARS-CoV-2 infection, and severe SARS-CoV-2 infection.

METHODS

A case-control study was performed for all deliveries, at 28 weeks' gestation or greater, who had standard indications for placental pathologic examination. Three groups were formed: (1) control group (no SARS-CoV-2 infection), (2) mild SARS-CoV-2 infection, (3) severe SARS-CoV-2 infection. High-risk pregnancies were registered in all cases in the study groups. The examination of the placenta and the selection of fragments of placental tissue were carried out in accordance with the consensus recommendations of the Amsterdam Placental Workshop Group. The sections were subjected to standard processing and stained with hematoxylin and eosin according to the standard protocol. All cases were reviewed by two pathologists, which did not know any information on pregnancy outcome and clinical data. Statistical analysis was performed using SPSS, p<0.05 was considered statistically significant.

RESULTS

Women with severe SARS-CoV-2 infection had an increased rate of multimorbidity including diabetes, chronic hypertension and obesity (p<0.01) compared with the other groups. Placentas at severe COVID-19 course were damaged by both chronic and acute injuries, in comparison to the mild and control groups (p<0.001). Also an important finding in severe COVID-19 was diffuse necrosis of the villous trophoblast - homogenization, diffuse circular eosinophilic masses surrounding the chorionic villi.

CONCLUSIONS

Women with multimorbidity are an "at-risk" subgroup for severe SARS-CoV-2 infection and greater likelihood of both placental damage and perinatal hypoxic-ischemic events. These results suggest that patient education, SARS-CoV-2 disease monitoring and preventive measures would be of benefit to this group.

Assessment of Levels of Anxiety and Fear of Covid-19 in a Population of Pregnant Women in Spain

Objective

The aim of the study was to assess the levels of fear and anxiety in the particularly vulnerable population group of women during pregnancy.

Methods

Cross-sectional study between March 2022 and July 2022 involving 978 pregnant women aged 16 to 50 years. It was carried out based on the scale for the assessment of fear and anxiety in pregnant women (AMICO_Pregnant) and the collection of sociodemographic data. Normality analysis was performed prior to univariate and bivariate statistical analysis.

Results

The sample was composed of a total of 978 pregnant women. The mean of the AMICO_Pregnant scale was intermediate (5.04 points; SD=2.36). The bivariate analysis showed a statistically significant relationship between the AMICO_Pregnant scale and the following variables: vaccination schedule status, contact with the disease, weeks of gestation, altered delivery or birth plan.

Conclusion

Women with pregnancies closer to term, with no contact with the disease, without a complete vaccination schedule, or who had undergone changes in their delivery or birth plans, showed higher levels of fear and anxiety.

Pregnancy and SARS-CoV-2 infection with a focus on its vertical transmission, breastfeeding, cord blood banking, and vaccination during COVID-19 infection

The SARS-CoV-2 outbreak led to a health crisis worldwide. This infection can infect individuals, particularly pregnant women. In this review, we tried to find the possibility of vertical transmission of COVID-19 and investigate the effects of COVID-19 on pregnancy, breastfeeding, cord blood banking, and the effects of recommended vaccines on pregnant and lactating women. Keywords include COVID-19, congenital infection, SARS-CoV-2, pregnancy, and COVID-19 vaccines. Vertical transmission of SARS-CoV-2 was searched in scientific databases, such as PubMed, Google Scholar, and Scopus. The criteria for including studies in this article are the study of SARS-CoV-2 infection in pregnant women, fetuses, and neonates during pregnancy and while breastfeeding, and also the effect of COVID-19 vaccines on them. There are several conflicting results in the transmission of SARS-CoV-2 from the maternal-fetal interface. Since many neonates born from COVID-19-infected mothers had no signs of this infection, the possibility of SARS-CoV-2 congenital transmission cannot be confirmed. Also, SARS-CoV-2-infected women can breastfeed their babies if they have mild symptoms. Up till now, no adverse effect of COVID-19 vaccines has been identified on mothers, infants, and the fertility of men or women. Even so, more investigations are needed on the long-term effects of COVID-19 vaccines.

Early Postnatal Infection of Neonates Born to Mothers Infected by SARS-CoV-2 Omicron Variant

OBJECTIVES

To evaluate the rate of postnatal infection during the first month of life in neonates born to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-positive mothers during the predominant circulation of the omicron (B.1.1.529) variant.

METHODS

This prospective, 10-center study enrolled mothers infected by SARS-CoV-2 at delivery and their infants, if both were eligible for rooming-in, between December 2021 and March 2022. Neonates were screened for SARS-CoV-2 RNA at 1 day of life (DOL), 2 to 3 DOL, before discharge, and twice after hospital discharge. Mother-infant dyads were managed under a standardized protocol to minimize the risk of viral transmission. Sequencing data in the study area were obtained from the Italian Coronavirus Disease 2019 Genomic platform. Neonates were included in the final analysis if they were born when the omicron variant represented >90% of isolates.

RESULTS

Eighty-two percent (302/366) of mothers had an asymptomatic SARS-CoV-2 infection. Among 368 neonates, 1 was considered infected in utero (0.3%), whereas the postnatal infection rate during virtually exclusive circulation of the omicron variant was 12.1%. Among neonates infected after birth, 48.6% became positive during the follow-up period. Most positive cases at follow-up were detected concurrently with the peak of coronavirus disease 2019 cases in Italy. Ninety-seven percent of the infected neonates were asymptomatic.

CONCLUSIONS

The risk of early postnatal infection by the SARS-CoV-2 omicron variant is higher than that reported for previously circulating variants. However, protected rooming-in practice should still be encouraged given the paucity of symptoms in infected neonates.

Neonatal Outcomes of Premature Infants Born to Women with the Novel Coronavirus (SARS-CoV-2) Infection: A Case Control Study

OBJECTIVE

Novel coronavirus disease 2019 (COVID-19) is a disease associated with atypical pneumonia caused by the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). The first cases of COVID-19 were reported in Wuhan at the end of 2019. Transmission usually occurs via infected droplets and close personal contact; the possibility of vertical transmission is still under debate. This retrospective study aimed to analyze clinical characteristics of premature infants born to mothers with symptomatic COVID-19 disease.

STUDY DESIGN

This case control study compared the clinical and laboratory data of 20 premature infants born to mothers infected with SARS-CoV-2 with sex and gestational age-matched historical controls.

RESULTS

The median gestational age and birth weight in both groups were similar. Respiratory distress developed in 11 (55.5%) infants in study group and 19 (47.5%) infants in control group. Mechanical ventilation and endotracheal surfactant administration rates were similar. Median duration of hospitalization was 8.5 (2-76) days in study group and 12 days in historical controls. Real-time reverse-transcription polymerase chain reaction tests (RT-PCR) of nasopharyngeal swab samples for SARS-CoV-2 were found to be negative twice, in the first 24 hours and later at 24 to 48 hours of life. No neutropenia or thrombocytopenia was detected in the study group. Patent ductus arteriosus, bronchopulmonary dysplasia, and necrotizing enterocolitis rates were similar between groups. No mortality was observed in both groups.

CONCLUSION

To the best of our knowledge, this is one of the few studies evaluating the clinical outcomes of premature infants born to SARS-CoV-2 infected mothers. There was no evidence of vertical transmission of SARS-CoV-2 from symptomatic SARS-CoV-2-infected women to the neonate in our cohort. The neonatal outcomes also seem to be favorable with no mortality in preterm infants.

KEY POINTS

· SARS-CoV-2 pandemic is a challenge for pregnant women.. · Neonatal outcomes of premature infants born to mothers infected with SARS-CoV-2 not well defined.. · SARS-CoV-2 infection seems to have no adverse effect on mortality and morbidity in premature infants..

Pregnancy outcomes following natural conception and assisted reproduction treatment in women who received COVID-19 vaccination prior to conception: a population-based cohort study in China

Introduction

The coronavirus disease-2019 (COVID-19) pandemic has swept across the world and continues to exert serious adverse effects on vulnerable populations, including pregnant women and neonates. The vaccines available at present were designed to prevent infection from COVID-19 strains and control viral spread. Although the incidence of pregnancy cycle outcomes are not likely to increase patients vaccinated prior to pregnancy compared with unvaccinated patients based on our knowledge of vaccination safety, there is no specific evidence to support this hypothesis. Therefore, the current study aimed to investigate the association between maternal vaccination prior to conception and pregnancy outcomes.

Methods

We retrospectively analyzed 2,614 women who received prenatal care and delivered in the Obstetrical Department of The First Affiliated Hospital of Anhui Medical University between February 2022 and November 2022. Of the 1,380 eligible pregnant women, 899 women who had received preconception vaccination were assigned to a vaccine group and 481 women who were not vaccinated were control group. Of the enrolled patients, 291 women received fertility treatment (141 vaccinated women, 150 unvaccinated women). The primary outcomes were pregnancy complications (hypothyroidism, gestational diabetes mellitus, pregnancy-induced hypertension, polyhydramnios, oligohydramnios, premature rupture of membranes and postpartum hemorrhage), obstetric outcomes (preterm birth rate, cesarean section rate) and neonatal outcomes (birth-weight, body length, low-birth-weight rate, rate of congenital defects, neonatal mortality and admission to the neonatal intensive care unit).

Results

There was no significant difference in the incidence of complications during pregnancy and delivery when compared between the vaccine group and control group in either univariate- or multivariate-models. The type of vaccine was not associated with the odds of adverse pregnancy outcome. Among the women with infertility treatment, the vaccinated group and the unvaccinated group had similar pregnancy outcomes.

Conclusion

Women who received COVID-19 vaccination prior to conception had similar maternal and neonatal outcomes as women who were unvaccinated. Our findings indicate that COVID-19 vaccinations can be safely administered prior to pregnancy in women who are planning pregnancy or assisted reproductive treatment. During new waves of COVID-19 infection, women who are planning pregnancy should be vaccinated as soon as possible to avoid subsequent infections.

Adaptation and psychometric study of the scale for the measurement of fear and anxiety of COVID-19 disease in pregnant women (AMICO_Pregnant)

Objective

The aim of this research was to adapt and explore the psychometric properties of a specific scale to assess the levels of fear and anxiety of COVID-19 disease in pregnant women.

Methods

An adaptation phase, by a panel of experts, and a psychometric descriptive cross-sectional study were carried out on the final version of the 16-item, self-administered AMICO_Pregnant scale. Univariate and bivariate analyses were carried out, followed by exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). The consistency of the scale was assessed using the Omega coefficient and Cronbach's Alpha.

Results

With a sample of 1,013 pregnant women living in Spain and over 18 years of age, the mean age was 33 years. The scale showed a bifactor structure (anxiety and fear) that was confirmed with good fit parameters. Reliability was assessed in terms of internal consistency by calculating Cronbach's Alpha coefficient (0.95) and McDonald's Omega coefficient (0.94) as indicators of robustness of the scale's reliability.

Conclusion

The AMICO_Pregnant scale of 16 items with scores ranging from 1 to 10 is a valid and reliable tool to assess levels of anxiety and fear of COVID_19 in Spanish pregnant women. Pregnant women have shown moderate levels of anxiety and fear regarding the COVID_19 disease in the final phase of the pandemic.

CO-Sprout-A Pilot Double-Blinded Placebo-Controlled Randomised Trial of Broccoli Sprout Powder Supplementation for Pregnant Women with COVID-19 on the Duration of COVID-19-Associated Symptoms: Study Protocol

Since its discovery in late 2019, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been estimated to be responsible for at least 769.3 million infections and over 6.95 million deaths. Despite significant global vaccination efforts, there are limited therapies that are considered safe and effective for use in the management of COVID-19 during pregnancy despite the common knowledge that pregnant patients have a much higher risk of adverse outcomes. A bioactive compound found in broccoli sprout-sulforaphane-is a potent inducer of phase-II detoxification enzymes promoting a series of potentially beneficial effects notably as an antioxidant, anti-inflammatory, and anti-viral. A pilot, double-blinded, placebo-controlled randomised trial is to be conducted in Melbourne, Australia, across both public and private hospital sectors. We will assess a commercially available broccoli sprout extract in pregnant women between 20+0 and 36+0 weeks gestation with SARS-CoV-2 infection to investigate (i) the duration of COVID-19 associated symptoms, (ii) maternal and neonatal outcomes, and (iii) biomarkers of infection and inflammation. We plan to enrol 60 outpatient women with COVID-19 irrespective of vaccination status diagnosed by PCR swab or RAT (rapid antigen test) within five days and randomised to 14 days of oral broccoli sprout extract (42 mg of sulforaphane daily) or identical microcrystalline cellulose placebo. The primary outcome of this pilot trial will be to assess the feasibility of conducting a larger trial investigating the duration (days) of COVID-19-associated symptoms using a broccoli sprout supplement for COVID-19-affected pregnancies. Pregnant patients remain an at-risk group for severe disease following infection with SARS-CoV-2 and currently unclear consequences for the offspring. Therefore, this study will assess feasibility of using a broccoli sprout supplement, whilst providing important safety data for the use of sulforaphane in pregnancy.

Placental Infection Associated with SARS-CoV-2 Wildtype Variant and Variants of Concern

The original SARS-CoV-2 lineages have been replaced by successive variants of concern (VOCs) over time. The aim of this study was to perform an assessment of the placental infection by SARS-CoV-2 according to the predominant variant at the moment of COVID-19 diagnosis. This was a prospective study of SARS-CoV-2-positive pregnant women between March 2020 and March 2022. The population was divided into pregnancies affected by COVID-19 disease during 2020 (Pre-VOC group) and pregnancies affected after December 2020 by SARS-CoV-2 variants of concern (VOC group). The presence of virus was assessed by RT-PCR, and the viral variant was determined by whole genome sequencing. A total of 104 placentas were examined, among which 54 cases belonged to the Pre-VOC group and 50 cases belonged to the VOC group. Sixteen positive placental RT-PCR tests for SARS-CoV-2 were reported. The NGS analysis confirmed the SARS-CoV-2 lineage in placenta tissue. All samples corresponded to the Pre-VOC group, whereas no placental presence of SARS-CoV-2 was detected in the VOC group (16, 29.6% vs. 0, 0.0% p = 0.000). Preterm birth (9, 16.7% vs. 2, 4%; p = 0.036) and hypertensive disorders of pregnancy (14, 25.9% vs. 3, 6%; p = 0.003) were more frequent in the Pre-VOC group than in the VOC group. Finally, the VOC group was composed of 23 unvaccinated and 27 vaccinated pregnant women; no differences were observed in the sub-analysis focused on vaccination status. In summary, SARS-CoV-2-positive placentas were observed only in pregnancies infected by SARS-CoV-2 wildtype. Thus, placental SARS-CoV-2 presence could be influenced by SARS-CoV-2 variants, infection timing, or vaccination status. According to our data, the current risk of SARS-CoV-2 placental infection after maternal COVID disease during pregnancy should be updated.

Balance between maternal antiviral response and placental transfer of protection in gestational SARS-CoV-2 infection

The intricate interplay between maternal immune response to SARS-CoV-2 and the transfer of protective factors to the fetus remains unclear. By analyzing mother-neonate dyads from second and third trimester SARS-CoV-2 infections, our study shows that neutralizing antibodies (NAbs) are infrequently detected in cord blood. We uncovered that this is due to impaired IgG-NAb placental transfer in symptomatic infection and to the predominance of maternal SARS-CoV-2 NAbs of the IgA and IgM isotypes, which are prevented from crossing the placenta. Crucially, the balance between maternal antiviral response and transplacental transfer of IgG-NAbs appears to hinge on IL-6 and IL-10 produced in response to SARS-CoV-2 infection. In addition, asymptomatic maternal infection was associated with expansion of anti-SARS-CoV-2 IgM and NK cell frequency. Our findings identify a protective role for IgA/IgM-NAbs in gestational SARS-CoV-2 infection and open the possibility that the maternal immune response to SARS-CoV-2 infection might benefit the neonate in 2 ways, first by skewing maternal immune response toward immediate viral clearance, and second by endowing the neonate with protective mechanisms to curtail horizontal viral transmission in the critical postnatal period, via the priming of IgA/IgM-NAbs to be transferred by the breast milk and via NK cell expansion in the neonate.

Prenatal transmission of severe acute respiratory syndrome coronavirus 2, resulting in neonatal severe acute pneumonia, from an asymptomatic mother: a case report

BACKGROUND

We report a case of prenatal coronavirus disease 2019, which evolved 6 days after birth into severe pneumonia with signs of multiple organ failure, in a mother with asymptomatic coronavirus disease 2019.

CASE PRESENTATION

At minute 11 of life, our patient from Afro-Caribbean had polypnea with mild signs of struggle; Silverman's index was scored at three. Chest radiography showed bilateral opacities consistent with respiratory distress syndrome. On the 6th day of life, a thoracic computed tomography scan showed bilateral parenchymatous lesions (10-20%) in ground glass, compatible with coronavirus disease 2019-type infection. At the same time, the neonate showed signs of multiple organ failure (elevated liver and cardiac enzyme levels). She was treated with azithromycin (20 mg/kg/day) for 5 days. All the signs recovered fully by day 12. Real-time polymerase chain reaction results were positive in the first 30 min of life, suggesting prenatal transmission. Our patient has been followed until 2 years old and is developing well with no sequelae.

CONCLUSION

This case report demonstrates the incompatibility between maternal asymptomatic coronavirus disease 2019 and severe neonatal lung involvement. We emphasize the need for vigilance to avoid missing the most severe forms of neonatal coronavirus disease 2019.

Risk for stillbirth among pregnant individuals with SARS-CoV-2 infection varied by gestational age

BACKGROUND

Despite previous research findings on higher risks of stillbirth among pregnant individuals with SARS-CoV-2 infection, it is unclear whether the gestational timing of viral infection modulates this risk.

OBJECTIVE

This study aimed to examine the association between timing of SARS-CoV-2 infection during pregnancy and risk of stillbirth.

STUDY DESIGN

This retrospective cohort study used multilevel logistic regression analyses of nationwide electronic health records in the United States. Data were from 75 healthcare systems and institutes across 50 states. A total of 191,403 pregnancies of 190,738 individuals of reproductive age (15-49 years) who had childbirth between March 1, 2020 and May 31, 2021 were identified and included. The main outcome was stillbirth at ≥20 weeks of gestation. Exposures were the timing of SARS-CoV-2 infection: early pregnancy (<20 weeks), midpregnancy (21-27 weeks), the third trimester (28-43 weeks), any time before delivery, and never infected (reference).

RESULTS

We identified 2342 (1.3%) pregnancies with COVID-19 in early pregnancy, 2075 (1.2%) in midpregnancy, and 12,697 (6.9%) in the third trimester. After adjusting for maternal and clinical characteristics, increased odds of stillbirth were observed among pregnant individuals with SARS-CoV-2 infection only in early pregnancy (odds ratio, 1.75, 95% confidence interval, 1.25-2.46) and midpregnancy (odds ratio, 2.09; 95% confidence interval, 1.49-2.93), as opposed to pregnant individuals who were never infected. Older age, Black race, hypertension, acute respiratory distress syndrome or acute respiratory failure, and placental abruption were found to be consistently associated with stillbirth across different trimesters.

CONCLUSION

Increased risk of stillbirth was associated with COVID-19 only when pregnant individuals were infected during early and midpregnancy, and not at any time before the delivery or during the third trimester, suggesting the potential vulnerability of the fetus to SARS-CoV-2 infection in early pregnancy. Our findings underscore the importance of proactive COVID-19 prevention and timely medical intervention for individuals infected with SARS-CoV-2 during early and midpregnancy.

Unmasking the enigma: An in-depth analysis of COVID-19 impact on the pediatric population

OBJECTIVES

COVID-19, caused by the novel coronavirus, has had a profound and wide-reaching impact on individuals of all age groups across the globe, including children. This review article aims to provide a comprehensive analysis of COVID-19 in children, covering essential topics such as epidemiology, transmission, pathogenesis, clinical features, risk factors, diagnosis, treatment, vaccination, and others. By delving into the current understanding of the disease and addressing the challenges that lie ahead, this article seeks to shed light on the unique considerations surrounding COVID-19 in children and contribute to a deeper comprehension of this global health crisis affecting our youngest population.

METHODS

A comprehensive literature search was conducted to gather the most recent and relevant information regarding COVID-19 in children. Multiple renowned databases, including MEDLINE, PubMed, Scopus, as well as authoritative sources such as the World Health Organization (WHO), the U.S. Food and Drug Administration (FDA), the European Medicines Agency (EMA), and the National Institutes of Health (NIH) websites and others were thoroughly searched. The search included articles, guidelines, reports, clinical trials results and expert opinions published within the past three years, ensuring the inclusion of the latest research findings on COVID-19 in children. Several relevant keywords, including "COVID-19," "SARS-CoV-2," "children," "pediatrics," and related terms were used to maximize the scope of the search and retrieve a comprehensive set of articles.

RESULTS AND CONCLUSION

Three years since the onset of the COVID-19 pandemic, our understanding of its impact on children has evolved, but many questions remain unanswered. While SAR-CoV-2 generally leads to mild illness in children, the occurrence of severe cases and the potential for long-term effects cannot be overlooked. Efforts to comprehensively study COVID-19 in children must continue to improve preventive strategies, identify high-risk populations, and ensure optimal management. By unraveling the enigma surrounding COVID-19 in children, we can strive towards safeguarding their health and well-being in the face of future global health challenges.

Comparative Analysis of Hematological and Biochemical Changes in Neonates among Women with and without COVID-19 Infection during Pregnancy

The aim of this study is to evaluate the test results of neonates delivered by COVID-19-positive mothers during pregnancy with those of neonates born to unvaccinated mothers who are COVID-19-free. A cohort study was conducted on 367 pregnant women who gave birth at Premiere Hospital, Timisoara, Romania, between May 2021 and February 2022. Two groups were established: Group 1, with 167 pregnant women infected with COVID-19, and Group 2, with 200 pregnant women who were not affected by COVID-19 during pregnancy. Maternal laboratory examination did not exhibit significant variations except for platelet count. In neonatal blood tests, WBC had a significantly lower median value in the group born to COVID-19-free mothers. Neonatal anemia and leukocytosis showed slightly higher prevalence in Group 1, but the differences were not statistically significant. This study suggests that maternal COVID-19 infection during pregnancy does not have significant associations with most maternal and neonatal characteristics.

Effects of the Severe Acute Respiratory Syndrome Coronavirus 2 Inactivated Vaccine on the Outcome of Frozen Embryo Transfers: A Large Scale Clinical Study

Background

Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is a life-threatening infectious disease that has become a global pandemic.

Objective

This study aimed to explore the effects of SARS-CoV-2 inactivated vaccine on the outcome of frozen embryo transfer (FET).

Methods

We grouped patients who underwent FET between August 2021 and March 2022 based on their vaccination status, number of doses, and the interval between the last dose and the FET, and then compared the differences in pregnancy outcomes among the groups.

Results

There were 1084 vaccinated patients and 1228 non-vaccinated ones. There were significant differences in the live birth rate between the vaccination and non-vaccination groups (16.61% vs 28.26%), among the one-dose, two-dose, and three-dose groups (22.28% vs 19.51% vs 7.27%), and among the groups with interval ≤ 1 month, 1-2 months, and ≥ 2 months (38.38% vs 27.27% vs 12.03%). There were significant differences in the persistent pregnancy rate between the vaccination and non-vaccination groups (22.88% vs 14.09%), among the one-dose, two-dose, and three-dose groups (14.51% vs 23.80% vs 38.18%), and among the groups with interval ≤ 1 month, 1-2 months, and ≥ 2 months (1.01% vs 8.44% vs 28.16%). There were significant differences in the neonatal weight between the vaccination and non-vaccination groups [3805.50 (3746.00-3863.50) vs 2970.00 (2500.00-3400.00)]. There were significant differences in the premature birth rate among the one-dose, two-dose, and three-dose groups (23.26% vs 34.59% vs 100.00%), and among the groups with interval ≤ 1 month, 1-2 months, and ≥ 2 months (15.79% vs 21.43% vs 37.00%).

Conclusion

Pregnancy outcomes were not affected by taking the SARS-CoV-2 inactivated vaccine before FET, the number of doses, and the interval between doses. These findings provide evidence supporting the safety of administering the SARS-CoV-2 inactivated vaccine during pregnancy, which can be used as a guide for vaccinating patients undergoing ART.