Assessment of Maternal and Neonatal SARS-CoV-2 Viral Load, Transplacental Antibody Transfer, and Placental Pathology in Pregnancies During the COVID-19 Pandemic

COVID-19 on Pregnancy Outcomes, Mental Health and Placenta: Focus in Latin America

The COVID-19 pandemic has impacted many aspects of health and society worldwide. One vulnerable group that faced SARS-CoV-2 infection is pregnant women, who were considered to have potentiated risk factors. In physiological pregnancy, maternal systems have several changes and adaptations to support fetal development. These changes involve regulations of cardiovascular, respiratory, and immunologic systems, among others, which SARS-CoV-2 could severely alter. Furthermore, the systemic effects of viral infection could be associated with placental dysfunction and adverse pregnancy outcomes, which have been studied from the start of the pandemic to date. Additionally, pregnancy is a condition of more significant mental health vulnerability, especially when faced with highly stressful situations. In this chapter, we have collected information on the effect of COVID-19 on maternal mortality, the SARS-CoV-2 infection rate in pregnancy, and the impact on pregnancy outcomes, maternal mental health, and placental function, with a particular focus on studies that consider the Latin American population.

A large series of molecular and serological specimens to evaluate mother-to-child SARS-CoV-2 transmission: a prospective study from the Italian Obstetric Surveillance System

OBJECTIVES

To assay the presence of the SARS-CoV-2 genome in vaginal, rectal, and placental swabs among pregnant women and in newborn nasopharyngeal swabs and to investigate the immunological response and maternal antibody transfer through the umbilical cord blood and milk of unvaccinated mothers.

METHODS

Vaginal, rectal, and placental specimens, maternal and neonatal serum, and milk were collected from a wide cohort of pregnant Italian women with confirmed SARS-CoV-2 infection admitted to the hospital between February 25, 2020 and June 30, 2021. Samples were tested in selected reference laboratories according to a shared interlaboratory protocol.

RESULTS

Among 1086 enrolled women, the SARS-CoV-2 positive rate detected in all specimens ranged from 0.7% to 8.4%. Respectively, 45.2% of maternal sera collected during pregnancy and 39.7% of those collected at birth tested positive for immunoglobulin G, whereas 50.5% tested positive among neonates. Nasopharyngeal swabs were positive in 0.8% of the newborns, and immunoglobulin G was detected in 3.0% of the milk samples. The highest immunological response was recorded within 30 days during pregnancy and within 60 days of birth and in the neonatal population.

CONCLUSION

Vertical transmission should be considered a rare event; although, a good maternal immunological response and antibodies transfer throughout the umbilical cord blood was detected.

Severe acute respiratory syndrome coronavirus 2 seroprevalence and longitudinal antibody response following natural infection in pregnancy: A prospective cohort study

BACKGROUND

Antenatal care provides unique opportunities to assess severe acute respiratory syndrome coronavirus 2 seroprevalence and antibody response duration after natural infection detected during pregnancy; transplacental antibody transfer may inform peripartum and neonatal protection. We estimated seroprevalence and durability of antibodies from natural infection (anti-nucleocapsid immunoglobulin G) among pregnant people, and evaluated transplacental transfer efficiency.

OBJECTIVE AND DESIGN

We conducted a cross-sectional study to measure severe acute respiratory syndrome coronavirus 2 seroprevalence, and a prospective cohort study to longitudinally measure anti-nucleocapsid immunoglobulin G responses and transplacental transfer of maternally derived anti-nucleocapsid antibodies.

METHODS

We screened pregnant people for the seroprevalence study between 9 December 2020 and 19 June 2021 for anti-nucleocapsid immunoglobulin G in Seattle, Washington. We enrolled anti-nucleocapsid immunoglobulin G positive people from the seroprevalence study or identified through medical records with positive reverse transcription polymerase chain reaction or antigen positive results in a prospective cohort between 9 December 2020 and 9 August 2022.

RESULTS

In the cross-sectional study (N = 1284), 5% (N = 65) tested severe acute respiratory syndrome coronavirus 2 anti-nucleocapsid immunoglobulin G positive, including 39 (60%) without prior positive reverse transcription polymerase chain reaction results and 42 (65%) without symptoms. In the prospective cohort study (N = 107 total; N = 65 from the seroprevalence study), 86 (N = 80%) had anti-nucleocapsid immunoglobulin G positive results during pregnancy. Among 63 participants with delivery samples and prior anti-nucleocapsid positive results, 29 (46%) were anti-nucleocapsid immunoglobulin G negative by delivery. Of 34 remaining anti-nucleocapsid immunoglobulin G positive at delivery with paired cord blood, 19 (56%) had efficient transplacental anti-nucleocapsid immunoglobulin G antibody transfer. Median time from first anti-nucleocapsid immunoglobulin G positive to below positive antibody threshold was 19 weeks and did not differ by prior positive reverse transcription polymerase chain reaction status.

CONCLUSIONS

Maternally derived severe acute respiratory syndrome coronavirus 2 antibodies to natural infection may wane before delivery. Vaccines are recommended for pregnant persons to reduce severe illness and confer protection to infants.

COVID-19 Vaccination Prioritization Strategies in Malaysia: A Retrospective Analysis of Early Evidence

The coronavirus disease 2019 (COVID-19) that can cause extreme acute respiratory syndrome has posed a catastrophic threat to public health. The vaccines had indeed restored optimism and, after more than two years of battling the pandemic, there is renewed hope for the transition to endemicity. At the start of vaccination efforts, when supply shortages of vaccines were inevitable, every nation determined the high-risk population groups to be given priority for the COVID-19 vaccines. In this paper, the characteristics of the initial COVID-19 vaccine recipients in Malaysia are described. In line with the policies of many other countries, Malaysia firstly inoculated frontline healthcare workers, and subsequently the list of front liners grew to include defense and security personnel and those involved in the provision of essential services. People with disabilities or those with special needs and several underlying medical conditions that increased their risk of developing severe COVID-related illnesses were included in the priority categories. These included patients with severe lung disease, chronic heart disease, chronic kidney disease, chronic liver disease, neurological disease, diabetes mellitus and obesity in adults, splenic dysfunction, and severe mental illness. With little information and under circumstances of great uncertainty, the Health Ministry of a middle-income country had developed a vaccination priority-list based on the disease's epidemiology and clinical data, vaccine type, operational considerations, and risk evaluation. Early evidence was presented and suggested that the full vaccination with any of the three predominant vaccines (AZD1222, BNT162b2, and CoronaVac) in the country had been highly effective in preventing COVID-19 infections, COVID-19-related ICU admissions, and death. As many SARS-CoV-2 variants of concern (VoC), such as the Omicron BA.2/4/5, are emerging, future vaccination strategies may necessitate the need to change the immunogen of the vaccine, as well as considerations for when to give high-risk groups booster injections. These considerations are valuable for future planning by policymakers and healthcare providers to make vaccination policy and decisions, especially for the inclusion of the COVID-19 vaccines into national immunization programs.

The COVID-19 Vaccine and Pregnant Minority Women in the US: Implications for Improving Vaccine Confidence and Uptake

The American College of Obstetricians and Gynecologists (AGOG) recommends the FDA-approved Pfizer and Moderna mRNA COVID-19 vaccines and boosters for all eligible pregnant women in the US. However, COVID-19 vaccine confidence and uptake among pregnant minority women have been poor. While the underlying reasons are unclear, they are likely to be associated with myths and misinformation about the vaccines. Direct and indirect factors that deter minority mothers in the US from receiving the mRNA COVID-19 vaccines require further investigation. Here, we examine the historical perspectives on vaccinations during pregnancy. We will examine the following aspects: (1) the influenza and tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccinations during pregnancy; (2) the exclusion of pregnant and lactating women from COVID-19 vaccine trials; (3) COVID-19 vaccine safety during pregnancy, obstetric complications associated with symptomatic COVID-19 during pregnancy, COVID-19 vaccine hesitancy among pregnant minority women, and racial disparities experienced by pregnant minority women due to the COVID-19 pandemic as well as their potential impact on pregnancy care; and (4) strategies to improve COVID-19 vaccine confidence and uptake among pregnant minority women in the US. COVID-19 vaccine hesitancy among minority mothers can be mitigated by community engagement efforts that focus on COVID-19 vaccine education, awareness campaigns by trusted entities, and COVID-19-appropriate perinatal counseling aimed to improve COVID-19 vaccine confidence and uptake.

Antepartum SARS-CoV-2 infection and adverse birth outcomes in South African women

Background

SARS-CoV-2 infection in pregnant women has been associated with severe illness in the women and higher rates of premature delivery. There is, however, paucity of data on the impact of the timing of SARS-CoV-2 infection and on symptomatic or asymptomatic infections on birth outcomes. Data from low-middle income settings is also lacking.

Methods

We conducted a longitudinal study from April 2020 to March 2021, in South Africa, where symptomatic or asymptomatic pregnant women were investigated for SARS-CoV-2 infection during the antepartum period. We aimed to evaluate if there was an association between antepartum SARS-CoV-2 infection on birth outcomes. SARS-CoV-2 infection was investigated by nucleic acid amplification test (NAAT), histological examination was performed in a sub-set of placentas.

Results

Overall, 793 women were tested for SARS-CoV-2 antenatally, including 275 (35%) who were symptomatic. SARS-CoV-2 infection was identified in 138 (17%) women, of whom 119 had symptoms (COVID-19 group) and 19 were asymptomatic. The 493 women who were asymptomatic and had a negative SARS-CoV-2 NAAT were used as the referent comparator group for outcomes evaluation. Women with COVID-19 compared with the referent group were 1.66-times (95% confidence interval (CI) = 1.02-2.71) more likely to have a low-birthweight newborn (30% vs 21%) and 3.25-times more likely to deliver a very low-birthweight newborn (5% vs 2%). Similar results for low-birthweight were obtained comparing women with SARS-CoV-2 confirmed infection (30%) with those who had a negative NAAT result (22%) independent of symptoms presentation. The placentas from women with antenatal SARS-CoV-2 infection had higher percentage of chorangiosis (odds ratio (OR) = 3.40, 95% CI = 1.18-.84), while maternal vascular malperfusion was more frequently identified in women who tested negative for SARS-CoV-2 (aOR = 0.28, 95% CI = 0.09-0.89).

Conclusions

Our study demonstrates that in a setting with high HIV infection prevalence and other comorbidities antenatal SARS-CoV-2 infection was associated with low-birthweight delivery.

Mother to Newborn Transmission of SARS-CoV-2 Infection: Evolution of Evidence in 1.5 Years of COVID-19 Pandemic

Coronavirus disease 2019 (COVID-19) pandemic caused significant mortality and morbidity in people of all age groups worldwide. Given the uncertainty regarding the mode of transmission and potential effects of COVID-19 on pregnant mothers and their newborns, guidelines for taking care of maternal-newborn dyads have evolved tremendously since the pandemic began. There has been an enormous influx of published materials regarding the outcomes of mothers and newborns. Still, multiple knowledge gaps regarding comprehensive information about risk to the mothers and newborns exist, which need to be addressed. Current evidence suggests that mothers with symptomatic COVID-19 infection are at increased risk of severe illness during pregnancy, with a higher need for respiratory support and premature deliveries. Neonates born to mothers with COVID-19 are at increased risk of needing intensive care; however, most newborns do well after birth. As new mutant variants arise, we need to be cautious while proactively understanding any new evolving patterns. All leading health authorities strongly recommend COVID-19 vaccination before or during pregnancy to reduce the risk of maternal morbidities and benefit from passing antibodies to newborns prenatally and via breastmilk. Additionally, there are racial, ethnic, and socioeconomic disparities in outcomes and vaccination coverage for pregnant women. This article summarizes the rapidly evolving evidence for the last 1.5 years and aims to help health care professionals care for mothers with COVID-19 and their newborns. KEY POINTS: · COVID-19 in pregnancy can cause perinatal morbidities.. · Breastfeeding and breast milk are safe for newborns.. · COVID-19 vaccination reduces the risk for morbidities..

Infection and transmission of ancestral SARS-CoV-2 and its alpha variant in pregnant white-tailed deer

ABSTRACTSARS-CoV-2 was first reported circulating in human populations in December 2019 and has since become a global pandemic. Recent history involving SARS-like coronavirus outbreaks have demonstrated the significant role of intermediate hosts in viral maintenance and transmission. Evidence of SARS-CoV-2 natural infection and experimental infections of a wide variety of animal species has been demonstrated, and in silico and in vitro studies have indicated that deer are susceptible to SARS-CoV-2 infection. White-tailed deer (WTD) are amongst the most abundant and geographically widespread wild ruminant species in the US. Recently, WTD fawns were shown to be susceptible to SARS-CoV-2. In the present study, we investigated the susceptibility and transmission of SARS-CoV-2 in adult WTD. In addition, we examined the competition of two SARS-CoV-2 isolates, representatives of the ancestral lineage A and the alpha variant of concern (VOC) B.1.1.7 through co-infection of WTD. Next-generation sequencing was used to determine the presence and transmission of each strain in the co-infected and contact sentinel animals. Our results demonstrate that adult WTD are highly susceptible to SARS-CoV-2 infection and can transmit the virus through direct contact as well as vertically from doe to fetus. Additionally, we determined that the alpha VOC B.1.1.7 isolate of SARS-CoV-2 outcompetes the ancestral lineage A isolate in WTD, as demonstrated by the genome of the virus shed from nasal and oral cavities from principal infected and contact animals, and from the genome of virus present in tissues of principal infected deer, fetuses and contact animals.

Adverse Maternal Outcomes in Pregnant Women Affected by Severe-Critical COVID-19 Illness: Correlation with Vaccination Status in the Time of Different Viral Strains' Dominancy

This is a monocentric and cross-sectional study conducted at the COVID-19 Division of the Obstetrical and Gynecological Unit and Intensive Care Units (ICUs) of Policlinico di Bari, in Bari, Italy, between September 2020 and April 2022. This study aimed to identify the prevalence of severe-critical COVID-19 illness requiring access to the Intensive Care Unit (ICU) among 287 pregnant patients, and possible correlations between the SARS-CoV-2 variants, the specific pandemic wave (dominated by wild, Alpha, Delta, and Omicron strains), and severe-critical adverse maternal outcomes. The prevalence of severe-critical COVID-19 illness was 2.8% (8/287), reaching 4.9% (8/163) excluding the 4th wave (Omicron dominant). The Delta variant determined the highest risk ratio and odds for access to the ICU due to severe-critical COVID-19-related symptoms compared to the other variants (wild, Alpha, Omicron). During the third wave (Delta), the ICU cases underwent a higher rate of hyperimmune plasma infusion (75%), antibiotic therapy (75%), and remdesivir (33%); all of the patients were intubated. During the Omicron wave, the patients were asymptomatic or with few symptoms: most of them (70%) were vaccinated with a median of two doses. The maternal outcome worsened in the case of Alpha and, especially, Delta variants for severe-critical COVID-19-related symptoms and ICU access.

Characterization of SARS-CoV-2 antibodies in human milk from 21 women with confirmed COVID-19 infection

BACKGROUND

One potential mechanism for protection from SARS-CoV-2 in children is through passive immunity via breast milk from a mother infected with the novel coronavirus. The primary objectives of this study were to establish the presence of SARS-CoV-2-specific IgA and IgG and to characterize the antigenic regions of SARS-CoV-2 proteins that were reactive with antibodies in breast milk.

METHODS

Between March 2020 and September 2020, 21 women with confirmed SARS-CoV-2 infection were enrolled in Mommy's Milk. Participants donated serial breast milk samples around their time of illness. Breast milk samples were used to probe a multi-coronavirus protein microarray containing full-length and variable-length overlapping fragments of SARS-CoV-2 proteins. Samples were also tested against S and N proteins by electrochemiluminescence assay.

RESULTS

The breast milk samples contained IgA reactive with a variety of SARS-CoV-2 antigens. The most IgA-reactive SARS-CoV-2 proteins were N (42.9% of women responded to ≥1 N fragment) and S proteins (23.9% responded to ≥1 fragment of S1 or S2). IgG responses were similar. A striking observation was the dissimilarity between mothers in antibody recognition, giving distinct antibody reactivity and kinetic profiles.

CONCLUSIONS

Individual COVID-19 cases had diverse and unique milk IgA profiles following the onset of symptoms.

IMPACT

In this observational longitudinal case series of 21 women with confirmed SARS-CoV-2 infection, IgA binding to SARS-CoV-2 proteins detected by orthologous proteome microarray and electrochemiluminescence assays was observed in >75% of women, but there was heterogeneity in which antigens and how many were reactive between women. Immunological profiles of protein regions recognized by each woman were distinct. Diverse repertoires of mucosal breast milk antibody to SARS-CoV-2 reflect heterogeneous passive transfer of maternal antibody to exposed breastfeeding infants.

Placental Vascular and Inflammatory Findings from Pregnancies Diagnosed with Coronavirus Disease 2019: A Systematic Review and Meta-analysis

We aimed to perform a meta-analysis of the literature concerning histopathologic findings in the placentas of women with SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection during pregnancy. Searches for articles in English included PubMed, Web of Science, Google Scholar, and reference lists (up to April 2021). Studies presenting data on placental histopathology according to the Amsterdam Consensus Group criteria in SARS-CoV-2 positive and negative pregnancies were identified. Lesions were categorized into: maternal and fetal vascular malperfusion (MVM and FVM, respectively), acute placental inflammation with maternal and fetal inflammatory response (MIR and FIR, respectively), chronic inflammatory lesions (CILs), and increased perivillous fibrin deposition (PVFD). A total of 15 studies reporting on 19,025 placentas, n = 699 of which were derived from women who were identified as being infected with SARS-CoV-2 and 18,326 as SARS-CoV-2-negative controls, were eligible for analysis. No significant difference in incidence of MVM (odds ratio [OR]: 1.18, 95% confidence interval [CI]: 0.73-1.90), FVM (OR: 1.23, 95% CI: 0.63-2.42), MIR (OR: 0.66, 95% CI: 0.29-1.52) or FIR (OR: 0.85, 95% CI: 0.44-1.63), and CILs (OR: 0.97, 95% CI: 0.55-1.72) was found between placentae from gravida identified as being SARS-CoV-2 infected. However, placenta from gravida identified as being infected with SARS-CoV-2 were associated with significantly increased occurrence of PVFD (OR: 2.77, 95% CI: 1.06-7.27). After subgroup analyses based on clinical severity of COVID-19 infection, no significant difference was observed in terms of reported placental pathology between symptomatic or asymptomatic SARS-CoV-2 gravidae placenta. Current evidence based on the available literature suggests that the only pathologic finding in the placentae of women who are pregnant identified as having been infected with SARS-CoV-2 was an increased prevalence of PVFD. KEY POINTS: · No association between SARS-CoV-2 and maternal or fetal placental malperfusion.. · No association between SARS-CoV-2 and maternal or fetal inflammatory response.. · SARS-CoV-2 is associated with increased perivillous fibrin deposition in placenta..

Infants Born Following SARS-CoV-2 Infection in Pregnancy

OBJECTIVES

To evaluate outcomes of neonates born to mothers with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy, the dynamics of placental transfer of maternal antibodies, and its persistence during infancy.

METHODS

Cohort study enrolling neonates born to mothers with SARS-CoV-2 infection in pregnancy. All infants were evaluated at birth. Those born to women with infection onset within 2 weeks before delivery were excluded from further analyses. Remaining infants underwent cerebral and abdominal ultrasound, fundoscopy evaluation, and were enrolled in a 12 month follow-up. Qualitative immunoglobulin G (IgG)/immunoglobulin M and quantitative IgG to S1/S2 subunits of spike protein were assessed in mother-neonate dyads within 48 hours postdelivery and during follow-up.

RESULTS

Between April 2020 and April 2021, 130 of 2745 (4.7%) neonates were born to mothers with SARS-CoV-2 infection in pregnancy, with 106 of 130 infections diagnosed before 2 weeks before delivery. Rates of preterm and cesarean delivery were comparable between women with and without infection (6% vs 8%, P = .57; 22% vs 32%, P = .06). No clinical or instrumental abnormalities were detected at birth or during follow-up. There was a positive correlation between maternal and neonatal SARS-CoV-2 IgG levels (r = 0.81, P < .001). Transplacental transfer ratio was higher after second-trimester maternal infections as compared with first and third trimester (P = .03). SARS-CoV-2 IgG level progressively decreased in all infants, with 89 of 92 (97%) infants seronegative at 6 months of age.

CONCLUSIONS

Clinical outcomes were favorable in all infants. Matching peak IgG level after infection and higher IgG transplacental transfer might result in the most durable neonatal passive immunity.

Maternal-foetal transfer of severe acute respiratory syndrome coronavirus 2 antibodies among women with and those without HIV infection

In pregnant women, antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein cross the placenta and can be detected in cord-blood at the time of delivery. We measured SARS-CoV-2 full-length antispike IgG in blood samples collected from women living with HIV (WLWHIV) and without HIV when presenting for labour, and from paired cord-blood samples. Antispike IgG was measured in maternal blood at delivery on the Luminex platform. Cord-blood samples from newborns of women in with detectable antispike IgG were analysed. The IgG geometric mean concentrations (GMCs) and the percentage of cord-blood samples with detectable antispike IgG were compared between WLWHIV and without HIV. A total of 184 maternal and cord-blood pairs were analysed, including 47 WLWHIV and 137 without HIV. There was no difference in antispike GMCs between WLWHIV and without HIV [157 binding antibody units (BAU)/ml vs. 187 BAU/ml; P  = 0.17)]. Cord-blood samples from newborns of WLWHIV had lower GMCs compared with those without HIV (143 vs. 205 BAU/ml; P  = 0.033). Cord-to-maternal blood antibody ratio was 1.0 and similar between the two HIV groups. In WLWHIV, those who were 30 years old or less had lower cord-to-maternal blood antibody ratio (0.75 vs. 1.10; P  = 0.037) and their newborns had lower cord-blood GMCs (94 vs. 194 BAU/ml; P  = 0.04) compared with the older women. Independently of maternal HIV infection status, there was efficient transplacental transfer of antispike antibodies. The GMCs in cord-blood from newborns of WLWHIV were lower than those in HIV-unexposed newborns.

Disseminated intravascular coagulation complicating mild or asymptomatic maternal COVID-19

BACKGROUND

Hypercoagulability frequently complicates moderate or severe COVID-19 and can result in venous thromboembolism, arterial thrombosis, or microvascular thrombosis. Disseminated intravascular coagulation, however, is uncommon.

OBJECTIVE

We sought to describe the clinical presentation and outcome in a series of pregnant patients with mild or asymptomatic COVID-19 who had disseminated intravascular coagulation.

STUDY DESIGN

This was a retrospective case series. Cases were solicited via e-mails targeted to obstetrical providers in the Mednax National Medical Group and a restricted maternal-fetal medicine Facebook page. Inclusion criteria were: hospital admission during pregnancy, positive test for SARS-CoV-2 within 2 weeks of admission, and maternal disseminated intravascular coagulation defined as ≥2 of the following: platelet count ≤100,000 per mm3, fibrinogen ≤200 mg/dL, and prothrombin time ≥3 seconds above the upper normal limit. Exclusion criteria were severe COVID-19 requiring ventilation within an hour of diagnosis of coagulopathy or use of anticoagulants at the time of diagnosis. Maternal and newborn records were abstracted and summarized with descriptive statistics.

RESULTS

Inclusion criteria were met in 19 cases from October 2020 through December 2021. Of these, 18 had not received any COVID-19 vaccine, and 1 had unknown vaccination status. Median gestational age on hospital admission was 30 weeks (interquartile range, 29-34 weeks). The main presenting symptom or sign was decreased fetal movement (56%) or nonreassuring fetal heart rate pattern (16%). COVID-19 was asymptomatic in 79% of cases. Two of the 3 defining coagulation abnormalities were found in 89% of cases and all 3 in the remaining 11%. Aspartate aminotransferase was elevated in all cases and ≥2 times the upper normal limit in 69%. Only 2 cases (11%) had signs of preeclampsia other than thrombocytopenia or transaminase elevation. Delivery was performed on the day of admission in 74% and on the next day in the remaining 26%, most often by cesarean delivery (68%) under general anesthesia (62%) because of nonreassuring fetal heart rate pattern (63%). Postpartum hemorrhage occurred in 47% of cases. Blood product transfusions were given in 95% of cases, including cryoprecipitate (89% of cases), fresh/frozen plasma (79%), platelets (68%), and red cells (63%). Placental histopathology was abnormal in 82%, with common findings being histiocytic intervillositis, perivillous fibrin deposition, and infarcts or necrosis. Among the 18 singleton pregnancies and 1 twin pregnancy, there were 13 live newborns (65%) and 7 stillbirths (35%). Among liveborn neonates, 5-minute Apgar score was ≤5 in 54%, and among cases with umbilical cord blood gases, pH ≤7.1 was found in 78% and base deficit ≥10 mEq/L in 75%. Positive COVID-19 tests were found in 62% of liveborn infants.

CONCLUSION

Clinicians should be alert to the possibility of disseminated intravascular coagulation when a COVID-19 patient complains of decreased fetal movement in the early third trimester. If time allows, we recommend evaluation of coagulation studies and ordering of blood products for massive transfusion protocols before cesarean delivery if fetal tracing is nonreassuring.

Secondary Impact of the Coronavirus Disease 19 Pandemic on Patients and the Cellular Therapy Healthcare Ecosystem

The Coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has significantly impacted global health and healthcare delivery systems. To characterize the secondary effects of the COVID-19 pandemic and mitigation strategies used in the delivery of hematopoietic stem cell transplantation (HSCT) care, we performed a comprehensive literature search encompassing changes in specific donor collection, processing practices, patient outcomes, and patient-related concerns specific to HSCT and HSCT-related healthcare delivery. In this review, we summarize the available literature on the secondary impacts the COVID-19 pandemic on the fields of HSCT and cellular therapy. The COVID-19 pandemic has had numerous secondary impacts on patients undergoing HSCT and the healthcare delivery systems involved in providing complex care to HSCT recipients. Institutions must identify these influences on outcomes and adjust accordingly to maintain and improve outcomes for the transplantation and cellular therapy community.

Characterization of the SARS-CoV-2 co-receptor NRP1 expression profiles in healthy people and cancer patients: Implication for susceptibility to COVID-19 disease and potential therapeutic strategy

Neuropilin-1 (NRP1) is a transmembrane protein involved in many physiological and pathological processes, and it functions as a co-receptor to facilitate the entry of SARS-CoV-2 into host cells. Therefore, it is critical to predict the susceptibility to SARS-CoV-2 and prognosis after infection among healthy people and cancer patients based on expression of NRP1. In the current study, we analyzed the conservation and isoform of NRP1 using public databases. NRP1 expression landscape in healthy people, COVID-19 patients, and cancer patients at both bulk and single-cell RNA-seq level was also depicted. We also analyzed the relationship between tissue-specific NRP1 expression and overall survival (OS), as well as tumor immune environment at a pan-cancer level, providing a comprehensive insight into the relationship between the vulnerability to SARS-CoV-2 infection and tumorigenesis. In conclusion, we identified NRP1 as a potential biomarker in predicting susceptibility to SARS-CoV-2 infection among healthy people and cancer patients.

Issues related to pregnancy, pregnancy prevention and abortion in the context of the COVID-19 pandemic: a WHO qualitative study protocol

INTRODUCTION

WHO has generated standardised clinical and epidemiological research protocols to address key public health questions for SARS-CoV-2 (COVID-19) pandemic. We present a standardised protocol with the aim to fill a gap in understanding the needs, attitudes and practices related to sexual and reproductive health in the context of COVID-19 pandemic, focusing on pregnancy, pregnancy prevention and abortion.

METHODS AND ANALYSIS PLAN

This protocol is a prospective qualitative research, using semi-structured interviews with at least 15 pregnant women at different gestational ages and after delivery, 6 months apart from the first interview. At least 10 partners, 10 non-pregnant women and 5 healthcare professionals will be interviewed once during the course of the research. Higher number of subjects may be needed if a saturation is not achieved with these numbers. Data collection will be performed in a standardised way by skilled trained interviewers using written notes or audio-record of the interview. The data will be explored using the thematic content analysis and the researchers will look for broad patterns, generalisations or theories from these categories.

ETHICS AND DISSEMINATION

The current protocol was first technically assessed and approved by the WHO scientific committee and then approved by its ethics review committee as a guidance document. It is expected that each country/setting implementing such a generic protocol adapted to their conditions also obtain local ethical approval. Comments for the user's consideration are provided the document, as the user may need to modify methods slightly because of the local context in which this study will be carried out.

COVID-19 Pandemic and Infant Neurodevelopmental Impairment: A Systematic Review and Meta-analysis

IMPORTANCE

Primary studies proposed that aberrant maternal antiviral immunity and/or giving birth in quarantine, such as during the ongoing COVID-19 pandemic, may be associated with the risk of neurodevelopmental impairment (NDI) in offspring.

OBJECTIVES

To evaluate the associations of birth and being raised during the COVID-19 pandemic with risk of NDI among infants and to assess the association of gestational exposure to SARS-CoV-2 with risk of NDI.

DATA SOURCES

PubMed, Web of Science, Scopus, Embase, and preprint servers were systematically searched from inception to March 25, 2022.

STUDY SELECTION

Studies evaluating the neurodevelopment of infants born during the SARS-CoV-2 pandemic were included in this systematic review and meta-analysis. Studies using Ages and Stages Questionnaires, Third Edition (ASQ-3), were used for quantitative meta-analysis.

DATA EXTRACTION AND SYNTHESIS

Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses, a random-effects model meta-analysis was used to pool the proportion and odds ratios (ORs) of overall NDI, as well as each developmental domain on ASQ-3 with the corresponding 95% CI.

MAIN OUTCOMES AND MEASURES

The primary outcome was the risk of overall NDI among infants screened during the pandemic vs prepandemic. The secondary outcome was the comparison of NDI by ASQ-3 domain among infants born to women with known gestational exposure to SARS-CoV-2 vs no exposure.

RESULTS

A total of 8 studies were included, including 21 419 infants (11 438 screened in pandemic and 9981 in prepandemic period). NDI was present in 330 of 8992 infants (7%; 95% CI, 4%-10%) screened during the COVID-19 pandemic from January 2020 to January 2021. Among the pandemic cohort, the prevalence of NDI among infants with gestational exposure to SARS-CoV-2 was 77 of 691 (12%; 95% CI, 6%-18%). Compared with the prepandemic cohort (2015-2019), the pandemic cohort was more likely to have communication impairment (OR, 1.70; 95% CI, 1.37-2.11; P < .001), without significant differences in other ASQ-3 domains (eg, gross motor, fine motor, personal-social, and problem-solving). In contrast, maternal SARS-CoV-2 infection was not associated with significant differences in any neurodevelopment domain in offspring, except for increasing the odds of fine motor impairment (OR, 3.46; 95% CI, 1.43-8.38; P < .001).

CONCLUSIONS AND RELEVANCE

In this systematic review and meta-analysis examining the association between COVID-19 pandemic and the risk of NDI, findings suggest that overall neurodevelopment in the first year of life was not changed by either being born or raised during the SARS-CoV-2 pandemic or by gestational exposure to SARS-CoV-2. Interestingly, the first year of life during the COVID-19 pandemic, regardless of maternal infection, was significantly associated with the risk of communication delay among the offspring.

Maternal and neonatal immune response to SARS-CoV-2, IgG transplacental transfer and cytokine profile

SARS-CoV-2 infected pregnant women are at increased risk of severe COVID-19 than non-pregnant women and have a higher risk of adverse pregnancy outcomes like intrauterine/fetal distress and preterm birth. However, little is known about the impact of SARS-CoV-2 infection on maternal and neonatal immunological profiles. In this study, we investigated the inflammatory and humoral responses to SARS-CoV-2 in maternal and cord blood paired samples. Thirty-six pregnant women were recruited at delivery at Hospital Sant Joan de Déu, Barcelona, Spain, between April-August 2020, before having COVID-19 available vaccines. Maternal and pregnancy variables, as well as perinatal outcomes, were recorded in questionnaires. Nasopharyngeal swabs and maternal and cord blood samples were collected for SARS-CoV-2 detection by rRT-PCR and serology, respectively. We measured IgM, IgG and IgA levels to 6 SARS-CoV-2 antigens (spike [S], S1, S2, receptor-binding domain [RBD], nucleocapsid [N] full-length and C-terminus), IgG to N from 4 human coronaviruses (OC43, HKU1, 229E and NL63), and the concentrations of 30 cytokines, chemokines and growth factors by Luminex. Mothers were classified as infected or non-infected based on the rRT-PCR and serology results. Sixty-four % of pregnant women were infected with SARS-CoV-2 (positive by rRT-PCR during the third trimester and/or serology just after delivery). None of the newborns tested positive for rRT-PCR. SARS-CoV-2 infected mothers had increased levels of virus-specific antibodies and several cytokines. Those with symptoms had higher cytokine levels. IFN-α was increased in cord blood from infected mothers, and in cord blood of symptomatic mothers, EGF, FGF, IL-17 and IL-15 were increased, whereas RANTES was decreased. Maternal IgG and cytokine levels showed positive correlations with their counterparts in cord blood. rRT-PCR positive mothers showed lower transfer of SARS-CoV-2-specific IgGs, with a stronger effect when infection was closer to delivery. SARS-CoV-2 infected mothers carrying a male fetus had higher antibody levels and higher EGF, IL-15 and IL-7 concentrations. Our results show that SARS-CoV-2 infection during the third trimester of pregnancy induces a robust antibody and cytokine response at delivery and causes a significant reduction of the SARS-CoV-2-specific IgGs transplacental transfer, with a stronger negative effect when the infection is closer to delivery.

SARS-CoV-2 Infection and Pregnancy: Maternal and Neonatal Outcomes and Placental Pathology Correlations

There is accumulating evidence on the perinatal aspects of COVID-19, but available data are still insufficient. The reports on perinatal aspects of COVID-19 have been published on a small group of patients. Vertical transmission has been noted. The SARS-CoV-2 genome can be detected in umbilical cord blood and at-term placenta, and the infants demonstrate elevated SARS-CoV-2-specific IgG and IgM antibody levels. In this work, the analysis of clinical characteristics of RT-PCR SARS-CoV-2-positive pregnant women and their infants, along with the placental pathology correlation results, including villous trophoblast immunoexpression status for SARS-CoV-2 antibody, is presented. RT-PCR SARS-CoV-2 amniotic fluid testing was performed. Neonatal surveillance of infection status comprised RT-PCR testing of a nasopharyngeal swab and the measuring of levels of anti-SARS-CoV-2 in blood serum. In the initial study group were 161 pregnant women with positive test results. From that group, women who delivered during the hospital stay were selected for further analysis. Clinical data, laboratory results, placental histomorphology results, and neonatal outcomes were compared in women with immunohistochemistry (IHC)-con SARS-CoV-2-positive and IHC SARS-CoV-2-negative placentas (26 cases). A positive placental immunoprofile was noted in 8% of cases (n = 2), whereas 92% of cases were negative (n = 24). Women with placental infection proven by IHC had significantly different pathological findings from those without. One infected neonate was noted (n = 1; 4%). Infection was confirmed in perinatal autopsy, as there was the intrauterine fetal demise. The potential course of the infection with the risk of vertical transmission and implications for fetal–neonatal condition is critical for proper clinical management, which will involve comprehensive, multidisciplinary perinatal care for SARS-CoV-2-positive patients.

Virological and clinical features of acute respiratory failure associated with COVID-19 in pregnancy: a case-control study

Objective: Pregnancy is a risk factor for acute respiratory failure (ARF) following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We hypothesised that SARS-CoV-2 viral load in the respiratory tract might be higher in pregnant intensive care unit (ICU) patients with ARF than in non-pregnant ICU patients with ARF as a consequence of immunological adaptation during pregnancy. Design: Single-centre, retrospective observational case-control study. Setting: Adult level 3 ICU in a French university hospital. Participants: Eligible participants were adults with ARF associated with coronavirus disease 2019 (COVID-19) pneumonia. Main outcome measure: The primary endpoint of the study was viral load in pregnant and non-pregnant patients. Results: 251 patients were included in the study, including 17 pregnant patients. Median gestational age at ICU admission amounted to 28 + 3/7 weeks (interquartile range [IQR], 26 + 1/7 to 31 + 5/7 weeks). Twelve patients (71%) had an emergency caesarean delivery due to maternal respiratory failure. Pregnancy was independently associated with higher viral load (-4.6 ± 1.9 cycle threshold; P < 0.05). No clustering or over-represented mutations were noted regarding SARS-CoV-2 sequences of pregnant women. Emergency caesarean delivery was independently associated with a modest but significant improvement in arterial oxygenation, amounting to 32 ± 12 mmHg in patients needing invasive mechanical ventilation. ICU mortality was significantly lower in pregnant patients (0 v 35%; P < 0.05). Age, Simplified Acute Physiology Score (SAPS) II score, and acute respiratory distress syndrome were independent risk factors for ICU mortality, while pregnancy status and virological variables were not. Conclusions: Viral load was substantially higher in pregnant ICU patients with COVID-19 and ARF compared with non-pregnant ICU patients with COVID-19 and ARF. Pregnancy was not independently associated with ICU mortality after adjustment for age and disease severity.

Correlation between Pregnancy Outcome and Placental Pathology in COVID-19 Pregnant Women

Background

Vertical transmission of several viruses during pregnancy has been shown to cause adverse fetal outcomes. The question about the possibility of a similar outcome in association with SARS-CoV-2 has been raised in recently published articles. Indeed, the rate of transmission through the placenta to the fetus reported in women with COVID-19 has been shown to form a minority. The aim of this study was to explore the possible histopathological changes in the placenta of pregnant women with COVID-19 after delivery and those changes in the umbilical cord.

Methods

A case-control study including a total of 50 full-term pregnant women with COVID-19 and 60 control pregnant females. Histopathological evaluation of placental tissues and umbilical cords were reported.

Results

The main findings in the umbilical cord were increased thickness of vessels, thrombus formation, endothelins, and narrow lumen; except for the increased thickness of blood vessels, these findings were more frequently seen in women with COVID-19, in comparison with control women in a significant manner (p < 0.05). Increased thickness of blood vessels was more significantly observed in the control group compared to the COVID-19 group (p < 0.01). Findings of the placenta included avascular villi, fibrin, thrombosis, and meconium macrophage in various combinations. Except for fibrin as the sole findings, all other findings including combinations were more frequently encountered in the study group in comparison to the control group (p < 0.05).

Conclusion

Pregnant women with COVID-19 have significant pathological alterations in the placenta and umbilical cord. These findings reflect the capability of SARS-CoV-2 in causing immunological reactions to the placenta, either directly or indirectly, and these pathologies may be linked to the higher rate of adverse neonatal outcomes and maternal admission to the intensive care unit.

Absence of SARS-CoV-2 Spike glycoprotein expression in placentas from individuals after mRNA SARS-CoV-2 vaccination

Current public health initiatives to contain the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) global pandemic focus on expanding vaccination efforts to include vulnerable populations such as pregnant people. Vaccines using messenger ribonucleic acid (mRNA) technology rely on translation by immune cells, primarily at the injection site. Hesitancy remains among the general population regarding the safety of mRNA vaccines during gestation, and it remains unknown whether the SARS-CoV-2 Spike protein (the product of mRNA vaccines available) accumulates in the placenta after vaccination. Objective: To determine whether Spike protein translation and accumulation occurs in placental tissue in the context of recent mRNA SARC-CoV-2 vaccination during pregnancy. We identified 48 patients receiving one or two doses of mRNA SARS-CoV-2 vaccine during gestation and used immunohistochemistry against SARS-CoV-2 Spike protein in formalin-fixed, paraffin-embedded placental tissue. One placenta, positive for SARS-CoV-2 RNA by in situ hybridization (ISH) was used as positive control. Seven term placentas collected prior to the emergence of SARS-CoV-2 served as negative controls. Eighty one percent of patients in the study group underwent third-trimester delivery; remaining had a first-trimester spontaneous abortion or elective second-trimester termination. Patients received two (52%) or one (48%) vaccine doses during pregnancy, with a median interval between latest dose and delivery of 13 days (range 2-79 days). Most (63%) cases had their latest dose within 15 days prior to delivery. All the placentas in the study and negative control groups were negative for SARS-CoV-2 immunohistochemistry. Six study cases with short vaccine-delivery intervals (2-7 days) were subjected to SARS-CoV-2 ISH and were negative. Our findings suggest that mRNA vaccines do not reach significant concentrations in the placenta given the absence of definitive SARS-CoV-2 Spike protein accumulation in placental tissue. This observation provides evidence supporting the safety of mRNA vaccines to the placental-fetal unit.

Review of Impact of COVID-19 on Maternal, Neonatal Outcomes, and Placental Changes

Coronavirus disease (COVID-19), caused by SARS-CoV-2, is a disease that has caused a global impact. COVID-19 is transmitted through airborne droplets, respiratory secretions, and direct contact. The pandemic has affected individuals of different ages, and studying the impact of COVID-19 on maternal and newborn outcomes is critical. In this review, we highlight the impact of COVID-19 infection in pregnancy and its repercussion in the maternal-fetal binomial. Physiological changes that occur during pregnancy have significant effects on the immune system, cardiopulmonary system, and coagulation, and these changes can result in an altered response to COVID-19 infection. The symptoms, risk factors, and maternal health consequences of COVID-19 were discussed. In addition, the impact of newborns born to mothers with COVID-19 was reviewed. Finally, placental changes and vertical transmission of COVID-19 during pregnancy were also discussed in this review.

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

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

Pregnancy-specific responses to COVID-19 are revealed by high-throughput proteomics of human plasma

Pregnant women are at greater risk of adverse outcomes, including mortality, as well as obstetrical complications resulting from COVID-19. However, pregnancy-specific changes that underlie such worsened outcomes remain unclear. Herein, we profiled the plasma proteome of pregnant and non-pregnant COVID-19 patients and controls and showed alterations that display a dose-response relationship with disease severity; yet, such proteomic perturbations are dampened during pregnancy. In both pregnant and non-pregnant state, the proteome response induced by COVID-19 showed enrichment of mediators implicated in cytokine storm, endothelial dysfunction, and angiogenesis. Shared and pregnancy-specific proteomic changes were identified: pregnant women display a tailored response that may protect the conceptus from heightened inflammation, while non-pregnant individuals display a stronger response to repel infection. Furthermore, the plasma proteome can accurately identify COVID-19 patients, even when asymptomatic or with mild symptoms. This study represents the most comprehensive characterization of the plasma proteome of pregnant and non-pregnant COVID-19 patients.

Fetoplacental transmission and placental response to SARS-CoV-2: Evidence from the literature

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a dreadful novel coronavirus with global health concerns among pregnant women. To date, the vertical transmission of SARS-CoV-2 during pregnancy remains controversial. We briefly report recent findings of placental response to SARS-CoV-2 infection and updates on vertical transmission. We systematically searched PubMed and Google Scholar databases according to PRISMA guidelines for studies reporting the effects of SARS-CoV-2 infection on the placenta and possibility of vertical transmission. We identified 45 studies reporting 1,280 human placentas that were analyzed by molecular pathology methods and 11,112 placenta-derived cells from a publicly available database that was analyzed using bioinformatics tools. The main finding of this study is that the SARS-CoV-2 canonical entry receptors (ACE2 and TMPRSS2) are abundantly expressed on the placenta during the first trimester, and this expression diminishes across gestational age. Out of 45 eligible studies identified, 24 (53.34%) showed no evidence of vertical transmission, 15 (33.33%) supported the hypothesis of very rare, low possibility of vertical transmission and 6 (13.33%) were indecisive and had no comment on vertical transmission. Furthermore, 433 placentas from 12 studies were also identified for placental pathology investigation. There was evidence of at least one form of maternal vascular malperfusion (MVM), 57/433 (13.1%), fetal vascular malperfusion (FVM), 81/433 (18.7%) and placental inflammation with excessive infiltration of CD3+ CD8+ lymphocytes, CD68+ macrophages and CD20+ lymphocytes in most of the eligible studies. Decidual vasculopathy (3.2%), infarction (3.2%), chronic histiocytic intervillositis (6.0%), thrombi vasculopathy (5.1%) were also observed in most of the MVM and FVM reported cases. The results indicated that SARS-CoV-2 induces placenta inflammation, and placenta susceptibility to SARS-CoV-2 decreases across the pregnancy window. Thus, SARS-CoV-2 infection in early pregnancy may adversely affect the developing fetus.

Contribution of the ex vivo placental perfusion model in understanding transplacental immunoglobulin G transfer

INTRODUCTION

The acquisition of humoral immunity in utero is essential for the fetus. The crucial protein, which is responsible for this part of immunity, is immunoglobulin-G (IgG). Immune functions of IgGs are mediated via the interaction of the crystallizable fragment (Fc) region of IgG with specific Fc γ receptors (FcγRs). However, an atypical FcγR, the neonatal Fc receptor (FcRn), is a key regulator of IgG transfer across the human placenta. During the last four decades ex vivo placental perfusion studies have contributed significantly to the study of mechanisms of IgG transfer across the multicellular placental barrier.

METHOD

A PubMed search was conducted by using specific keywords: placenta, perfusion and IgG to review manuscripts using human placental perfusion to study the transplacental transfer of IgG. Relevant studies found in reference lists of these manuscripts were also added to the review, and references were included that supported or gave nuance to the discussion of the mechanisms of IgG kinetics in the placenta.

RESULTS AND DISCUSSION

We found twenty publications on the study of transplacental transfer of IgG using human ex vivo placental perfusion, by research groups with partly different settings. This review summarizes knowledge about placental IgG transfer, with a strong focus on the contributions from ex vivo placental perfusion studies.

Utility of Newborn Dried Blood Spots to Ascertain Seroprevalence of SARS-CoV-2 Antibodies Among Individuals Giving Birth in New York State, November 2019 to November 2021

IMPORTANCE

Serosurveys can be used to monitor population-level dynamics of COVID-19 and vaccination. Dried blood spots (DBSs) collected from infants contain maternal IgG antibodies and are useful for serosurveys of individuals recently giving birth.

OBJECTIVES

To examine SARS-CoV-2 antibody prevalence in pregnant individuals in New York State, identify associations between SARS-CoV-2 antibody status and maternal and infant characteristics, and detect COVID-19 vaccination among this population.

DESIGN, SETTING, AND PARTICIPANTS

A population-based, repeated cross-sectional study was conducted to detect SARS-CoV-2 nucleocapsid (N) and spike (S) IgG antibodies. Deidentified DBS samples and data submitted to the New York State Newborn Screening Program between November 1, 2019, and November 30, 2021, were analyzed.

EXPOSURES

Prenatal exposure to SARS-CoV-2 antibodies.

MAIN OUTCOMES AND MEASURES

The presence of IgG antibodies to SARS-CoV-2 N and S antigens was measured using a microsphere immunoassay. Data were analyzed by geographic region and compared with reported COVID-19 cases and vaccinations among reproductive-aged females (15-44 years of age). Data were stratified by infant birth weight, gestational age, maternal age, and multiple birth status.

RESULTS

Dried blood spot samples from 415 293 infants (median [IQR] age, 1.04 [1.00-1.20] days; 210 805 [51.1%] male) were analyzed for SARS-CoV-2 antibodies. The first known antibody-positive infant in New York State was born on March 29, 2020. SARS-CoV-2 seroprevalence reflected statewide and regional COVID-19 cases among reproductive-aged females in the prevaccine period. From February through November 2021, S seroprevalence was strongly correlated with cumulative vaccinations in each New York State region and in the state overall (rs = 0.92-1.00, P ≤ .001). S and N seroprevalences were significantly lower in newborns with very low birth weight (720 [14.8%] for S and 138 [2.8%] for N, P < .001) and low birth weight (5160 [19.3%] for S and 1233 [4.6%] for N, P = .009) compared with newborns with normal birth weight (77 116 [20.1%] for S and 19 872 [5.2%] for N). Lower N and higher S seroprevalences were observed in multiple births (odds ratio [OR], 0.84; 95% CI, 0.75-0.94; P = .002 for N and OR, 1.24; 95% CI, 1.18-1.31; P < .001 for S) vs single births and for maternal age older than 30 years (OR, 0.87; 95% CI, 0.80-0.94; P < .001 for N and OR, 1.17; 95% CI, 1.11-1.23; P < .001 for S) vs younger than 20 years.

CONCLUSIONS AND RELEVANCE

In this study, seroprevalence in newborn DBS samples reflected COVID-19 case fluctuations and vaccinations among reproductive-aged women during the study period. These results demonstrate the utility of using newborn DBS testing to estimate SARS-CoV-2 seroprevalence in pregnant individuals.

Maternal COVID-19 Disease and COVID-19 Immunization

Aim This study aimed to evaluate the immune response and vertical transmission of anti-severe acute respiratory syndrome (SARS) antibodies in vaccinated, expectant mothers infected with coronavirus disease 2019 (COVID-19) and to study the sequelae. Study design This was a retrospective study of pregnant women conducted at Bahrain Defense Force Hospital from March 2021 to September 2021. The study population was divided into two groups: group 1 was vaccinated with Sinopharm or Pfizer/BioNTech during pregnancy and never infected with COVID-19. Group 2 was unvaccinated and had been infected with COVID-19. Immune responses such as anti-nucleocapsid (anti-N) and anti-spike (anti-S) from paired samples of maternal and umbilical cord blood were measured with Elecsys immunoassay (Roche Holding AG: Basel, Switzerland) at the time of delivery. Obstetric complications such as preterm labor, preeclampsia, and stillbirth were assessed. Analysis was performed using SPSS version 26.0 (IBM Corp: Armonk, NY) and Minitab version 18 (Minitab, LLC: State College, PA). A p-value of less than 0.05 was considered statistically significant. Results The study included 90 vaccinated and 90 COVID-19-recovered pregnant women. Matched samples were available for 80 vaccinated and 74 COVID-19-recovered women. Group 1 had significantly higher levels of anti-S for both the mother and the cord blood and a significantly higher transfer ratio of anti-S. Group 2 had higher levels of anti-N. In group 1, the paired sample titer of anti-S had a weak negative correlation with maternal age whereas, in group 2, the mother's anti-N had a weak positive correlation with age. Antibodies of COVID-19-recovered mothers and cord blood had a moderate negative correlation with gestational age, except for the mother's anti-N. In group 1, the transfer ratio of anti-N and anti-S had a statistically significant association with gestational age. Preterm delivery had a high prevalence of anti-transfer ratios of <1, and delivery at >37 weeks had a high prevalence of ≥1. In group 2, 90% of preterm deliveries had transfer ratios of anti-S <1. The latency period of the COVID-19 group had a statistically significant association with the antibody transfer ratio. An interval of less than 100 days had a high prevalence in the ratio of <1. An interval of more than 100 days had a high prevalence in the ratio of ≥1. There was no significant latency period in group 1. Group 1 had a 75% prevalence of an anti-S transfer ratio ≥1 with a birth weight of >3500 g; group 2 had no significance in birth weight. We did not find significance in the sequelae of morbidities in either group. Conclusion The production of the antibody N in the COVID-19-infected and antibody S in the vaccinated pregnant women as well as the vertical transmission of antibodies was efficacious. Significant variation was found regarding maternal age in both groups. The transfer ratio of the antibodies in the vaccinated and COVID-19-recovered women was significantly higher in terms of babies of the vaccinated and the infected population. The transfer ratios were distinct according to the latency period and birth weight of the infants.

COVID-19 vaccination in pregnancy

Despite a recent endorsement from official and professional bodies unequivocally recommending COVID-19 vaccination, vaccine hesitancy among pregnant people remains high. The accumulated evidence demonstrates that pregnant people are a special risk group for COVID-19, with an increased risk of intensive care unit admission, extracorporeal membranous oxygenation requirement, preterm birth, and perinatal death. These risks are further increased with some variants of concern, and vaccination of pregnant people reduces the COVID-19-related increase in maternal or fetal morbidity. Data from more than 180,000 vaccinated persons show that immunization against COVID-19 with an mRNA vaccine is safe for pregnant people. Many observational studies comparing perinatal outcomes between vaccinated and unvaccinated pregnant people have had reassuring findings and did not demonstrate harmful effects on pregnancy or the newborn. Immunization with mRNA vaccines does not increase the risk of miscarriage, preterm delivery, low birthweight, maternal or neonatal intensive care unit admission, fetal death, fetal abnormality, or pulmonary embolism. Moreover, observational data corroborate the findings of randomized trials that mRNA vaccination is highly effective at preventing severe SARS-CoV-2 infection in pregnant people, emphasizing that the potential maternal and fetal benefits of vaccination greatly outweigh the potential risks of vaccination. Ensuring pregnant people have unrestricted access to COVID-19 vaccination should be a priority in every country worldwide.

SARS-CoV-2 in infant urine and fecal samples after in utero COVID-19 exposure

BACKGROUND

Coronavirus disease 2019 (COVID-19) is a pandemic that has and will continue to affect many pregnant women. Knowledge regarding the risk of vertical transmission is limited. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) real-time reverse transcriptase-polymerase chain reaction (RT-PCR) of nasopharyngeal swabs typically have been used to confirm the diagnosis among infants, but whether the virus can be detected in other biological specimens, and therefore potentially transmitted in other ways, is unknown. Positive SARS-CoV-2 RT-PCR has been reported from feces and urine from adult patients. We hypothesize that the presence of SARS-CoV-2 in infant urine and fecal samples after prenatal COVID-19 exposure is low.

METHODS

We examined the presence of SARS-CoV-2 RNA using RT-PCR in urine and fecal samples among 42 infants born to SARS-CoV-2-infected mothers during different stages of pregnancy.

RESULTS

A urine sample was collected from 39 of 42 infants and fecal samples from all 42 infants shortly after birth. Although the majority of the women had the symptomatic disease (85.6%), we were unable to detect the presence of SARS-CoV-2 virus from any infant urine or fecal samples.

CONCLUSIONS

SARS-CoV-2 was not detected in infant urine or feces after maternal infection during pregnancy, providing further evidence for low rates of perinatal transmission.

IMPACT

SARS-CoV-2 was not detected in the urine or feces of infants of mothers with COVID-19 during various time points in pregnancy. This study provides further evidence for low rates of perinatal transmission of SARS-CoV-2. Results help to provide guidance on perinatal care practices for infants exposed to COVID-19 in utero.

Evaluation of transplacental transfer of mRNA vaccine products and functional antibodies during pregnancy and infancy

Studies are needed to evaluate the safety and effectiveness of mRNA SARS-CoV-2 vaccination during pregnancy, and the levels of protection provided to their newborns through placental transfer of antibodies. Here, we evaluate the transplacental transfer of mRNA vaccine products and functional anti-SARS-CoV-2 antibodies during pregnancy and early infancy in a cohort of 20 individuals vaccinated during late pregnancy. We find no evidence of mRNA vaccine products in maternal blood, placenta tissue, or cord blood at delivery. However, we find time-dependent efficient transfer of IgG and neutralizing antibodies to the neonate that persists during early infancy. Additionally, using phage immunoprecipitation sequencing, we find a vaccine-specific signature of SARS-CoV-2 Spike protein epitope binding that is transplacentally transferred during pregnancy. Timing of vaccination during pregnancy is critical to ensure transplacental transfer of protective antibodies during early infancy.

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

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

Coronavirus disease 2019 and the placenta: A literature review

Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has been implicated in the clinical pathology of multiple organs and organ systems. Due to the novelty of the disease, there is a need to review emerging literature to understand the profile of SARS-CoV-2 in the placenta. This review sought to evaluate the literature on the mediators, mechanism of entry, pathogenesis, detection, and pathology of SARS-CoV-2 in the placenta. Systematic literature searches found 96 eligible studies. Our review revealed that SARS-CoV-2 canonical mediators, angiotensin-converting enzyme-2 (ACE2), and transmembrane serine protease-2 (TMPRSS2) are variably expressed in various placenta compartments, including the villous cytotrophoblasts, syncytiotrophoblasts (STBs), and extravillous trophoblasts (EVTs) throughout pregnancy. Placental SARS-CoV-2 and coronavirus-associated receptors and factors (SCARFs), including basigin (BSG/CD147), dipeptidyl peptidase-4 (DPP4/CD26), cathepsin B/L (CTL B/L), furin, interferon-induced transmembrane protein (IFITM1-3), and lymphocyte antigen 6E (LY6E) may increase or reduce the permissiveness of the placenta to SARS-CoV-2. EVTs express genes that code for proteins that may drive viral pathogenesis in the placenta. Viral RNA, proteins, and particles were detected primarily in the STBs by in situ hybridization, immunohistochemistry, electron microscopy, and polymerase chain reaction. Placental pathology in SARS-CoV-2-infected placentas included maternal and fetal vascular malperfusion and a generally nonspecific inflammatory-immune response. The localization of SARS-CoV-2 receptors, proteases, and genes involved in coding proteins that drive viral pathogenesis in the placenta predisposes the placenta to SARS-CoV-2 infection variably in all pregnancy trimesters, with antecedent placental pathology. There is a need for further studies to explicate the mechanism of entry and pathogenesis of SARS-CoV-2 in the placenta.

Restriction of SARS-CoV-2 replication in the human placenta

Although SARS-CoV-2 can infect human placental tissue, vertical transmission is rare. Therefore, the placenta may function as a barrier to inhibit viral transmission to the foetus, though the mechanisms remain unclear. In this study, we confirmed the presence of the SARS-CoV-2 genome in human placental tissue by in situ hybridization with antisense probes targeting the spike protein; tissue staining was much lower when using sense probes for the spike protein. To the best of our knowledge, this is the first evidence directly indicating inefficient viral replication in the SARS-CoV-2-infected placenta. Additional studies are required to reveal the detailed mechanisms.

Humoral response to anti-SARS-CoV-2 vaccine in breastfeeding mothers and mother-to-infant antibody transfer through breast milk

The magnitude of mother-to-infant transfer of anti-SARS-CoV-2 antibodies through breast milk (BM) after maternal vaccination during breastfeeding, in the absence of transplacental transfer of IgG, remains unclear. Here, we quantified anti-S and anti-RBD IgG, IgA, IgA1, and IgA2 in maternal serum, maternal saliva, BM, infant buccal swabs, and infant feces up to 90 days after the second maternal vaccine dose. BNT162b2 vaccine induced long-lasting IgG in maternal serum, but weaker mucosal antibody production, with anti-SARS-CoV-2 IgG and IgA amounts in BM between 10- and 150-fold lower compared to serum. BM IgA were exclusively of the IgA1 isotype, with no production of the mucosal-specific and protease-resistant IgA2. Accordingly, only traces of antibodies were retrieved from the feces of breastfed infants, and no IgG nor IgA were retrieved from infants' buccal swabs. Newly engineered anti-SARS-CoV-2 vaccines may be needed to stimulate the antibody production at mucosal sites such as breast milk.

Neutralizing antibody activity against SARS-CoV-2 variants in gestational age-matched mother-infant dyads after infection or vaccination

Pregnancy confers unique immune responses to infection and vaccination across gestation. To date, there are limited data comparing vaccine- and infection-induced neutralizing Abs (nAbs) against COVID-19 variants in mothers during pregnancy. We analyzed paired maternal and cord plasma samples from 60 pregnant individuals. Thirty women vaccinated with mRNA vaccines (from December 2020 through August 2021) were matched with 30 naturally infected women (from March 2020 through January 2021) by gestational age of exposure. Neutralization activity against the 5 SARS-CoV-2 spike sequences was measured by a SARS-CoV-2-pseudotyped spike virion assay. Effective nAbs against SARS-CoV-2 were present in maternal and cord plasma after both infection and vaccination. Compared with WT spike protein, these nAbs were less effective against the Delta and Mu spike variants. Vaccination during the third trimester induced higher cord-nAb levels at delivery than did infection during the third trimester. In contrast, vaccine-induced nAb levels were lower at the time of delivery compared with infection during the first trimester. The transfer ratio (cord nAb level divided by maternal nAb level) was greatest in mothers vaccinated in the second trimester. SARS-CoV-2 vaccination or infection in pregnancy elicits effective nAbs with differing neutralization kinetics that are influenced by gestational time of exposure.

Single-cell RNA sequencing reveals immunological rewiring at the maternal-fetal interface following asymptomatic/mild SARS-CoV-2 infection

While severe coronavirus 2019 (COVID-19) is associated with immune activation at the maternal-fetal interface, responses to asymptomatic/mild severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy remain unknown. Here, we assess immunological adaptations in blood and term decidua in response to asymptomatic/mild disease in pregnant women. We report attenuated antigen presentation and type I interferon (IFN) signaling pathways, loss of tissue-resident decidual macrophages, and upregulated cytokine/chemokine signaling in monocyte-derived decidual macrophages. Furthermore, we describe increased frequencies of activated tissue-resident T cells and decreased abundance of regulatory T cells with infection while frequencies of cytotoxic CD4/CD8 T cells are increased in the blood. In contrast to decidual macrophages, type I IFN signaling is higher in decidual T cells. Finally, infection leads to a narrowing of T cell receptor diversity in both blood and decidua. Collectively, these observations indicate that asymptomatic/mild COVID-19 during pregnancy results in remodeling of the immunological landscape of the maternal-fetal interface, with a potential for long-term adverse outcomes for the offspring.

Impact of Gestational COVID-19 on Neonatal Outcomes: Is Vertical Infection Possible?

BACKGROUND

The vertical transmission of severe acute respiratory coronavirus-2 (SARS-CoV-2) remains highly debated. Here, we evaluated SARS-CoV-2-transmission in newborns with intrauterine conditions.

METHODS

This was a prospective, observational and multicentric study involving 13 Spanish hospitals included in the GEStational and NEOnatal-COVID cohort. Pregnant women with microbiologically confirmed SARS-CoV-2 infection during any trimester of pregnancy or delivery and their newborns were included from March to November 2020. Demographic, clinical and microbiological data were also obtained. Viral loads were analyzed in different maternal and newborn biological samples (placenta, breast milk and maternal blood; urine, meconium and newborn blood).

RESULTS

A total of 177 newborns exposed to SARS-CoV-2 were included. Newborns were tested by reverse transcriptase-polymerase chain reaction using nasopharyngeal swabs within the first 24-48 hours of life and at 14 days of life. In total 5.1% were considered to have SARS-CoV-2 infection in the neonatal period, with 1.7% considered intrauterine and 3.4% intrapartum or early postnatal transmission cases. There were no differences in the demographic and clinical characteristics of the pregnant women and their newborns' susceptibility to infections in their perinatal history or background.

CONCLUSIONS

Intrauterine transmission of SARS-CoV-2 is possible, although rare, with early postnatal transmission occurring more frequently. Most infected newborns remained asymptomatic or had mild symptoms that evolved well during follow-up. We did not find any maternal characteristics predisposing infants to neonatal infection. All infected newborn mothers had acute infection at delivery.Although there was no presence of SARS-CoV2 in cord blood or breast milk samples, SARS-CoV-2 viral load was detected in urine and meconium samples from infected newborns.

Life After Amsterdam: Placental Pathology Consensus Recommendations and Beyond

The Amsterdam Placental Workshop Group Consensus Statement on Sampling and Definitions of Placental Lesions has become widely accepted and is increasingly used as the universal language to describe the most common pathologic lesions found in the placenta. This review summarizes the most salient aspects of this seminal publication and the subsequent emerging literature based on Amsterdam definitions and criteria, with emphasis on publications relating to diagnosis, grading, and staging of placental pathologic conditions. We also provide an overview of the recent expert recommendations on the pathologic grading of placenta accreta spectrum, with insights on their clinical context. Finally, we discuss the emerging entity of SARS-CoV2 placentitis.

What to Expect from COVID-19 and from COVID-19 Vaccine for Expecting or Lactating Women

Recent studies identified pregnancy as a high-risk condition for the development of maternal-fetal complications in the case of the SARS-CoV-2 infection. Therefore, the scientific community is now considering pregnant women a "fragile" category that should be vaccinated with high priority. The number of pregnant women undergoing hospitalization since summer 2021, including Intensive Care Unit admission, is growing, as well as the risk of preterm birth. Evidence from both animals and humans suggest that, similarly to other vaccines routinely administered in pregnancy, COVID-19 vaccines are not crossing the placenta, do not increase the risk of miscarriage, preterm birth, stillbirth, the birth of small gestational age neonates, as well as the risk of congenital abnormalities. To date, the World Health Organization and scientific literature are promoting and encouraging the vaccination of all pregnant and lactating women. The aim of our narrative review is to present the available literature regarding this issue with the aim to provide appropriate answers to the most frequent requests, doubts, and fears that have led many expecting and lactating women not to become vaccinated during this pandemic period.

Inflammatory responses in the placenta upon SARS-CoV-2 infection late in pregnancy

The effect of SARS-CoV-2 infection on placental function is not well understood. Analysis of placentas from women who tested positive at delivery showed SARS-CoV-2 genomic and subgenomic RNA in 22 out of 52 placentas. Placentas from two mothers with symptomatic COVID-19 whose pregnancies resulted in adverse outcomes for the fetuses contained high levels of viral Alpha variant RNA. The RNA was localized to the trophoblasts that cover the fetal chorionic villi in direct contact with maternal blood. The intervillous spaces and villi were infiltrated with maternal macrophages and T cells. Transcriptome analysis showed an increased expression of chemokines and pathways associated with viral infection and inflammation. Infection of placental cultures with live SARS-CoV-2 and spike protein-pseudotyped lentivirus showed infection of syncytiotrophoblast and, in rare cases, endothelial cells mediated by ACE2 and Neuropilin-1. Viruses with Alpha, Beta, and Delta variant spikes infected the placental cultures at significantly greater levels.

[Epidemiology and characteristics of SARS-CoV-2 infection in the newborn and pregnant woman. Transplacemental transfer of immunoglobulins]

Introduction

SARS-CoV-2 infection during pregnancy and its impact on the newborn were, in the first months of the pandemic, unknown. Recent studies have provided information on the clinical involvement in the newborn and its evolution.This work shows how passive immunity varies in the newborn in relation to the moment of maternal SARS-CoV-2 infection during pregnancy.

Population and method

Observational, prospective and longitudinal study in a third level hospital. Epidemiological and clinical data from mothers and their newborns were collected from May 2020 to June 2021.

Results

A total of 109 mothers and 109 neonates have been included. 28.4% of maternal infections were in the first trimester, 24.8% during the second and 58.8% in the third. 56% of maternal infections were symptomatic and only one pregnant woman with severe respiratory infection was admitted to intensive care. The mean gestational age of the newborns was 39 weeks, with a mean weight of 3232 g and a head circumference of 35 cm. Eight newborns born from mothers with SARS-CoV-2 required admission to the neonatal ICU: 2 due to jaundice, 2 due to respiratory distress, 1 due to moderate prematurity, and 3 due to other causes unrelated to infection attributable to SARS-CoV-2. IgG-type antibodies were positive in 56.9% of newborns. Of the mothers infected during the 1 st trimester, IgG were positive in 32.2% of the newborns, in the second trimester 81.5% were positive and in the third 58.8%. No neonate had positive IgM.

Conclusions

SARS-CoV-2 infection during pregnancy provides IgG antibodies to half of newborns. The presence of antibodies in the newborn is more likely when the infection has occurred in the second trimester of pregnancy.

Severe Acute Respiratory Syndrome Coronavirus 2 Infection Versus Vaccination in Pregnancy: Implications for Maternal and Infant Immunity

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been associated with adverse maternal and neonatal outcomes, yet uptake of SARS-CoV-2 vaccines during pregnancy and lactation has been slow. As a result, millions of pregnant and lactating women and their infants remain susceptible to the virus.

METHODS

We measured spike-specific immunoglobulin G (anti-S IgG) and immunoglobulin A (anti-S IgA) in serum and breastmilk (BM) samples from 3 prospective mother-infant cohorts recruited in 2 academic medical centers. The primary aim was to determine the impact of maternal SARS-CoV-2 immunization vs infection and their timing on systemic and mucosal immunity.

RESULTS

The study included 28 mothers infected with SARS-CoV-2 in late pregnancy (INF), 11 uninfected mothers who received 2 doses of the BNT162b2 vaccine in the latter half of pregnancy (VAX-P), and 12 uninfected mothers who received 2 doses of BNT162b2 during lactation. VAX dyads had significantly higher serum anti-S IgG compared to INF dyads (P < .0001), whereas INF mothers had higher BM:serum anti-S IgA ratios compared to VAX mothers (P = .0001). Median IgG placental transfer ratios were significantly higher in VAX-P compared to INF mothers (P < .0001). There was a significant positive correlation between maternal and neonatal serum anti-S IgG after vaccination (r = 0.68, P = .013), but not infection.

CONCLUSIONS

BNT161b2 vaccination in late pregnancy or lactation enhances systemic immunity through serum anti-S immunoglobulin, while SARS-CoV-2 infection induces mucosal over systemic immunity more efficiently through BM immunoglobulin production. Next-generation vaccines boosting mucosal immunity could provide additional protection to the mother-infant dyad. Future studies should focus on identifying the optimal timing of primary and/or booster maternal vaccination for maximal benefit.

Assessment of Neonatal Cord Blood SARS-CoV-2 Antibodies after COVID-19 Vaccination in Pregnancy: A Prospective Cohort Study

Introduction Maternally derived antibodies are a key element of neonatal immunity. So far, limited data has shown transplacental transmission of antibodies after coronavirus disease 2019 (COVID-19) vaccination with BNT162b2 in the third trimester. Our aim was to detect vertically transferred immunity after COVID-19 vaccination with BNT162b2 (Comirnaty, BioNTech-Pfizer) or mRNA-1273 (Spikevax, Moderna) in the first, second or third trimester of pregnancy, and investigate the impact of maternal characteristics on umbilical cord antibody titre in newborns after delivery. Study Design Women who gave birth in our department and were vaccinated against COVID-19 during pregnancy were enrolled in CRONOS Satellite, a subproject of the German COVID-19-Related Obstetric and Neonatal Outcome Study. The titre of immunoglobulin G (IgG) antibodies to the receptor-binding domain of the SARS-CoV-2 spike protein was quantified in umbilical cord blood using the SARS-CoV-2 IgG II Quant immunoassay. Correlations between antibody titre and variables, including week of pregnancy when vaccinated, interval between vaccination and delivery, age and body mass index (BMI) were assessed with Spearman's rank correlation. A follow-up was conducted by phone interview 4 - 6 weeks after delivery. Results The study cohort consisted of 70 women and their 74 newborns. Vaccine-generated antibodies were present in all samples, irrespective of the vaccination type or time of vaccination. None of the parameters of interest showed a meaningful correlation with cord blood antibody concentrations (rho values < 0.5). No adverse outcomes (including foetal malformation) were reported, even after vaccination in the first trimester. Conclusions Transplacental passage of SARS-CoV-2 antibodies from mother to child was demonstrated in all cases in the present study. It can therefore be assumed that the newborns of mothers vaccinated at any time during pregnancy receive antibodies via the placenta which potentially provide them with protection against COVID-19. This is an additional argument when counselling pregnant women about vaccination in pregnancy.

Antibody Response and Maternofetal Antibody Transfer in SARS-CoV-2-Positive Pregnant Women: A Multicenter Observational Study

Introduction Awareness of SARS-CoV-2 infection in pregnant women and the potential risk for infection of their neonates is increasing. The aim of this study was to examine the immune status of affected women and evaluate the dynamics of placental antibody transfer. Materials and Methods The study included 176 women with SARS-CoV-2 infection during pregnancy who delivered between April 2020 and December 2021 at eight obstetric maternity sites. Demographic data, maternal and neonatal characteristics were summarized. Antibody testing for IgA and IgG in maternal blood sera and umbilical cord samples was evaluated and IgG transfer ratios were calculated. Values were related to the time of infection during pregnancy and birth. Results The percentage of IgG positive women increased from 29.0% (95% CI 23.8 - 37.8) at presentation with a positive PCR test result to 75.7% (95% CI 71.6 - 79.8), the percentage of IgG positive umbilical cord blood samples increased from 17.1% (95% CI 13.0 - 21.3) to 76.4% (95% CI 72.2 - 80.7) at more than six weeks after infection. Regression lines differed significantly between maternal and fetal IgG responses (p < 0.0001). Newborns react with a latency of about one week; umbilical cord blood antibody concentrations are highly correlated with maternal concentration levels (ρ = 0.8042; p < 0.0001). IgG transplacental transfer ratios were dependent on infection-to-birth interval. Two of the umbilical cord blood samples tested positive for IgA. Conclusions These findings confirm vertical SARS-CoV-2 transmission is rare; however, antibodies are transferred to the fetus soon after infection during pregnancy. Since transplacental antibody transfer might have a protective value for neonatal immunization this information may be helpful when counseling affected women.