Benefits and Risks of IgG Transplacental Transfer

Canine Amniotic Fluid at Birth Holds Information about Neonatal Antibody Titres against Core Vaccine Viruses

There is a growing interest in the composition of amniotic fluid (AF) in both humans and animals. In addition to its nutritional and protective functions for the foetus, current knowledge demonstrates that AF also serves advanced diagnostic, prognostic, and therapeutic roles. Newborn dogs have an underdeveloped immune system, making them highly susceptible to dangerous pathogens such as canine parvovirus (CPV-2), canine infectious hepatitis virus (CAdV-1), and canine distemper virus (CDV), thus exposing them to a high risk of mortality in the first weeks of life. Immunoglobulins G (IgGs) represent the only antibody isotype capable of crossing the placenta in a small amount and have been detected also in canine AF. The primary aim of this study was to investigate the reliability of AF collected at birth as a marker of passive immunity in canine species. For this purpose, total and specific IgGs against CPV-2, CAdV-1, and CDV were investigated and quantified in both maternal plasma and AF collected at the time of caesarean section. The vaccination status of the bitches was also taken into consideration. Since the immune system can be influenced by gestational age, with preterm infants having immature innate and adaptive immunity, IgG concentrations were correlated with amniotic lecithin, sphingomyelin, cortisol, surfactant protein A, and pentraxin 3 levels. In a previous study from our group on foetal maturity these molecules were measured in the same samples. Finally, correlations between their amniotic content and neonatal outcomes were investigated. This study demonstrates that AF analysis at birth can provide valuable insights into neonatal immunity in puppies, offering a non-invasive method to detect potential early health risks, for improved puppy care and management.

Altered cytokine and chemokine profile linked to autoantibody and pathogen reactivity in mothers of autistic children

Maternal autoimmunity, and more specifically, the production of specific maternal autoantibodies, has been associated with altered offspring neurodevelopment. Maternal autoantibody-related (MAR) autism is a subtype of autism that is linked to gestational exposure to certain combinations of autoantibodies to proteins known to be important for fetal neurodevelopment. We wanted to address whether mothers with autism-specific patterns of autoantibodies have a skewed cytokine and chemokine profile during an immune response to infection. To do so, we examined a subset of mothers from the Early Markers for Autism (EMA) study who either produced known patterns of MAR autoantibodies (MAR+) or did not (MAR-). We compared the cytokine/chemokine profiles of MAR+ and MAR- mothers in the context of positive immunoglobulin G (IgG) reactivity to several viral and parasitic agents. We observed that MAR+ mothers have a higher level of proinflammatory cytokine interferon-gamma regardless of IgG status. Additionally, when comparing MAR+ and MAR- mothers in the context of the different pathogens, MAR+ mothers consistently had increases in multiple proinflammatory cytokines and chemokines.

Use of Sotrovimab in Pregnancy: Experiences from the COVID-19 International Drug Pregnancy Registry

INTRODUCTION

Available data regarding the safety and efficacy of sotrovimab in pregnant patients remain limited due to their exclusion from clinical trials.

METHODS

The COVID-19 International Drug Pregnancy Registry (COVID-PR) was established to gather comprehensive safety data from pregnant women who have received monoclonal antibody (mAb) or antiviral treatments for mild, moderate, or severe coronavirus disease 2019 (COVID-19) during pregnancy. Participants actively contributed self-reported data concerning their COVID-19 symptoms, in addition to sociodemographic and health-related characteristics. Obstetric, neonatal, and infant outcomes were also documented, with follow-up extending up to 12 months after childbirth.

RESULTS

As of 30 November 2023, sotrovimab was administered to 39 participants enrolled in the COVID-PR. At the time of this report, 26 participants had given birth, with nine deliveries performed via cesarean section. The infants' birthweight ranged from 2381 g to 4762 g, with a mean of 3439.91 g. Twenty-five infants were born at ≥37 weeks. A total of 31 adverse events (AEs) were reported by 12 participants. The most frequently reported AE was gestational hypertension, observed in three participants. COVID-19 re-infection, fatigue, gestational diabetes, headache, and morning sickness were each reported by two participants. Of the reported AEs, eight (in five participants) were classified as serious, including four AEs (prolonged labor, pre-eclampsia, polyhydramnios, premature labor) that affected pregnancy. Seven of these eight serious AEs (SAEs) were found to be unrelated to sotrovimab, with one event (urinary retention) not assessable. A total of 44 AEs were reported in 19 delivered infants or in utero fetuses. The most common were COVID-19 (n = 6 events), ear infection (n = 5 events), neonatal dyspnea (n = 3 events), and respiratory syncytial virus infection (n = 3 events). Sixteen AEs (in 11 infants/fetuses) were classified as serious, including one report each of fetal cardiac disorder, congenital ankyloglossia, persistent right umbilical vein, and congenital hydronephrosis; the latter was considered a major congenital malformation. For all assessable SAEs, causality of sotrovimab treatment was ruled out based on lack of a temporal relationship alone or in combination with absence of a plausible mechanism.

CONCLUSION

A sizable proportion of sotrovimab-treated participants in the COVID-PR had underlying medical conditions associated with an increased risk of severe COVID-19. None of the assessable SAEs were considered to be related to sotrovimab treatment.

Placenta: an old organ with new functions

The transition from oviparity to viviparity and the establishment of feto-maternal communications introduced the placenta as the major anatomical site to provide nutrients, gases, and hormones to the developing fetus. The placenta has endocrine functions, orchestrates maternal adaptations to pregnancy at different periods of pregnancy, and acts as a selective barrier to minimize exposure of developing fetus to xenobiotics, pathogens, and parasites. Despite the fact that this ancient organ is central for establishment of a normal pregnancy in eutherians, the placenta remains one of the least studied organs. The first step of pregnancy, embryo implantation, is finely regulated by the trophoectoderm, the precursor of all trophoblast cells. There is a bidirectional communication between placenta and endometrium leading to decidualization, a critical step for maintenance of pregnancy. There are three-direction interactions between the placenta, maternal immune cells, and the endometrium for adaptation of endometrial immune system to the allogeneic fetus. While 65% of all systemically expressed human proteins have been found in the placenta tissues, it expresses numerous placenta-specific proteins, whose expression are dramatically changed in gestational diseases and could serve as biomarkers for early detection of gestational diseases. Surprisingly, placentation and carcinogenesis exhibit numerous shared features in metabolism and cell behavior, proteins and molecular signatures, signaling pathways, and tissue microenvironment, which proposes the concept of "cancer as ectopic trophoblastic cells". By extensive researches in this novel field, a handful of cancer biomarkers has been discovered. This review paper, which has been inspired in part by our extensive experiences during the past couple of years, highlights new aspects of placental functions with emphasis on its immunomodulatory role in establishment of a successful pregnancy and on a potential link between placentation and carcinogenesis.

Practical Considerations for Managing Pregnancy in Patients With Multiple Sclerosis: Dispelling the Myths

Purpose of Review

Lack of consistent data and guidance have led to variations between clinicians in the management of pregnancy in women with multiple sclerosis (MS). Pregnant and/or lactating women are often excluded from clinical trials conducted in MS, and thus, the labeling for most disease-modifying therapies (DMTs) excludes use during pregnancy. This has led to heterogeneity in interpretation and labeling regarding the safety of DMTs during pregnancy and lactation and the required preconception washout periods. This review identifies key themes where there is conflicting information surrounding family planning and pregnancy in MS, focusing on the most common discussion points between physicians and patients during preconception planning, pregnancy, postpartum, and lactation. The goal was to inform the patient-physician conversation and provide best practice recommendations based on expert clinical expertise and experience.

Recent Findings

We outline the latest evidence-based data for DMT use during pregnancy and lactation, the effect of MS on fertility and fertility treatments, the risk of adverse pregnancy and delivery outcomes, the risk of postpartum relapse, and immunization and clinical imaging safety during pregnancy and breastfeeding.

Summary

Management of family planning and pregnancy in patients with MS requires the most current information. Health care providers should discuss family planning early and frequently with patients with MS, and partners where practicable. Because management of pregnant people with MS will often require a risk/benefit analysis of their needs, shared decision-making in family planning discussions is emphasized. Additional data are needed for specific and underrepresented populations with MS (e.g., single parents or those from the LGBTQ+ community) and those at risk of racial and socioeconomic disparities in care. Pregnancy registries and the design and conduct of clinical trials focused on pregnant and lactating patients should provide additional data to guide the ongoing management of patients with MS.

Life-threatening infections in human newborns: Reconciling age-specific vulnerability and interindividual variability

In humans, the interindividual variability of clinical outcome following exposure to a microorganism is immense, ranging from silent infection to life-threatening disease. Age-specific immune responses partially account for the high incidence of infection during the first 28 days of life and the related high mortality at population level. However, the occurrence of life-threatening disease in individual newborns remains unexplained. By contrast, inborn errors of immunity and their immune phenocopies are increasingly being discovered in children and adults with life-threatening viral, bacterial, mycobacterial and fungal infections. There is a need for convergence between the fields of neonatal immunology, with its in-depth population-wide characterization of newborn-specific immune responses, and clinical immunology, with its investigations of infections in patients at the cellular and molecular levels, to facilitate identification of the mechanisms of susceptibility to infection in individual newborns and the design of novel preventive and therapeutic strategies.

Maternal vaccination against RSV can substantially reduce childhood mortality in low-income and middle-income countries: A mathematical modeling study

Background

Respiratory syncytial virus (RSV) is a leading cause of childhood mortality in infants below 6 months of age. In low-income and middle-income countries (LMICs), the public health burden is substantial and resources are limited. It is critical to inform decision makers about effectiveness of new interventions.

Methods

We developed a mathematical model where individual RSV subtype A (RSV-A) and B (RSV-B) maternally derived neutralizing titers were predicted at time of birth after maternal vaccination with the RSV prefusion F protein-based vaccine. We estimated the subsequent duration of vaccine-induced immunity and compared this to the age at time of death distribution in the RSV GOLD Mortality Database to predict the potential impact of maternal vaccination on RSV-related childhood mortality. We used country-specific timing of antenatal care visits distributions and mortality estimates to make country-specific predictions for number of cases averted.

Findings

The model predicts that on average a neonate born at 40 weeks gestational age will be protected between 6 and 7 months from RSV-A and approximately 5 months from RSV-B related mortality. We estimated the potential impact of RSV-related mortality for in-hospital and out-of-hospital cases in LMICs and predicted that in 51 GAVI-eligible countries maternal vaccination could avert between 55% and 63% of the RSV-related in-hospital mortality cases below 6 months of age.

Interpretation

We show that maternal vaccination could substantially decrease RSV-A and RSV-B related in-hospital and out-of-hospital mortality in LMICs in the first 6 months of life.

Maternally derived antibody titer dynamics and risk of hospitalized infant dengue disease

Infants less than 1 y of age experience high rates of dengue disease in dengue virus (DENV) endemic countries. This burden is commonly attributed to antibody-dependent enhancement (ADE), whereby concentrations of maternally derived DENV antibodies become subneutralizing, and infection-enhancing. Understanding antibody-related mechanisms of enhanced infant dengue disease risk represents a significant challenge due to the dynamic nature of antibodies and their imperfect measurement processes. Further, key uncertainties exist regarding the impact of long-term shifts in birth rates, population-level infection risks, and maternal ages on the DENV immune landscape of newborns and their subsequent risks of severe dengue disease in infancy. Here, we analyze DENV antibody data from two infant cohorts (N = 142 infants with 605 blood draws) and 40 y of infant dengue hospitalization data from Thailand. We use mathematical models to reconstruct maternally derived antibody dynamics, accounting for discretized measurement processes and limits of assay detection. We then explore possible antibody-related mechanisms of enhanced infant dengue disease risk and their ability to reconstruct the observed age distribution of hospitalized infant dengue cases. We find that ADE mechanisms are best able to reconstruct the observed data. Finally, we describe how the shifting epidemiology of dengue in Thailand, combined with declining birth rates, have decreased the absolute risk of infant dengue disease by 88% over a 40-y period while having minimal impact on the mean age of infant hospitalized dengue disease.

Maternal and neonatal antibody levels on pertussis vaccination in pregnant women on immune-modulating therapy for rheumatic disease

OBJECTIVES

While protection against pertussis following maternal tetanus-diphtheria-and-acellular-pertussis (Tdap) vaccination was demonstrated in healthy term-born infants, no evidence is available on Tdap vaccination in combination with immune-modulating therapy during pregnancy. In this pilot study, we explored whether treatment with tumour necrosis factor alpha inhibitors (TNFis) in pregnant patients with rheumatic disease interferes with Tdap vaccine responses and affects maternal anti-pertussis IgG antibody levels in newborns.

METHODS

Patients were included by a rheumatologist during pregnancy in case they received maternal Tdap vaccination in the late-second or early-third trimester of pregnancy. Blood samples were obtained from mothers during the first pregnancy trimester, 3 months after delivery and from the umbilical cord. IgG antibody levels against Tdap-included antigens were measured using a bead-based multiplex immunoassay. Findings on patients exposed to TNFis were compared with those from TNFi-unexposed patients and with data from a historical comparator study among healthy Tdap vaccinated mother-infant pairs (n=53).

RESULTS

66 patients (46 exposed and 20 unexposed to TNFIs) were enrolled. No major differences in IgG antibody levels were observed between TNFi-exposed and unexposed mothers before maternal Tdap vaccination and 3 months after delivery. In cord sera, however, antibody levels against pertussis toxin were significantly lower after TNFi-treatment (35.94 IU/mL, 95% CI 20.68 to 62.45) compared with no TNFi-treatment of mothers with rheumatic disease (94.61 IU/mL, 95% CI 48.89 to 183.07) and lower compared with a cohort of healthy mothers (125.12 IU/mL, 95% CI 90.75 to 172.50). We observed similar differences for filamentous haemagglutinin, pertactin, tetanus toxoid and diphtheria toxoid.

CONCLUSION

These preliminary data indicate no major differences in IgG antibody levels on maternal Tdap vaccination in pregnant women with or without immune-modulating treatment, although our findings suggest that TNFis during pregnancy induce lower maternal anti-pertussis-specific protective antibody levels in newborns.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Immunological and Histological Studies of Different Concentrations of Rosmarinus officinalis and Thymus vulgaris Extracts on Thymus Gland of Chick Embryos

Humanity has an ancient history of consuming medicinal plants for prophylaxis. Within hours, and even months, embryonic cells undergo several processes to form an organism. This study aimed to prove the positive or negative effects of using rosemary and thyme extract on the thymus gland and level of IL-10, IgM, and IgG in serum of chick embryos. The immunological effect was measured by histological and immunological studies. A total of 160 fertilized eggs were randomly distributed into 8 groups; on the 0 and 8th day of incubation, all treated groups received a dose of 0.1 mL/egg. On the 14th and 20th days of incubation, the embryos were sacrificed and the samples were collected (serum and thymus gland). The data were analyzed using ANOVA. Simple damage in thymic tissue with a low cell density in the embryos was treated with high concentrations of rosemary and thyme extracts, as well as in the mixed group. A significant decrease in IgM levels in the group treated by a high concentration of thyme. A decrease in IgG levels was found in the group treated with a high concentration of rosemary and in the mixed group, while the group treated with a high concentration of thyme and the mixed group showed decreases on the 14th day. A significant decrease in IL-10 levels was found on the 14th day, followed by an increase on the 20th day. Despite the benefits of rosemary and thyme, inflammation signs appeared on embryos treated with these herbs.

Transplacental Transfer of SARS-CoV-2 Receptor-Binding Domain IgG Antibodies from Mothers to Neonates in a Cohort of Pakistani Unvaccinated Mothers

The presence of COVID-19 antibodies in the maternal circulation is assumed to be protective for newborns against SARS-CoV-2 infection. We investigated whether maternal COVID-19 antibodies crossed the transplacental barrier and whether there was any difference in the hematological parameters of neonates born to mothers who recovered from COVID-19 during pregnancy. The cross-sectional study was conducted at the Saidu Group of Teaching Hospitals, located in Swat, Khyber Pakhtunkhwa. After obtaining written informed consent, 115 healthy, unvaccinated mother-neonate dyads were included. A clinical history of COVID-19-like illness, laboratory-confirmed diagnosis, and contact history were obtained. Serum samples from mothers and neonates were tested for SARS-CoV-2 anti-receptor-binding domain (anti-RBD) IgG antibodies. Hematological parameters were assessed with complete blood counts (CBC) and peripheral blood smear examinations. The study population consisted of 115 mothers, with a mean age of 29.44 ± 5.75 years, and most women (68/115 (59.1%)) were between 26 and 35 years of age. Of these mothers, 88/115 (76.5 percent) tested positive for SARS-CoV-2 anti-RBD IgG antibodies, as did 83/115 (72.2 percent) neonatal cord blood samples. The mean levels of SARS-CoV-2 IgG antibodies in maternal and neonatal blood were 19.86 ± 13.82 (IU/mL) and 16.16 ± 12.90 (IU/mL), respectively, indicating that maternal antibodies efficiently crossed the transplacental barrier with an antibody transfer ratio of 0.83. The study found no significant difference in complete blood count (CBC) parameters between seropositive and seronegative mothers, nor between neonates born to seropositive and seronegative mothers.

Iodine and Thyroid Maternal and Fetal Metabolism during Pregnancy

Thyroid hormones and iodine are required to increase basal metabolic rate and to regulate protein synthesis, long bone growth and neuronal maturation. They are also essential for protein, fat and carbohydrate metabolism regulation. Imbalances in thyroid and iodine metabolism can negatively affect these vital functions. Pregnant women are at risk of hypo or hyperthyroidism, in relation to or regardless of their medical history, with potential dramatic outcomes. Fetal development highly relies on thyroid and iodine metabolism and can be compromised if they malfunction. As the interface between the fetus and the mother, the placenta plays a crucial role in thyroid and iodine metabolism during pregnancy. This narrative review aims to provide an update on current knowledge of thyroid and iodine metabolism in normal and pathological pregnancies. After a brief description of general thyroid and iodine metabolism, their main modifications during normal pregnancies and the placental molecular actors are described. We then discuss the most frequent pathologies to illustrate the upmost importance of iodine and thyroid for both the mother and the fetus.

Outcomes of pregnant women exposed to Sotrovimab for the treatment of COVID-19 in the BA.1 Omicron predominant era (PRESTO)

BACKGROUND

Sotrovimab, a monoclonal antibody with efficacy against SARS-CoV-2 including certain Omicron variants, has been used in treatment of mild-moderate COVID-19. Limited data exists regarding its use in pregnant women.

METHODS

Electronic medical record review of pregnant COVID-19 patients treated with sotrovimab from 12/30/21 - 1/31/22 (Yale New Haven Health Hospital System [YNHHS]) was performed. Included were pregnant individuals ≥ 12 years, weighing ≥ 40 kg, with positive SARS-CoV-2 test (within 10 days). Those receiving care outside YNHHS or receiving other SARS-CoV-2 treatment were excluded. We assessed demographics, medical history, and Monoclonal Antibody Screening Score (MASS). The primary composite clinical outcome assessed included emergency department (ED) visit < 24 h, hospitalization, intensive care unit (ICU) admission, and/or death within 29 days of sotrovimab. Secondarily, adverse feto-maternal outcomes and events for neonates were assessed at birth or through the end of the study period, which was 8/15/22.

RESULTS

Among 22 subjects, median age was 32 years and body mass index was 27 kg/m2. 63% were Caucasian, 9% Hispanic, 14% African-American, and 9% Asian. 9% had diabetes and sickle cell disease. 5% had well-controlled HIV. 18%, 46%, and 36% received sotrovimab in trimester 1, 2, and 3, respectively. No infusion/allergic reactions occurred. MASS values were < 4. Only 12/22 (55%) received complete primary vaccination (46% mRNA-1273; 46% BNT162b2; 8% JNJ-78,436,735); none received a booster.

CONCLUSIONS

Pregnant COVID-19 patients receiving sotrovimab at our center tolerated it well with good clinical outcomes. Pregnancy and neonatal complications did not appear sotrovimab-related. Though a limited sample, our data helps elucidate the safety and tolerability of sotrovimab in pregnant women.

Single-center serological surveillance of SARS-CoV-2 in pregnant patients presenting to labor and delivery

OBJECTIVE

To measure maternal/fetal SARS-CoV-2 antibody levels.

METHODS

A prospective observational study of eligible parturients admitted to the hospital for infant delivery was conducted between April and September 2020. SARS-CoV-2 antibody levels were measured in maternal and umbilical cord specimens using an in-house ELISA based on the receptor-binding domain (RBD) of the spike protein. Among SARS-CoV-2 seropositive patients, spike RBD antibody isotypes (IgG, IgM, and IgA) and ACE2 inhibiting antibodies were measured.

RESULTS

In total, 402 mothers were enrolled and spike RBD antibodies in 388 pregnancies were measured (336 maternal and 52 cord specimens). Of them, 19 were positive (15 maternal, 4 cord) resulting in a seroprevalence estimate of 4.8% (95% confidence interval 2.9-7.4). Of the 15 positive maternal specimens, all had cord blood tested. Of the 15 paired specimens, 14 (93.3%) were concordant. Four of the 15 pairs were from symptomatic mothers, and all four showed high spike-ACE2 blocking antibody levels, compared to only 3 of 11 (27.3%) from asymptomatic mothers.

CONCLUSION

A variable antibody response to SARS-CoV-2 in pregnancy among asymptomatic infections compared to symptomatic infections was found, the significance of which is unknown. Although transfer of transplacental neutralizing antibodies occurred, additional research is needed to determine how long maternal antibodies can protect the infant against SARS-CoV-2 infection.

Clinical challenges to the concept of ectogestation

Since the publication of the successful animal trials of the Biobag, a prototypical extrauterine support for extremely premature neonates, numerous ethicists have debated the potential implications of such a device. Some have argued that the Biobag represents a natural evolution of traditional newborn intensive care, while others believe that the Biobag would create a new class of being for the patients housed within. Kingma and Finn argued in Bioethics for making a categorical distinction between fetuses, newborns and 'gestatelings' in a Biobag on the basis of a conceptual distinction between ectogenesis versus ectogestation. Applying their arguments to the clinical realities of newborn intensive care, however, demonstrates the inapplicability of their ideas to the practice of medicine. Here, I present three clinical examples of the difficulty and confusion their argument would create for clinicians and offer a possible remedy: namely, discarding the term 'artificial womb' in favour of 'Biobag'.

A Review of Coronavirus Disease 2019 in Pregnancy

Pregnancy is an independent risk factor for morbidity and mortality in coronavirus disease 2019 (COVID-19) with increased rates of operative delivery, intensive care unit admission, and mechanical ventilation as well as a possible increased risk of death, independent of other risk factors, compared with nonpregnant women with COVID-19. Furthermore, pregnancy outcomes are worse in those with COVID-19 with increased risk for preeclampsia, venous thromboembolism, preterm birth, miscarriage, and stillbirth compared with pregnant women without COVID-19. Importantly, pregnant women of nonwhite ethnicity appear to be at greater risk of severe COVID-19, necessitating improved access to care and closer monitoring in these women. The management of COVID-19 in pregnancy is largely similar to that in nonpregnant people; however, there is an important emphasis on multidisciplinary team involvement to ensure favorable outcomes in both mother and baby. Similarly, vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is safe in pregnancy and improves maternal and neonatal outcomes.

Gestational Alloimune Liver Disease-Case Report

We describe the case of a newborn with the antenatal onset of hepatic failure, which has been investigated for all etiologies that can cause liver damage: infectious, metabolic, genetic, and immune. The lack of a clear answer regarding the etiology and the response to immunoglobulin therapy led us to the diagnosis of gestational alloimmune liver disease. Gestational alloimunne liver disease is an uncommon and very severe cause of neonatal acute liver failure (NALF). Initially, the therapeutic approach aimed at correcting the effects produced by iron loading, respectively, iron chelators and antioxidants. Since all aspects of this case indicated characteristic features typical for GALD, therapy with intravenous immunoglobulins (IVIG) was introduced. If such therapy alters the prognosis of newborns with GALD, the etiology and pathophysiology remain uncertain. However, in cases regarding severe hepatic failure with the perinatal onset and apparently unknown etiology, immunoglobulin or exchange transfusion therapy should be taken into account even before finalizing all the etiological investigations. The prognosis is uncertain and varies between clinical resolution, chronic hepatitis/cirrhosis, and the need for a hepatic transplant, and overall survival depends on prompt therapeutic intervention.

Immune Checkpoint Inhibitors and Pregnancy: Analysis of the VigiBase® Spontaneous Reporting System

In pregnancy, immune checkpoint pathways are involved in the maintenance of fetomaternal immune tolerance. Preclinical studies have shown that immune checkpoint inhibitors (ICIs) increase the risk of fetal death. Despite the fact that using ICIs in pregnant women and women of childbearing potential is not recommended, some case reports of ICI exposure in pregnancy have been published showing favorable fetal outcomes. This study aimed to gain further insight into ICI safety in pregnancy by querying VigiBase^®, the World Health Organization's spontaneous reporting system. We performed raw and subgroup disproportionality analyses using the reporting odds ratio and comparing ICIs with the entire database, other antineoplastic agents, and other antineoplastic agents gathered in VigiBase^® since 2011. Across 103 safety reports referring to ICI exposure during the peri-pregnancy period, 56 reported pregnancy-related outcomes, of which 46 were without concomitant drugs as potential confounding factors. No signals of disproportionate reporting were found for spontaneous abortion, fetal growth restriction, and prematurity. In light of the expanding indications of ICIs, continuous surveillance by clinicians and pharmacovigilance experts is warranted, along with pharmacoepidemiological studies on other sources of real-world evidence, such as birth records, to precisely assess ICI exposure during the peri-pregnancy period and further characterize relevant outcomes.

Preparing for Pregnancy in Women with Systemic Lupus Erythematosus—A Multidisciplinary Approach

Pregnancy is one of the most challenging processes the human body is exposed to: the healthy mother can carry to term a genetically different new-born, while her immune system adapts to tolerate this new status and avoids rejection. In autoimmune disorders, motherhood is even more challenging, with additional medical counselling, mother care, and foetus development checks being necessary. While the aspects of supplementary mother care and pregnancy progress tracking are associated with well-established medical procedures and protocols, counselling, be it pre- or post-conception, is still underestimated and scarcely applied. Indeed, over the past decades, medical counselling for this particular population has changed significantly, but from a healthcare’s provider point of view, more is required to ensure a smooth, controllable pregnancy evolution. One of the most frequent autoimmune diseases affecting young females during their fertile years is Systemic Lupus Erythematosus (SLE). Like other heterogenous diseases, it exposes the mother to severe, organ-threatening complications and unpredictable evolution. Both the disease and its treatment can significantly affect the mother’s willingness to engage in a potentially risky pregnancy, as well as the likeliness to carry it to term without any impairments. A good collaboration between the patient’s rheumatologist and obstetrician is therefore mandatory in order to: (a) allow the mother to make an informed decision on pursuing with the pregnancy; (b) ensure a perfect synchronization between pregnancy terms and treatment; and (c) avoid or minimize potential complications. The best approach to achieve these outcomes is pregnancy planning. Moreover, knowing one desired prerequisite for a successful pregnancy evolution in SLE mothers is a stable, inactive, quiescent disease for at least six months prior to conception, planning becomes more than a recommended procedure. One particular aspect that requires attention before conception is the treatment scheme applied before delivery as autoantibodies can influence significantly the course of pregnancy. In this view, future SLE mothers should ideally benefit from preconception counselling within their agreed care pathway. A multidisciplinary team including at least the rheumatologist and obstetrician should be employed throughout the pregnancy, to decide on the appropriate timing of conception and compatible medication with respect to disease activity, as well as to monitor organ involvement and foetus development progress.

Preconception Counseling in Patients with Hypothyroidism and/or Thyroid Autoimmunity

Preconception counseling is an essential tool for preventing adverse pregnancy outcomes associated with thyroid dysfunction. The high prevalence of thyroid disease among women of reproductive age, and the increased risk of adverse pregnancy outcomes associated with thyroid dysfunction, emphasize the necessity for well-established screening and treatment criteria in the preconception period. We therefore conducted a literature review for relevant information on the screening, diagnosis and treatment of subclinical and overt hypothyroidism in women seeking pregnancy. While screening for thyroid disease is recommended only in the presence of risk factors, iodine supplementation should be recommended in most regions, with higher doses in areas with severe deficiency. Known hypothyroid women should be counseled about increasing their levothyroxine dose by 20–30% in the case of suspected or confirmed pregnancy (missed menstrual cycle or positive pregnancy test). Treating subclinical hypothyroidism appears to be beneficial, especially in the presence of autoimmunity or in patients undergoing artificial reproductive techniques. Regarding the management of TPOAb negative SCH women or euthyroid women with positive TPOAb, further research is necessary in order to make evidence-based recommendations.

Pulmonary Alveolar Proteinosis and Pregnancy: A Review of the Literature and Case Presentation

Pulmonary Alveolar Proteinosis (PAP) is a rare, usually autoimmune, disease, where surfactant accumulates within alveoli due to decreased clearance, causing dyspnea and hypoxemia. The disease is even more rare in pregnancy; nevertheless, it has been reported in pregnant women and can even appear for the first time during pregnancy as an asthma-like illness. Therefore, awareness is important. Similarly to many autoimmune diseases, it can worsen during pregnancy and postpartum, causing maternal and fetal/neonatal complications. This paper offers a narrative literature review of PAP and pregnancy, while illustrating a case of a pregnant patient with known PAP who developed preeclampsia in the third trimester but had an overall fortunate maternal and neonatal outcome.

Routing kinetics of human immunoglobulin-G after transamniotic fetal immunotherapy (TRAFIT) in a rodent model

PURPOSE

The transamniotic route was recently discovered as a minimally invasive means of fetal immunoglobulin administration, however by unclear mechanisms. We sought to examine IgG routing after intra-amniotic delivery.

METHODS

Sprague-Dawley fetuses (n = 78) received intra-amniotic injections of 15 mg/mL of human IgG on gestational-day 18 (E18; term=21 and 22 days). Amniotic fluid, amnion, chorion, placenta, fetal serum, liver, and stomach-aspirate samples were procured on E19, E20, and E21 for IgG quantification by ELISA. Statistical analysis was by median regression with Bonferroni-adjusted significance at p < 0.017.

RESULTS

Human IgG was detected at all sampled sites across all time points, though at significantly higher levels in the gestational membranes and fetal serum than in the stomach aspirate and liver (p < 0.001 for both). Gestational membranes showed a daily decrease after injection, stabilizing by E20 and E21 (p = 0.792 to < 0.001). Placental levels were significantly lower at E21 than E19 (p = 0.010). Fetal serum showed the highest human IgG levels at term.

CONCLUSIONS

The chronology of exogenous IgG kinetics after intra-amniotic injection is suggestive of direct placental transport leading to consistently high fetal serum levels, possibly combined with some fetal ingestion. Transamniotic fetal immunotherapy (TRAFIT) may become a practicable strategy for the prenatal treatment of select alloimmune disorders and infections.

LEVEL OF EVIDENCE

N/A (Animal and Laboratory study).

TYPE OF STUDY

Animal and Laboratory Study.

ZIKV can infect human term placentas in the absence of maternal factors

Zika virus infection can result in devastating pregnancy outcomes when it crosses the placental barrier. For human pregnancies, the mechanisms of vertical transmission remain enigmatic. Utilizing a human placenta-cotyledon perfusion model, we examined Zika virus exposure in the absence of maternal factors. To distinguish responses related to viral infection vs. recognition, we evaluated cotyledons perfused with either active or inactivated Zika virus. Active Zika virus exposure resulted in infection, cell death and syncytium injury. Pathology corresponded with transcriptional changes related to inflammation and innate immunity. Inactive Zika virus exposure also led to syncytium injury and related changes in gene expression but not cell death. Our observations reveal pathologies and innate immune responses that are dependent on infection or virus placenta interactions independent of productive infection. Importantly, our findings indicate that Zika virus can infect and compromise placentas in the absence of maternal humoral factors that may be protective.

Villazana-Kretzer et al. compare histology, physiology and gene expression in cotyledons from term placentas perfused with either active or UV-inactivated Zika virus. They show that ZIKV can infect human term placentas in the absence of maternal factors and identify unique transcriptional responses to active ZIKA virus.

Recurrent Congenital Heart Block Due to Maternal Anti-Ro Antibodies: Successful Prevention of Poor Pregnancy Outcome with Hydroxychloroquine and Added Dexamethasone

Autoimmune Congenital Heart Block (CHB) is an immune-mediated disease caused by transplacental passage of maternal circulating anti-Ro/SSA and anti-La/SSB antibodies which can bind to fetal cardiac tissue, damaging conduction tissues by inflammation and fibrosis. Approximately 2% of pregnancies with positive anti-Ro antibodies will be complicated by fetal atrioventricular block and the risk of recurrence in subsequent pregnancies is 10 times higher. We report a case of a clinically asymptomatic patient diagnosed with anti-Ro antibodies who had two pregnancies complicated by CHB with different outcomes. Despite preventive treatment with hydroxychloroquine (HCQ) from 6 weeks of pregnancy onward, the fetus developed second to third degree CHB. Dexamethasone was added. The pregnancy evolved to near-term with persistent intermittent CHB. It is not clear how pregnancies with recurrent fetal CHB despite prophylaxis with HCQ should be managed and there is a need for controlled studies to answer the remaining questions in relation to this subject.

Frequency and Molecular Characterization of Staphylococcus aureus from Placenta of Mothers with Term and Preterm Deliveries

Globally, prematurity is the leading cause of neonatal mortality (babies in the first four weeks of life) and now the second leading cause of mortality after pneumonia in children under age five. The neonatal gut microbial colonization is crucial in the human life cycle. Placental microbiota transmits from the gut microbiota plays a significant role in association with kinship. Simultaneously, this transition is being made from mother to infant. This comparative study explored the diversity of microbiota associated with term and preterm neonates by evaluating the placental samples. The study found that 16/68 (23.5%) full-term placental samples were positive for S. aureus; on the other hand, 4/16 (25%) preterm placental samples confirmed culture growth for S. aureus. Antimicrobial susceptibility patterns showed that Staphylococcusaureus (S. aureus) isolates from both types of samples were resistant to Ofloxacin, Trimethoprim-sulfamethoxazole, Oxacillin, and Cefoxitin. However, Methicillin-Resistant Staphylococcus aureus (MRSA) detection was 43.75% in full-term and 75% in preterm placental samples. Moreover, two isolates were positive for both mecA and PVL virulent genes, and the rest were positive only for the mecA gene. Interestingly few isolates lacked both characteristic MRSA genes, mecA and PVL. Notably, resistances were more inclined towards preterm samples for antimicrobial susceptibility and MRSA screening. It may be concluded that there is a significant presence of S. aureus in the placenta of mothers with term and preterm deliveries which might be responsible for preterm deliveries. Therefore, judicious use of antibiotics during pregnancies may help prevent preterm births.

Pregnancy and Autoimmune Disease: Diseases of the Nervous System, Connective Tissue, and the Bowel

BACKGROUND

Pregnancies in women with chronic disease are on the rise. This pertains to autoimmune diseases in particular since these tend to affect women of childbearing age. The interaction between pregnancy and autoimmune disease may increase the risk of maternal, fetal, and obstetric complications; additional care may be required.

METHODS

This review is based on a selective literature search in PubMed (2015-2020).

RESULTS

In women with autoimmune diseases, the course of pregnancy is highly variable. Some autoimmune diseases tend to improve during pregnancy and do not to result in any serious obstetric complications. Others may worsen during pregnancy, with deterioration of the maternal condition as well as obstetric and perinatal complications. In systemic lupus erythematosus and myasthenia gravis, placental transfer of specific autoantibodies may cause fetal or neonatal disease.

CONCLUSION

The care of pregnant women with chronic diseases requires collaboration between specialists of the pertinent levels of care. A stable course of disease before conception, close interdisciplinary care, and pregnancy-compatible medication contribute to a reduction in maternal and perinatal complications.

The Potential Benefit of Hydroxychloroquine in Chronic Placental Inflammation of Unknown Etiology Associated with Adverse Pregnancy Outcomes

The placenta is the site of connection between maternal and fetal circulation, and the liaison is established early in pregnancy. A large variety of pregnancy complications such as preterm birth, fetal growth restriction, or pregnancy loss have placental expression and can be accompanied in some cases of acute or chronic identifiable placental inflamatory lesions. Chronic placental inflammatory (CPI) lesions include chronic villitis of unknow etiology (CVUE), chronic intervillositis of unknown etiology, CIUE (also described as chronic histiocytic intervillositis, CHI), and chronic deciduits. Hydroxychloroquine (HCQ) has been prescribed with good results during pregnancy to prevent adverse perinatal outcomes in maternal autoimmune conditions. Its success has paved the way to its use in CPI as CIUE/CHI; however, to date, there are no prospective, informatively designed, controlled studies on its value in these setting. This review aims to explore the potential role of HCQ in CPI of unknown etiology. Ideally, properly designed, probably multicentric studies should be undertaken to fully understand HCQ's role for prevention of adverse pregnancy outcomes after a chronic placental inflammation.

Fetal Surveillance in Pregnancies with Myasthenia Gravis

Myasthenia gravis (MG) is an autoimmune condition, that commonly impacts adult women of reproductive age. Myasthenia gravis in pregnancy is rare, but the incidence is higher in different geographical areas. Pregnancies in mothers with MG can have an unfortunate outcome. Acetylcholine receptor antibodies may pass into the fetal circulation and can affect the fetal neuromuscular junction, generating transient MG or even fetal arthrogryposis. The 2016 and 2021 International Consensus Guidance for Management of Myasthenia Gravis issued by Myasthenia Gravis Foundation of America is lacking in recommendation for fetal surveillance for pregnancies in women with MG. The aim of this paper is to highlight fetal and neonatal complications in mothers with MG and to offer antenatal care insights. Close maternal and pregnancy monitoring can improve pregnancy outcome. Patients with MG should be encouraged to conceive, to avoid triggers for exacerbations of the disease during pregnancy and a multidisciplinary team should be established to ensure the optimal support and therapy.

[Current aspects of antirheumatic therapy in pregnancy planning, during pregnancy and breastfeeding]

Active rheumatic disease is a known factor for increased fetomaternal risks during pregnancy. Remission or inactive disease should therefore be targeted to reduce these risks by using pregnancy-compatible antirheumatic drugs as recommended by international guidelines. Teratogenic antirheumatic drugs, such as mycophenolate, methotrexate, cyclophosphamide and thalidomide should be stopped about 3 months prior to conception. Leflunomide is a weak human teratogen that should be stopped and eliminated with cholestyramine prior to conception. Furthermore, drugs with limited data, such as apremilast and JAK inhibitors as well as new biologics should be avoided during gestation. Pregnancy-compatible drugs are the antirheumatic drugs hydroxychloroquine, sulfasalazine, azathioprine, cyclosporine, tacrolimus, colchicine, non-selective NSAIDs, low-dose prednisone/prednisolone and TNF inhibitors. These drugs as well as other biologics, such as rituximab can be used during lactation. In a preconception counselling visit, the benefits and the international recommendations of pregnancy-compatible antirheumatic drugs should be discussed with the patient and be weighed against the possible fetomaternal risks of an active disease to enable a shared decision-making.

Multisystem inflammatory syndrome with persistent neutropenia in neonate exposed to SARS-CoV-2 virus: A case report and review of literature

BACKGROUND

Multisystem inflammatory syndrome in Children (MIS-C) is a postinfectious immune mediated hyperinflammatory state seen in children and adolescent below 21 year of age and develop after 4-6 weeks of severe acute respiratory syndrome coronavirus -2 (SARS-CoV-2) infection, however, it is rare in neonates. We report an extremely rare and first of its kind case of MIS-C in a neonate with persistent neutropenia.

CASE DESCRIPTION

A 19-day old boy presented with complaints of fever and loose stools for 1 day and developed rash after admission. Baby was investigated for sepsis and commenced on IV antibiotics empirically. In view of persistent fever, diarrhoea, rash and absence of obvious microbial etiology of inflammation, with elevated inflammatory marker and an epidemiologic link to SARS-CoV-2 infection, the diagnosis of MIS-C-was made. Intravenous immunoglobulin (IVIg) was administered and defervescence occurred within 24 hours. He also developed neutropenia during course of illness which persisted on follow up.

CONCLUSION

MIS-C in neonates is uncommon and fever with elevated inflammatory markers during COVID-19 pandemic should alert the pediatrician to the possibility of MIS-C. Neutropenia may be associated with MIS-C in neonates and warrants prolonged follow up.

Inhibition of Maternal-to-Fetal Transfer of IgG Antibodies by FcRn Blockade in a Mouse Model of Arthrogryposis Multiplex Congenita

Objective

To determine whether blocking the neonatal Fc receptor (FcRn) during gestation with an anti-FcRn monoclonal antibody (mAb) reduces transfer of pathogenic maternal antibodies in utero and decreases the likelihood of maternal antibody-mediated neonatal disease in the offspring.

Methods

Using a previously established maternal-to-fetal transfer mouse model of arthrogryposis multiplex congenita (AMC), we assessed the effect of 4470, an anti-FcRn mAb, on the transfer of total human immunoglobulin G (IgG) and specific acetylcholine receptor (AChR)-antibodies from mother to fetus, as well as its effect on the prevention of neurodevelopmental abnormalities in the offspring.

Results

Offspring of pregnant dams treated with 4470 during gestation showed a substantial reduction in total human IgG and AChR antibody levels compared with those treated with the isotype mAb control. Treatment with 4470 was also associated with a significant reduction in AMC-IgG–induced deformities (limb or spinal curve malformations) when compared with mAb control–exposed embryos and a nonsignificant increase in the percentage of fetuses showing spontaneous movements. 4470 exposure during pregnancy was not associated with changes in general parameters of maternal well-being or fetal development; indeed, male neonates showed faster weight gain and shorter time to reach developmental milestones.

Conclusions

FcRn blockade is a promising therapeutic strategy to prevent the occurrence of AMC and other human maternal autoantibody-related diseases in the offspring.

Presumptive Neonatal Multisystem Inflammatory Syndrome in Children Associated with Coronavirus Disease 2019

OBJECTIVE

The study aimed to alert the neonatal community to the possibility of multisystem inflammatory syndrome in children (MIS-C) like disease in critically ill neonates born to mothers with coronavirus disease 2019 (COVID-19).

STUDY DESIGN

Diagnosis of MIS-C like disease was pursued after echocardiography showed severely depressed ventricular function and pathological coronary artery dilation in the setting of medically refractory multisystem organ failure and maternal COVID-19 infection. The neonate did not respond to standard medical therapy, and there was no alternative disease that could explain the clinical course. High index of clinical suspicion coupled with low risk of intravenous immunoglobulin (IVIG) prompted us to pursue IVIG administration even though the neonate did not meet classic criteria for MIS-C.

RESULT

Following treatment with IVIG, there was rapid clinical improvement. Ventricular function improved within 15 hours and coronary artery dilation resolved in 8 days. There was no recurrence of disease during follow-up.

CONCLUSION

COVID-19 associated MIS-C like disease has not been well described in neonates. As typical features may be conspicuously absent, a high index of suspicion is warranted in critically ill neonates born to mothers with COVID-19. Echocardiography may provide critical diagnostic information and narrow the differential diagnosis.

KEY POINTS

· COVID-19 associated MIS-C can present in neonates.. · Echocardiography is helpful in raising suspicion for MIS-C in neonates.. · Consider MIS-C in the differential diagnosis of ill neonates born to mothers with COVID-19..

COVID-19-Related Potential Multisystem Inflammatory Syndrome in Childhood in a Neonate Presenting as Persistent Pulmonary Hypertension of the Newborn

A term infant with persistent pulmonary hypertension of newborn developed clinical and laboratory features of multisystem inflammatory syndrome in childhood (MIS-C) between days 12 and 14. Mother and baby were anti-SARS-Coronavirus-2 (SARS-CoV-2) IgG positive and anti-SARS-CoV-2 IgM negative on day 18, with negative COVID-19 PCR on repeated testing; possible first documentation of neonatal MIS-C following passive transfer of maternal antibodies.

Sexually dimorphic placental responses to maternal SARS-CoV-2 infection

There is a persistent male bias in the prevalence and severity of COVID-19 disease. Underlying mechanisms accounting for this sex difference remain incompletely understood. Interferon responses have been implicated as a modulator of disease in adults, and play a key role in the placental anti-viral response. Moreover, the interferon response has been shown to alter Fc-receptor expression, and therefore may impact placental antibody transfer. Here we examined the intersection of viral-induced placental interferon responses, maternal-fetal antibody transfer, and fetal sex. Placental interferon stimulated genes (ISGs), Fc-receptor expression, and SARS-CoV-2 antibody transfer were interrogated in 68 pregnancies. Sexually dimorphic placental expression of ISGs, interleukin-10, and Fc receptors was observed following maternal SARS-CoV-2 infection, with upregulation in males. Reduced maternal SARS-CoV-2-specific antibody titers and impaired placental antibody transfer were noted in pregnancies with a male fetus. These results demonstrate fetal sex-specific maternal and placental adaptive and innate immune responses to SARS-CoV-2.

Safety considerations when using drugs in pregnant patients with systemic lupus erythematosus

Introduction: Systemic lupus erythematosus (SLE) mainly affects young females during childbearing age; therefore, reproductive issues are of major interest.Areas covered: Pregnancy planning is crucial to adjust the treatment toward drugs that are safe throughout pregnancy and breastfeeding. The evidence about drug safety is limited to post-marketing surveillance, registries, case series, and case reports, as pregnant patients are excluded from randomized clinical trials. The aim of this review is to report the safety considerations when treating pregnant SLE patients. Regarding maternal side effects of drugs, we focused on metabolic, infectious, and hemorrhagic complications. Fetal safety was analyzed looking at drugs teratogenicity, their possible effects on immune system, and on the long-term neuropsychological development of children.Expert opinion: The management of pregnancy in SLE has changed when knowledge about the safety of drugs has become available. Keeping SLE disease activity under control before, during and after pregnancy is of fundamental importance to ensure the best possible outcomes for mother and child. All these issues must be discussed with the patient and her family during preconception counseling. International efforts in terms of pregnancy registries and reproductive health guidelines help physicians improve their communication with SLE patients.

Anti-CD20 therapies and pregnancy in neuroimmunologic disorders: A cohort study from Germany

OBJECTIVE

To report pregnancy outcomes and disease activity (DA) in women with MS, neuromyelitis optica spectrum disorders (NMOSDs), and other neuroimmunologic diseases (ONID) after treatment with rituximab (RTX)/ocrelizumab (OCR) 12 months before or during pregnancy.

METHODS

Data were collected in the German MS and pregnancy registry and centers from the Neuromyelitis Optica Study Group. Sixty-eight known outcomes of 88 pregnancies from 81 women (64 MS, 10 NMOSD, and 7 ONID) were included and stratified in 3 exposure groups: >6M-group = RTX/OCR >6 but ≤12 months before the last menstrual period (LMP) (n = 8); <6M group = RTX/OCR <6 months before the LMP (n = 47); preg group = RTX/OCR after the LMP (n = 13).

RESULTS

Pregnancy outcomes were similar between groups, but significantly more preterm births (9.8% vs 45%) occurred after exposure during pregnancy. Overall, 2 major congenital abnormalities (3.3%), both in the preg group, were observed. Three women had severe infections during pregnancy. All women with MS (35) and 12/13 women with NMOSD, RTX/OCR exposure before the LMP and known pregnancy outcomes after gestational week 22 were relapse free during pregnancy. Five of 29 (17.2%) women with relapsing-remitting MS (RRMS) and 1 of 12 (8.3%) with NMOSD and at least 6 months postpartum follow-up experienced a relapse postpartum. Duration of RTX/OCR and early retreatment but not detection of B-cells were possible predictors for postpartum relapses in patients with RRMS/NMOSD.

CONCLUSIONS

Although RTX/OCR might be an interesting option for women with RRMS/NMOSD who plan to become pregnant to control DA, more data on pregnancy outcomes and rare risks are needed.

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

Importance

Biological data are lacking with respect to risk of vertical transmission and mechanisms of fetoplacental protection in maternal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

Objective

To quantify SARS-CoV-2 viral load in maternal and neonatal biofluids, transplacental passage of anti-SARS-CoV-2 antibody, and incidence of fetoplacental infection.

Design, Setting, and Participants

This cohort study was conducted among pregnant women presenting for care at 3 tertiary care centers in Boston, Massachusetts. Women with reverse transcription-polymerase chain reaction (RT-PCR) results positive for SARS-CoV-2 were recruited from April 2 to June 13, 2020, and follow-up occurred through July 10, 2020. Contemporaneous participants without SARS-CoV-2 infection were enrolled as a convenience sample from pregnant women with RT-PCR results negative for SARS-CoV-2.

Exposures

SARS-CoV-2 infection in pregnancy, defined by nasopharyngeal swab RT-PCR.

Main Outcomes and Measures

The main outcomes were SARS-CoV-2 viral load in maternal plasma or respiratory fluids and umbilical cord plasma, quantification of anti-SARS-CoV-2 antibodies in maternal and cord plasma, and presence of SARS-CoV-2 RNA in the placenta.

Results

Among 127 pregnant women enrolled, 64 with RT-PCR results positive for SARS-CoV-2 (mean [SD] age, 31.6 [5.6] years) and 63 with RT-PCR results negative for SARS-CoV-2 (mean [SD] age, 33.9 [5.4] years) provided samples for analysis. Of women with SARS-CoV-2 infection, 23 (36%) were asymptomatic, 22 (34%) had mild disease, 7 (11%) had moderate disease, 10 (16%) had severe disease, and 2 (3%) had critical disease. In viral load analyses among 107 women, there was no detectable viremia in maternal or cord blood and no evidence of vertical transmission. Among 77 neonates tested in whom SARS-CoV-2 antibodies were quantified in cord blood, 1 had detectable immunoglobuilin M to nucleocapsid. Among 88 placentas tested, SARS-CoV-2 RNA was not detected in any. In antibody analyses among 37 women with SARS-CoV-2 infection, anti-receptor binding domain immunoglobin G was detected in 24 women (65%) and anti-nucleocapsid was detected in 26 women (70%). Mother-to-neonate transfer of anti-SARS-CoV-2 antibodies was significantly lower than transfer of anti-influenza hemagglutinin A antibodies (mean [SD] cord-to-maternal ratio: anti-receptor binding domain immunoglobin G, 0.72 [0.57]; anti-nucleocapsid, 0.74 [0.44]; anti-influenza, 1.44 [0.80]; P < .001). Nonoverlapping placental expression of SARS-CoV-2 receptors angiotensin-converting enzyme 2 and transmembrane serine protease 2 was noted.

Conclusions and Relevance

In this cohort study, there was no evidence of placental infection or definitive vertical transmission of SARS-CoV-2. Transplacental transfer of anti-SARS-CoV-2 antibodies was inefficient. Lack of viremia and reduced coexpression and colocalization of placental angiotensin-converting enzyme 2 and transmembrane serine protease 2 may serve as protective mechanisms against vertical transmission.