Is SARS-CoV-2 Infection a Risk Factor for Early Pregnancy Loss? ACE2 and TMPRSS2 Coexpression and Persistent Replicative Infection in Primitive Trophoblast

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

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

Possibility of intrauterine transmission from mother to fetus/newborn: Systematic review and meta-analysis of diagnostic methods to detect SARS-CoV-2 infection

Several studies have reported vertical transmission of SARS-CoV-2; however, information regarding intrauterine transmission based on diagnostic methods to detect SARS-CoV-2 infection is scarce. A systematic review and meta-analysis was conducted to identify and explore the studies that attempt to ascertain the possibility of intrauterine transmission of SARS-CoV-2 infection according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA 2020) statement. The results demonstrate that SARS-CoV-2 can be transmitted intrauterine, as detected by clinical manifestations (1.00, 95 % CI: 1.00 - 1.00, 0.51, 95 % CI: 0.22 - 0.80), imaging (0.50, 95 % CI: 0.24 - 0.76, 0.03, 95 % CI: 0.00 - 0.17), molecular (1. 00, 95 % CI: 1.00 - 1.00, 0.92, 95 % CI: 0.77 - 1.00), immunological (0.32, 95 % CI: 0.10 - 0.57, 0.34, 95 % CI: 0.11 - 0.61), and histological approaches (0.79, 95 % CI: 0.52 - 0.98) in maternal and fetal/neonatal specimens, respectively. The possibility of intrauterine transmission of SARS-CoV-2 from mother to fetus/newborn was 41 % (95 % CI 0.37 - 0.45). We might confirm/verify the intrauterine transmission of SARS-CoCV-2 from mother to fetus/newborn.

The Multi-faceted Effects of COVID-19 on Female Reproductive Health: An Updated Narrative Review

Concerns about the SARS-CoV-2 pandemic's possible impact on sexual and reproductive health have grown significantly. In this narrative review, the latest research on the effects of SARS-CoV-2 infection on several facets of sexual and reproductive health is reviewed. The review starts initially by going through the possible consequences of SARS-CoV-2 on female menstrual cycles. The virus may interfere with the menstrual cycle, which could affect hormone synthesis and endometrial reactions, according to newly available evidence. Menstrual blood loss may be impacted by COVID-19's potential to influence endothelial cell function and systemic hemostasis. Hypothalamic amenorrhea may be brought on by severe COVID-19 disease. There is little research on this subject, although most women resume their regular menstrual cycles after 1-2 months of recuperation. The review also examines how SARS-CoV-2 infection may affect assisted reproductive technology (ART) treatments. There are few clinical data, although some research points to potential effects on embryo quality. Overall, ART results, however, did not materially change from the time before the epidemic. Obstetric problems are more likely when SARS-CoV-2 infection occurs during pregnancy, especially in the third trimester. Even though the maternal death rate is still low, pregnant women, especially those with comorbidities, are more likely to experience serious sickness. The review emphasizes how the COVID-19 vaccine affects menstrual cycles, showing brief, modest modifications without serious health hazards. Also included are the psychological effects of family planning choices during the pandemic. In conclusion, this narrative review offers a thorough assessment of the complicated and changing effects of SARS-CoV-2 on sexual and reproductive health. The different requirements of people and couples during and after the pandemic are highlighted, underscoring the necessity for ongoing study and specialized healthcare practices.

Causes and Effects of COVID-19 Vaccine Hesitancy Among Pregnant Women and its Association with Adverse Maternal, Placental, and Perinatal Outcomes

Populations identified to be severely affected by COVID-19, such as pregnant patients, require special consideration in vaccine counseling, access, and provider education. Maternal infection with COVID-19 poses a significant risk to the maternal-fetal dyad with known adverse placenta destruction [1-5]. Despite the widespread access and availability of vaccinations, vaccine hesitancy continues to persist and is highly prevalent in pregnant populations [6-9]. Addressing the multitude of social ecological factors surrounding vaccine hesitancy can aid in providing holistic counseling [10]. However, such factors are foremost shaped by maternal concern over possible fetal effects from vaccination. While changes in policy can help foster vaccine access and acceptance, increasing global provider education and incorporation of motivational interviewing skills are the first steps towards increasing maternal acceptance.

Gestational diabetes mellitus in the era of COVID-19: Challenges and opportunities

BACKGROUND AND AIMS

The impact of the coronavirus disease 2019 (COVID-19) pandemic on pregnant women, especially those with gestational diabetes mellitus (GDM), has yet to be fully understood. This review aims to examine the interaction between GDM and COVID-19 and to elucidate the pathophysiological mechanisms underlying the comorbidity of these two conditions.

METHODS

We performed a systematic literature search using the databases of PubMed, Embase, and Web of Science with appropriate keywords and MeSH terms. Our analysis included studies published up to January 26, 2023.

RESULTS

Despite distinct clinical manifestations, GDM and COVID-19 share common pathophysiological characteristics, which involve complex interactions across multiple organs and systems. On the one hand, infection with severe acute respiratory syndrome coronavirus 2 may target the pancreas and placenta, resulting in β-cell dysfunction and insulin resistance in pregnant women. On the other hand, the hormonal and inflammatory changes that occur during pregnancy could also increase the risk of severe COVID-19 in mothers with GDM. Personalized management and close monitoring are crucial for treating pregnant women with both GDM and COVID-19.

CONCLUSIONS

A comprehensive understanding of the interactive mechanisms of GDM and COVID-19 would facilitate the initiation of more targeted preventive and therapeutic strategies. There is an urgent need to develop novel biomarkers and functional indicators for early identification and intervention of these conditions.

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

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

The immune checkpoint molecule, VTCN1/B7-H4, guides differentiation and suppresses proinflammatory responses and MHC class I expression in an embryonic stem cell-derived model of human trophoblast

The placenta acts as a protective barrier to pathogens and other harmful substances present in the maternal circulation throughout pregnancy. Disruption of placental development can lead to complications of pregnancy such as preeclampsia, intrauterine growth retardation and preterm birth. In previous work, we have shown that expression of the immune checkpoint regulator, B7-H4/VTCN1, is increased upon differentiation of human embryonic stem cells (hESC) to an in vitro model of primitive trophoblast (TB), that VTCN1/B7-H4 is expressed in first trimester but not term human placenta and that primitive trophoblast may be uniquely susceptible to certain pathogens. Here we report on the role of VTCN1 in trophoblast lineage development and anti-viral responses and the effects of changes in these processes on major histocompatibility complex (MHC) class I expression and peripheral NK cell phenotypes.

Human Maternal-Fetal Interface Cellular Models to Assess Antiviral Drug Toxicity during Pregnancy

Pregnancy is a period of elevated risk for viral disease severity, resulting in serious health consequences for both the mother and the fetus; yet antiviral drugs lack comprehensive safety and efficacy data for use among pregnant women. In fact, pregnant women are systematically excluded from therapeutic clinical trials to prevent potential fetal harm. Current FDA-recommended reproductive toxicity assessments are studied using small animals which often do not accurately predict the human toxicological profiles of drug candidates. Here, we review the potential of human maternal-fetal interface cellular models in reproductive toxicity assessment of antiviral drugs. We specifically focus on the 2- and 3-dimensional maternal placental models of different gestational stages and those of fetal embryogenesis and organ development. Screening of drug candidates in physiologically relevant human maternal-fetal cellular models will be beneficial to prioritize selection of safe antiviral therapeutics for clinical trials in pregnant women.

Human early syncytiotrophoblasts are highly susceptible to SARS-CoV-2 infection

Direct in vivo investigation of human placenta trophoblast's susceptibility to SARS-CoV-2 is challenging. Here we report that human trophoblast stem cells (hTSCs) and their derivatives are susceptible to SARS-CoV-2 infection, which reveals heterogeneity in hTSC cultures. Early syncytiotrophoblasts (eSTBs) generated from hTSCs have enriched transcriptomic features of peri-implantation trophoblasts, express high levels of angiotensin-converting enzyme 2 (ACE2), and are productively infected by SARS-CoV-2 and its Delta and Omicron variants to produce virions. Antiviral drugs suppress SARS-CoV-2 replication in eSTBs and antagonize the virus-induced blockage of STB maturation. Although less susceptible to SARS-CoV-2 infection, trophoblast organoids originating from hTSCs show detectable viral replication reminiscent of the uncommon placental infection. These findings implicate possible risk of COVID-19 infection in peri-implantation embryos, which may go unnoticed. Stem cell-derived human trophoblasts such as eSTBs can potentially provide unlimited amounts of normal and genome-edited cells and facilitate coronavirus research and antiviral discovery.