The Inflammatory Cytokine Imbalance for Miscarriage, Pregnancy Loss and COVID-19 Pneumonia

Bioinformatics-based analysis of the dialog between COVID-19 and RSA

Pregnant women infected with SARS-CoV-2 in early pregnancy may face an increased risk of miscarriage due to immune imbalance at the maternal-fetal interface. However, the molecular mechanisms underlying the crosstalk between COVID-19 infection and recurrent spontaneous abortion (RSA) remain poorly understood. This study aimed to elucidate the transcriptomic molecular dialog between COVID-19 and RSA. Based on bioinformatics analysis, 307 common differentially expressed genes were found between COVID-19 (GSE171110) and RSA (GSE165004). Common DEGs were mainly enriched in ribosome-related and cell cycle-related signaling pathways. Using degree algorithm, the top 10 hub genes (RPS27A, RPL5, RPS8, RPL4, RPS2, RPL30, RPL23A, RPL31, RPL26, RPL37A) were selected from the common DEGs based on their scores. The results of the qPCR were in general agreement with the results of the raw letter analysis. The top 10 candidate drugs were also selected based on P-values. In this study, we provide molecular markers, signaling pathways, and small molecule compounds that may associate COVID-19. These findings may increase the accurate diagnosis and treatment of COVID-19 patients.

COVID-19 in pregnant women: a systematic review and meta-analysis on the risk and prevalence of pregnancy loss

BACKGROUND

Pregnant women infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are more likely to experience preterm birth and their neonates are more likely to be stillborn or admitted to a neonatal unit. The World Health Organization declared in May 2023 an end to the coronavirus disease 2019 (COVID-19) pandemic as a global health emergency. However, pregnant women are still becoming infected with SARS-CoV-2 and there is limited information available regarding the effect of SARS-CoV-2 infection in early pregnancy on pregnancy outcomes.

OBJECTIVE AND RATIONALE

We conducted this systematic review to determine the prevalence of early pregnancy loss in women with SARS-Cov-2 infection and compare the risk to pregnant women without SARS-CoV-2 infection.

SEARCH METHODS

Our systematic review is based on a prospectively registered protocol. The search of PregCov19 consortium was supplemented with an extra electronic search specifically on pregnancy loss in pregnant women infected with SARS-CoV-2 up to 10 March 2023 in PubMed, Google Scholar, and LitCovid. We included retrospective and prospective studies of pregnant women with SARS-CoV-2 infection, provided that they contained information on pregnancy losses in the first and/or second trimester. Primary outcome was miscarriage defined as a pregnancy loss before 20 weeks of gestation, however, studies that reported loss up to 22 or 24 weeks were also included. Additionally, we report on studies that defined the pregnancy loss to occur at the first and/or second trimester of pregnancy without specifying gestational age, and for second trimester miscarriage only when the study presented stillbirths and/or foetal losses separately from miscarriages. Data were stratified into first and second trimester. Secondary outcomes were ectopic pregnancy (any extra-uterine pregnancy), and termination of pregnancy. At least three researchers independently extracted the data and assessed study quality. We calculated odds ratios (OR) and risk differences (RDs) with corresponding 95% CI and pooled the data using random effects meta-analysis. To estimate risk prevalence, we performed meta-analysis on proportions. Heterogeneity was assessed by I2.

OUTCOMES

We included 120 studies comprising a total of 168 444 pregnant women with SARS-CoV-2 infection; of which 18 233 women were in their first or second trimester of pregnancy. Evidence level was considered to be of low to moderate certainty, mostly owing to selection bias. We did not find evidence of an association between SARS-CoV-2 infection and miscarriage (OR 1.10, 95% CI 0.81-1.48; I2 = 0.0%; RD 0.0012, 95% CI -0.0103 to 0.0127; I2 = 0%; 9 studies, 4439 women). Miscarriage occurred in 9.9% (95% CI 6.2-14.0%; I2 = 68%; 46 studies, 1797 women) of the women with SARS CoV-2 infection in their first trimester and in 1.2% (95% CI 0.3-2.4%; I2 = 34%; 33 studies; 3159 women) in the second trimester. The proportion of ectopic pregnancies in women with SARS-CoV-2 infection was 1.4% (95% CI 0.02-4.2%; I2 = 66%; 14 studies, 950 women). Termination of pregnancy occurred in 0.6% of the women (95% CI 0.01-1.6%; I2 = 79%; 39 studies; 1166 women).

WIDER IMPLICATIONS

Our study found no indication that SARS-CoV-2 infection in the first or second trimester increases the risk of miscarriages. To provide better risk estimates, well-designed studies are needed that include pregnant women with and without SARS-CoV-2 infection at conception and early pregnancy and consider the association of clinical manifestation and severity of SARS-CoV-2 infection with pregnancy loss, as well as potential confounding factors such as previous pregnancy loss. For clinical practice, pregnant women should still be advised to take precautions to avoid risk of SARS-CoV-2 exposure and receive SARS-CoV-2 vaccination.

Association between COVID-19 Infection and Miscarriages, What We Really Know?

BACKGROUND

COVID-19 is a modern worldwide pandemic that affected and continues to affect millions of people around the world. Since the discovery that angiotensin-converting enzyme 2 (ACE2) is the binding site for COVID-19 to achieve cell entry, there has been a continuous debate about the effect of COVID-19 infection in first and second trimester abortions. The aim of this review is to investigate the impact of COVID-19 infection on the incidence of miscarriage. Furthermore, we seek to identify potential pathophysiological mechanisms of early pregnancy loss present in infected women.

METHODS

A literature review was conducted on different databases, including PubMed, Google Scholar, Ovid, Science Direct, Scopus, and Cochrane library, between 1 January 2020 and 31 August 2023. A total of 364 articles were identified and 32 articles were ultimately included in the review.

RESULTS

There are several case studies that provide evidence that early pregnancy loss is associated with COVID-19 infection. These findings are not further confirmed by the majority of systematic reviews and meta-analyses, which demonstrate that the total number of miscarriages do not differ significantly between infected and non-infected groups. Furthermore, there are also case reports that associate COVID-19 infection with late second trimester abortions.

CONCLUSIONS

Given that the virus persists globally, it is important to gain a better understanding of its associated risks in the reproductive process, and larger, more homogeneous, and controlled studies are required to obtain more robust data that can be meta-analyzed to obtain an overview of this potential relationship.

Genetic Correlation of miRNA Polymorphisms and STAT3 Signaling Pathway with Recurrent Implantation Failure in the Korean Population

The growing prevalence of in vitro fertilization-embryo transfer procedures has resulted in an increased incidence of recurrent implantation failure (RIF), necessitating focused research in this area. STAT3, a key factor in maternal endometrial remodeling and stromal proliferation, is crucial for successful embryo implantation. While the relationship between STAT3 and RIF has been studied, the impact of single nucleotide polymorphisms (SNPs) in miRNAs, well-characterized gene expression modulators, on STAT3 in RIF cases remains uncharacterized. Here, we investigated 161 RIF patients and 268 healthy control subjects in the Korean population, analyzing the statistical association between miRNA genetic variants and RIF risk. We aimed to determine whether SNPs in specific miRNAs, namely miR-218-2 rs11134527 G>A, miR-34a rs2666433 G>A, miR-34a rs6577555 C>A, and miR-130a rs731384 G>A, were significantly associated with RIF risk. We identified a significant association between miR-34a rs6577555 C>A and RIF prevalence (implantation failure [IF] ≥ 2: adjusted odds ratio [AOR] = 2.264, 95% CI = 1.007-5.092, p = 0.048). These findings suggest that miR-34a rs6577555 C>A may contribute to an increased susceptibility to RIF. However, further investigations are necessary to elucidate the precise mechanisms underlying the role of miR-34a rs6577555 C>A in RIF. This study sheds light on the genetic and molecular factors underlying RIF, offering new avenues for research and potential advancements in the diagnosis and treatment of this complex condition.

Vitamin D and biomarkers of inflammation and oxidative stress among pregnant women: a systematic review of observational studies

OBJECTIVE

This systematic review aimed to map the evidence evaluated the relationship between vitamin D and redox and inflammatory status during gestation.

METHODS

Three databases (PubMed/MEDLINE, Scopus, and Web of Science (WoS)) and reference list of included documents were searched for related observational studies published until 2nd October 2023. To determine the quality of the selected observational studies, the Newcastle-Ottawa Scale (NOS) was used.

RESULTS

After a primary search of three databases, 19492records were appeared. When duplicates and irrelevant documents were removed, 14 articles were found to have eligible criteria. The design of the identified studies was cross-sectional, case-control and cohort. Evidence showed an adverse association between 25(OH)D and the biomarkers of inflammation, such as high-sensitivity C-reactive protein (hs-CRP), Interleukin-1beta (IL-1β), Interleukin-6 (IL-6), and tumor necrosis factor- alfa (TNF-α) during pregnancy. On the contrary, some studies represented that 25(OH)D positively correlated with hs-CRP in the cord blood. One study suggested a direct association between serum concentrations of 25(OH)D and Interleukin-8 (IL-8), macrophage inflammatory protein (MIP), and TNF-α levels in mothers with gestational diabetes mellitus (GDM). A case-control study showed that lower serum concentration of 25(OH)D positively correlated with total antioxidant capacity (TAC) levels in participants.

CONCLUSIONS

Evidence confirmed the supposition of the direct relationship between vitamin D levels and biomarkers with anti-inflammatory and anti-oxidative properties. However, the Existence of inconsistent evidence confirms the need for further studies in mothers with GDM and hypertensive disorders.

PROSPERO REGISTRATION CODE

CRD42020202600.

Neuroimaging assessment of pediatric cerebral changes associated with SARS-CoV-2 infection during pregnancy

Background

SARS-CoV-2 infection and perinatal neurologic outcomes are still not fully understood. However, there is recent evidence of white matter disease and impaired neurodevelopment in newborns following maternal SARS-CoV-2 infection. These appear to occur as a consequence of both direct viral effects and a systemic inflammatory response, with glial cell/myelin involvement and regional hypoxia/microvascular dysfunction. We sought to characterize the consequences of maternal and fetal inflammatory states in the central nervous system of newborns following maternal SARS-CoV-2 infection.

Methods

We conducted a longitudinal prospective cohort study from June 2020 to December 2021, with follow-up of newborns born to mothers exposed or not exposed to SARS-CoV-2 infection during pregnancy. Brain analysis included data from cranial ultrasound scans (CUS) with grayscale, Doppler studies (color and spectral), and ultrasound-based brain elastography (shear-wave mode) in specific regions of interest (ROIs): deep white matter, superficial white matter, corpus callosum, basal ganglia, and cortical gray matter. Brain elastography was used to estimate brain parenchymal stiffness, which is an indirect quantifier of cerebral myelin tissue content.

Results

A total of 219 single-pregnancy children were enrolled, including 201 born to mothers exposed to SARS-CoV-2 infection and 18 from unexposed controls. A neuroimaging evaluation was performed at 6 months of adjusted chronological age and revealed 18 grayscale and 21 Doppler abnormalities. Predominant findings were hyperechogenicity of deep brain white matter and basal ganglia (caudate nuclei/thalamus) and a reduction in the resistance and pulsatility indices of intracranial arterial flow. The anterior brain circulation (middle cerebral and pericallosal arteries) displayed a wider range of flow variation than the posterior circulation (basilar artery). Shear-wave US elastography analysis showed a reduction in stiffness values in the SARS-CoV-2 exposed group in all analyzed regions of interest, especially in the deep white matter elasticity coefficients (3.98 ± 0.62) compared to the control group (7.76 ± 0.77); p-value < 0.001.

Conclusion

This study further characterizes pediatric structural encephalic changes associated with SARS-CoV-2 infection during pregnancy. The maternal infection has been shown to be related to cerebral deep white matter predominant involvement, with regional hyperechogenicity and reduction of elasticity coefficients, suggesting zonal impairment of myelin content. Morphologic findings may be subtle, and functional studies such as Doppler and elastography may be valuable tools to more accurately identify infants at risk of neurologic damage.

Periodontitis in Pregnant Women: A Possible Link to Adverse Pregnancy Outcomes

BACKGROUND

Periodontitis develops in 11% of pregnant women, and it is independently linked to severe complications during pregnancy such as preterm birth, low birth weight, and gestational diabetes.

METHODS

A literature search (Pubmed/MEDLINE, and Scopus) from 2003 to 2023 was conducted to analyze studies focused on periodontitis and adverse pregnancy outcomes.

RESULTS

16 articles have been included. Most of the studies showed adverse outcomes, like preterm birth and the low weight of the unborn child, are among the most frequent consequences (respectively 62.5% and 68.7% of articles); pre-eclampsia is also linked to this condition (12.5% of articles); and perinatal mortality (12.5% of articles).

CONCLUSIONS

Periodontal disease appears to be associated with adverse events in pregnancy due to the transport of biofilm bacteria into the bloodstream and into placental tissue; what would cause adverse events is the body's immune response to infection.

Mitochondrial ROS Accumulation Contributes to Maternal Hypertension and Impaired Remodeling of Spiral Artery but Not IUGR in a Rat PE Model Caused by Maternal Glucocorticoid Exposure

Increased maternal glucocorticoid levels have been implicated as a risk factor for preeclampsia (PE) development. We found that pregnant rats exposed to dexamethasone (DEX) showed hallmarks of PE features, impaired spiral artery (SA) remodeling, and elevated circulatory levels of sFlt1, sEng IL-1β, and TNFα. Abnormal mitochondrial morphology and mitochondrial dysfunction in placentas occurred in DEX rats. Omics showed that a large spectrum of placental signaling pathways, including oxidative phosphorylation (OXPHOS), energy metabolism, inflammation, and insulin-like growth factor (IGF) system were affected in DEX rats. MitoTEMPO, a mitochondria-targeted antioxidant, alleviated maternal hypertension and renal damage, and improved SA remodeling, uteroplacental blood flow, and the placental vasculature network. It reversed several pathways, including OXPHOS and glutathione pathways. Moreover, DEX-induced impaired functions of human extravillous trophoblasts were associated with excess ROS caused by mitochondrial dysfunction. However, scavenging excess ROS did not improve intrauterine growth retardation (IUGR), and elevated circulatory sFlt1, sEng, IL-1β, and TNFα levels in DEX rats. Our data indicate that excess mitochondrial ROS contributes to trophoblast dysfunction, impaired SA remodeling, reduced uteroplacental blood flow, and maternal hypertension in the DEX-induced PE model, while increased sFlt1 and sEng levels and IUGR might be associated with inflammation and an impaired energy metabolism and IGF system.

Sialylation status in placentas from pregnancies with SARS-CoV-2 infection

INTRODUCTION

Recent investigations suggest the potential negative impact of SARS-CoV-2 infection on pregnant women and pregnancy outcome. In addition, some studies have described pathological changes in the placental tissue of SARS-CoV-2-positive mothers, which are related or not to the infection severity and/or infection trimester. Among the various molecules involved in the normal structure and functionality of the placenta, sialic acids (Sias) seem to play an important role. Hence, we aimed to investigate possible changes in the distribution and content of Sias with different glycosidic linkages, namely α2,3 and α2,6 Galactose- or N-acetyl-Galactosamine-linked Sias and polymeric Sia (PolySia), in placentas from pregnant women infected by SARS-CoV-2 during the three different pregnancy trimesters.

METHODS

α2,3 and α2,6 Galactose-linked Sias were evaluated by lectin histochemistry (Maackia amurensis agglutinin (MAA) and Sambucus nigra agglutinin (SNA), respectively), while immunohistochemistry was used for PolySia detection.

RESULTS

Data showed lower levels of α2,3 Galactose-linked Sias in the trophoblast and underlying basement membrane/basal plasma membrane in placentas from women infected during the second and third infection trimester compared with uninfected cases and those infected during first trimester. On the other hand, higher levels of PolySia were detected in the trophoblast during the second and third infection trimester.

CONCLUSIONS

Our findings suggest that changes in the sialylation status of trophoblast and its basement membrane/basal plasma membrane, together with other concomitant factors, could be at the basis of the most common placental histopathological alterations and gestational complications found especially in pregnancies with SARS-CoV-2 infection during the second and third trimester.

SARS-CoV-2 variant-related abnormalities detected by prenatal MRI: a prospective case-control study

Background

There are known complications for fetuses after infection with SARS-CoV-2 during pregnancy. However, previous studies of SARS-CoV-2 in pregnancy have largely been limited to histopathologic studies of placentas and prenatal studies on the effects of different SARS-CoV-2 variants are scarce to date. To examine the effects of SARS-CoV-2 variants on the placenta and fetus, we investigated fetal and extra-fetal structures using prenatal MRI.

Methods

For this prospective case-control study, two obstetric centers consecutively referred pregnant women for prenatal MRI after confirmed SARS-CoV-2 infection. Thirty-eight prenatal MRI examinations were included after confirmed infection with SARS-CoV-2 and matched 1:1 with 38 control cases with respect to sex, MRI field strength, and gestational age (average deviation 1.76 ± 1.65, median 1.5 days). Where available, the pathohistological examination and vaccination status of the placenta was included in the analysis. In prenatal MRI, the shape and thickness of the placenta, possible lobulation, and vascular lesions were quantified. Fetuses were scanned for organ or brain abnormalities.

Findings

Of the 38 included cases after SARS-CoV-2 infection, 20/38 (52.6%) were infected with pre-Omicron variants and 18/38 (47.4%) with Omicron. Prenatal MRIs were performed on an average of 83 days (±42.9, median 80) days after the first positive PCR test. Both pre-Omicron (P = .008) and Omicron (P = .016) groups showed abnormalities in form of a globular placenta compared to control cases. In addition, placentas in the pre-Omicron group were significantly thickened (6.35, 95% CI .02-12.65, P = .048), and showed significantly more frequent lobules (P = .046), and hemorrhages (P = .002). Fetal growth restriction (FGR) was observed in 25% (n = 5/20, P = .017) in the pre-Omicron group.

Interpretation

SARS-CoV-2 infections in pregnancy can lead to placental lesions based on vascular events, which can be well visualized on prenatal MRI. Pre-Omicron variants cause greater damage than Omicron sub-lineages in this regard.

Funding

Vienna Science and Technology Fund.

Placental Characteristics of a Large Italian Cohort of SARS-CoV-2-Positive Pregnant Women

The variety of placental morphological findings with SARS-CoV-2 maternal infections has raised the issue of poor agreement in histopathological evaluation. The aims of this study were: to describe the histopathological placental features of a large sample of SARS-CoV-2-positive women who gave birth in Italy during the COVID-19 pandemic, to analyse the factors underlying these lesions, and to analyse the impact of placental impairment on perinatal outcomes. From 25 February 2020 to 30 June 2021, experienced perinatal pathologists examined 975 placentas of SARS-CoV-2-positive mothers enrolled in a national prospective study, adopting the Amsterdam Consensus Statement protocol. The main results included the absence of specific pathological findings for SARS-CoV-2 infections, even though a high proportion of placentas showed signs of inflammation, possibly related to a cytokine storm induced by the virus, without significant perinatal consequences. Further research is needed to better define the clinical implications of placental morphology in SARS-CoV-2 infections, but the results of this large cohort suggest that placentas do not seem to be a preferential target for the new Coronavirus infection.