Impact of COVID-19 Pandemic Interventions on Sudden Unexpected Death in Infancy Incidence in France.

OBJECTIVE: To study the impact of non-pharmaceutical interventions (NPIs) implemented during the COVID-19 pandemic on the monthly incidence of sudden unexpected death in infancy (SUDI) cases overall and those with a viral or bacterial identification. STUDY DESIGN: We conducted an interrupted time-series analysis using seasonally adjusted Poisson regression models from the French national prospective and multicenter SUDI registry, that included all SUDI cases under age one year who died from 2016 to 2021 in mainland France. RESULTS: Of 998 SUDI cases analyzed, 750 were recorded during the pre-pandemic period (January 2016 through March 2020) and 248 during the NPI period (April 2020 through December 2021). We found a significant seasonal pattern of overall monthly SUDI incidence, with a peak observed periodically from November to February. The monthly SUDI incidence decreased significantly from the pre-pandemic to NPI periods (adjusted incidence rate ratio 0.83 [95% confidence interval 0·72-0·96]). In particular, the monthly incidence of SUDI cases with a viral or bacterial identification decreased, while no significant difference was found for SUDI cases without a viral or bacterial identification. CONCLUSION: NPIs were associated with a significant change in the incidence of SUDI cases with a viral or bacterial identification. Further investigations are needed to analyze the pathophysiologic role of viruses and bacteria in the SUDI.

Neonatal Cardiac and Respiratory Arrest During Linezolid Therapy: A Case Report.

Lactic acidosis is one of the severe adverse reactions of linezolid. Its clinical manifestations are non-specific, primarily including abdominal discomfort, nausea, vomiting, diarrhea, weakness, lethargy, rapid breathing, and tachycardia, with no reports of cardiac and respiratory arrest. In this case report, we present a 13-day-old male infant with omphalitis caused by methicillin-resistant Staphylococcus aureus (MRSA) infection, who was treated with linezolid. He had lactic acidosis before treatment, which was not severe and was likely related to the infection. After linezolid therapy, he experienced cardiac and respiratory arrest, and re-measurement showed an increase in lactate levels. After resuscitation, linezolid withdrawal, and symptomatic treatment, lactate levels decreased. However, due to hypoxic-ischemic encephalopathy and uncorrectable ventricular arrhythmia caused by post-cardiopulmonary resuscitation myocardial damage, the infant died. A comprehensive autopsy and genetic testing were performed after death, and no congenital diseases or inherited metabolic diseases were found. Given that this case was a sudden infant death without typical symptoms of lactic acidosis and linezolid is often mistakenly considered safer than vancomycin in the treatment of special populations, this paper analyzes and discusses this to draw attention to clinical treatment. More research is needed in the future to fully demonstrate its causal relationship and mechanism of action.

Sudden infant death syndrome "Gray Zone" in newborn with pneumonia.

Sudden infant death syndrome (SIDS) "gray zone" or borderline cases are those in which it is challenging to define whether the pathological findings are sufficiently severe to lead to death. We report a case of a 17-day old male newborn who came to our attention for unexplained death. A complete autopsy was performed, including close examination of the cardiac conduction system. Lungs presented diffuse alveolar damage and interstitial inflammation, the cardiac conduction system showed fetal dispersion, resorptive degeneration, junctional tissue islands and cartilaginous hypermetaplasia of the central fibrous body. The final cause of death was a "gray zone" SIDS. This case report will highlight the intersection of SIDS and pneumonia in newborns, exploring the challenges and controversies surrounding the diagnosis and management of this complex condition.

Physiology during sleep in preterm infants: Implications for increased risk for the sudden infant death syndrome.

Approximately 15 million babies are born preterm (<37 weeks of completed gestation) worldwide annually. Although neonatal and perinatal medicine have contributed to the increased survival rate of preterm newborn infants, premature infants are at increased risk of mortality in the first years of life. Infants born preterm are at four times the risk of Sudden Infant Death Syndrome (SIDS) compared to infants born at term. SIDS is believed to be multifactorial in origin. The Triple Risk hypothesis has been proposed to explain this. The model suggests that when a vulnerable infant, such as one born preterm, is at a critical but unstable developmental period in homeostatic control, death may occur if exposed to an exogenous stressor, such as being placed prone for sleep. The highest risk period is at ages 2-4 months, with 90 % of deaths occurring before 6 months. The final pathway to SIDS is widely believed to involve some combination of immature cardiorespiratory control and a failure of arousal from sleep. This review will focus on the physiological factors which increase the risk for SIDS in preterm infants and how these factors may be identified and potentially lead to effective preventative strategies.

The study of the microbiome in forensic investigations on pediatric deaths.

Background: Sudden infant death syndrome (SIDS) is a tragic and devastating condition whose causes remain largely unknown. Recent studies have shown that the composition of a child's gut flora can play a significant role in the development of SIDS. Methods: This work aims to research those factors that influence the composition of the intestinal flora, the role they have in the development of SIDS and the new strategies for preventing SIDS showing a new interpretation through a detailed review of the literature. The gut in physiological conditions is mainly composed of Bacteroidetes, Firmicutes, Actinobacteria, and Proteobacteria, but when there is the presence of dysbiotic or different microbial communities, the onset of the disease is more likely as an altered microbial community can lead to an interruption of the gut-brain axis and an increased risk of SIDS. Conclusions: All this implies that the composition of the microbiome can be modified to reduce the risk of sudden death in newborns. The results of the literature provide valuable information on the potential role of the intestinal microbiome in SIDS even if not all mechanisms are yet clear, especially in the mechanisms of death. Therefore, it is necessary in cases of SIDS when carrying out an autopsy to also investigate this area; to this end, we suggest a questionnaire to be administered to family members to understand the eating habits of the newborn and the family and integrate with microbiological investigations to explore every possible hypothesis.

A Finnish nationwide register-based study shows a further 50% decline in already low child mortality.

AIM: Child mortality declined significantly in Finland in 1969-2004. We investigated whether the already low mortality rate could still decline from 2005 to 2020. METHODS: This was a nationwide register-based study. The subjects were children under 16 years of age who had resided in Finland between 2005 and 2020. The study population was identified from Finland's Population Information System of the Digital and Population Data Services Agency. Causes of death were obtained from Statistics Finland. Changes in annual overall and cause-specific mortality rates were evaluated. RESULTS: 3685 children (55% boys) under 16 years of age died in Finland in 2005-2020 from 325 causes. Overall annual child mortality declined by 50% (95% confidence interval 37 to 64%) during the study period, from 0.31/1000 in 2005 to 0.16/1000 in 2020. The mortality rate in children under one year of age declined from 3.1/1000 in 2005 to 1.8/1000 in 2020. The deaths from sudden infant death syndrome fell by 84%, congenital malformations by 62%, infectious diseases by 60%, external causes by 52%, and perinatal disorders by 41%. CONCLUSION: Finland's low child mortality further declined over the past two decades. Contributing factors likely include achievements in paediatric research, public health, and clinical practice.

Using Social Vulnerability Indices to Predict Priority Areas for Prevention of Sudden Unexpected Infant Death in Cook County, IL: Cross-Sectional Study.

Background: The incidence of sudden unexpected infant death (SUID) in the United States has persisted at roughly the same level since the mid-2000s, despite intensive prevention efforts around safe sleep. Disparities in outcomes across racial and socioeconomic lines also persist. These disparities are reflected in the spatial distribution of cases across neighborhoods. Strategies for prevention should be targeted precisely in space and time to further reduce SUID and correct disparities. Objective: We sought to aid neighborhood-level prevention efforts by characterizing communities where SUID occurred in Cook County, IL, from 2015 to 2019 and predicting where it would occur in 2021-2025 using a semiautomated, reproducible workflow based on open-source software and data. Methods: This cross-sectional retrospective study queried geocoded medical examiner data from 2015-2019 to identify SUID cases in Cook County, IL, and aggregated them to "communities" as the unit of analysis. We compared demographic factors in communities affected by SUID versus those unaffected using Wilcoxon rank sum statistical testing. We used social vulnerability indicators from 2014 to train a negative binomial prediction model for SUID case counts in each given community for 2015-2019. We applied indicators from 2020 to the trained model to make predictions for 2021-2025. Results: Validation of our query of medical examiner data produced 325 finalized cases with a sensitivity of 95% (95% CI 93%-97%) and a specificity of 98% (95% CI 94%-100%). Case counts at the community level ranged from a minimum of 0 to a maximum of 17. A map of SUID case counts showed clusters of communities in the south and west regions of the county. All communities with the highest case counts were located within Chicago city limits. Communities affected by SUID exhibited lower median proportions of non-Hispanic White residents at 17% versus 60% (P<.001) and higher median proportions of non-Hispanic Black residents at 32% versus 3% (P<.001). Our predictive model showed moderate accuracy when assessed on the training data (Nagelkerke R2=70.2% and RMSE=17.49). It predicted Austin (17 cases), Englewood (14 cases), Auburn Gresham (12 cases), Chicago Lawn (12 cases), and South Shore (11 cases) would have the largest case counts between 2021 and 2025. Conclusions: Sharp racial and socioeconomic disparities in SUID incidence persisted within Cook County from 2015 to 2019. Our predictive model and maps identify precise regions within the county for local health departments to target for intervention. Other jurisdictions can adapt our coding workflows and data sources to predict which of their own communities will be most affected by SUID.

A Simple and Systematic Approach to Qualitative Data Extraction From Social Media for Novice Health Care Researchers: Tutorial.

Social media analyses have become increasingly popular among health care researchers. Social media continues to grow its user base and, when analyzed, offers unique insight into health problems. The process of obtaining data for social media analyses varies greatly and involves ethical considerations. Data extraction is often facilitated by software tools, some of which are open source, while others are costly and therefore not accessible to all researchers. The use of software for data extraction is accompanied by additional challenges related to the uniqueness of social media data. Thus, this paper serves as a tutorial for a simple method of extracting social media data that is accessible to novice health care researchers and public health professionals who are interested in pursuing social media research. The discussed methods were used to extract data from Facebook for a study of maternal perspectives on sudden unexpected infant death.

Death from Failed Protection? An Evolutionary-Developmental Theory of Sudden Infant Death Syndrome.

Sudden infant death syndrome (SIDS) has been mainly described from a risk perspective, with a focus on endogenous, exogenous, and temporal risk factors that can interact to facilitate lethal outcomes. Here we discuss the limitations that this risk-based paradigm may have, using two of the major risk factors for SIDS, prone sleep position and bed-sharing, as examples. Based on a multipronged theoretical model encompassing evolutionary theory, developmental biology, and cultural mismatch theory, we conceptualize the vulnerability to SIDS as an imbalance between current physiologic-regulatory demands and current protective abilities on the part of the infant. From this understanding, SIDS appears as a developmental condition in which competencies relevant to self-protection fail to develop appropriately in the future victims. Since all of the protective resources in question are bound to emerge during normal infant development, we contend that SIDS may reflect an evolutionary mismatch situation-a constellation in which certain modern developmental influences may overextend the child's adaptive (evolutionary) repertoire. We thus argue that SIDS may be better understood if the focus on risk factors is complemented by a deeper appreciation of the protective resources that human infants acquire during their normal development. We extensively analyze this evolutionary-developmental theory against the body of epidemiological and experimental evidence in SIDS research and thereby also address the as-of-yet unresolved question of why breastfeeding may be protective against SIDS.

Dried Blood Spot Postmortem Metabolic Autopsy With Genotype Validation for Sudden Unexpected Deaths in Infancy and Childhood in Hong Kong.

Background Inborn errors of metabolism (IEM) are collectively rare but potentially preventable causes of sudden unexpected death (SUD) in infancy or childhood, and metabolic autopsy serves as the final tool for establishing the diagnosis. We conducted a retrospective review of the metabolic and molecular autopsy on SUD and characterized the biochemical and genetic findings. Methodology A retrospective review of postmortem metabolic investigations (dried blood spot acylcarnitines and amino acid analysis, urine metabolic profiling where available, and next-generation sequencing on a panel of 75 IEM genes) performed for infants and children who presented with SUD between October 2016 and December 2021 with inconclusive autopsy findings or autopsy features suspicious of underlying IEM in our locality was conducted. Clinical and autopsy findings were reviewed for each case. Results A total of 43 infants and children aged between zero days to 10 years at the time of death were referred to the authors' laboratories throughout the study period. One positive case of multiple acyl-CoA dehydrogenase deficiency was diagnosed. Postmortem reference intervals for dried blood spot amino acids and acylcarnitines profile were established based on the results from the remaining patients. Conclusions Our study confirmed the importance of metabolic autopsy and the advantages of incorporating biochemical and genetic testing in this setting.

Added value of postmortem mri in sudden unexpected infant death cases.

We aimed to investigate the potential added value of postmortem MRI (PMMRI) in sudden unexpected infant death (SUID) cases referred to our center between September 2020 and June 2023. Ultimately, 19 SUID cases underwent PMMRI alongside standard autopsy procedures, which included technical examinations such as postmortem CT (PMCT). Four radiologists, two with prior PMMRI experience, provided structured reports following consensus. For each case, the responsible forensic medicine specialist documented the cause of death before and after reviewing the PMMRI report. Additionally, they assessed the overall impact of the PMMRI report and had the opportunity to provide written comments. The results of our study indicate that none of the PMMRI reports altered the prior determined cause of death, which included cases of infection, asphyxia, and sudden infant death syndrome (SIDS). However, we observed a moderate impact in one case and a low impact in 10 cases. The moderate impact arose from the PMMRI report identifying hypoxic-ischemic changes, where histologic examination of the brain was perceived as normal. Conversely, in the 10 cases with a low impact, the PMMRI reports supported the autopsy findings, specifically indicating brain injury and intra-alveolar cellular infiltrates. In conclusion, our study suggests that while PMMRI may not be pivotal in determining the cause of death in SUID cases, it could aid in detecting hypoxic-ischemic changes and reinforcing brain and lung observations. However, distinguishing genuine lung pathology from postmortem changes using PMMRI remains challenging. Further research is warranted to clarify the role of PMMRI in forensic SUID investigations.

Does citing early SIDS research skew contemporary conclusions?

Research on infants who have allegedly succumbed to sudden infant death syndrome (SIDS) has been of variable quality over the years. Even now peer-reviewed papers are being published on cases termed 'SIDS' without autopsies having been performed, despite this being a requirement of the three major definitions for over five decades. Clearly cases used in earlier research studies could not have complied with the requirements of as-yet unpublished definitions/guidelines. For this reason care must be taken in citing initial papers as their results may have been skewed by the presence of non-SIDS cases. This may have particular relevance for meta analyses. Reviewing the literature on substance P and its relationship to SIDS provides an excellent example of how diametrically opposed conclusions were reached at different time points. Early studies on SIDS, and studies that use cases that were classified before the standard NICHD and San Diego definitions, should, therefore, be approached with a degree of scepticism and not cited in contemporary papers or at meetings as they have the potential to confuse rather than clarify.

Early Screening for Long QT Syndrome and Cardiac Anomalies in Infants: A Comprehensive Study.

(1) Background: Sudden Infant Death Syndrome (SIDS) represents sudden and unexplained deaths during the sleep of infants under one year of age, despite thorough investigation. Screening for a prolonged QTc interval, a marker for Long QT Syndrome (LQTS), should be conducted on all newborns to reduce the incidence of SIDS. Neonatal electrocardiograms (ECGs) could identify congenital heart defects (CHDs) early, especially those not detected at birth. Infants with prolonged QTc intervals typically undergo genetic analysis for Long QT Syndrome. (2) Methods: The study involved infants aged 20-40 days, born with no apparent clinical signs of heart disease, with initial ECG screening. Infants with prenatal diagnoses or signs/symptoms of CHDs identified immediately after birth, as well as infants who had previously had an ECG or echocardiogram for other medical reasons, were excluded from the study. We used statistical software (SPSS version 22.0) to analyze the data. (3) Results: Of the 42,200 infants involved, 2245 were enrolled, with 39.9% being males. Following this initial screening, 164 children (37.8% males) with prolonged QTc intervals underwent further evaluation. Out of these 164 children, 27 children were confirmed to have LQTS. However, only 18 children were finally investigated for genetic mutations, and mutations were identified in 11 tests. The most common mutations were LQT1 (54.5%), LQT2 (36.4%), and LQT3 (1 patient). Treatment options included propranolol (39.8%), nadolol (22.2%), inderal (11.1%), metoprolol (11.1%), and no treatment (16.7%). The most common abnormalities were focal right bundle branch block (54.5%), left axis deviation (9.2%), and nonspecific ventricular repolarization abnormalities (7.1%). Multiple anomalies were found in 0.47% of children with focal right bundle branch block. Structural abnormalities were associated with specific features in 267 patients (11.9%), primarily isolated patent foramen ovale (PFO) at 61.4%. (4) Conclusions: This screening approach has demonstrated effectiveness in the early identification of LQTS and other cardiac rhythm anomalies, with additional identification of mutations and/or prolonged QTc intervals in family members. Identifying other ECG abnormalities and congenital heart malformations further enhances the benefits of the screening.

Promoting Safe Sleep: The Role of Doulas in Black Communities.

BACKGROUND: Accidental suffocation and strangulation in bed continues to be a critical issue in Black communities, despite the widespread initiatives to promote safe sleep. Doulas are in an ideal position to promote safe sleep, particularly in hard-to-reach communities that are more distrusting of conventional medical providers. Little is known about their practices and perspectives for putting infants down to rest. This study informs this gap in the literature. PURPOSE: The purpose of this study was to explore doulas' perspectives and practices in the field of putting infants down to sleep. The researchers aimed to determine whether Black caregivers that work with doulas are likely to encounter safe sleep education. METHODS: The researchers used a descriptive approach to inquiry. They conducted three focus groups with a total of 17 Black doulas. The researchers independently and critically reviewed the transcriptions and observation notes from each group to identify codes. They then triangulated the results using Artificial Intelligence-driven tools. FINDINGS: The study found four themes: (1) Individualized Services, (2) Cultural Sensitivity, (3) Negotiating Safety, and (4) Safe Sleep Education. CONCLUSIONS: The study concluded doulas have a commitment to promoting safe sleep. The researchers found that doulas engage in practices that help caregivers to integrate safe sleep practices into their lifestyle and to adapt them to meet their needs. The researchers also documented a desire for more information and instruction on safe sleep among practicing doulas.

Investigating cardiac genetic background in sudden infant death syndrome (SIDS).

Sudden infant death syndrome (SIDS) is still the leading cause of death for newborns in developed countries. The pathophysiological mechanisms have not been fully clarified, but in some of SIDS cases variants of genes associated with inherited cardiac conditions are found. In this study, an analysis of SCD-related genes was performed to determine the prevalence of rare pathogenic (P) or likely pathogenic (LP) variants that could provide an unambiguous explanation for the fatal event. A cohort of 76 SIDS cases underwent Next-Generation Sequencing (NGS) analysis with a custom panel of SCD-related genes. Rare variants were classified according to the guidelines provided by the American College of Medical Genetics and Genomics (ACMG) and the specifications of the ClinGen association. Post-mortem genetic testing identified 50 (65.8%) carriers of at least one variant in SCD genes. 104 rare genetic variants were found, 65.4% in genes encoding structural proteins. Only 4 out of 76 cases (5.3%) hosted at least a P or LP variant found in genes with structural or structural/arrhythmogenic functions (SLC22A5, SCN5A, MYL3and TTN). 99 variants were classified as of uncertain significance (VUS). The difference in the distribution of variants between gene groups by function was not statistically significant (chi square, p = 0,219). Despite this, most of the variants concerned structural genes that were supposed to have a close interaction with ion channels, thus providing an explanation for the arrhythmic event. Segregation analysis, reclassification of VUS variants and identification of new associated genes could clarify the implications of the current findings.

Promoting infant safe sleep practices among neonatal and paediatric nurses through simulation-based training program.

PURPOSE: To evaluate the effect of a Simulation-based training (SBT) program on neonatal and paediatric nurses' knowledge regarding infant safe sleep practices. BACKGROUND: Sudden infant death syndrome (SIDS) presents a major public health concern, preventable through the promotion of optimal safe sleep practices, particularly among neonatal and paediatric nurses. Despite its effectiveness in enhancing nurses' knowledge and clinical skills, SBT is not an adopted training method for nurses in Egypt. DESIGN AND METHODS: A single-group pre- and post-test design involved 57 nurses from Neonatal Intensive Care Unit, Paediatric Intensive Care Unit, and Paediatric In-patient Unit. The study consisted of two stages. In the first stage, knowledge assessment to identify deficiencies. The second stage, researchers developed four SBT scenarios. Two of these scenarios were recorded for training purposes, while the other two were intended for nurses to actively participate in. Data were collected from May 2022 to January 2023. RESULTS: A significant improvement in nurses' knowledge of infant safe sleep practices and SIDS prevention was observed (p = 0.000). Nurses expressed high satisfaction with the training program (mean score 45.035 ± 4.38). CONCLUSION: This study provides evidence that simulation-based training is an effective approach to promoting safe infant sleep practices among neonatal and paediatric nurses. PRACTICE IMPLICATIONS: Integrating SBT programs into nursing education can enhance nurses' knowledge and skills in infant-safe sleep practices, providing a realistic and interactive learning experience.

Implementing a Safe Sleep Shelter and Baby Bundle Kit Distribution Program.

The Georgia Department of Public Health developed the Safe Sleep Shelter Program to expand Georgia Safe to Sleep campaign efforts. The program focused on engaging with housing support agencies, homeless shelters, and domestic violence shelters. The program offered a menu of resources that agencies could choose from, including portable cribs for agency use and distribution to families, safe sleep education for staff, assistance with creating/updating agency safe sleep policies, and Baby Bundle Safe Sleep kits with education and resources for families. The program showed promising results: 44 agencies across the state applied, serving an estimated 20,950 individuals annually. Agencies expressed strong interest in expanding safe sleep education and resources for the families they served. Most agencies reported that the program filled gaps in services, including having enough cribs to meet demand and limited safe sleep education and resources. Agencies reported that parents appreciated the cribs and Baby Bundle Safe Sleep kits as most did not have money to purchase an infant sleep surface. Agencies reported that the resources provided new information to infant parents, facilitated discussion, and reinforced safe sleep messaging. Evaluation challenges included difficulties collecting distribution data and a low response rate for parent surveys. Implications are discussed for others interested in implementing such a program, including to develop processes for communicating updated recommendations, leverage existing relationships to engage additional agencies, evaluate efforts to refine program components, and consider strategies to increase parent survey response rates.

The role of alcohol in infant cosleeping deaths.

The well-established epidemiological and neuropathological differences between infants who die alone compared to those in shared sleeping environments indicate that these cohorts have differences. Risk factors in both situations depend on both exogenous and endogenous factors. Although parental consumption of alcohol continues to be cited as a risk factor for sudden infant death syndrome (SIDS) it is difficult to understand how a substance which impairs parental consciousness rather than infant arousal could contribute to SIDS. Surely a more logical mechanism to explain these deaths would be suffocation by a sedated adult rather than evoking predisposing factors for SIDS.

Correlation of gestational age and age at death in sudden infant death syndrome: another pointer to the role of critical developmental period?

BACKGROUND: Filiano and Kinney proposed a triple-risk model for the sudden infant death syndrome (SIDS) that involves the intersection of three risks: (1) a vulnerable infant, (2) a critical developmental period in homeostatic control, and (3) an exogenous stressor(s). The primary evidence for the role of a critical developmental period in SIDS etiology is the peak of cases around the third month of life. Independently, several studies pointed to correlation between gestational age and age at death in SIDS, but used that to assess the SIDS risk for preterm infants, ignoring further ramifications. METHODS: We did a detailed analysis of CDC data spanning over two decades (1983-2011). We focused not only on the correlation between two age variables (gestational and age at death), but also on the possibility of misdiagnosis. Also, we attempted to account for potential biases in the data induced by the ICD-9/ICD-190 transition or the "Back to Sleep" campaign. RESULTS: The peak of deaths in the third month of life, that was the main argument for the role of the critical development period, wasn't unique to SIDS. However, we confirmed an almost linear and negative correlation between gestational age and the week of death due to SIDS. This pattern (slope of correlation < 0 and significance of correlation p < 0.05) is characteristic of SIDS among all diseases analyzed in the study. CONCLUSIONS: We interpret the results as the evidence of the role of the critical development period in SIDS etiology. Possibly more attention in the future research should be put to theories that are based on homeostatic control.

Prenatal and postnatal factors associated with sudden infant death syndrome: an umbrella review of meta-analyses.

BACKGROUND: Comprehensive quantitative evidence on the risk and protective factors for sudden infant death syndrome (SIDS) effects is lacking. We investigated the risk and protective factors related to SIDS. METHODS: We conducted an umbrella review of meta-analyses of observational and interventional studies assessing SIDS-related factors. PubMed/MEDLINE, Embase, EBSCO, and Google Scholar were searched from inception until January 18, 2023. Data extraction, quality assessment, and certainty of evidence were assessed by using A Measurement Tool Assessment Systematic Reviews 2 following PRISMA guidelines. According to observational evidence, credibility was graded and classified by class and quality of evidence (CE; convincing, highly suggestive, suggestive, weak, or not significant). Our study protocol was registered with PROSPERO (CRD42023458696). The risk and protective factors related to SIDS are presented as equivalent odds ratios (eORs). RESULTS: We identified eight original meta-analyses, including 152 original articles, covering 12 unique risk and protective factors for SIDS across 21 countries/regions and five continents. Several risk factors, including prenatal drug exposure [eOR = 7.84 (95% CI = 4.81-12.79), CE = highly suggestive], prenatal opioid exposure [9.55 (95% CI = 4.87-18.72), CE = suggestive], prenatal methadone exposure [9.52 (95% CI = 3.34-27.10), CE = weak], prenatal cocaine exposure [4.38 (95% CI = 1.95-9.86), CE = weak], prenatal maternal smoking [2.25 (95% CI = 1.95-2.60), CE = highly suggestive], postnatal maternal smoking [1.97 (95% CI = 1.75-2.22), CE = weak], bed sharing [2.89 (95% CI = 1.81-4.60), CE = weak], and infants found with heads covered by bedclothes after last sleep [11.01 (95% CI = 5.40-22.45), CE = suggestive], were identified. On the other hand, three protective factors, namely, breastfeeding [0.57 (95% CI = 0.39-0.83), CE = non-significant], supine sleeping position [0.48 (95% CI = 0.37-0.63), CE = suggestive], and pacifier use [0.44 (95% CI = 0.30-0.65), CE = weak], were also identified. CONCLUSIONS: Based on the evidence, we propose several risk and protective factors for SIDS. This study suggests the need for further studies on SIDS-related factors supported by weak credibility, no association, or a lack of adequate research.