Respiratory syncytial virus (RSV) remains a leading cause of lower respiratory tract infection and hospitalization in infancy worldwide. Historically, prevention relied on monthly palivizumab administration for selected high-risk infants, despite evidence that a substantial proportion of severe RSV disease occurs in previously healthy term infants. The recent introduction of maternal RSV vaccination and long-acting monoclonal antibodies has transformed the prevention landscape. Clesrovimab (MK-1654; Enflonsia) is a long-acting monoclonal antibody designed to provide season-long protection following a single dose. In the pivotal phase 2b/3 CLEVER trial, clesrovimab reduced RSV-associated medically attended lower respiratory tract infection and hospitalization among infants entering their first RSV season, with a safety profile comparable to placebo. The absolute risk reduction for RSV hospitalization was approximately 1.9 percentage points, corresponding to an estimated number needed to treat of 51 infants over 150 days of follow-up. In this policy-focused clinical perspective informed by a narrative review, we examine the emerging role of clesrovimab within contemporary RSV prevention strategies. We discuss efficacy, safety, implementation challenges, economic considerations, and remaining evidence gaps, including the absence of head-to-head comparisons with nirsevimab, limited post-licensure data, and uncertainties regarding long-term effectiveness and affordability. Future success will depend not only on efficacy but also on equitable access, sustainable implementation, and ongoing surveillance. CLINICAL RELEVANCE: The emergence of long-acting monoclonal antibodies has expanded preventive options for infants at risk of RSV-associated lower respiratory tract disease during their first RSV season. For clinicians, the key shift is that RSV prevention is increasingly being considered within a broader population-health framework rather than solely as a risk-based intervention for selected high-risk groups. Clesrovimab, alongside nirsevimab and maternal RSV vaccination, represents one component of an evolving prevention strategy aimed at reducing RSV-associated morbidity and hospitalization during early infancy. From a practical perspective, successful implementation will depend on timely administration, integration into neonatal discharge planning and well-child care pathways, and coordination with maternal immunization programs. As RSV prevention moves into routine clinical practice, equitable access, sustained coverage, affordability, and ongoing post-licensure surveillance will be as important as efficacy demonstrated in clinical trials. Ultimately, the greatest reductions in RSV-related hospitalization are likely to result from effective delivery of preventive strategies to the infants at highest risk during the RSV season. KEY POINTS: RSV continues to impose a substantial burden on infants worldwide despite decades of clinical recognition and supportive care. Most RSV hospitalizations occur in infants without traditional high-risk conditions, highlighting the limitations of selective prophylaxis strategies. Long-acting monoclonal antibodies and maternal RSV vaccination have transformed prevention from a niche intervention into a population-level public health strategy. Clesrovimab demonstrated significant protection against RSV-associated medically attended lower respiratory tract infection and hospitalization in healthy infants entering their first RSV season. Future research should focus on comparative effectiveness, cost-effectiveness, long-term safety, implementation in low-resource settings, and optimization of delivery strategies to maximize population impact.

Intrauterine growth restriction (IUGR) is associated with long-term neurobehavioural alterations. This scoping review mapped evidence on neurobehavioural outcomes following IUGR in term-born humans and preclinical animal models. Following PRISMA-ScR guidelines, six databases were searched from January 1985 to February 2025. Clinical studies were included if they assessed motor, cognitive, or anxiety outcomes in adolescents or young adults born at term with IUGR, small for gestational age (SGA), or low birth weight (LBW). Preclinical studies were included if IUGR was induced via placental insufficiency and behavioural outcomes evaluated at equivalent developmental stages. Data were charted and synthesised narratively. Twenty-eight studies (16 clinical, 12 preclinical) were included. Motor and cognitive outcomes were frequently assessed; anxiety-related behaviours were examined in fewer clinical studies despite frequent assessment in preclinical models. Motor coordination and memory outcomes were reported in both human and animal studies, though inconsistent diagnostic criteria and heterogeneous outcome measures limited cross-species comparisons. Most clinical studies classified participants as SGA or LBW; only two applied antenatal criteria to confirm IUGR. This evidence map reveals broad coverage of motor and cognitive domains but limited examination of anxiety outcomes in clinical populations. Standardising diagnostics and aligning behavioural assessments across species are priorities for translational comparability. This review was originally registered in PROSPERO (CRD42020197400) as a systematic review. The protocol has since been adapted to a scoping review framework; the PROSPERO registration reflects the original systematic review methodology, as PROSPERO does not accept scoping review registration. The adapted methodology is described in the Methods section below. Available from: https://www.crd.york.ac.uk/PROSPERO/view/CRD42020197400 . IMPACT: This is the first scoping review to map both clinical and preclinical evidence on neurobehavioural outcomes following IUGR beyond childhood into adolescence and young adulthood. Motor and cognitive outcomes are widely studied across species, but anxiety domains remain under-examined, particularly in human cohorts. Diagnostic inconsistency (SGA/LBW used as proxies for IUGR) and narrow species representation in preclinical studies are major barriers to translational alignment.

Infants born at 22-23 weeks' gestation represent the limits of viability with substantial international variation in outcomes. Japan has consistently reported some of the highest survival rates; however, the underlying healthcare systems and clinical practices have not been comprehensively synthesized. This review summarizes Japan's national experience using data from a nationwide network database, epidemiologic studies, clinical practice surveys, and international comparisons. Survival at discharge is approximately 60% and 80% for infants born at 22 and 23 weeks' gestation, respectively, with relatively low rates of severe intraventricular hemorrhage and necrotizing enterocolitis. Key healthcare system features include regionalized perinatal care promoting antenatal maternal transfer, a nationwide clinical network for benchmarking, and universal health insurance. Clinical practice is characterized by active resuscitation and meticulous, individualized, pathophysiology-based management, including invasive respiratory support, echocardiography-guided hemodynamic management, intensive neuroprotection, and specialized nursing care. The effectiveness of these practices remains uncertain, and further research is needed. Continuous outcome monitoring and quality improvement are essential to refine context-specific strategies. IMPACT: This review provides the comprehensive synthesis of Japan's national experience in the care of infants born at 22-23 weeks' gestation, integrating outcomes with healthcare system structures and clinical practices. It identifies key system-level and clinical factors-such as regionalized perinatal care, nationwide data-driven quality improvement, and pathophysiology-based management-that may contribute to Japan's high survival rates and relatively low morbidity. It highlights the importance of integrated "package-of-care" approaches and continuous outcome monitoring, offering insights that may inform strategies to improve outcomes at the limits of viability globally.

Screen use among U.S. adolescents is ubiquitous. There is a lack of information on sociodemographic differences in time-specific usage patterns using objective measures of screen use. We examined sociodemographic differences in objectively measured time-specific smartphone use among a national, diverse sample of 233 U.S. adolescents (13-18 y; M ± SD = 15.9 ± 1.3; 46% female, 6% other gender). Participants self-reported sociodemographic characteristics, then installed a passive sensing meter on their smartphones for ≥3 days to monitor smartphone activity, including application use, duration, and timing. Multiple linear regression examined differences in smartphone usage patterns by sociodemographic factors. In fully adjusted analyses, teens who were LGBTQIA+ versus non-LGBTQIA+ (24 hr use: +0.94 h/day; evening use, 20:00-22:59: +0.22 h/evening; nighttime use, 23:00-5:59: +0.39 h/night), with less parental education (nighttime use: +0.37 h/night), and with no parental screen use limits (24 hr use: +1.24 h/day; evening use: +0.24 h/evening; nighttime use: +0.34 h/night) had greater smartphone use. This national study demonstrated that LGBTQIA+ adolescents and those with lower parental education may be at heightened risk for excessive screen use with possible impacts on wellbeing. Parental restrictions on screen use are potentially modifiable markers of youth smartphone use. IMPACT: The present study examined levels of objectively measured smartphone use among a national, diverse sample of adolescents. Our findings have broad public health implications for American adolescents. We demonstrated that adolescents who were LGBTQIA+ and those with lower parental education had higher levels of smartphone use, with potential for both beneficial and harmful impacts on health and well-being. Moreover, parental restrictions on screen use are important potential targets to help reduce smartphone use among U.S. youth.