Delivery Strategies Supporting School-Age Child Health: A Systematic Review.

CONTEXT: School-aged children (SAC; 5-9 years) remain understudied in global efforts to examine intervention effectiveness and scale up evidence-based interventions. OBJECTIVE: This review summarizes the available evidence describing the effectiveness of key strategies to deliver school-age interventions. DATA SOURCES: We searched Medline, PsycINFO, Campbell Collaboration, and The Cochrane Library during November 2020. STUDY SELECTION: Systematic reviews and meta-analyses that: target SAC, examine effective delivery of well-established interventions, focus on low- and middle-income countries (LMICs), were published after 2010, and focus on generalizable, rather than special, populations. DATA EXTRACTION: Two reviewers conducted title and abstract screening, full-text screening, data extraction, and quality assessments. RESULTS: Sixty reviews met the selection criteria, with 35 containing evidence from LMICs. The outcomes assessed and the reported effectiveness of interventions varied within and across delivery strategies. Overall, community, school, and financial strategies improved several child health outcomes. The greatest evidence was found for the use of community-based interventions to improve infectious disease outcomes, such as malaria control and prevention. School-based interventions improved child development and infectious disease-related outcomes. Financial strategies improved school enrollment, food security, and dietary diversity. LIMITATIONS: Relatively few LMIC studies examined facility, digital, and self-management strategies. Additionally, we found considerable heterogeneity within and across delivery strategies and review authors reported methodological limitations within the studies. CONCLUSIONS: Despite limited research, available information suggests community-based strategies can be effective for the introduction of a range of interventions to support healthy growth and development in SAC. These also have the potential to reduce disparities and reach at-risk and marginalized populations.

Prevention and Management of High-Burden Noncommunicable Diseases in School-Age Children: A Systematic Review.

BACKGROUND AND OBJECTIVES: Noncommunicable diseases (NCDs) are chronic conditions requiring health care, education, social and community services, addressing prevention, treatment, and management. This review aimed to summarize and synthesize the available evidence on interventions from systematic reviews of high-burden NCDs and risk factors among school-aged children. METHODS: The following databases were used for this research: Medline, Embase, The Cochrane Library, and the Campbell library. The search dates were from 2000 to 2021. We included systematic reviews that synthesized studies to evaluate intervention effectiveness in children aged 5 to 19 years globally. Two reviewers independently extracted data and assessed methodological quality of included reviews using the AMSTAR 2 tool. RESULTS: Fifty studies were included. Asthma had the highest number of eligible reviews (n = 19). Of the reviews reporting the delivery platform, 27% (n = 16) reported outpatient settings, 13% (n = 8) home and community-based respectively, and 8% (n = 5) school-based platforms. Included reviews primarily (69%) reported high-income country data. This may limit the results' generalizability for school-aged children and adolescents in low- and middle- income countries. CONCLUSIONS: School-aged children and adolescents affected by NCDs require access to quality care, treatment, and support to effectively manage their diseases into adulthood. Strengthening research and the capacity of countries, especially low- and middle- income countries, for early screening, risk education and management of disease are crucial for NCD prevention and control.

Interventions for Health and Well-Being in School-Aged Children and Adolescents: A Way Forward.

The health and well-being of school-aged children has received little attention compared with younger children aged < 5 years and adolescents. In this final article in a supplement of reviews that have assessed the effectiveness of interventions for school-aged children across a variety of health-related domains (including infectious diseases, noncommunicable diseases, healthy lifestyle, mental health, unintentional injuries, and sexual and reproductive health), we summarize the main findings and offer a way forward for future research, policy, and implementation. We complement this evidence base on interventions with a summary of the literature related to enabling policies and intersectoral actions supporting school-aged child health. The school represents an important platform for both the delivery of preventive interventions and the collection of data related to child health and academic achievement, and several frameworks exist that help to facilitate the creation of a health-promoting environment at school.

Mental Health and Positive Development Prevention Interventions: Overview of Systematic Reviews.

CONTEXT: Previous reviews of mental health interventions have focused on adolescents (10-19 years), with a paucity of comprehensive evidence syntheses on preventive interventions for school-aged children (5-10 years). OBJECTIVE: To summarize and synthesize the available evidence from systematic reviews of mental health and positive development interventions for children aged 5-14.9 years in both high-income (HIC) and low- and middle-income countries (LMIC), with a focus on preventive and promotive strategies. DATA SOURCES: This overview includes all relevant reviews from OVID Medline, The Cochrane Library, and Campbell Systematic Reviews through December 2020. STUDY SELECTION: We included systematic reviews that synthesized empirical studies using experimental or quasi-experimental designs to evaluate the effectiveness of interventions in children aged 5-14.9 years. DATA EXTRACTION: Data extraction and quality assessment were completed independently and in duplicate by two review authors. The AMSTAR2 tool was used to assess methodological quality. RESULTS: We included 162 reviews. The greatest evidence was found in support of school-based universal and anti-bullying interventions in predominantly HIC. Moderate evidence was found for the use of substance abuse prevention, and early learning and positive development interventions in mixed settings. In LMIC-only contexts, the most promising evidence was found for positive youth development programs. LIMITATIONS: The review was primarily limited by paucity of high-quality research due to methodological issues and high heterogeneity. CONCLUSIONS: This overview of reviews highlights the need for further research to consolidate findings and understand the specific criteria involved in creating positive mental health and development outcomes from the various interventions considered.

Interventions to Promote Physical Activity and Healthy Digital Media Use in Children and Adolescents: A Systematic Review.

OBJECTIVES: To identify effective interventions that promote healthy screen time use and reduce sedentary behavior in school-age children and adolescents (SACA) in all settings, over the last 20 years. METHODS: Searches were conducted from 2000 until March 2021 using PubMed, Embase, Medline, PsycINFO, Ovid SP, The Cochrane Library, Cochrane Central Register of Controlled Trials, Cochrane Methodology Register, and the WHO regional databases, including Google Scholar and reference lists of relevant articles and reviews. Randomized-controlled trials and quasi-experimental studies assessing interventions to reduce sedentary behaviors and screen time in healthy SACA (aged 5-19.9 years) globally. Data were extracted by 2 reviewers and where possible, pooled with a random-effects model. RESULTS: The review included 51 studies, of which 23 were included in meta-analyses with 16 418 children and adolescents. Nondigital randomized-controlled trials reported a small, but significant reduction of TV-specific screen time (minutes per day) (mean difference, -12.46; 95% confidence interval, -20.82 to -4.10; moderate quality of evidence) and sedentary behavior (minutes per day) (mean difference, -3.86; 95% confidence interval, -6.30 to -1.41; participants = 8920; studies = 8; P = .002; moderate quality of evidence) as compared with control groups. For quasi-experimental studies, nondigital interventions may make little or no difference on screen time (minutes per day) or sedentary behavior (minutes per day), given the high uncertainty of evidence. Most studies were conducted in a high-income country. Generalizability of results to low- and middle- income countries remain limited. CONCLUSIONS: Public health policies and programs will be necessary to reduce excessive sedentary behavior and screen time, especially in the post-coronavirus disease 2019 reality.

Digital Interventions for Universal Health Promotion in Children and Adolescents: A Systematic Review.

BACKGROUND AND OBJECTIVES: Digital media has been used mostly to deliver clinical treatments and therapies; however limited evidence evaluates digital interventions for health promotion. The objective of this review is to identify digital interventions for universal health promotion in school-aged children and adolescents globally. METHODS: Eligible articles were searched in PubMed, Embase, Medline, Ovid SP, The Cochrane Library, Cochrane Central Register of Controlled Trials, WHO regional databases, Google Scholar, and reference lists from 2000 to March 2021. Randomized controlled trials and quasi-experimental studies evaluating interventions that promote health in school-aged children and adolescents (5-19.9 years) were included. Methods were conducted in duplicate. Where possible, data were pooled with a random-effects model. RESULTS: Seventy-four studies were included (46 998 participants), of which 37 were meta-analyzed (19 312 participants). Interventions increased fruit and vegetable consumption (servings per day) (mean difference [MD] 0.63, 95% confidence interval [CI] 0.21 to 1.04; studies = 6; P = .003; high quality of evidence), and probably reduced sedentary behavior (MD -19.62, 95% CI -36.60 to -2.65; studies = 6; P = .02; moderate quality of evidence), and body fat percentage (MD -0.35%, 95% CI -0.63 to -0.06; studies = 5; P = .02; low quality of evidence). The majority of studies were conducted in high-income countries and significant heterogeneity in design and methodology limit generalizability of results. CONCLUSIONS: There is great potential in digital platforms for universal health promotion; however, more robust methods and study designs are necessitated. Continued research should assess factors that limit research and program implementation in low- to middle-income countries.

Health and development from preconception to 20 years of age and human capital.

Optimal health and development from preconception to adulthood are crucial for human flourishing and the formation of human capital. The Nurturing Care Framework, as adapted to age 20 years, conceptualises the major influences during periods of development from preconception, through pregnancy, childhood, and adolescence that affect human capital. In addition to mortality in children younger than 5 years, stillbirths and deaths in 5-19-year-olds are important to consider. The global rate of mortality in individuals younger than 20 years has declined substantially since 2000, yet in 2019 an estimated 8·6 million deaths occurred between 28 weeks of gestation and 20 years of age, with more than half of deaths, including stillbirths, occurring before 28 days of age. The 1000 days from conception to 2 years of age are especially influential for human capital. The prevalence of low birthweight is high in sub-Saharan Africa and even higher in south Asia. Growth faltering, especially from birth to 2 years, occurs in most world regions, whereas overweight increases in many regions from the preprimary school period through adolescence. Analyses of cohort data show that growth trajectories in early years of life are strong determinants of nutritional outcomes in adulthood. The accrual of knowledge and skills is affected by health, nutrition, and home resources in early childhood and by educational opportunities in older children and adolescents. Linear growth in the first 2 years of life better predicts intelligence quotients in adults than increases in height in older children and adolescents. Learning-adjusted years of schooling range from about 4 years in sub-Saharan Africa to about 11 years in high-income countries. Human capital depends on children and adolescents surviving, thriving, and learning until adulthood.

What can work and how? An overview of evidence-based interventions and delivery strategies to support health and human development from before conception to 20 years.

Progress has been made globally in improving the coverage of key maternal, newborn, and early childhood interventions in low-income and middle-income countries, which has contributed to a decrease in child mortality and morbidity. However, inequities remain, and many children and adolescents are still not covered by life-saving and nurturing care interventions, despite their relatively low costs and high cost-effectiveness. This Series paper builds on a large body of work from the past two decades on evidence-based interventions and packages of care for survival, strategies for delivery, and platforms to reach the most vulnerable. We review the current evidence base on the effectiveness of a variety of essential and emerging interventions that can be delivered from before conception until age 20 years to help children and adolescents not only survive into adulthood, but also to grow and develop optimally, support their wellbeing, and help them reach their full developmental potential. Although scaling up evidence-based interventions in children younger than 5 years might have the greatest effect on reducing child mortality rates, we highlight interventions and evidence gaps for school-age children (5-9 years) and the transition from childhood to adolescence (10-19 years), including interventions to support mental health and positive development, and address unintentional injuries, neglected tropical diseases, and non-communicable diseases.

Improving health and social systems for all children in LMICs: structural innovations to deliver high-quality services.

Despite health gains over the past 30 years, children and adolescents are not reaching their health potential in many low-income and middle-income countries (LMICs). In addition to health systems, social systems, such as schools, communities, families, and digital platforms, can be used to promote health. We did a targeted literature review of how well health and social systems are meeting the needs of children in LMICs using the framework of The Lancet Global Health Commission on high-quality health systems and we reviewed evidence for structural reforms in health and social sectors. We found that quality of services for children is substandard across both health and social systems. Health systems have deficits in care competence (eg, diagnosis and management), system competence (eg, timeliness, continuity, and referral), user experience (eg, respect and usability), service provision for common and serious conditions (eg, cancer, trauma, and mental health), and service offerings for adolescents. Education and social services for child health are limited by low funding and poor coordination with other sectors. Structural reforms are more likely to improve service quality substantially and at scale than are micro-level efforts. Promising approaches include governing for quality (eg, leadership, expert management, and learning systems), redesigning service delivery to maximise outcomes, and empowering families to better care for children and to demand quality care from health and social systems. Additional research is needed on health needs across the life course, health system performance for children and families, and large-scale evaluation of promising health and social programmes.

Stunting in childhood: an overview of global burden, trends, determinants, and drivers of decline.

BACKGROUND: Progress has been made worldwide in reducing chronic undernutrition and rates of linear growth stunting in children under 5 y of age, although rates still remain high in many regions. Policies, programs, and interventions supporting maternal and child health and nutrition have the potential to improve child growth and development. OBJECTIVE: This article synthesizes the available global evidence on the drivers of national declines in stunting prevalence and compares the relative effect of major drivers of stunting decline between countries. METHODS: We conducted a systematic review of published peer-reviewed and gray literature analyzing the relation between changes in key determinants of child linear growth and contemporaneous changes in linear growth outcomes over time. RESULTS: Among the basic determinants of stunting assessed within regression-decomposition analyses, improvement in asset index score was a consistent and strong driver of improved linear growth outcomes. Increased parental education was also a strong predictor of improved child growth. Of the underlying determinants of stunting, reduced rates of open defecation, improved sanitation infrastructure, and improved access to key maternal health services, including optimal antenatal care and delivery in a health facility or with a skilled birth attendant, all accounted for substantially improved child growth, although the magnitude of variation explained by each differed substantially between countries. At the immediate level, changes in several maternal characteristics predicted modest stunting reductions, including parity, interpregnancy interval, and maternal height. CONCLUSIONS: Unique sets of stunting determinants predicted stunting reduction within countries that have reduced stunting. Several common drivers emerge at the basic, underlying, and immediate levels, including improvements in maternal and paternal education, household socioeconomic status, sanitation conditions, maternal health services access, and family planning. Further data collection and in-depth mixed-methods research are required to strengthen recommendations for those countries where the stunting burden remains unacceptably high.

Drivers of stunting reduction in Peru: a country case study.

BACKGROUND: Peru reduced its under-5 child stunting prevalence notably from 31.3% in 2000 to 13.1% in 2016. OBJECTIVES: We aimed to study factors and key enablers of child stunting reduction in Peru from 2000-2016. METHODS: Demographic and Health Surveys were used to conduct descriptive analyses [height-for-age z scores (HAZ) means and distributions, equity analysis, predicted child growth curves through polynomial regressions] and advanced regression analyses. An ecological (at department level) multilevel regression analysis was conducted to identify the major predictors of stunting decline from 2000 to 2016, and Oaxaca-Blinder decomposition was conducted to identify the relative contribution of each factor to child HAZ change. A systematic literature review, policy and program analysis, and interviews with relevant stakeholders were conducted to understand key drivers of stunting decline in Peru. RESULTS: The distribution of HAZ scores showed a slight rightward shift from 2000 to 2007/2008, and a greater shift from 2007/2008 to 2016. Stunting reduction was higher in the lowest wealth quintile, in rural areas, and among children with the least educated mothers. Decomposing predicted changes showed that the most important factors were increased maternal BMI and maternal height, improved maternal and newborn health care, increased parental education, migration to urban areas, and reduced fertility. Key drivers included the advocacy role of civil society and political leadership around poverty and stunting reduction since the early 2000s. Key enablers included the economic growth and the consolidation of democracy since the early 2000s, and the acknowledgement that stunting reduction needs much more than food supplementation. CONCLUSIONS: Peru reduced child stunting owing to improved socioeconomic determinants, sustained implementation of out-of-health-sector and within-health-sector changes, and implementation of health interventions. These efforts were driven through a multisectoral approach, strong civil society advocacy, and keen political leadership. Peru's experience offers useful lessons on how to tackle the problem of stunting under differing scenarios, with the participation of multiple sectors.

Understanding multifactorial drivers of child stunting reduction in Exemplar countries: a mixed-methods approach.

BACKGROUND: Several countries have notably reduced childhood stunting relative to economic growth over the past 15-20 y. The Exemplars in Stunting Reduction project, or "Exemplars," studies success factors among these countries with a lens toward replicability. OBJECTIVES: This paper details the standardized mixed-methods framework for studying determinants of childhood stunting reduction applied in Exemplars studies. METHODS: An expert technical advisory group (TAG), criteria for identifying Exemplar countries, evidence-based frameworks, mixed methodologies (quantitative, qualitative, policy, literature review), effective research partnerships, case study process and timeline, and data triangulation and corroboration are presented. RESULTS: Experts in health, nutrition, and evaluation methods were selected at the study outset to provide technical support to all phases of research (TAG). Exemplar countries were selected by the TAG, who considered quantitative data (e.g., annual rates of stunting change compared with economic growth, country population size) and qualitative insights (e.g., logistics of country work, political stability). Experienced country research partners were selected and an inception meeting with stakeholder consultations was held to launch research and garner support. Evidence-based conceptual frameworks underpinned all Exemplars research activities. A systematic review of published peer-reviewed and grey literature was undertaken, along with in-depth policy and program analysis of nutrition-specific and -sensitive investments. Both descriptive and advanced quantitative analysis was undertaken (e.g., equity analyses, difference-in-difference regression, Oaxaca-Blinder decomposition). Qualitative data collection using in-depth interviews and focus groups was conducted with national and community stakeholders (i.e., child care workers and mothers) to understand country experiences. The case study process was iterative, and all research outputs were triangulated to develop the stunting reduction narrative for each country. Findings were shared with country experts for weigh-in and corroboration through dissemination events. CONCLUSIONS: Exemplars research uses a mixed-methods framework for studying positive outliers that can be applied across diverse health and development outcomes.

How countries can reduce child stunting at scale: lessons from exemplar countries.

BACKGROUND: Child stunting and linear growth faltering have declined over the past few decades and several countries have made exemplary progress. OBJECTIVES: To synthesize findings from mixed methods studies of exemplar countries to provide guidance on how to accelerate reduction in child stunting. METHODS: We did a qualitative and quantitative synthesis of findings from existing literature and 5 exemplar country studies (Nepal, Ethiopia, Peru, Kyrgyz Republic, Senegal). Methodology included 4 broad research activities: 1) a series of descriptive analyses of cross-sectional data from demographic and health surveys and multiple indicator cluster surveys; 2) multivariable analysis of quantitative drivers of change in linear growth; 3) interviews and focus groups with national experts and community stakeholders and mothers; and 4) a review of policy and program evolution related to nutrition. RESULTS: Several countries have dramatically reduced child stunting prevalence, with or without closing geographical, economic, and other population inequalities. Countries made progress through interventions from within and outside the health sector, and despite significant heterogeneity and differences in context, contributions were comparable from health and nutrition sectors (40% of change) and other sectors (50%), previously called nutrition-specific and -sensitive strategies. Improvements in maternal education, maternal nutrition, maternal and newborn care, and reductions in fertility/reduced interpregnancy intervals were strong contributors to change. A roadmap to reducing child stunting at scale includes several steps related to diagnostics, stakeholder consultations, and implementing direct and indirect nutrition interventions related to the health sector and nonhealth sector . CONCLUSIONS: Our results show that child stunting reduction is possible even in diverse and challenging contexts. We propose that our framework of organizing nutrition interventions as direct/indirect and inside/outside the health sector should be considered when mapping causal pathways of child stunting and planning interventions and strategies to accelerate stunting reduction to achieve the 2030 Sustainable Development Goals.

Drivers of stunting reduction in the Kyrgyz Republic: A country case study.

BACKGROUND: Chronic malnutrition among infants and children continues to represent a global public health concern. The Kyrgyz Republic has achieved rapid declines in stunting over the last 20 y, despite modest increases in gross domestic product per capita. OBJECTIVE: This study aimed to conduct a systematic, in-depth assessment of national, community, household, and individual drivers of nutrition change and stunting reduction, as well as nutrition-specific and -sensitive policies and programs, in the Kyrgyz Republic. METHODS: This mixed methods study employed 4 inquiry methods, including: 1) a systematic scoping literature review; 2) retrospective quantitative data analyses, including linear regression multivariable hierarchical modeling, difference-in-difference analysis, and Oaxaca-Blinder decomposition; 3) qualitative data collection and analysis; and 4) analysis of key nutrition-specific and -sensitive policies and programs. RESULTS: Stunting prevalence has decreased in the Kyrgyz Republic, however, subnational variations and inequities persist. Child growth Victora curves show improvements in height-for-age z-scores (HAZ) for children in the Kyrgyz Republic between 1997 and 2014, indicating increased intrauterine growth and population health improvements. The decomposition analysis explained 88.9% (0.637 SD increase) of the predicted change in HAZ for children under 3 y (1997-2012). Key factors included poverty (61%), maternal nutrition (14%), paternal education (6%), fertility (6%), maternal age (3%), and wealth accumulation (2%). Qualitative analysis revealed poverty reduction, increased migration and remittances, food security, and maternal nutrition as key drivers of stunting decline. Systematic scoping literature review findings supported quantitative and qualitative results, and indicated that land reforms and improved food security represented important factors. Key nutrition-specific and -sensitive policies and programs implemented involved breastfeeding promotion, social protection schemes, and land and health sector reforms. CONCLUSIONS: Improvements in stunting were achieved amidst political and economic changes. Multilevel enablers, including poverty reduction, improved food security, and introduction of land and health reforms have contributed to improvements in health, nutrition, and stunting among children in the Kyrgyz Republic.

Water, sanitation and hygiene interventions for acute childhood diarrhea: a systematic review to provide estimates for the Lives Saved Tool.

BACKGROUND: In the Sustainable Development Goals (SDGs) era, there is growing recognition of the responsibilities of non-health sectors in improving the health of children. Interventions to improve access to clean water, sanitation facilities, and hygiene behaviours (WASH) represent key opportunities to improve child health and well-being by preventing the spread of infectious diseases and improving nutritional status. METHODS: We conducted a systematic review of studies evaluating the effects of WASH interventions on childhood diarrhea in children 0-5 years old. Searches were run up to September 2016. We screened the titles and abstracts of retrieved articles, followed by screening of the full-text reports of relevant studies. We abstracted study characteristics and quantitative data, and assessed study quality. Meta-analyses were performed for similar intervention and outcome pairs. RESULTS: Pooled analyses showed diarrhea risk reductions from the following interventions: point-of-use water filtration (pooled risk ratio (RR): 0.47, 95% confidence interval (CI): 0.36-0.62), point-of-use water disinfection (pooled RR: 0.69, 95% CI: 0.60-0.79), and hygiene education with soap provision (pooled RR: 0.73, 95% CI: 0.57-0.94). Quality ratings were low or very low for most studies, and heterogeneity was high in pooled analyses. Improvements to the water supply and water disinfection at source did not show significant effects on diarrhea risk, nor did the one eligible study examining the effect of latrine construction. CONCLUSIONS: Various WASH interventions show diarrhea risk reductions between 27% and 53% in children 0-5 years old, depending on intervention type, providing ample evidence to support the scale-up of WASH in low and middle-income countries (LMICs). Due to the overall low quality of the evidence and high heterogeneity, further research is required to accurately estimate the magnitude of the effects of these interventions in different contexts.

Promoting Early Child Development With Interventions in Health and Nutrition: A Systematic Review.

CONTEXT: Although effective health and nutrition interventions for reducing child mortality and morbidity exist, direct evidence of effects on cognitive, motor, and psychosocial development is lacking. OBJECTIVE: To review existing evidence for health and nutrition interventions affecting direct measures of (and pathways to) early child development. DATA SOURCES: Reviews and recent overviews of interventions across the continuum of care and component studies. STUDY SELECTION: We selected systematic reviews detailing the effectiveness of health or nutrition interventions that have plausible links to child development and/or contain direct measures of cognitive, motor, and psychosocial development. DATA EXTRACTION: A team of reviewers independently extracted data and assessed their quality. RESULTS: Sixty systematic reviews contained the outcomes of interest. Various interventions reduced morbidity and improved child growth, but few had direct measures of child development. Of particular benefit were food and micronutrient supplementation for mothers to reduce the risk of small for gestational age and iodine deficiency, strategies to reduce iron deficiency anemia in infancy, and early neonatal care (appropriate resuscitation, delayed cord clamping, and Kangaroo Mother Care). Neuroprotective interventions for imminent preterm birth showed the largest effect sizes (antenatal corticosteroids for developmental delay: risk ratio 0.49, 95% confidence interval 0.24 to 1.00; magnesium sulfate for gross motor dysfunction: risk ratio 0.61, 95% confidence interval 0.44 to 0.85). LIMITATIONS: Given the focus on high-quality studies captured in leading systematic reviews, only effects reported within studies included in systematic reviews were captured. CONCLUSIONS: These findings should guide the prioritization and scale-up of interventions within critical periods of early infancy and childhood, and encourage research into their implementation at scale.

Evidence-based interventions for improvement of maternal and child nutrition in low-income settings: what's new?

PURPOSE OF REVIEW: Maternal and child malnutrition continues to disproportionately affect low and middle-income countries, contributing to high rates of morbidity, mortality, and suboptimal development. This article reviews evidence from recent systematic reviews and studies on the effectiveness of interventions to improve nutritional status in these especially vulnerable populations. RECENT FINDINGS: Macronutrients provided to expectant mothers in the form of balanced protein energy supplements can improve fetal growth and birth outcomes, and new research suggests that lipid nutrient supplements can reduce both stunting and wasting in newborns. Maternal multiple micronutrient supplementations can also improve fetal growth, and reduce the risk of stillbirth. Nutrition education and supplementation provided to pregnant adolescents can also improve birth outcomes in this vulnerable population. New evidence is broadening our understanding of the development of gut microbiota in malnourished infants, and the possible protective role of breastmilk. SUMMARY: The reviewed evidence on nutrition interventions reinforces the importance of packaging interventions delivered within critical windows throughout the life course: before conception, during pregnancy, and throughout childhood. Emerging evidence continues to refine our understanding of which populations and contexts benefit from which intervention components, which should allow for more nuanced and tailored approaches to the implementation of nutrition interventions.