11 March 2025

In a pivotal issue published at the end of 2024, The Lancet unveiled a groundbreaking series titled “The Next 1000 Days: Building on Early Investments for the Health and Development of Young Children”. This two-part series offers a comprehensive exploration of the critical developmental phase from 2 to 5 years of age, emphasizing the necessity of sustained nurturing care, equitable access to early interventions, and multisectoral collaboration to ensure optimal outcomes for children worldwide. Building on the foundational gains of the first 1000 days (from conception to age two), the series examines how the next phase of early childhood can shape lifelong health, learning, and well-being.

The Importance of the Next 1000 Days
The first paper in the series underscores the importance of the next 1000 days as a sensitive period for rapid cognitive, motor, and socio-emotional development. It reveals that only 25.4% of children aged 3 to 4 years in low- and middle-income countries (LMICs) receive adequate nurturing care, leaving approximately 182 million children at risk of developmental setbacks. Key dimensions of nurturing care—health, nutrition, responsive caregiving, safety, and early learning—are often unevenly accessible, with disparities exacerbated by poverty, geographic location, and gender. For example, while 86.2% of children in LMICs maintain a healthy weight, less than one-third benefit from developmental stimulation or are protected from physical punishment.

The series also highlights the urgent need for scalable, high-quality early childhood care and education (ECCE) programs. Currently, only 38.8% of children in LMICs participate in ECCE, with significant gaps in service quality and equity. The COVID-19 pandemic has further disrupted access to essential services, exacerbating existing vulnerabilities. The authors advocate for integrated interventions that combine health, nutrition, and education services, particularly within ECCE settings, to address the multifaceted needs of young children and their families.

Challenges Faced by Children in Conflict-Affected Regions
A mapping review included in the series reveals a stark disparity between the global regions where interventions are most needed and where they are being implemented. While 70% of published interventions originate from high-income countries, only 5% are conducted in LMICs, despite the disproportionate burden of developmental risks in these settings. The review emphasizes the importance of culturally relevant, evidence-based interventions that prioritize vulnerable populations, including children with disabilities and those in humanitarian contexts.

The issue is particularly urgent in conflict-affected regions, including many low-income and Arab countries, where wars and displacement have devastated early childhood development systems. Millions of children in war zones such as Palestine, Syria, Yemen, Lebanon, and Sudan are growing up in environments of chronic instability, lacking access to adequate nutrition, healthcare, and education. Prolonged exposure to violence and trauma severely impacts brain development, increasing the risks of toxic stress, emotional distress, and cognitive delays. In these regions, where entire generations are at risk of being left behind, targeted interventions that provide psychological support, safe learning spaces, and emergency nutrition programs are essential. Yet, these efforts remain critically underfunded, with international aid often insufficient to meet the growing needs of displaced and war-affected children. Addressing these challenges requires a concerted global effort to integrate early childhood support into humanitarian responses, ensuring that even in the midst of conflict, children receive the care and protection necessary for healthy development.

The Lancet series concludes with a compelling call to action for policymakers, researchers, and practitioners to prioritize the next 1000 days as a critical window for intervention. It advocates for increased investments in ECCE systems, the integration of multisectoral strategies, and the development of robust monitoring frameworks to track progress and outcomes. By addressing inequities in access to nurturing care and leveraging the potential of ECCE, the global community will contribute to the achievement of the Sustainable Development Goals (SDGs).

This landmark series serves as an essential resource for understanding the challenges and opportunities in early childhood development, offering evidence-based recommendations to guide future research, policy, and practice. It underscores the importance of continuity in nurturing care from the first to the next 1000 days, highlighting the interconnections of early childhood interventions and their profound long-term impact on individual and societal well-being.