Guidance for international growth standards: when, where, and how to apply international growth standards

Ohuma, Eric, Vesel Linda, Parker Simon, Ngatia Bancy

London School of Hygiene & Tropical Medicine, London, United Kingdom of Great Britain and Northern Ireland; 2Ariadne Labs, Harvard T.H. Chan School of Public Health /Brigham and Women's Hospital, Boston, Massachusetts, USA, Boston, United States of America

Abstract: Infant growth is a commonly used proxy of population health, human capital, and socioeconomic development. Additionally, failure to achieve growth potential is associated with increased risk of mortality and morbidity throughout an individual's life. Therefore, accurate growth assessment using international prescriptive growth standards is a key step towards efficient, accurate, and comparable tracking of progress towards achieving the Sustainable Development Goal 3.2, which aims to reduce preventable newborn and child mortality by 2030. Different growth standards exist and can lead to differences in growth estimates due to lack of comparability as a result of how they were constructed, study design, statistical methodology, etc. There is a lack of clear guidance on which growth charts to use when, and for whom. Consequently, growth standards are often applied incorrectly, leading to inappropriate assessment and interpretation of growth trajectories This can alter prevalence estimates for stunting, wasting, and other indicators of non-optimal growth. In light of these challenges, the Guidance for International Growth Standards (GIGS) project has developed guidance and software to facilitate consistent, standardized, and accurate application of child growth based on the international standards from the INTERGROWTH-21stand WHO Child Growth Standards. This talk will detail guidance from GIGS on when, for whom, and how to apply international growth standards in settings where gestational age data is available. We will first discuss the rationale for the GIGS project, then present case studies of individual infants from a large cohort of moderately low birthweight infants in India, Malawi and Tanzania. We will use scenario-based approach to demonstrate the implication of using/applying existing standards inappropriately and further, provide clear guidance on appropriate application of these international standards based on the GIGS- recommended approach.