Anne C.C. LeeJoanne KatzHannah BlencoweSimon CousensNaoko KozukiJoshua P. VogelLinda AdairAbdullah H. BaquiZulfiqar A. BhuttaLaura E. CaulfieldParul ChristianSiân E. ClarkeMajid EzzatiWafaie FawziRogelio GonzalezLieven HuybregtsSimon KariukiPatrick KolsterenJohn LusinguTanya MarchantMario MerialdiAroonsri MongkolchatiLuke C. MullanyJames NdiranguMarie Louise NewellJyh Kae NienDavid OsrinDominique RoberfroidHeather E. RosenAyesha SaniaMariangela F. SilveiraJames TielschAnjana VaidyaBarbara A. WilleyJoy E. LawnRobert E. BlackJohns Hopkins Bloomberg School of Public HealthBrigham and Women's HospitalLondon School of Hygiene &amp; Tropical MedicineUniversity of Western AustraliaOrganisation Mondiale de la SanteThe University of North Carolina at Chapel HillThe Aga Khan UniversityImperial College LondonHarvard School of Public HealthPontificia Universidad Catolica de ChileUniversiteit GentPrins Leopold Instituut voor Tropische GeneeskundeCenters for Disease Control and Prevention, KenyaNational Institute Medical ResearchMahidol UniversityUniversity of KwaZulu-NatalUCL Institute of Child HealthUniversidad de los Andes, SantiagoUniversidade Federal de PelotasGeorge Washington University School of Public Health and Health ServicesSave the Children USA2018-10-192018-10-192013-09-01The Lancet Global Health. Vol.1, No.1 (2013)2214109X2-s2.0-84886445962https://repository.li.mahidol.ac.th/handle/20.500.14594/32198Background: National estimates for the numbers of babies born small for gestational age and the comorbidity with preterm birth are unavailable. We aimed to estimate the prevalence of term and preterm babies born small for gestational age (term-SGA and preterm-SGA), and the relation to low birthweight (<2500 g), in 138 countries of low and middle income in 2010. Methods: Small for gestational age was defined as lower than the 10th centile for fetal growth from the 1991 US national reference population. Data from 22 birth cohort studies (14 low-income and middle-income countries) and from the WHO Global Survey on Maternal and Perinatal Health (23 countries) were used to model the prevalence of term-SGA births. Prevalence of preterm-SGA infants was calculated from meta-analyses. Findings: In 2010, an estimated 32·4 million infants were born small for gestational age in low-income and middle-income countries (27% of livebirths), of whom 10·6 million infants were born at term and low birthweight. The prevalence of term-SGA babies ranged from 5·3% of livebirths in east Asia to 41·5% in south Asia, and the prevalence of preterm-SGA infants ranged from 1·2% in north Africa to 3·0% in southeast Asia. Of 18 million low-birthweight babies, 59% were term-SGA and 41% were preterm-SGA. Two-thirds of small-for-gestational-age infants were born in Asia (17·4 million in south Asia). Preterm-SGA babies totalled 2·8 million births in low-income and middle-income countries. Most small-for-gestational-age infants were born in India, Pakistan, Nigeria, and Bangladesh. Interpretation: The burden of small-for-gestational-age births is very high in countries of low and middle income and is concentrated in south Asia. Implementation of effective interventions for babies born too small or too soon is an urgent priority to increase survival and reduce disability, stunting, and non-communicable diseases. Funding: Bill & Melinda Gates Foundation by a grant to the US Fund for UNICEF to support the activities of the Child Health Epidemiology Reference Group (CHERG). © 2013 Lee et al.Mahidol UniversityMedicineArticleSCOPUS10.1016/S2214-109X(13)70006-8