The first 1000 days of life is crucial to establish foundations for growth, metabolism and development. With over 100 different fetal growth charts in use, diagnosis of ‘small for gestational age’ depends more upon location and choice of chart, than failure to attain physiological growth. Consequently in 2015 we have few effective interventions for this major global health problem. The International Fetal and Newborn Growth consortium for the 21st century (INTERGROWTH-21st) was established to define optimal growth and development and the conditions required for this to occur. The INTERGROWTH-21st study was conducted in eight diverse international settings selected as social, nutritional and health care needs of mothers were largely met. In 2014 the study published it’s primary findings that under these conditions, linear fetal growth from 9 weeks gestation is strikingly similar around the world. International standards for CRL, fetal growth and newborn size at birth have now been released. The challenge will now be in implementing the standards and addressing the burden of nutritional problems evident from birth.