The fetal and developmental origins of disease hypothesis suggests that pre-conception (maternal and paternal) and intrauterine (maternal) prenatal factors can influence postnatal health, including growth and adiposity. Birth weight is a marker of intrauterine growth and has been associated with risk of overweight and obesity, as have preterm birth, and small and large for gestational age. To the best of our knowledge, no study has investigated the association between continuous birthweight (for gestational age) centiles beyond the traditional thresholds for small or large for gestational age and longitudinal growth throughout infancy and childhood. This study will address this evidence gap.