ECHO’s mission is to enhance the health of children for generations to come. ECHO investigators study the effects of a broad range of early environmental influences on child health and development. The program consists of 69 existing and ongoing observational studies and a pediatric clinical trials network. Research conducted through ECHO focuses on five key pediatric outcomes with a high public health impact: pre-, peri- and postnatal outcomes; upper and lower airway health; obesity; neurodevelopment; and positive health, such as happiness and a sense of well-being.