The DNBC is presently the largest birth cohort in the world including about 100,000 participants and has up to 12 years of follow up. Detailed information on social conditions, life style behaviors, food intake and environmental exposures were obtained during pregnancy and again when the newborn child reached 6 and 18 months as well as 7 years of age. DNBC and its data system includes links to all hospitalizations from birth and onward for all participating children and their parents. Blood from the first and second trimester as well as umbilical cord blood are stored in the biobank.