Early childhood health in Bielefeld, Germany (BaBi study): study protocol of a social-epidemiological birth cohort

INTRODUCTION: The heterogeneity among the German population is increasing. Sociodemographic differentials (eg, in education and migrant status) have been associated with health disparities. Life course studies show that a considerable part of these disparities is determined by exposures during pregnancy and early childhood. The BaBi study was established in 2012 to investigate the production of health disparities from foetal life to childhood in the city of Bielefeld, Germany. METHODS AND ANALYSIS: Between 2013 and 2016, detailed information on socioeconomic characteristics, migration background, lifestyle factors, environmental factors, healthcare use, and health status of 995 newborns, including 24 twins, and their families was collected using standardised instruments. Data collection started during pregnancy or shortly after birth with a computer-assisted personal interview of the pregnant woman/mother. Follow-up data will be collected until 2018 by computer-assisted telephone interviews around the first, second and after the third birthday of the child and by linking routine healthcare data. Blood samples are collected from a small subsample of 50 mothers for a substudy about stress during pregnancy (BaBi-Stress study). ETHICS AND DISSEMINATION: The study was approved by the ethical committee of the Medical Faculty of Muenster University and the Data Protection Board of Bielefeld University. Results will be published in scientific journals. Data sets and questionnaires will be made accessible for researchers based on access proposals and data usage contracts.