Norwegian Mother and Child Cohort Study (MoBa) The MoBa dataset is a large, population based prospective birth cohort that follows 114 000 children, 95 000 mothers and 75 000 fathers recruited across Norway between 1998 2009. It combines extensive questionnaire data (maternal, paternal and child health, lifestyle, psychosocial factors) with a biobank of biological specimens (blood, urine, DNA, placenta, cord blood, and repeated child samples). The cohort is linked to national health registries, providing longitudinal information on pregnancy outcomes, childhood development, and later life diseases. The study was created and is managed by the Norwegian Institute of Public Health (FHI), with an operational board that includes scientific directors and data controller officials 6 L0-L3 . Its primary purpose is to investigate genetic and environmental determinants of health across the life course, enabling family based designs (trios, twins, siblings) and Mendelian randomisation analyses. Typical use cases include epidemiologic research on prenatal exposures, gene environment interactions, developmental origins of health and disease, and validation of biomarkers. Unique aspects are the triad structure (mother father child), the large, multi generational sample size, and the integration of questionnaire, biospecimen, and registry data making MoBa one of the world s most comprehensive resources for longitudinal family health research 2 L0-L4 4 L0-L7 .