1. Material and methods Background and purpose For more information on The Norwegian Mother and Child Cohort Study go to : http://www.fhi.no/morogbarn.http://www.fhi.no/morogbarn Data collection - status September 2011 Scientific activity status MoBa is a nationwide population-based pregnancy cohort study. Recruitment started in one county in 1999, and was gradually stepped up to include all parts of Norway from 2005-2008. The aim of the study is to elucidate the aetiology and pathogenesis of disorders that may originate in early life. Pregnant women and their partners were recruited in connection with their routine hospital ultrasound examination at week 17-19 of pregnancy. 50 hospitals in Norway participated in the study. Participation is based on informed consent. Mothers are asked to complete 3 questionnaires during pregnancy and again when the child is 6, 18 and 36 months, and further at 5, 7 and 8 years. Fathers are asked to complete one questionnaire during pregnancy. The data are linked to the Medical Birth Registry of Norway (MBRN) for pregnancy-outcome data and other information related to pregnancy. Blood samples are collected from the mother (prenatal and at birth), the father and the child (cord blood). Urine samples are collected from the mother (prenatal). DNA, RNA, whole blood, plasma and urine are aliquoted and stored at -20ºC and -80ºC, respectively. Milk teeth are collected when the child is about 7 years old. No. of pregnancies 107 000 No. of pregnancies with father’s consent 82 400 No. of mothers 90 700 No. of mothers with >1 pregnancy 15 300 No. of children 108 600 No. of sets of twins 1 864 Biological samples Blood sample of mother at week 17-19 93 500 Blood sample of mother at birth 83 500 Blood sample of father 67 800 Umbilical cord blood sample 89 600 Urine 75 300 Questionnaire response 17 weeks questionnaire 106 95695.2 % Diet questionnaire (week 22) 105 35992.3 % 30 weeks questionnaire 103 73691.0 % Child’s 6 months questionnaire 105 96584.8 % Child’s 18 months questionnaire 105 54372.4 % Child’s 3 years questionnaire 92 24258.6 % Child’s 5 years questionnaire 38 47050.3 % Child’s 7 years questionnaire 30 21854.1 % Child’s 8 years questionnaire 8 18951.6 % Father’s questionnaire (17 weeks) 82 42894.4 % Ultrasound measurements87 60081.9 % Medical Birth Registry of Norway108 26499.4 % Cancer cases – status December 2009 Through linkage to the Cancer Registry we have identified all children in MoBa who received a cancer diagnosis per December 31, 2009. In total there are 106 cases. 41 are cases of leukemia (80 % ALL, 20 % AML). We have also identified 36 cases of cancer of the brain/nervous system. The MoBa Study has 216 subprojects, of which 149 are active. Of these,12 sub-studies have additional data collection and 6 sub-studies have linkages to external registries. Two of the large projects are: The Autism Birth Cohort (ABC) Study is a collaboration between the Norwegian Institute of Public Health, Columbia University and NIH/NINDS. The ADHD Study is a collaboration between NIPH and Oslo University Hospital. Publication status 116 publications 60 submitted publications 14 Doctoral theses (PhD) 9 Theses of Master of Science