The Odense Child Cohort: aims, design, and cohort profile.

BACKGROUND: The importance of the environment on the development of the fetus and infant throughout early life is increasingly recognised. To study such effects, biological samples and accurate data records are required. Based on multiple data collection from a healthy pregnant population, the Odense Childhood Cohort (OCC) study aims to provide new information about the environmental impact on child health by sequential follow-up to 18 years of age among children born between 2010 and 2012.
METHODS: A total of 2874 of 6707 pregnancies (43%) were recruited between January 2010 and December 2012. Three hundred seventy-four have since left the study, leaving 2500 active families. The non-participants act as controls contributing data through local registries. Biological material, questionnaires, and registry data were compiled. Anthropometric data and other physical data were collected.
RESULTS: Two thousand five hundred families actively participated in the study with 2549 children. Sixty-four per cent of the fathers and 60% and 58% of the mothers, respectively, donated a blood sample at 10 and 28 weeks of gestation. On average, 69% completed questionnaires, 78% of the children were regularly examined, and had a blood sample taken (46%). The participating pregnant women differed from the non-participants in several respects: age, body mass index, smoking, parity, education, and ethnicity. The infants were comparable with respect to gender and mode of delivery.
CONCLUSIONS: The OCC provides material for in-depth analysis of environmental and genetic factors that are important for child health and disease. Registry data from non-participating women and infants are available which ensures a high degree of comparable data.