The Danish National Birth Cohort - its background, structure and aim

Abstract

To investigate these issues the Danish National Birth Cohort (Better health for mother and child) was established. A large cohort of pregnant women with long-term follow-up of the offspring was the obvious choice because many of the exposures of interest cannot be reconstructed with sufficient validity back in time. The study needs to be large, and it is aimed to recruit 100,000 women early in pregnancy, and to continue follow-up for decades. The Nordic countries are better suited for this kind of research than most other countries because of their population-based registers on diseases, demography and social conditions, linkable at the individual level by means of the unique ID-number given to all citizens. Exposure information is mainly collected by computer-assisted telephone interviews with the women twice during pregnancy and when their children are six and 18 months old. Participants are also asked to fill in a self-administered food frequency questionnaire in mid-pregnancy. Furthermore, a biological bank has been set up with blood taken from the mother twice during pregnancy and blood from the umbilical cord taken shortly after birth. Data collection started in 1996 and the project covered all regions in Denmark in 1999. By August 2000. a total of 60,000 pregnant women had been recruited to the study. It is expected that a large number of gene-environmental hypotheses need to be based on case-control analyses within a cohort like this.

Iron supplement use among Danish pregnant women

“…The strengths of this study are the large number of participants and the wide variety of information on lifestyle and sociodemographic factors collected routinely in DNBC. A limitation of the cohort is that the participants cannot be regarded as representative for the whole population of Danish pregnant women 26 . The latter is assumed to cause a selection of women in the cohort who are more concerned about health matters in relation to pregnancy compared with the background population 43 .…”

“…Data were collected through four telephone interviews: in week 12 and week 30 of gestation, and when the child was 6 and 18 months old. Further, all participants received a food-frequency questionnaire (FFQ) in week 25 of gestation, covering diet and use of dietary supplements in mid-pregnancy 26 .…”

Influence of maternal serum levels of vitamins C and E during the second trimester on birth weight and length

“…It has been suggested that maternal exposure during the period from conception to birth may have an impact on fetal growth as well as the child's health (Strauss & Dietz, 1998;Godfrey & Barker, 2000;Olsen, 2001). In particular, maternal nutrition during pregnancy has been regarded as an important determinant for fetal growth (Godfrey et al, 1997;Kramer, 2002).…”

Early development in Rett syndrome – the benefits and difficulties of a birth cohort approach

“…31,32 They were interviewed by telephone during pregnancy and when the offspring was 6 and 18 months old. The interviews were designed to study the mother’s lifestyle during pregnancy and the short- and long-term effects of this on the child, assessing a wide range of neurodevelopmental features in children but not to detect specific developmental disorders.…”

“…The interviews were designed to study the mother’s lifestyle during pregnancy and the short- and long-term effects of this on the child, assessing a wide range of neurodevelopmental features in children but not to detect specific developmental disorders. 31 Details can be found at the DNBC homepage (DNBC 2013; www.dnbc.dk). At 12 weeks’ gestation, information on the socio-economic status and educational background of the parents was collected.…”