Nine months that last a lifetime. Experience from the Danish National Birth Cohort and lessons learned

A growing body of evidence indicates that antenatal care should focus not only on preventing perinatal complications but needs to see the early phase of life as important for a number of adult diseases as well. Most of the research comes from animal studies, since cohorts starting early in life that include biomarkers and have long term follow-up are few, the best known being the National Collaborative Perinatal Project (1959-1974) where only a part of the cohort are being followed (www.birthcohorts.net). Many cohorts are, however, in the planning phase, and the paper provides ten suggestions/recommendations for principal investigators of new or recently established cohorts. (C) 2011 Elsevier GmbH. All rights reserved.