BACKGROUND: Research involving minors has been the subject of much ethical debate. The growing number of longitudinal, pediatric studies that involve genetic research present even more complex challenges to ensure appropriate protection of children and families as research participants. Long-term studies with a genetic component involve collection, retention and use of biological samples and personal information over many years. Cohort studies may be established to study specific conditions (e.g. autism, asthma) or may have a broad aim to research a range of factors that influence the health and development of children. Studies are increasingly intended to serve as research platforms by providing access to data and biological samples to researchers over many years.This study examines how six birth cohort studies in North America and Europe that involve genetic research handle key ethical, legal and social (ELS) issues: recruitment, especially parental authority to include a child in research; initial parental consent and subsequent assent and/or consent from the maturing child; withdrawal; confidentiality and sample/data protection; handling sensitive information; and disclosure of results. METHODS: Semi-structured telephone interviews were carried out in 2008/09 with investigators involved in six birth cohort studies in Canada, Denmark, England, France, the Netherlands and the United States. Interviewees self-identified as being knowledgeable about ELS aspects of the study. Interviews were conducted in English. RESULTS: The studies vary in breadth of initial consent, but none adopt a blanket consent for future use of samples/data. Ethics review of new studies is a common requirement. Studies that follow children past early childhood recognise a need to seek assent/consent as the child matures. All studies limit access to identifiable data and advise participants of the right to withdraw. The clearest differences among studies concern handling of sensitive information and return of results. In all studies, signs of child abuse require reports to authorities, but this disclosure duty is not always stated in consent materials. Studies vary in whether they will return to participants results of routine tests/measures, but none inform participants about findings with unknown clinical significance. CONCLUSIONS: Analysis of how cohort studies in various jurisdictions handle key ELS issues provides informative data for comparison and contrast. Consideration of these and other examples and further scholarly exploration of ELS issues provides insight on how best to address these aspects in ways that respect the well-being of participants, especially children who become research subjects at the start of their lives.