Author Contributions: Dr Moster had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Moster, Wilcox, Vollset, Markestad, Lie.
Acquisition of data: Moster.
Analysis and interpretation of data: Moster, Wilcox, Vollset, Markestad, Lie.
Drafting of the manuscript: Moster.
Critical revision of the manuscript for important intellectual content: Moster, Wilcox, Vollset, Markestad, Lie.
Statistical analysis: Moster, Lie.
Administrative, technical, or material support: Moster.
Study supervision: Moster, Wilcox, Vollset, Markestad, Lie.
Financial Disclosures: None reported.
Funding/Support: This research was supported in part by the Intramural Research Program of the National Institutes of Health, National Institute of Environmental Health Sciences; the Unger-Vetlesen Charitable Fund; The US-Norway Fulbright Foundation; the Norwegian Society of Pediatricians; the University of Bergen; and the Research Council of Norway.
Role of the Sponsors: The funding agencies had no role in the design and conduct of the study; in the collection, analysis, and interpretation of the data; or in the preparation, review, or approval of the manuscript.