1. Division of Epidemiology and Community Health, School of Public Health, University of Minnesota-Twin Cities, Minneapolis, Minnesota, USA.
2. The Mayo Clinic, Division of Community Pediatric and Adolescent Medicine, Minneapolis, Minnesota, USA.
3. Department of Pediatrics, University of Oklahoma College of Medicine, Oklahoma City, Oklahoma, USA.
4. Department of Genetics, Cell Biology, and Development, University of Minnesota-Twin Cities, Minneapolis, Minnesota, USA.
5. HealthPartners Institute, Bloomington, Minnesota, USA.
6. Maternal-Fetal Medicine, University of Oklahoma College of Medicine, Oklahoma City, Oklahoma, USA.