1. Department of Epidemiology, Gillings School of Global Public Health University of North Carolina at Chapel Hill Chapel Hill North Carolina USA
2. Carolina Population Center University of North Carolina at Chapel Hill Chapel Hill North Carolina USA
3. Department of Pediatrics Stanford University School of Medicine Stanford California USA
4. Department of Obstetrics and Gynecology Stanford University School of Medicine Stanford California USA
5. Department of Pediatrics, Division of Genetics and Metabolism, School of Medicine University of North Carolina at Chapel Hill Chapel Hill North Carolina USA
6. Department of Epidemiology, College of Public Health The University of Iowa Iowa City Iowa USA
7. Division of Birth Defects and Infant Disorders National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention Atlanta Georgia USA
8. Eagle Global Scientific LLC San Antonio Texas USA
9. Division of Medical Genetics, Department of Pediatrics University of Utah School of Medicine Salt Lake City Utah USA
10. Bureau of Environmental and Occupational Epidemiology Center for Environmental Health, New York State Department of Health Albany New York USA
11. Department of Epidemiology and Biostatistics, School of Public Health University at Albany Rensselaer New York USA
12. Department of Epidemiology, Fay W. Boozman College of Public Health University of Arkansas for Medical Sciences Little Rock Arkansas USA
13. Arkansas Center for Birth Defects Research and Prevention, Fay W. Boozman College of Public Health University of Arkansas for Medical Sciences Little Arkansas USA
14. Texas Department of State Health Services Birth Defects Epidemiology and Surveillance Branch Austin Texas USA
15. Department of Epidemiology Boston University School of Public Health Boston Massachusetts USA