1. Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland;
2. Social, Statistical and Environmental Sciences Unit, RTI International, Research Triangle Park, North Carolina;
3. Department of Pediatrics, University of Iowa, Iowa City, Iowa;
4. Department of Pediatrics, Emory University School of Medicine and Children’s Healthcare of Atlanta, Atlanta, Georgia;
5. Department of Pediatrics, University of Utah, Salt Lake City, Utah;
6. Department of Pediatrics, Wayne State University, Detroit, Michigan;
7. Department of Pediatrics, Case Western Reserve University and Rainbow Babies & Children’s Hospital, Cleveland, Ohio;
8. Department of Pediatrics, Brown University and Women & Infants Hospital of Rhode Island, Providence, Rhode Island;
9. Social, Statistical and Environmental Sciences Unit, RTI International, Rockville, Maryland;
10. Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana;
11. Perinatal Institute, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio;
12. Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama;
13. Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, Texas;
14. Department of Pediatrics, Duke University, Durham, North Carolina;
15. Department of Pediatrics, University of Rochester School of Medicine and Dentistry, Rochester, New York;
16. Department of Pediatrics, Stanford University School of Medicine and Lucile Packard Children’s Hospital, Palo Alto, California; and
17. Department of Pediatrics, University of New Mexico Health Sciences Center, Albuquerque, New Mexico