1. National Center on Birth Defects and Developmental Disabilities Centers for Disease Control and Prevention Atlanta Georgia USA
2. Chiles Center, College of Public Health University of South Florida Tampa Florida USA
3. National Center for Chronic Disease Prevention and Health Promotion Centers for Disease Control and Prevention Atlanta Georgia USA
4. Department of Epidemiology, Fay W. Boozman College of Public Health University of Arkansas for Medical Sciences Little Rock Arkansas USA
5. Arkansas Center for Birth Defects Research and Prevention Little Rock Arkansas USA
6. Illinois Department of Public Health Springfield Illinois USA
7. Department of Pediatrics University of Texas Southwestern Medical Center Dallas Texas USA
8. South Carolina Department of Health and Environmental Control Columbia South Carolina USA
9. Division for Surveillance, Research, and Promotion of Perinatal Health Massachusetts Department of Public Health Boston Massachusetts USA