1. National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention; Atlanta Georgia
2. Division of Neonatal and Developmental Medicine, Department of Pediatrics, Stanford University; Stanford California
3. Center for Birth Defects Research and Prevention at the Massachusetts Department of Public Health; Boston Massachusetts
4. Congenital Malformations Registry, New York State Department of Health; Albany New York
5. Department of Epidemiology; College of Public Health, The University of Iowa; Iowa City Iowa
6. Birth Defects Monitoring Program, State Center for Health Statistics, North Carolina Division of Public Health; Raleigh North Carolina
7. Department of Pediatrics, College of Medicine; University of Arkansas for Medical Sciences; Little Rock Arkansas