1. Division of Congenital and Developmental Disorders, National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia.
2. Division of STD Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia.
3. U.S. Public Health Service, Rockville, Maryland.
4. Massachusetts Department of Public Health, Massachusetts Center for Birth Defects Research and Prevention, Boston, Massachusetts.
5. Pennsylvania Department of Health, Bureau of Epidemiology, Harrisburg, Pennsylvania.
6. Office of Science, Centers for Disease Control and Prevention, Atlanta, Georgia.