1. Special Child Health and Early Intervention Services, Division of Family Health Services, New Jersey Department of Health, Trenton, New Jersey;
2. National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia;
3. Department of Pediatrics, The Children's Hospital of Philadelphia and University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania;
4. Department of Pediatrics, Cohen Children's Medical Center, New Hyde Park, New York;
5. Department of Pediatrics, University of Medicine and Dentistry New Jersey, Robert Wood Johnson Medical School, New Brunswick, New Jersey; and
6. Duke Clinical Research Institute and Department of Pediatrics, Duke University, Durham, North Carolina