1. Department of Epidemiology, The University of Iowa, Iowa City, IA, USA;
2. Departments of Neurology and Pediatrics, University of Rochester Medical Center, Rochester, NY, USA;
3. Department of Physical Medicine & Rehabilitation, University of Colorado School of Medicine and Children’s Hospital Colorado, Aurora, CO, USA;
4. New York State Department of Public Health, Congenital Malformations Registry (CMR), Albany, NY, USA;
5. Department of Family Medicine, Colorado School of Public Health, Aurora, CO, USA;
6. National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, GA, USA