1. National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia;
2. Duke University Medical Center, Durham, North Carolina;
3. Department of Orthopaedic Surgery, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama;
4. Department of Neurosurgery, College of Medicine, Pennsylvania State University, Hershey, Pennsylvania; and
5. College of Nursing, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin