1 From the Division of Public Health Information Dissemination, Center for Surveillance, Epidemiology, and Laboratory Services (S.A.R.), Division of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion (D.J.J.), and Division of Congenital and Developmental Disorders, National Center on Birth Defects and Developmental Disabilities (M.A.H.), Centers for Disease Control and Prevention, Atlanta; and the Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, CO (L.R.P.).