Early childhood development typically follows a trajectory of achieving physical, cognitive, communication, social-emotional, and self-help milestones within a specified age range. Although most children reach these milestones within a similar range, others exhibit mild to severe developmental delays that indicate potential developmental disabilities. Developmental disabilities are a group of conditions caused by an impairment in one or more developmental domains (e.g., physical, learning, communication, behavior, or self-help). Developmental disabilities can become evident during the prenatal period through age 22 years, affect day-to-day functioning, and usually are lifelong (1). Approximately 15% of children aged 3–17 years in 2008 were estimated to have developmental disabilities of varying severity, such as language or learning disorders, intellectual disabilities, cerebral palsy, seizures, hearing loss, blindness, autism spectrum disorder* (ASD), or other developmental delays (2).
Complete report in