Infantile idiopathic scoliosis is a type of scoliosis that is first diagnosed in a child between birth and 3 years old. The term idiopathic means the cause is unknown and implies that the child is otherwise healthy. Congenital spinal anomalies (i.e., misshapen and connected vertebrae) are also often diagnosed during this period, but are not included in the infantile category. Most infantile idiopathic scoliosis curves are left sided curves in the thoracic (chest) area. It is more common in boys than girls. Many infants with infantile idiopathic scoliosis are healthy and normal, and simply have a small curvature of the spine. In some patients, however, there is an increased association with hip dysplasia, mental retardation, and congenital heart disease.