Developmental delays occur when a child does not reach developmental milestones, such as rolling over, sitting up, walking and talking, at the same time as other children. There are five main categories of developmental delays: gross motor, fine motor, language, cognitive and social. An example of a developmental delay includes a 4-year-old who is not talking. "My Child Without Limits" explains that children are often delayed in more than one area. A child with speech and language issues, for example, may also have cognitive or social delays.
Genetic factors cause some developmental delays. These include diagnoses such as Down syndrome, Fragile X syndrome, Rett syndrome and muscular dystrophy. All of these result in multiple delays that influence physical, communication and social development. Down syndrome might cause delays in several areas with significant delays relating to brain function. Muscular dystrophy, on the other hand, affects walking, breathing and other muscle-dependent functions, but not the brain.
Biological factors may affect developmental delays. These include hearing loss, vision loss, lead poisoning or head injuries. These biological factors generate delays ranging from mild to severe. A mild head injury may cause delays that are reversible through physical or occupational therapy. Alternatively, profound hearing loss may cause life-long issues regarding communication.
Pregnancy and delivery issues may cause developmental delays. Pregnancy-related issues affecting the fetus include Rh incompatibility (blood incompatibility), alcohol and drug exposure, viral infections and toxemia (blood borne toxic substances). During labor and delivery, difficulties may occur causing developmental delays. These include prolonged or difficult labor leading to head injuries or lack of oxygen. In addition, premature or low birth weight babies may experience developmental delays.
The environment and upbringing surrounding a child may cause developmental delays. An example of an environmental issue includes neglect and abuse. Dr. Bruce Perry, founder of ChildTrauma.org and professor of psychiatry and behavioral sciences at Northwestern University School of Medicine in Chicago, emphasizes that lack of consistent care in early childhood may result in motor, language, social and cognitive developmental delays. Other environmental issues causing developmental delays include parental depression, lack of immunizations and malnutrition.