Developmental delay

A term used if a baby or young child has not achieved new abilities within the normal time range. Normally, new abilities and new patterns of behaviour appear at given ages, and existing patterns of behaviour change and sometimes disappear (see child development). Delays vary in severity and may affect the development of hand–eye coordination, walking, listening, language, speech, or social interaction. Delay may first be noticed by parents or detected during a routine developmental check. There are many causes of developmental delay. A child who is late in most aspects of development usually has a generalized problem. This may be due to severe visual or hearing impairment, limited intellectual abilities (see learning difficulties), or damage to the brain before, during, or after birth. Specific areas of delay may occur in movement and walking. Often there is no serious cause. However, specific causes may include muscular dystrophy and spina bifida. Delay in developing manipulative skills is often due to lack of adequate stimulation. A lack of response to sound may be due to deafness. Autism is a rare cause of unresponsiveness to the human voice although hearing is normal. A hearing problem may cause delayed speech. Twins are often late talkers. Any generalized difficulty with muscle control can affect speech production; this may occur in children with cerebral palsy. Damage to, or structural defects of, the speech muscles, larynx (voice box), or mouth may also cause speech difficulties, as may any disorder affecting the speech area of the brain (see aphasia; dysarthria; dysphonia; speech disorders). Delay in bladder and bowel control have many possible causes (see encopresis; enuresis; soiling). A child who shows signs of developmental delay should undergo a full assessment by a paediatrician.