The term Global developmental delay (GDD) is used when a child is showing a significant delay (two standard deviations below the mean of age appropriate) in two or more developmental domains (gross motor, fine motor, language, personal/social and cognitive skills). More simply, the term Global Developmental Delay is used when a child does not progress as expected for his age in 2 or more areas of his development.
This term is usually used for children typically less than 5 years, whereas the term learning disability is preferred for older children. Global delay is estimated to be prevalent in 1–3% of children aged less than 5 years.
In some children delay in development is suspected very soon after birth (e.g. poor muscle tone) whereas for other children parents will notice the delay when comparing their child to his peers (e.g. behind with speech, slow to learn to walk) or difficulties will become apparent when the child starts nursery and flagged up by nursery staff.
There are many different causes for GDD: genetic causes (e.g. Down syndrome), metabolic causes, acquired prenatal (e.g. infection during pregnancy), perinatal (e.g. birth trauma) and post natal (e.g. meningitis) causes. Some causes are treatable, therefore, early recognition and diagnosis is important. In addition, some of the aetiologies are genetically transmitted so it can be useful to find out if it can affect future pregnancies or if other family members could also have the condition. Knowing the cause can also help in predicting how it may affect the child in the future.
Unfortunately it is not uncommon that a cause will be identified in only a small proportion of children despite several investigations being performed and/or after a thorough assessment with an experienced paediatrician. Sometimes parents feel relieved that no underlying condition was found but some can feel disappointed or frustrated by not knowing why it affects their child.
Even if no underlying cause is found, early recognition of the delay in development is important as it helps to guide intervention (e.g. need for speech and language therapy) without delay and it can also help other professionals (e.g. education) by understanding the condition to support your child.