Developmental Delay (DD) – Diagnosis and Prognosis

This article is intended to answer some questions you may have if you are concerned that a child has a developmental delay or if your child has recently been diagnosed with developmental delay.  Possible implications for further medical investigation into the cause of the developmental delay will also be discussed.

About developmental delay and the early signs

From birth onwards children learn important skills such as sitting up, rolling over, crawling, walking, babbling (making basic speech sounds), talking and becoming toilet trained as they grow up.  These skills are known as developmental milestones and usually occur in a predictable order at a fairly predictable age.   Developmental delay can be observed in the way a child moves, communicates, thinks and learns, or behaves with others.  While all children develop at different rates, and reach these milestones at different times, a child considered to have developmental delay will reach these much later, and have significant limitation in one or more areas of the following key developmental areas

  • Gross motor skill development – use of large muscles to sit, stand, walk, run, keep balance and change positions.
  • Fine motor skill development – use of small muscles (specifically hands and fingers) to eat, draw, play and write.
  • Cognitive development – the ability to perform mental activities mostly related to thinking, learning, and understanding, problem solving, reasoning and remembering.
  • Social and emotional development – ability to interact with others, to cooperate and respond to the feelings of others, e.g. with family, friends and teachers.
  • Speech and language development – speaking, using body language and gestures, communicating with others and understanding what others say.

A child may be described as having global developmental delay (GDD) when they have not reached two or more milestones in all five of these developmental areas.

Developmental delay can be short-term, long term or permanent.  There are many different reasons a child may develop more slowly than expected.  

Short-term delays can occur for babies born prematurely; or as a result of physical illness, prolonged hospitalisation; or as a result of mental illness, family stress or lack of learning opportunities.  Children with short term developmental delays may have a learning disability, but are unlikely to be intellectually disabled.

Permanent delays are also called ‘developmental disabilities’. These delays could be the first early signs of other conditions, for example:

  • Cerebral palsy
  • Down syndrome
  • Language delay
  • Hearing or vision impairment
  • Intellectual disability
  • Learning Disabilities, such as, dyslexia, dyspraxia, dyscalculia, dysgraphia
  • Attention Deficit Hyperactivity Disorder/Attention Deficit Disorder (ADHD/ADD)
  • Autism Spectrum Disorder (ASD)
  • Fetal Alcohol Spectrum Disorder (FASD)
  • Brain trauma/injury


There is no one cause of developmental delays, but some risk factors include:

  • Complications at birth, e.g. low birth weight or lack of oxygen.
  • Environmental issues, e.g. lead poisoning, poor nutrition, exposure to alcohol or drugs before birth, difficult family situations, trauma.
  • Medical conditions, e.g. chronic ear infections, vision problems, illnesses, conditions, or injuries that have a significant long-term effect on a child’s day to day activities.

The most common causes of global developmental delay include:

  • Problems with genes or chromosomes.
  • The structure or development of the brain or spinal cord.
  • Prematurity (born too early).
  • Childhood infection (e.g. meningitis) or metabolic diseases, such as having an underactive thyroid glad (hypothyroidism);
  • Other issues affecting babies before they are born, such as toxins (poisonous substances), e.g. alcohol in the case of fetal alcohol syndrome.

For some children, the cause of the GDD is never identified.  Though with advancements, for instance, in genetic testing, this is much less likely than in past generations.

Child concerns and diagnosis

Parents, caregivers, whānau know the child of concern best and often have an idea there is a problem long before it’s diagnosed by a professional.  If you have any concerns about your child’s development, it is a good idea to talk to your G.P, or child and family health nurse.  

Developmental delay can be diagnosed after a child’s health and development have been assessed by qualified health professionals, e.g. developmental pediatricians and clinical psychologists; and could include specialist assessments from a multidisciplinary team of experts, e.g. genetic services, education, and other professionals working in specialised fields such as speech and language.  Neurologically, there are four main reasons to investigate developmental delays further, 1) to identify a treatable condition or cause, 2) to initiate specific early intervention, 3) to expect and manage future comorbidities, and 4) to identify genetic counselling needs.

Health professionals usually use the term ‘developmental delay’ only until further assessments have been completed and a cause or a more fitting diagnosis has been identified.  If and when professionals find the cause, they will then use a name that better explains the child’s condition, e.g. a diagnosis of cerebral palsy.

Living with developmental delay and implications for early intervention

Children with developmental delay like other children keep learning.  This may be slower, with them taking more time to develop new skills and they may learn in slightly different or alternative ways.  For example, rather that learning a skill quickly by example, a child with developmental delay may need to be shown skills in smaller, simpler steps.  They may not be able to transfer learned skills from one environment to another with ease.  They might need more opportunities to practice, and in a variety of settings and contexts.

The following professionals may be involved in support and interventions planning for children:

  • G.P
  • Child and family health nurse
  • Paediatrician
  • Audiologist, deaf advisors
  • Occupational therapist
  • Speech pathologist
  • Psychologist
  • Psychiatrist
  • Social worker
  • Therapists, e.g. speech-language, physio
  • Special education teachers and support workers
  • Kaitakawaenga (Maori Cultural Advisors)

Key Takeaways

  • Developmental delays can be an early sign of specific learning or attention issues.
  • Further assessments and testing into the possible cause of developmental delay are likely from a team of professional experts and specialists.
  • Early detection and intervention is important to help children learn and develop essential skills.
  • Identification and diagnosis can help with planning specific intervention supports for the child, and any counselling needs for family members or caregivers.

Further information and support


Susan Findlay (BTchg)
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