DEVELOPMENTAL MILESTONES IN CHILDREN - a parent's guide
Dr Warwick Smith - General and Development Paediatrician

Introduction:

Most babies and children reach important milestones within the expected timeframes. But in some cases developmental delays can occur. It is important to recognise when a child may not be developing at an average pace. This article will help to explain normal developmental progress for adults and children, when to seek help, and what tests and investigations are necessary to establish any problem areas.

Early developmental intervention and education helps to influence a young, malleable and responsive brain.

It helps to maximise a child's developmental potential; their functional abilities such as social communication, mobility and adaptive skills. It also helps to limit maladaptive functioning.

Parents can learn how their child is developing in relation to other children, tailor their expectations to what the child can achieve, and provide stimulation, and toys to match the child's readiness for the different milestones. This allows family members to think that they are doing all their can to assist the child, and to bolster the child's sense of being appreciated for who he or she is - an important preventative measure against further emotional disability.

Early intervention will provide preventive strategies for environmentally, and possibly biologically, at-risk children.

In some cases early diagnosis of a genetic disorder, metabolic or infectious disease can prevent further damage, or another child being born with the same disability.

More severe developmental delays come to parents and doctors attention earlier - this includes mental retardation, cerebral palsy and vision problems. These disabilities are usually diagnosed before a child starts school. However, less severe problems like learning difficulties and attention deficit hyperactivity disorder (ADHD), are usually identified in school age children.

Doctors will look at the following factors when investigating concerns about developmental delays:

The best predictors of development are skills relating to brain functioning, rather than reaching specific movement milestones within the expected timeframe.

Motor milestones are excellent indicators of movement skills, but correlate poorly with intellectual functioning.

Language and problem solving milestones in infancy provide the best insights into intellectual potential, and their evolution is independent of motor skills which may be obscured by physical disability.

Psychosocial abilities are critical to understand the whole child and in making a meaningful assessment about behaviour, but they do little in assessing motor and intellectual skills.

A developmental delay is defined as absence of age specific developmental behaviours.

The following is a guideline by age and months of delay:

A delay in learning increases the risk for diagnosis of a specific mental disability or medical condition. These may include:

A developmental delay becomes Mental Retardation after the age 3 years due to ability to provide more accurate tests; however, a diagnosis may be made earlier where there is a significant degree of impairment. (Moderate mental retardation suspected at 12 months, established by 2 years; mild mental retardation suspected at 2 years, established at 3 years). However, parents need to maintain hope, therefore continue to use delay, where there is potential for catch up.

Risk factors

Prenatal maternal factors:

Physical characteristics of mental retardation: Intellectually handicapped children may show some unusual physical signs indicative of mental retardation, these may include a small or large head circumference, a short stature, obesity (Prader-Willi Syndrome), excessive height, limb deformities, unusually shaped ears or placement, and skeletal abnormalities.

Developmental evaluation

Various screening techniques are used to assess the level of intellectual functioning for babies and children. Some of these include:

Risk factors for developmental delay identified on developmental assessment:

Clinical evaluation by doctors only identifies about half the children in need due to some of the following factors:

Early intervention and treatment

What works?

There are several recognised factors which may help limit problems linked to slow development. These include: