• by parents, who are provided with guidance about normal development in their child’s personal child health record and in a book Birth to Five, given to all parents in the UK

• at regular child health surveillance checks

• whenever a young child is seen by a healthcare professional, when a brief opportunistic overview is made.

• help children achieve their maximum potential

• provide treatment or therapy promptly (particularly important for impairment of hearing and vision)

• act as an entry point for the care and management of the child with special needs.

Influence of heredity and environment

A child’s development represents the interaction of heredity and the environment on the developing brain. Heredity determines the potential of the child, while the environment influences the extent to which that potential is achieved. For optimal development, the environment has to meet the child’s physical and psychological needs (Fig. 3.1). These vary with age and stage of development:

Fields of development

There are four fields of developmental skills to consider whenever a young child is seen (Fig. 3.2):

Gross motor skills are the most obvious initial area of developmental progress. As fine motor skills require good vision, these are grouped together; similarly, normal speech and language development depends on reasonable hearing and so these are also considered together. Social, emotional and behavioural skills are a spectrum of psychological development.

The acquisition of developmental abilities for each skill field follows a remarkably constant pattern between children, but may vary in rate. It is like a sequential story. Thus, the normal pattern for acquisition of skills:

A deficiency in any one skill area can have an impact on other areas. For instance, a hearing impairment may affect a child’s language, social and communication skills and behaviour. As a child grows, additional skills become important, such as attention and concentration and how an individual child manages to integrate their skills.

Developmental milestones

Chronological age, physical growth and developmental skills usually evolve hand in hand. Just as there are normal ranges for changes in body size with age, so there are ranges over which new skills are acquired. Important developmental stages are called developmental milestones.

When considering developmental milestones:

Variation in the pattern of development

There is variation in the pattern of development between children. Taking motor development as an example, normal motor development is the progression from immobility to walking, but not all children do so in the same way. While most achieve mobility by crawling (83%), some bottom-shuffle and others crawl with their abdomen on the floor, so-called commando crawling (creeping) (Fig. 3.3). A very few just stand up and walk. The locomotor pattern (crawling, creeping, shuffling, just standing up) determines the age of sitting, standing and walking.

The limit age of 18 months for walking applies predominantly to children who have had crawling as their early mobility pattern. Children who bottom-shuffle or commando crawl tend to walk later than crawlers, so that within those not walking at 18 months there will be some children who demonstrate a locomotor variant pattern, with their developmental progress still being normal. For example, of children who become mobile by bottom-shuffling, 50% will walk independently by 18 months and 97.5% by 27 months of age, with even later ages for those who initially commando crawl.

Is development normal?

When evaluating a child’s developmental progress and considering whether it is normal or not:

This will enable you to decide if the child’s developmental progress is normal or delayed. Normal development implies steady progress in all four developmental fields with acquisition of skills occurring before limit ages are reached. If there is developmental delay, does it affect all four developmental fields (global delay), or one or more developmental field only (specific developmental delay)? As children grow older and acquire further skills, it becomes easier to make a more accurate assessment of their abilities and developmental status.

Pattern of child development

This is shown pictorially for each field of development, including key developmental milestones and limit ages:

• Gross motor development (Fig. 3.4 and Table 3.1)

Table 3.1

The primitive reflexes present at birth gradually disappear as postural reflexes develop, which are essential for independent sitting and walking

Primitive reflexes	Postural reflexes
Moro – sudden extension of the head causes symmetrical extension, then flexion of the arms Grasp – flexion of fingers when an object is placed in the palm Rooting – head turns to the stimulus when touched near the mouth Stepping response. – stepping movements when held vertically and dorsum of feet touch a surface Asymmetrical tonic neck reflex. – lying supine, the infant adopts an outstretched arm to the side to which the head is turned	Labyrinthine righting. – head moves in opposite direction to which the body is tilted
	Postural support. – when held upright, legs take weight and may push up (bounce)
	Lateral propping. – in sitting, the arm extends on the side to which the child falls as a saving mechanism
	Parachute – when suspended face down, the arms extend as though to save themself

• Vision and fine motor (Fig. 3.5)

• Hearing, speech and language (Fig. 3.6)

• Social, emotional and behavioural (Fig. 3.7).

In order to screen a young child’s development, it is necessary to know only a limited number of key developmental milestones and their limit ages.

Cognitive development

Cognition refers to higher mental function. This evolves with age. In infancy, thought processes are centred around immediate experiences. The thought processes of preschool children (which have been called preoperational thought by Piaget, who described children’s intellectual development) tend to be that:

In middle-school children, the dominant mode of thought is practical and orderly, tied to immediate circumstances and specific experiences. This has been called operational thought.

It is only in the mid-teens that an adult style of abstract thought (formal operational thought) begins to develop, with the ability for abstract reasoning, testing hypotheses and manipulating abstract concepts.

Summary

Fields of development with limit ages

Analysing developmental progress

Detailed assessment

So far, emphasis has been mainly on thinking about developmental progress in a longitudinal way, taking each skill field and its progression separately, and then relating the progress in each to the others and to chronological age. This is the fundamental concept of learning how to think about developmental assessment of children. Detailed questioning and observation is required to assess children with developmental problems but is unnecessary when screening developmental progress in normal clinical practice, when a short-cut approach can be adopted.

The short-cut approach

This concentrates on the most actively changing skills for the child’s age. The age at which developmental progress accelerates differs in each of the developmental fields. Figure 3.8 demonstrates the age when there is the most rapid emergence of skills in each developmental field. This means there is for:

• gross motor development: an explosion of skills during the first year of life

• vision and fine motor development: more evident acquisition of skills from 1 year onwards

• hearing, speech and language: a big expansion of skills from 18 months

• social, emotional and behavioural development: expansion in skills is most obvious from 2.5 years.

Understanding the time when acceleration in each skill field becomes more obvious and knowing the child’s age helps guide the direction of initial developmental questioning. Thus for a child aged:

• <18 months – it is likely to be most useful to begin questions around gross motor abilities, acquisition of vision and hearing skills, followed by questions about hand skills.

• 18 months to 2.5 years – initial developmental questioning is likely to be most usefully directed at acquisition of speech and language and fine motor (hand) skills with only later and brief questioning about gross motor skills (as it is likely the child would have presented earlier if these were of concern).

• 2.5 to 3.5 years – initial questions are best focused around speech and language and social, emotional and behaviour development.

Developmental questioning needs to cover all areas of developmental progression but this more focused way of taking a developmental history allows a useful short-cut approach. It directs the assessment to current abilities instead of concentrating on parents trying to remember the age when their child acquired developmental milestones some time in the past.

Observation during questioning

Of equal importance to taking the developmental history is the examiner’s ability to observe the child throughout any visit. Not only will this provide an almost immediate guide to where to begin questioning but also it will offer the opportunity for a rapid overview of the child’s abilities, behaviour, peer group and parent–child relationships, all of which will go towards determining the overall picture about the child and his developmental abilities.

Equipment for developmental testing

Simple basic equipment is all that is needed for most developmental assessments. Equipment is aimed at bringing out the child’s skills using play. Cubes, a ball, picture book, doll and miniature toys such as a tea-set, crayons and paper allow a quick but useful screen of mobility, hand skills, play, speech and language. These items allow the child to relax by having fun at the same time as facilitating observer assessment of his skills.

Developmental screening and assessment

Developmental screening (checks of whole populations of children at set ages by trained professionals) is a formal process within the child health surveillance and promotion programme. It is also an essential role of all health professionals to screen a young child’s developmental progress opportunistically at every health contact, e.g. by the general practitioner for a sore throat, in the Accident and Emergency department for a fall or on admission to a paediatric ward. In this way, every child contact is optimised to check that development is progressing normally.

There are a number of problems inherent in developmental screening:

The reliability of screening tests can be improved by adding a questionnaire completed by parents beforehand. Screening is being increasingly targeted towards children at high risk or when there are parental concerns.

Developmental assessment is the detailed analysis of particular areas of development and follows concern after screening that a child’s developmental progress may be abnormal in some way. It is part of the diagnostic process and includes investigation, therapy and advice on how to optimise the child’s progress. Developmental assessment is by referral to a specialist service and this may be the developmental paediatrician, therapy disciplines, or the local multidisciplinary child development service, which will include a paediatrician.

A range of tests have been developed to screen or to assess development in a formal reproducible manner. Screening tests include the Schedule of Growing Skills and the Denver Developmental Screening Test. Standardised tests that assess the development of infants and young children include the Griffiths and the Bailey Infant Development Scales. They are used, for example, in follow-up studies of preterm infants. There are also standardised tests concentrating on assessing specific aspects of development (e.g. the Reynell language scale, the Gross Motor Function Measure (GMFM) and the Autism Diagnostic Interview). All but the screening tests are time-consuming and require training for reliable results.

Cognitive function (higher mental function) can be assessed objectively with formal IQ tests by clinical or educational psychologists. However, IQ tests:

‘Verbal’ intelligence tests, especially those for younger children, reflect general intellectual skills, particularly relating to language. ‘Performance’ or ‘non-verbal’ intelligence tests assess abilities independent of language. Verbal and performance intelligence testing allows formulation of a verbal IQ (VIQ) and performance IQ (PIQ), which together give an overall IQ figure. Children with disabilities may have problems with speech or hand skills that may compromise testing, so that results in these situations have to be interpreted with care.

Cognitive (higher mental function) assessment of school-age children using IQ and other tests is carried out by clinical or educational psychologists.

Child health surveillance

In the UK, the healthy child programme (HCP) was introduced in 2009 (previously the child health promotion programme). It spans from pregnancy to 19 years old, but the main emphasis is on ages 0–5 years.

It offers families a programme of:

There is a ‘universal’ programme, and a ‘progressive’ programme for families thought to be more at risk. Those in the progressive programme include infants or children with health or developmental problems, children at increased risk of obesity or families considered to be at higher risk, e.g. at-risk first-time mothers; parents with learning difficulties, drug or alcohol abuse or serious mental illness, insensitive (i.e. intrusive or passive) parenting interactions or domestic violence. These families receive additional intervention according to need. The programme is a compromise between the desire to detect problems and provide early intervention for all, while avoiding an excessive number of assessments. The way the healthy child programme (HCP) is organised is shown in Table 3.2. At each review, a check is made for specific physical abnormalities and on the child’s overall development, health and growth. Selected health promotion topics are considered. There is an emphasis on parental opinion for vision, hearing, speech and language, as parents are usually excellent at the early detection of these problems. Details of each review are entered into the child’s personal child health record kept by parents and brought whenever the child is seen by a health professional.

Table 3.2

The healthy child programme (HCP) provided by integrated local services, usually led by a health visitor

Age and checked by whom	Screening	General examination and immunisation	Health promotion
Antenatal (by 12th week of pregnancy) Midwife, GP or obstetrician	Antenatal screening for fetal conditions (see NICE guidelines for antenatal care)	Maternal health, fetal growth, maternal immunisation (rubella)	Universal: smoking and alcohol intake, mental health, breast-feeding
Newborn–72 h Usually hospital doctor; may be trained midwife, neonatal nurse practitioner or GP	Screening on examination includes eyes (red reflex), developmental dysplasia of the hip (DDH), testes in boys. Newborn Hearing Screening Programme Bilirubin check by 48 h if jaundiced	Normal newborn examination: general examination, weight and head circumference plotted on centile graph, BCG offered (repeated at 1, 2, 12 months) if at risk Hepatitis B vaccine if indicated (mother HepBsAg positive) Vitamin K	Universal: feeding, personal child health record and Birth to Five book, promoting sensitive parenting, prevention of sudden infant death syndrome
5–8 days (ideally Day 5) Midwife	Blood spot test for biochemical and haematological screening
New baby review (by 14 days) Home visit by midwife or health visitor	Assess child and family health needs, including parental mental health needs	Examine baby for nutritional status and prolonged jaundice	Infant feeding, promote sensitive parenting, advice on promoting development, home safety
6–8 weeks General practitioner	Physical examination: cardiac abnormalities (heart murmurs and femoral pulses), DDH, testicular descent in boys, red reflex of fundus, matters of parental concern	Full physical examination, weight, head circumference and plot growth centiles Vision/hearing – any parental concern? 1st immunisation – DTaP/IPV, Hib, PCV	Nutrition, immunisations, recognition of illness, avoid passive smoking, crying and sleep problems, maternal mental health
3 months Child health clinic	General review of progress, address parental concerns such as growth	2nd immunisation – DTaP/IPV/Hib, MenC, rotovirus	Support families by providing access to parenting and child health information
4 months Child health clinic	General review of progress	Third immunisation – DTaP/IPV/Hib, PCV MenC	Weaning on to solids around 6 months
7–9 months Health visiting team	Systematic assessment of the child’s physical, emotional and social development and family needs	If parental concern – hearing, vision, development, growth	Distribution of books,a accident prevention: choking, scalds and burns, safety gates, nutrition and dental care, skin care (sunburn)
12–13 months Child health clinic	General review of progress	Immunisation – Hib, MenC, PCV, MMR	Dental health
year review Health visiting team coordinate this key review	Nutrition, active play, personal, social and emotional development, speech, language and communication	Review immunisation status and physical status according to parental concerns	Obesity prevention, injury prevention, advice on how to seek medical help
3–5 years (preschool) Heath visiting team	General review of progress	3-4 years immunisation – MMR, DTaP/IPV	Health promotion and supporting parents
By 5 years (to be completed soon after school entry) School nurse	Orthoptist: screen all children for visual impairment (4–5 years) School nurse: hearing screening (audiometry), growth	Review immunisation status Measure height and weight, plot centilesb Physical examination if parental concern	Health promotion and supporting parents
5–11 years School nurse	Share information about preschool background, assessment of emotional health, psychological well-being and mental health	Nursing care provided according to needs	Promote healthy weight, support for parents and carers
11–16 years School nurse	Health review at school transition at 10–11 and 15–16 years by questionnaires, engaging primary care in mid-teens, emotional health, psychological well-being and mental health	Immunisation (13–16 years) – Td/IPV Human papilloma virus (HPV) in girls If at risk – BCG, Hep B, influenza	Sexual health, promote healthy weight
16–19 years (Further Education) School nurse, GP	Share information from school with adult services, emotional health, psychological well-being and mental health	Review immunisation status	Sexual health, encourage physical activity, support for parents and carers

DTaP/IPV: Diphtheria, tetanus, pertussis, polio immunization; Hib: Haemophilus B influenzae; PCV: Pneumococcal;

MenC: Meningitis C; Td/IPV: Diphtheria, tetanus, polio; MMR: Measles, Mumps and Rubella

^aBookstart – national programme to encourage parents and carers to enjoy books with their children from an early age.

^bThe national child measurement programme – height and weight of all reception and year 6 children.

Adapted from: The Healthy Child Programme 2009, Department of Health, London, UK.

The HCP is carried out in primary care, usually by health visitors. If problems are identified, an action plan is made for the child, which could involve advice and monitoring progress or referral to the general practitioner or specialist.

Hearing

During the later stages of pregnancy, the fetus responds to sound. At birth, a baby startles to sound, but there is a marked preference for voices. The ability to locate and turn towards sounds comes later in the first year. A checklist for parents of normal hearing responses during infancy is shown in Box 3.1.

Hearing tests

Newborn

Early detection and treatment of hearing impairment improves the outcome for speech and language and behaviour. In order to detect hearing impairment in the newborn period, hearing can be tested by:

• Evoked otoacoustic emission (EOAE) (Fig. 3.9a) – an earphone produces a sound which evokes an echo or emission from the ear if cochlear function is normal.

• Auditory brainstem response (ABR) audiometry (Fig. 3.9b) – computer analysis of EEG waveforms evoked in response to a series of auditory stimuli.

Universal neonatal hearing screening has been introduced in many countries. In the UK, initial screening is performed using different combinations of EOAE testing or ABR audiometry. If a normal response cannot be obtained, the child is referred to an audiologist.

Hearing tests

Distraction testing

This was the mainstay of hearing screening but has been replaced by universal neonatal screening. It is now only used as a screening test for infants who have not had newborn screening or as a diagnostic test. It is performed at 7–9 months of age (Fig. 3.10). The test relies on the baby locating and turning appropriately towards sounds. High- and low-frequency sounds are presented out of the infant’s field of vision. Testing is unreliable if not carried out by properly trained staff, since it can be difficult to identify hearing-impaired infants as they are particularly adept at using non-auditory cues.

Visual reinforcement audiometry

This is particularly useful to assess impairment in infants between 10 and 18 months, although it can be used between the age of 6 months and 3 years. Hearing thresholds are established using visual rewards (illumination of toys) to reinforce the child’s head turn to stimuli of different frequencies. Localisation of the stimuli is not necessary and insert earphones may be used to obtain ear-specific information, thus making it more useful than free field tests such as distraction and performance testing (Fig. 3.11).

Performance and speech discrimination testing

Performance testing using high- and low-frequency stimuli and speech discrimination testing using miniature toys can be used for children with suspected hearing loss at 18 months to 4 years of age (Fig. 3.12).

Audiometry

Threshold audiometry using headphones, where the child responds to a pure tone stimulus, can be used to detect and assess the severity of hearing loss in children from 4 years old.

Vision

A newborn infant’s vision is limited; the visual acuity is only about 6/200 (can see at 6 metres what a normally sighted adult can see at 200 metres). The peripheral retina is well developed but the fovea is immature and the optic nerve unmyelinated. Well-focused images on the retina are required for the acquisition of visual acuity and any obstruction to this, e.g. from a cataract, will interfere with the normal development of the optic pathways and visual cortex unless corrected early in life.

Many newborn infants can fix and follow horizontally a face or coloured ball or the image of a target of concentric black and white circles. Most squint transiently, particularly when the baby tries to look at near objects and the eyes over-converge.

By about 6 weeks of age, both eyes should move together when following a light source. By 12 weeks, no squint should be present. Babies slowly develop the ability to focus at different distances. Visual acuity also improves: from 6/60 at 3 months to being able to poke at 1 cm objects at 8 months and at 1 mm objects (e.g. ‘hundreds and thousands’ cake sprinkles) at 15 months. Adult levels are reached by 3–4 years of age, when the child can match pictures or letters at 6/6 using both eyes together.

Vision testing

The assessment of vision at different ages is shown in Table 3.3. All children in the UK are screened for visual acuity and squint at school entry. In some parts of the UK, screening is carried out in preschool children at 4–5 years.

Table 3.3

Testing vision at different ages

Age	Test
Birth	Face fixation and following
6–8 weeks	Fix and follow bright toy, optokinetic nystagmus
6 months	Reaches well for toys, preferential looking tests
years	Can identify or match pictures of reducing size (Kay pictures)
4 years	Can identify or match letters in linear optotype book (Crowded LogMAR)
6 years onwards	Can identify or match letters on a LogMAR chart

Note: Using single letters/pictures instead of lines underestimates amblyopia severity (see Ch. 4).

Summary

Vision

• Term newborn infants can fix and follow horizontally and prefer to watch faces.

• Visual acuity is poor in the newborn but increases to adult levels by 4 years of age.

• Vision screening is performed at school entry or in preschool children.