01Purpose and principlesWhat the assessment is for and the core concepts behind it.
Development is the progressive acquisition and integration of skills. Domains are described separately for assessment but influence one another: hearing affects language, motor control affects exploration, vision affects fine motor function and social opportunity affects communication. A single delayed item may be normal variation; a persistent pattern, functional impairment or loss of skills needs structured assessment.
Gross motor development progresses through head and trunk control, rolling, sitting, mobility, standing, walking, running, jumping and balance. Examine how a skill is achieved, not only whether it is recorded. Bottom shuffling can be a normal locomotor variant when symmetry, tone and other development are normal. Persistent head lag, asymmetry, toe walking with abnormal tone, scissoring or loss of endurance suggests pathology.
Fine motor and visual development includes fixation and following, reaching, transferring, pincer grasp, releasing, stacking, scribbling, copying and tool use. Test with safe age-appropriate objects and each hand. A consistent hand preference before 1 year can mean contralateral weakness rather than advanced laterality. Visual inattention, squint or inability to reach accurately warrants vision assessment.
Speech and language separates receptive language, expressive language, speech production and social communication. Understanding generally precedes spoken output. Track response to name and sound, babble, gesture, joint attention, single words, word combinations and conversation. Count meaningful use rather than imitation alone. In multilingual children assess skills across all languages; learning more than one language does not itself cause disorder.
Social and emotional development includes social smile, reciprocal interaction, attachment behaviours, joint attention, imitation, pretend play, peer interest, emotional regulation and perspective-taking. Temperament and culture influence expression. Reduced eye contact alone is non-specific; look for an integrated pattern of reciprocal communication, flexible behaviour and relationships across contexts.
Cognitive and play development is inferred from exploration, object permanence, cause and effect, problem-solving, symbolic play, attention and learning. Adaptive development includes feeding, dressing, toileting and safety skills. Ask what the child can do independently and with prompting. Functional skill can reveal need for support even when a formal milestone appears present.
In early infancy, observe alertness, spontaneous symmetrical movement, visual fixation, response to sound, feeding and interaction. Around 6–8 weeks a social smile commonly emerges. By roughly 3–4 months, head control, reaching, laughing or vocal turn-taking develops. Exact timing varies; poor visual engagement, absent response to sound, marked hypotonia or asymmetry is more important than missing one calendar date.
Around 6 months, many infants roll, sit with support, reach accurately, transfer objects and babble. Around 9 months, many sit without support, move toward objects, use an emerging pincer grasp, respond socially and make repetitive consonant sounds. NICE uses failure to sit unsupported by 8 months corrected age as a referral threshold, so do not let a broad milestone range override a defined red flag.
Around 12 months, many infants pull to stand, cruise or take steps, use a mature pincer grasp, point or wave, understand simple familiar instructions and say one or more meaningful words. Variation in independent walking is wide. Early hand preference, persistent primitive reflexes, asymmetrical crawling or inability to bear weight requires neurological assessment rather than waiting for speech development.
Around 18 months, many children walk independently, climb with help, scribble, place blocks, use several meaningful words, follow simple commands and begin pretend play. NICE recommends referral if independent walking has not occurred by 15 months in girls or 18 months in boys, corrected for gestation. Consider CK in a boy with motor delay before specialist review to help exclude Duchenne muscular dystrophy.
Around 2 years, many children run, kick a ball, walk up steps with support, stack several blocks, use two-word combinations and demonstrate symbolic and parallel play. Around 3 years, speech becomes conversational, play more interactive, stairs and jumping improve and a circle may be copied. At 4–5 years, hopping, dressing, drawing, intelligible narrative, cooperative play and rule understanding mature. These examples guide observation, not replace a validated assessment.
Correct age when interpreting a preterm child's early development. Subtract the number of weeks born before 40 weeks from chronological age for the correction period on the relevant UK chart or pathway. Record both ages and stop correction at the recommended time. Prematurity also increases risk of motor, sensory and cognitive difficulty, so correction prevents false delay but should not dismiss abnormal quality or trajectory.
Developmental surveillance is longitudinal and opportunistic; developmental screening uses a structured tool at defined points; diagnostic assessment is a detailed multidisciplinary process. A screening questionnaire such as ASQ-3 can organise information but cannot diagnose cerebral palsy, autism or intellectual disability. An apparently normal score should not override regression, neurological findings or strong parent and professional concern.
End with a plan based on function and risk. Reassure a normal variant only when the overall profile, examination, trajectory and environment are reassuring and define review. Refer isolated speech concern to speech and language and audiology; motor thresholds to child development and therapy; social-communication concern to the local autism pathway; and global delay to community paediatrics. Begin support while the cause is investigated.
Key points
- Assess gross motor, fine motor and vision, speech and language, social and emotional, cognition or play, and adaptive or self-care development.
- Milestones are age ranges, not pass–fail dates; sequence, quality, symmetry, trajectory and impact matter more than memorising one median age.
- Correct developmental age for prematurity, generally until age 2 years for infants born before 32 weeks and until age 1 for those born at 32–36 weeks.
- Use parent concerns as clinical data and obtain nursery or school observations; children can perform differently across people, settings and languages.
- First-line assessment includes observation through play, developmental history, growth and head circumference, neurological examination, hearing and vision review.
- By around 6–8 weeks many infants show a social smile; lack of interaction later must be interpreted with vision, hearing and overall state.
- By around 6 months many infants reach and transfer objects, roll, sit with support and produce varied babble.
- By around 9 months many sit unsupported, use emerging pincer grasp, babble repetitively, show social referencing and enjoy interactive games.
- Around 12 months many pull to stand or cruise, use a mature pincer grasp, wave or point and say one or more meaningful words.
- Around 18 months many walk independently, scribble, build a small tower, use several words and begin simple pretend play.
- Around 2 years many run, manage stairs with help, build a tower, combine two words and engage in parallel and symbolic play.
- Regression, persistent asymmetry and missed NICE motor thresholds override watchful waiting; refer while beginning hearing, vision and cause-directed assessment.
02Indications, selection and cautionsWhen it is useful, when urgency changes and important limitations.
A skill emerges later within a broad range while sequence, quality, other domains, examination and continued acquisition remain reassuring.
One domain persistently lags while other domains and general examination are relatively preserved, directing sensory and domain-specific assessment.
Significant difficulty affects at least two developmental domains in a young child and raises genetic, neurological, metabolic, sensory and environmental causes.
Domains develop at notably different rates, such as motor impairment with preserved social understanding, which can guide the underlying diagnosis.
Skills appear in an unusual quality or sequence—persistent asymmetry, echolalia without reciprocal language or atypical movement—rather than simply late.
A previously established skill is lost, demanding confirmation, urgent cause assessment and referral rather than routine milestone monitoring.
03Method and interpretationA systematic approach to the test and its findings.
Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.
- 01
First-line: structured developmental historyFirst stepFirst line - Why
- Map acquisition, quality, sequence and any loss across all domains.
- Interpretation and limitations
- Use corrected age, examples of real function and parent plus nursery or school reports; clarify whether a skill was secure before calling regression.
- 02
First-line: play-based developmental observationFirst line - Why
- Observe motor, hand, communication, cognition and reciprocity in a low-distress setting.
- Interpretation and limitations
- Adapt for fatigue, language, sensory impairment and environment; one unfamiliar-clinic performance cannot define ability.
- 03
Growth and neurological examination - Why
- Identify abnormal head growth, tone, power, reflexes, asymmetry, movement, dysmorphism and systemic disease.
- Interpretation and limitations
- Neurological or syndromic signs change an isolated milestone concern into a specialist diagnostic pathway.
- 04
First-line: hearing and vision assessmentFirst line - Why
- Find sensory impairment that can cause or compound language, motor and social delay.
- Interpretation and limitations
- A clear newborn hearing screen does not exclude acquired, progressive or unilateral loss; use age-appropriate formal testing when concerned.
- 05
Validated developmental screening tool - Why
- Structure surveillance and quantify areas needing fuller assessment.
- Interpretation and limitations
- A positive result supports referral, while a negative score does not overrule regression, examination findings or persistent concern.
- 06
Multidisciplinary diagnostic assessment - Why
- Define strengths, needs, functional impact and likely cause when delay is significant or complex.
- Interpretation and limitations
- Community paediatrics integrates therapy, psychology, education, audiology, vision, genetics and neurology according to the profile.
04Clinical next stepsHow the result changes management or prompts escalation.
01Routine reviewSurvey every domainFirst stepA child attends a scheduled health or general clinical review.+
- 1Ask parent concerns first and review gross motor, fine motor or vision, language, social, cognitive and adaptive function.
- 2Observe play and interaction, plot growth and head circumference and perform focused sensory and neurological examination.
- 3Record acquired skills and quality, give development-promoting advice and state the next surveillance point.
02Possible normal variantConfirm continued progressOne milestone is later but the child otherwise appears well and continues to acquire skills.+
- 1Check exact and corrected age, opportunity, hearing, vision, neurological quality and the wider domain profile.
- 2Explain the range of normal, support practice without pressure and define a short, specific review interval.
- 3Refer if progress stops, another domain becomes affected, function is impaired or family concern persists.
03Motor red flagRefer at NICE thresholdsSitting, walking, symmetry, tone or gait meets a defined motor concern.+
- 1Refer to a child development service and consider physiotherapy or occupational therapy without waiting for a final diagnosis.
- 2For a boy with motor delay or regression, consider CK before specialist review as NICE advises.
- 3Use immediate acute paediatric referral for a new gait abnormality, acute weakness or encephalopathy.
04Communication concernAssess hearing and social communicationBabble, words, understanding, speech clarity or interaction is delayed or atypical.+
- 1Arrange age-appropriate hearing assessment and examine the ears even when newborn screening was clear.
- 2Refer abnormal speech development after age 2 to speech and language services and review all languages used.
- 3Use the local autism pathway for social-communication features or regression, with paediatric or neurology assessment according to age and domain lost.
05Multidomain or regressionEscalate and support in parallelEscalationAt least two domains are significantly delayed or a secure skill is lost.+
- 1Refer promptly to community paediatrics or paediatric neurology according to acuity and regression pattern.
- 2Complete growth, neurological, sensory and safeguarding assessment and begin phenotype-directed investigations.
- 3Start therapy, communication, educational and family support while diagnostic work continues.
05Risks, monitoring and follow-upComplications, safety checks and further assessment.
- Document specific functional examples rather than ‘development normal’, so later clinicians can identify plateau or loss.
- Use corrected age consistently for preterm children during the recommended period and state when correction will stop.
- Review every domain after an isolated concern because the pattern may evolve as developmental demands increase.
- Track hearing, vision, growth and head circumference alongside skills; sensory or head-growth change can precede clearer developmental signs.
- After referral, confirm therapy and educational support began and do not wait for aetiological diagnosis before meeting functional needs.
- Ask at each contact whether any skill has been lost, whether episodes suggest seizures and whether caregivers or nursery see deterioration.
06Special situationsVariants, exceptions and circumstances that change the usual approach.
Quality beats a tick box
A child who walks with persistent asymmetry or says words without communicative use needs more assessment than a milestone checklist shows.
Understanding precedes expression
Receptive language, gesture and joint attention help distinguish an expressive speech delay from broader communication difficulty.
Hand preference can be pathological
Consistent laterality before 1 year may represent reduced use of the opposite hand from hemiplegic cerebral palsy.
Correction has limits
Prematurity correction avoids false delay but does not explain abnormal tone, asymmetry, regression or a worsening developmental trajectory.
Screening is not diagnosis
A tool estimates likelihood and structures referral; multidisciplinary assessment determines the developmental profile and cause.
Support need not await a label
Physiotherapy, hearing support, communication strategies and educational adjustments can begin during diagnostic investigation.
07Common pitfallsFrequent interpretation and management errors.
- 01
Do not use one milestone age as a rigid developmental deadline outside a validated referral threshold.
- 02
Do not assess only the domain that prompted the appointment.
- 03
Do not forget corrected age in a preterm infant.
- 04
Do not treat bottom shuffling as pathological when symmetry, tone and the rest of development are normal.
- 05
Do not call early hand preference advanced development.
- 06
Do not assume a clear newborn hearing screen excludes later hearing loss.
- 07
Do not attribute language delay to bilingualism without assessing skills across all languages and hearing.
- 08
Do not let a normal screening score override regression or abnormal neurological examination.
- 09
Do not delay referral until a child has missed multiple later milestones after a NICE motor red flag is reached.
- 10
Do not reassure loss of skills as a normal plateau.