PassFinals
Paediatrics

Developmental milestones

Developmental milestones are approximate age-linked skills across several domains; the clinically important task is to assess the child's trajectory, pattern and examination, then act promptly on regression, sustained developmental arrest or guideline-defined referral thresholds.

In a nutshell

Developmental milestones are approximate age ranges across several domains, not pass-fail dates. Assess trajectory and pattern, correct for prematurity up to 2 years, and act on regression, sustained developmental arrest, abnormal neurology, parental concern or the exact NICE motor referral thresholds.

Core rule1,5,3

Use milestone ages as approximate anchors. Diagnose a pattern and trajectory, not one missed checklist item; act earlier if the child has sustained developmental arrest, regression, abnormal neurology or significant parental or professional concern.

Approximate milestone anchors3,4,20,21

These are revision anchors, not referral cutoffs. Normal acquisition spans a range.

AgeMotor / fine motorCommunicationSocial / adaptive
6-8 weeksBrief head lift prone; fixes and followsCooing; responds to voiceSocial smile
3-4 monthsGood head control; reachesCoos and laughsReciprocal interaction
6 monthsRolls; sits with support; transfers objectsTurns to sound; babblesRecognises familiar carers
6-8 monthsSits unsupported; transfers objects; raking graspReduplicative babbleStranger anxiety emerges
9-12 monthsPulls to stand and cruises; pincer grasp emergesGestures; 1-2 meaningful words may emergeWaves, points and plays interactive games
12-15 monthsTakes first independent steps; neat pincer graspUses a few meaningful words and follows a simple commandShows objects and imitates familiar actions
18 monthsWalks; running and scribbling emergeSeveral single words; simple commandsSymbolic play; attempts spoon
2 yearsRuns, kicks ball; tower about 6Two-word phrasesParallel and pretend play
3 yearsPedals tricycle; copies circleSentences of at least 3 wordsInteractive play emerges
4 yearsHops; copies crossLonger, usually intelligible sentencesCooperative imaginative play
5 yearsSkips or balances; copies squareTells a simple storyRule-based cooperative play

Red flags and exact action thresholds

Do not wait for the next routine review when any of these are present.

  • Any true regression. Under 3 with language or social regression: autism diagnostic assessment. Over 3 with language regression, or any age with motor regression: paediatrician or paediatric neurology first.5,6
  • Sustained developmental arrest after earlier progress: urgent paediatric assessment rather than waiting for definite skill loss.2
  • New-onset gait abnormality: immediate acute paediatric referral.5
  • Not sitting unsupported by 8 months corrected, not walking by 15 months in a girl or 18 months in a boy corrected, or hand preference before 1 year corrected: child development referral; consider physiotherapy or occupational therapy.5
  • Abnormal tone, paucity or asymmetry of movement, persistent feeding difficulty or other possible cerebral palsy features: urgent multidisciplinary child development assessment.7
  • Persistent toe walking: refer to a child development service for further assessment.7
  • Dysmorphic features with delay need urgent paediatric referral. In a child under 4 with suspected abnormal head size, a value below the 2nd centile requires paediatric assessment. A change across at least 2 centile lines also requires cranial imaging; if accompanied by tense fontanelle, sixth-nerve palsy, sunsetting, vomiting, ataxia or headache, refer immediately. If head circumference is above the 98th centile without a change of more than 2 centile lines, development and examination are normal and there are no raised-intracranial-pressure features, note biological-parent head sizes; likely familial macrocephaly alone does not need routine referral.5
  • Ongoing or prolonged seizure, acute deterioration, or acute, focal or rapidly progressive neurological change: use the emergency paediatric pathway.5
  • After recovery from a first suspected seizure, or after recurrence following remission: urgently refer to a paediatrician with expertise in first seizures, for an appointment within 2 weeks.10
  • Suspected or confirmed infantile spasms in a child under 2: within 24 hours seek tertiary paediatric-neurology guidance and refer urgently.11

Corrected age8

For developmental assessment in a child born preterm, corrected age = chronological age - (40 weeks - gestational age at birth). Use corrected age up to 2 years. Example: at 6 months chronological age, a child born at 32 weeks is assessed as 4 months corrected.

Rapid assessment

  1. Triage

    Ask first about acute change, loss of skill, seizures, weakness, gait change and systemic illness.5

  2. Characterise

    Record the exact trajectory across all domains and distinguish isolated delay from global delay, transient plateau, sustained developmental arrest and regression.2

  3. Contextualise

    Correct for prematurity, review pregnancy, birth, neonatal and family history, and seek nursery or school information. Assess the child's first language rather than attributing delay to multilingualism. Explore safeguarding sensitively when explanations, interaction, injuries or access to essential care raise concern.8,6,1,19

  4. Examine

    Observe play and communication; plot growth and head circumference; assess dysmorphism, skin, vision, hearing, tone, power, reflexes, symmetry, coordination and gait.5,7,2

Management and referral

Support and referral run in parallel with investigation.

  1. Escalate urgent features

    Use acute paediatrics for new gait or acute neurological change and urgent paediatric assessment for true regression or sustained developmental arrest; then follow the age- and domain-specific pathway.5,6,2

  2. Motor delay

    Use the exact NICE thresholds; refer to child development and consider physiotherapy or occupational therapy. Possible cerebral palsy features need urgent child development referral. In a boy with motor delay or regression, consider creatine kinase before specialist review.5,7

  3. Communication delay

    After age 2 consider speech and language therapy for abnormal speech development. Arrange audiology whenever hearing or vocal development is a concern, even after a passed newborn screen, and use the autism pathway when the whole pattern suggests it.5,9,12

  4. Multi-domain delay or abnormal examination

    Refer to community paediatrics for formal developmental and aetiological assessment. Dysmorphic features with delay require urgent paediatric referral.5,2

  5. Target investigations

    For global or otherwise unexplained delay, secondary care assesses correctable physical causes and chooses genomic, metabolic and imaging tests from the phenotype. In England, R27 whole-genome sequencing is used only when current eligibility is met; use R28 microarray for a recognisable chromosomal phenotype. Separate routine fragile X testing has been replaced within eligible R27 pathways.15,16,17

  6. Start support now

    Coordinate therapy, sensory, health visiting, early-years and special educational needs and disabilities (SEND) support by functional need without waiting for a final diagnosis; agree a named reviewer and safety-net. Explore safeguarding concerns sensitively without assuming that parenting, multilingualism, poverty or adversity explains the delay.1,7,19

  7. Treat causes and comorbidities

    Treat or refer identified hearing, vision, endocrine, nutritional, neurological, feeding and sleep problems while developmental assessment and needs-led support continue.2,7

Exam traps

  • Global developmental delay means significant delay in at least two domains under age 5, conventionally at least 2 standard deviations below age expectations on formal assessment.
  • The NICE sitting referral threshold is 8 months corrected, not 9 months chronological age.
  • The NICE walking thresholds are 15 months in girls and 18 months in boys, corrected for gestation.
  • Hand preference before 1 year is a red flag for unilateral motor dysfunction, not advanced handedness.
  • A passed newborn hearing screen does not rule out later-onset or acquired hearing loss.
  • Parallel play is an approximate 2-year anchor; interactive play emerges around 3 years.
  • A screening questionnaire supports surveillance but does not make a diagnosis.
  • Do not dismiss language delay because English is not the child's first language; assess communication in the first language.
  • Do not automatically request the retired microarray plus separate fragile X combination: in England, genomic testing follows the current Test Directory and phenotype-specific eligibility.

Illustrations

The four clinical developmental domainsA visual summary of gross motor, fine motor and vision, hearing and communication, and social, emotional, behavioural and adaptive development.PassFinals · original

Key sources

  1. GOV.UK: Delivery of the Healthy Child Programme, part 2 - health visiting ages 0 to 5Updated 12 Mar 2026
  2. NHS Genomics Education Programme: Patient with developmental delayUpdated 6 Feb 2026
  3. Just One Norfolk NHS children's service: Developmental milestones
  4. Frimley Healthier Together: Movement development
  5. NICE NG127: Suspected neurological conditions - recommendations for children aged under 16 (NICE NG127)Published 1 May 2019 | Updated 2 Oct 2023
  6. NICE CG128: Autism spectrum disorder in under 19s - recognition, referral and diagnosis (NICE CG128)Published 28 Sept 2011 | Updated 20 Dec 2017
  7. NICE NG62: Cerebral palsy in under 25s - assessment and management (NICE NG62)
  8. NICE NG72: Developmental follow-up of children and young people born preterm (NICE NG72)Published 9 Aug 2017
  9. NICE CG128: Features suggesting possible autism (NICE CG128 appendix)
  10. NICE NG217: Diagnosis and assessment of epilepsy - referral after a first seizure (NICE NG217 section 1.1)Published 27 Apr 2022 | Updated 30 Jan 2025
  11. NICE NG217: Treating childhood-onset epilepsies - infantile spasms syndrome (NICE NG217 section 6.3)Published 27 Apr 2022 | Updated 30 Jan 2025
  12. NHS England: Surveillance and audiological referral after newborn hearing screeningPublished 1 Jun 2012 | Updated 25 Feb 2026
  13. UK National Screening Committee: Child vision screeningPublished 28 Sept 2023
  14. NHS Genomics Education Programme: Child with developmental delay or intellectual disabilityUpdated 4 Feb 2026
  15. NHS England National Genomic Test Directory: Testing Criteria for Rare and Inherited Disease, version 9.1 (Version 9.1)Updated 20 May 2026
  16. NHS Genomics Education Programme: R27 Paediatric disorders (R27)Updated 1 May 2026
  17. NHS Genomics Education Programme: Child with suspected fragile X syndromeUpdated 21 Nov 2025
  18. GOV.UK: Delivery of the Healthy Child Programme, part 1 - principles of deliveryUpdated 12 Mar 2026
  19. NICE CG89: Child maltreatment - when to suspect maltreatment in under 18s (NICE CG89)Published 22 Jul 2009 | Updated 3 Dec 2025
  20. Somerset NHS Foundation Trust: Pre-writing developmental skills
  21. Oxford Health NHS Foundation Trust: Childhood developmentUpdated 21 Nov 2025
  22. Archives of Disease in Childhood: Current evidence-based recommendations on investigating children with global developmental delay (Arch Dis Child 2017;102:1071-1076)Published 20 Oct 2017
  23. RCPCH State of Child Health 2026: Early childhood developmentUpdated 14 Jul 2026

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.