Synopsis
Define a child's developmental profile, distinguish isolated from global delay and developmental difference, identify sensory, neurological, genetic, medical and environmental contributors, and begin needs-led support while diagnosis proceeds.
- Global developmental delay means significant delay in at least two domains in a child younger than 5; isolated delay predominantly affects one domain.
- Describe the profile and function before seeking an aetiological label: gross motor, fine motor or vision, speech and language, cognition or play, social-emotional and adaptive skills.
- Use exact and corrected age, serial acquisition and real-world examples from caregivers and nursery or school; one clinic performance is insufficient.
- First-line assessment is a comprehensive developmental, medical, birth, family and social history plus growth, dysmorphology, neurological, hearing and vision assessment.
- Support strong parental concern even when a screening questionnaire is reassuring; developmental tools structure assessment but do not exclude pathology.
- Isolated motor delay prompts examination of tone, power, reflexes, symmetry and CK consideration in boys; isolated language delay always prompts hearing assessment.
- Global delay has a broad differential including genomic disorders, prenatal exposure, brain malformation or injury, cerebral palsy, sensory loss, endocrine and metabolic disease and severe psychosocial adversity.
- Genomic testing follows the current NHS National Genomic Test Directory phenotype and eligibility criteria, with consent and clinical-genetics support where needed.
- Routine blanket MRI, EEG or metabolic panels are not appropriate for every child; abnormal neurology, head size, seizures, regression or metabolic features increase yield.
- A normal EEG cannot exclude epilepsy, and EEG is not a general test for developmental delay without episodes or regression suggesting epileptic activity.
- Management is needs led: therapy, communication support, hearing or vision correction, nutrition, education and family support begin before the cause is finalised.
- Reassess the diagnostic formulation over time because an apparently isolated delay may become multidomain as developmental demands increase.
Key red flags
Loss of any established developmental skill changes the problem from delay to regression and requires prompt neurodevelopmental or neurological referral.
Dysmorphism with developmental delay, congenital anomalies or abnormal head growth requires urgent or expedited paediatric and genomic assessment.
Seizures, episodic encephalopathy, unusual odour, organomegaly, movement disorder or deterioration during fasting or illness suggests a metabolic or neurodegenerative disorder.
Persistent asymmetry, abnormal tone, early hand preference, weakness or fatigability indicates cerebral palsy, neuromuscular disease or structural neurological pathology.
Inconsistent response to sound, visual inattention or speech delay warrants formal audiology and vision assessment rather than attributing the whole profile to cognition.
Poor growth, feeding difficulty, bruising, missed care, unsafe home conditions or lack of developmental opportunity requires coordinated medical and safeguarding assessment.
Investigation priorities
Define which domains are delayed, severity, strengths and functional support needs.
Detect sensory impairment causing or compounding delay.
Management branches
A caregiver, health visitor, nursery or clinician raises developmental concern.
- Map every domain, adaptive function, acquisition and any loss using exact and corrected age and reports from more than one setting.
- Plot growth and head circumference and complete sensory, neurological, dysmorphology and systemic assessment.
- Classify provisionally as isolated, global, dissociated, deviated or regressive and refer at defined motor or speech thresholds.