How can I differentiate between normal variations in development and significant developmental delay in preschool children?

Differentiating between normal variations in development and significant developmental delay in preschool children involves a combination of evaluating parental concerns, observing specific developmental milestones, and utilising structured assessment tools ¹.

• General Approach and Parental Concerns: Professionals should discuss and carefully evaluate any developmental concerns reported by parents or carers ¹. For children born preterm, development should be corrected for gestational age up to 2 years ¹.
• Key Indicators of Significant Delay:
  • Motor Development: Significant delay may be indicated by delayed motor milestones such as late sitting, crawling, or walking ¹,². For walking, watchful waiting is usually appropriate if a girl is younger than 15 months or a boy is younger than 18 months, provided they are well and have no other developmental concerns or red flag features ³. Referral for specialist assessment is indicated if walking is delayed after these ages, or if there are red flag features like waddling gait, enlarged muscle bulk, proximal muscle weakness, frequent falls, clumsiness, or regression of motor milestones ³,⁴. Unusual or absent fidgety movements, asymmetry, abnormal tone (hypotonia or spasticity), and persistent toe walking are also signs of potential concern ¹,².
  • Language and Communication Development: Speech, language, and communication problems can indicate a delay ¹. Regression of language developmental milestones, especially in a child under 3 years of age, is a significant concern ⁴.
  • Social and Emotional Development: Signs of autism spectrum disorder, including regression of social developmental milestones, or persistent and significant limitations to activities of daily living caused by clinical features suggestive of autism, warrant referral ¹,⁴. Social, attentional, emotional, and behavioural problems should also be checked ¹.
  • Cognitive and Global Development: Global developmental delay and learning disability (intellectual disability) are significant concerns ¹. Problems with inattention, impulsivity, hyperactivity, and executive function problems may also indicate delay ¹.
  • Other Concerns: Visual impairment, hearing impairment, feeding problems, and sleep problems can also be indicators of developmental issues ¹.
• Assessment Tools and Referral:
  • For children born preterm, enhanced developmental surveillance includes using parent questionnaires such as the Parent Report of Children's Abilities – Revised (PARCA-R) (for global developmental delay, learning disability, or language problems) ¹. At 4 years (uncorrected age), the Strengths and Difficulties Questionnaire (SDQ) (for social, attentional, emotional, and behavioural problems) and the Ages and Stages Questionnaire (ASQ) 48-month (for various aspects of development) are used ¹. Standardised IQ tests like the Wechsler Preschool and Primary Scales of Intelligence 4th Edition (WPPSI) may also be used ¹.
  • If a developmental problem or disorder is suspected or present at any stage of developmental surveillance, further investigation or referral to the appropriate local pathway is recommended ¹. This includes referral to a child development service for suspected cerebral palsy or significant motor delays ²,³. For suspected autism, referral to a local multidisciplinary autism team is advised if there are significant limitations to daily living, or if a child under 3 years has regression of language or social developmental milestones ⁴.