Developmental delay is a condition where children exhibit significant variation in achieving developmental milestones as expected for their actual or adjusted age. The extent of developmental delay can be further classified as mild (functional age < 33% below chronological age), moderate (functional age between 34%-36% of chronological age) and severe (functional age < 66% of chronological age). It is normal to have variations in the pattern of development where in some children prefer to bottom shuffle or commando crawl rather than crawling on hands and knees, or they skip the milestone completely, these children due to mild hypotonia in lower limbs tend to walk late. Familial pattern and environment may also contribute to the variations seen in achieving language, social skills, play skills and behaviour. A delay becomes significant if the performance of the child is two or more standard deviations below the mean age-appropriate standardised norm-referenced testing. A delay can be isolated or global depending on the number of developmental domains affected.
What causes Developmental Delay?
The aetiology of developmental delay is multifactorial. The common factors are:
- Prenatal Period – Genetic disorders, cerebral dysgenesis, antiepileptic or cytotoxic drugs, maternal infections, alcohol consumption or smoking.
- Perinatal Period – Prematurity, intrauterine growth retardation, intraventricular haemorrhage, periventricular leucomalacia, perinatal asphyxia, or metabolic syndromes.
- Postnatal Period – Meningitis, Encephalitis, Metabolic syndromes, Anoxia, Traumatic injury and Stroke.
How are Developmental Delays diagnosed?
Early detection of delays can be done through, Developmental monitoring for delays by caregivers, and early childhood care providers. Regular developmental screening by developmental paediatrician for delays at ages 3, 6, 9, 12, 18 and 30 months. And for Autism screening at ages 18 and 24 months. Ages and Stages Questionnaire – II (ASQ-II) and Denver-II are parent completed questionnaire with ASQ-II having an overall sensitivity and specificity of 83.3% and 75.4% respectively, for Indian children for detecting developmental delays at ages 4, 10, 18 and 24 months. Additional in-depth developmental evaluation if child at a higher risk for delays by using one-on-one diagnostic play sessions and evidence based measurement tools such as General Movement Assessment(GM), Bayley Scales of Infant and Toddler Development-III and the Peabody Picture Vocabulary Test IV assess the child’s mastery of motor, language and speech, social, cognitive and play skills.
How is Developmental Delay treated?
Early identification and intervention can play a crucial role in prevention as well as remediation of developmental delays. Early intervention targeting specific domains of development that show significant delay can enhance practise of meaningful and effective
skills in varied environments to help acquire skills that will allow them to be more independent with ADLs, reduce learning difficulties and functional impairments and increase their level of participation in society.
Early intervention to improve delayed motor and cognitive skills-
Environmental enrichment plus family engagement in task-specific and context specific active learning that incorporates infant generated motor and cognitive actions has a positive outcome. Thus Evidence based approaches such as early intervention that incorporates principles of bobath, neurodevelopmental therapy and sensory integration therapy is used to promote play based, child-initiated movements, task-specific and context-specific therapy to reach age-appropriate gross motor and fine motor milestones. Coaching families to engage their child in playful but targeted training ensures an adequate dose of practise.
Why Early Intervention is important in developmental delay?
There is a long-term financial impact on society in terms of healthcare, educational support and other special services related to developmental delay and/or disability. This is because the affected children require substantial resources and increased cost over their lifespan compared with those without such conditions. This further accentuates the significance of early identification to initiate appropriate interventions and/or rehabilitations with the intention of preventing further delays, stimulating emerging skills and creating a more encouraging and protective surroundings.
Dr. Snehal Gadhecha
Consultant at Surya Hospital
(Paediatric Physiotherapist, Certified Neonatal & Paediatric Early Intervention Specialist (UK), Paediatric Neuro-rehab Specialist, Neonatal Therapist, Feeding Specialist)
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- Damiano DL, Longo E. Early intervention evidence for infants with or at risk for cerebral palsy: an overview of systematic reviews. Dev Med Child Neurol. 2021 Jul;63(7):771-784. doi: 10.1111/dmcn.14855. Epub 2021 Apr 6. PMID: 33825199; PMCID: PMC9413025
- Choo YY, Agarwal P, How CH, Yeleswarapu SP. Developmental delay: identification and management at primary care level. Singapore Med J. 2019 Mar;60(3):119-123. doi: 10.11622/smedj.2019025. PMID: 30997518; PMCID: PMC6441684