Global Developmental Delay

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Global developmental delay (GDD)\: Delay in two or more developmental domains (gross motor,
language, social/emotional/behavioural) in children under
Incidence\: A
Learning disability\: Preferred term for school-aged children with intellectual and adaptive functioning issues beginning in
early childhood.
Common causes\: Genetic and structural brain abnormalities.
If only motor domains a
If speech and social communication a
Red
No social smile by 8 weeks
Not sitting by 9 months
Not walking by 18 months
No words by 2 years
Developmental regression at any time
Causes\:
Prenatal intrinsic\: Chromosomal (e.g. Down’s Syndrome), single gene disorders (e.g. Rett Syndrome), metabolic (e.g.
congenital hypothyroidism), congenital brain malformations.
Prenatal extrinsic\: Intrauterine infections (e.g. rubella), teratogens (e.g. alcohol).
Perinatal\: Prematurity, asphyxia, kernicterus, intracranial haemorrhage.
Postnatal\: Hypoglycaemia, infection (e.g. meningitis), traumatic brain injury, toxins (e.g. lead), chronic illness, psychosocial
factors (e.g. neglect).
Assessment\:
History\: Pregnancy (scans, maternal health), birth (gestation, weight), past medical history (chronic illnesses, admissions),
family and social history, developmental history (milestones).
Examination\: Growth (weight, height, head circumference), dysmorphic features, systemic examination, developmental
assessment.
Investigations\: FBC, U&Es, LFT, TFT, CK, ferritin, genetic testing (microarray), vision and hearing assessment, metabolic
screen, MRI brain.
Management\:
Identify underlying medical conditions for treatment.
Provide explanation and support for families.
Consider implications for other family members.
Multidisciplinary assessment and support (education, speech and language therapy, physiotherapy, occupational therapy,
community paediatrics).
Article 🔍
A comprehensive topic overviewIntroduction
Children typically gain skills in a stepwise progression, often called “meeting their milestones”
. There is a wide range of
normal for the ages at which children acquire these skills, but if they are outside of this range, their development is
considered “delayed”
.
Development can be assessed in four main categories\: gross motor,
(including hearing) and social, emotional and behavioural. For more information, see our guide to developmental
milestones.
If a child under
two or more of these domains this is referred to as global developmental delay (GDD), alternatively called early
1 2
developmental impairment (EDI). This a
In school age children, the term GDD is not used, with “learning disability” being preferred. This refers to issues with
intellectual and adaptive functioning, which begin in early childhood. 3
Learning disability can be classi
moderate, severe or profound based on IQ or by assessment of adaptive functioning. 3
The underlying causes are generally
the same as those for GDD.

Aetiology

There are many causes of global developmental delay, and these can be thought of under the main headings of “when” i.e.
prenatal, perinatal and postnatal; and “why” i.e. intrinsic or extrinsic.
The most common causes of GDD are genetic and structural brain abnormalities.
4
If only motor domains are acerebral palsy (a static insult to the developing brain a
posture).
If only speech and social communication are a
autism spectrum disorder.

Clinical features

Some children with global developmental delay will present to a healthcare setting due to parental concern about not
meeting their milestones, but these children can also be picked up incidentally or by targeted screening by health visitors.
Generally, the more severe delays and those involving gross motor skills will present earlier than those which are less
severe or involve speech and language or social skills (as these skills are acquired later).
Red
There are certain “red
ages listed can di
No social smile by 8 weeks
Not sitting by 9 months
Not walking by 18 months (need to exclude muscular dystrophy)
No words by 2 years
Developmental regression (loss of previously acquired skills) at any time

Di

As mentioned above, there are many di
list but demonstrates the broad variety of aetiologies.
Table 1. Di
Category CausesPrenatal intrinsic
Chromosomal (i.e. Trisomy 21- Down’s Syndrome)
Single gene disorders (i.e. Rett Syndrome, Fragile
X Syndrome)
Metabolic (i.e. congenital hypothyroidism,
homocystinuria)
Congenital brain malformations
Other (i.e. autism spectrum disorder)
Prenatal extrinsic
Intrauterine infections (i.e. rubella, CMV,
toxoplasmosis)
Teratogens (i.e. alcohol, valproate)
Perinatal
Postnatal
Prematurity
Asphyxia/ischaemia (hypoxic ischaemic
encephalopathy)
Kernicterus (acute bilirubin encephalopathy)
Intracranial haemorrhage (often leads to cerebral
palsy)
Hypoglycaemia
Infection (meningitis, encephalitis)
Traumatic brain injury
Toxins (i.e. lead)
Chronic illness (especially if extended hospital
admissions)
Psychosocial (neglect)

Assessment

It is important to undertake a detailed history and assessment to establish global developmental delay and to look for
evidence of the varied potential causes.
These children are generally referred to their local community paediatrics service for assessment and ongoing
management.
History
Important areas to cover in the history include\:
Pregnancy\: scans, maternal health/medications/drugs and alcohol
Birth\: gestation, weight, mode of delivery, complications
Past medical history\: early neonatal life (admission to NICU, infections, hypoglycaemia, jaundice), chronic illnesses,
admissions to hospital, injuries, seizures, abnormal movements, medications, allergies, immunisations
Family and social history\: family tree, who lives at home, history of consanguinity, any history of learning problems in the
family
Developmental history\: what milestones were achieved in each domain and when, any regression (loss of skills)
Clinical examination
Clinical examination should include assessment of\:
Growth (weight, height, head circumference)
Dysmorphic features or neurocutaneous markers/birth marks
Systemic examination (respiratory, cardiovascular, abdominal, neurological)Developmental assessment\: there are formal tools for this i.e. SOGS (Schedule of Growing Skills assessment), but you
can gather lots of information from observation of and playing with a child. Repeated assessments over time give more
information than a one-o
Investigations
Note that guidelines for the investigation of GDD vary across locations.
First line tests
First line blood tests include FBC, U&E, LFT, TFT, CK and ferritin.
With the easy availability of genetic testing, microarray/array CGH (which picks up signi
now included in 2,5 5
This has a diagnostic yield of 10-20% in GDD.
A formal assessment of vision and hearing should be arranged if there are concerns.
Autism assessment (if the delay is in speech, language and social communication, with typical features suggestive of
autism). Autism can also cause an apparent regression in speech ability.
6
Second line tests
Second line tests depend on the likely aetiologies.
This may include a metabolic screen (i.e. ammonia, lactate, amino acids). Many other tests are included in a metabolic
screen (e.g. homocysteine for homocystinuria, very long chain fatty acids for adrenoleukodystrophy and urine
glycosaminoglycans for mucopolysaccharidoses). These are beyond the scope of this article.
Further genetic testing (including single gene tests i.e. Fragile X) can be performed.
7
An MRI brain may be required, especially if microcephaly, focal neurology, epilepsy or developmental regression.
2,6
Case example 1
Theo is an 18 month old child who was born at 28 weeks, and unfortunately had a signi
haemorrhage. Even using corrected gestational age, he is delayed in gross motor (not yet walking, sat at 13 months),
and
The likely diagnosis here is hemiplegic cerebral palsy secondary to prematurity and intracranial haemorrhage. Theo
would likely have an abnormal MRI with right sided abnormalities.
Case example 2
Chloe is a 22 month old child who was developing normally until six months ago, when she started to have di
feeding and lost some words she had known previously. She can no longer walk steadily and has reduced tone,
unusual hand movements and has recently started to have seizures.
This is a concerning history as there is developmental regression and seizures. The likely diagnosis is Rett Syndrome,
but Chloe would require an MRI and extensive blood tests and genetics to establish the diagnosis urgently.
Case example 3
Sam is a 4 year old boy whose mother had an uneventful pregnancy and delivery. He has normal gross and
skills but is delayed in speech and language (only uses a few words) and social communication (plays alongside but
not with other children). He likes to line up his toys, makes minimal eye contact and gets upset if his normal routine is
not followed.
This is a common way that autism spectrum disorder presents in preschool children, and Sam would require a
formal autism assessment.Management
The aim of investigating global developmental delay is to identify children who have an underlying medical condition that
would require/bene
Genetic conditions also have potential implications for other family members, including siblings (who might be carriers or
asymptomatic) and any future children.
Children with GDD require multidisciplinary assessment and support, including education, speech and language,
physiotherapy, occupational therapy and community paediatrics. This should be “needs-led” and focus on the child’s
strengths and areas of di

References

Shevell MI, Majnemer A, Rosenbaum P, et al. Etiologic yield of subspecialists’ evaluation of young children with global
developmental delay. J Pediatr 2000;136\:593–8.
Mithyantha R, Kneen R, McCann E, et al. Current evidence-based recommendations on investigating children with global
developmental delay Arch Dis Child 2017;102\:1071–1076.
PRAM Network. Fifteen minute consultation\: Approach to a school age child with suspected learning disability. Arch Dis
Child Educ Pract Ed Epub ahead of print\: [Nov 2023]. doi\:10.1136/archdischild-2022-324224
Majnemer A, Shevell MI. Diagnostic yield of the neurologic assessment of the developmentally delayed child. J Pediatr
1995;127\:193–9.
Miller DT, Adam MP, Aradhya S, et al. Consensus statement\: chromosomal microarray is a
individuals with developmental disabilities or congenital anomalies. Am J Hum Genet 2010;86\:749–64
Smith T, Ram D. Fifteen-minute consultation\: A practical approach to developmental regression in children Arch Dis Child
Educ Pract Ed 2019;104\:173–177.
Coysh T, Hogg SL, Parker APJ. Fifteen-minute consultation\: E
impairment in the era of genomic sequencing. Arch Dis Child Educ Pract Ed 2020;105\:13-18.

Related notes

Attention De
Autism Spectrum Disorder (ASD)
Biliary Atresia
Bronchiolitis
Cerebral Palsy

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Contents

Introduction
Aetiology
Clinical featuresDi
Assessment
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