Global Developmental Delay

Global developmental delay (GDD) is defined as a delay in two or more developmental domains (gross/fine motor, cognition, speech/language, social/emotional, adaptive) in children younger than age 5 years. After age 5, the diagnosis of intellectual disability (ID) should be considered (see Intellectual Disability in this rotation guide). The developing brain in younger children is undergoing myelination. Thus, delays in young children may be transient and not necessarily continue as ongoing disability through adolescence and adulthood. All children with a diagnosis of ID have a prior diagnosis of GDD, although all children with GDD do not subsequently receive a diagnosis of ID.

Etiology

The etiology of GDD is multifactorial and may occur in the pre-, peri-, and postnatal periods. Factors may be genetic, infectious, toxic, traumatic, metabolic, nutritional, and environmental.

Risk factors for GDD include:

• a known genetic diagnosis (e.g., trisomy 21 or Down syndrome, fragile X syndrome, phenylketonuria)

• prenatal exposure (e.g., alcohol)

• prenatal infections (e.g., cytomegalovirus, Zika virus)

• perinatal or postnatal insult (e.g., hypoxic-ischemic event)

• postnatal bacterial meningitis infection

• postnatal severe malnutrition

• postnatal exposure to toxins (e.g., lead)

Screening

A developmental milestone history should be taken regularly at well child visits, and each of the domains of development should be assessed in conjunction with a standardized developmental screening tool (see Developmental History in this rotation guide).

Diagnosis

A diagnosis of GDD can be made by obtaining a thorough developmental history (see Developmental History). Additionally, a provider may administer a standardized tool to obtain objective data of the child’s functioning in different developmental domains, including assessment of adaptive skills.

Referral

Children who are identified with GDD should be referred promptly to appropriate services (see the Individuals with Disabilities Education Act [IDEA] in the Screening, Referrals, Evaluation, and Services section in this rotation guide). In addition, those at risk for GDD (see risk factors above) should be referred. A child’s developmental progress should be monitored closely and periodically reevaluated to assess developmental progress and determine need for referral to appropriate services.