Developmental Delay



  • Developmental delay is a descriptive term, not a specific diagnosis, comprising many disorders and encompassing a broad category of etiologies.
  • The term describes any situation where a child is not meeting age-appropriate milestones as expected in one or more streams of development. These streams of development include gross motor, fine motor, receptive and expressive language, adaptive, and social (Appendix, Table 1).
  • The key feature is that the rate of progress has been slow over time in the area(s) of delay.
  • Children with behavioral problems may also be masking developmental delays.
  • Children with delays in one stream of development may also have delays in other areas of development. For example, language delay may be an indication of general cognitive delays.
  • Hearing impairment may present as a delay in development.


Found in both sexes and all racial and socioeconomic groups


This is a heterogeneous group of disorders with different prevalence rates.

General Prevention

There is no known prevention of developmental delays, although prevention of some of the underlying causes is possible.


  • This is highly variable depending on etiology, which can include genetic, familial, metabolic, infectious, endocrinologic, traumatic, anatomic brain malformations, environmental toxins, and degenerative disorders as causes. These disorders often result in some neurologic or neuromuscular injury causing the delay. In many cases, the etiology is never determined.
  • Prevalence of this group of disorders may vary depending on the inclusiveness of the definition. The milder delays are quite common and can be found in any pediatric practice. Some disorders in this grouping are more prevalent in boys. The long-term outcome depends on the severity and type of delay, with the more involved children usually having lifelong disability.


Specific etiologies are too numerous to list completely, but a partial list of the more common causes includes the following:

  • Genetic/familial
    • Fragile X syndrome
    • Trisomy 21 (Down syndrome)
    • Other chromosomal abnormalities
    • Tuberous sclerosis
    • Neurofibromatosis
    • Phenylketonuria
    • Muscular dystrophy
  • Nervous system anomalies
    • Hydrocephalus
    • Lissencephaly
    • Spina bifida
    • Seizures
  • Infections
    • Prenatal cytomegalovirus
    • Rubella
    • Toxoplasmosis
    • HIV
    • Postnatal bacterial meningitis
    • Neonatal herpes simplex
  • Endocrinologic
    • Congenital hypothyroidism
  • Environment
    • Heavy metal poisoning such as lead
    • In utero drug or alcohol exposure
  • Trauma/injury
    • Closed head trauma
    • Asphyxia
    • Stroke
    • Perinatal cerebral hemorrhages

Commonly Associated Conditions

  • There are numerous associated findings including seizures, sensory impairments, feeding disorders, psychiatric disorders (especially depression), and behavioral disorders.
  • Having a child with significant developmental delays can also add stress to the family in terms of time, finances, and emotions.



A complete and detailed history is needed, including the following:

  • Pregnancy history
    • Maternal age and parity
    • Maternal complications (including infections and exposures)
    • Medications/drugs used
    • Tobacco or alcohol used, along with quantities
    • Fetal activity
  • Birth history
    • Gestational age
    • Birth weight
    • Route of delivery
    • Maternal or fetal complications/distress
    • Apgar scores
  • General health
    • Significant illnesses, hospitalizations, or surgeries
    • Accidents or injuries
    • Hearing and vision status
    • Medications used
    • Known exposures to toxins
    • Any new or unusual symptoms
  • Developmental history
    • Current developmental achievement in each stream of development
    • Age when developmental milestones were achieved
    • Any loss of skills
    • Where parents think their child is functioning developmentally
  • Educational history
    • Type of schooling and services received, if any
    • Any previous educational/developmental testing
  • Behavioral history
    • Any perseverative or stereotypical behaviors
    • Interaction skills
    • Attention and activity level
  • Family history
    • Anyone with developmental delays, neurologic disorders, syndromes, consanguinity

Physical Exam

  • A complete physical exam including growth parameters is needed looking for etiology.
  • Key features to include:
    • Observation of interactions and behavior: any atypical behaviors and general impression
    • Head circumference: Assess for macrocephaly or microcephaly.
    • Skin: Examine for neurocutaneous lesions.
    • Major or minor dysmorphic features: any indication of a syndrome or anatomic malformation
    • Neurologic examination: Assess for cranial nerve deficits, neuromuscular status, reflexes, balance and coordination, and any soft signs.
    • Developmental testing: Although considerable information will already be available on history and observation, a more formal developmental screening or testing should be done. Possible office tests include the Ages & Stages Questionnaires, the Parents’ Evaluation of Developmental Status, or the Capute Scales (formerly called the CAT/CLAMS). Referral to a specialist or a multidisciplinary team for more detailed testing is indicated when delay is suspected.

Differential Diagnosis

  • The differential can be extensive and may become more evident with further workup.
  • Broad diagnoses include the following:
    • Intellectual disability
    • Developmental language disorder
    • Autism spectrum disorder
    • Learning disability
    • Cerebral palsy
    • Attention-deficit/hyperactivity disorder
    • Significant visual or hearing impairment
    • Degenerative disorders

Diagnostic Tests and Interpretation

Initial Tests

  • There is no specific laboratory test battery for general developmental delays. The testing needs to be tailored to the individual situation based on the history and physical exam. A high index of suspicion should be maintained for any associated findings and delays in the other streams of development.
  • Some of the more common studies ordered for developmental delay workup:
    • Genetic testing: warranted for any dysmorphic features, a family history of delays, or genetic disorder. A karyotype and fragile X DNA testing should be considered, particularly for significant cognitive delays. The comparative genomic hybridization (CGH) microarray is now increasingly recommended as a 1st-line test for developmental delays.
    • Metabolic tests: Tests such as quantitative plasma amino acids, quantitative urine organic acids, lactate, pyruvate, or ammonia should be considered if there is any loss of skills, indication of a metabolic disorder, or newborn metabolic screen has not been done.
    • Thyroid function tests: Most infants will have had screening for hypothyroidism shortly after birth. This should be rechecked if symptoms indicate.
  • Head MRI: Consider a head MRI for head abnormalities, significant neurologic findings, loss of skills, or for workup of a specific disorder such as trauma or leukodystrophy.

Diagnostic Procedures/Other

  • Audiologic: Hearing should be checked in any child with speech and language and/or cognitive delays.
  • EEG: An EEG should be considered if there is any concern about seizures.
  • Subspecialists: Referral to other medical specialists may also be indicated. These specialists may include developmental pediatrics, neurology, genetics, orthopedics, or ophthalmology.


General Measures

  • Therapy should include appropriately treating any medical conditions and associated findings, for example, anticonvulsants for seizures or hearing aids when appropriate for hearing impairment. In addition, traditional therapy has included early intervention or special education services specifically addressing the areas of delay.
  • Therapy could include physical therapists, occupational therapists, speech/language therapists, special educators, psychologists, and audiologists, depending on the needs of the child.

Ongoing Care

Follow-Up Recommendations

Patient Monitoring

  • General pediatric care for well-child visits and to monitor any underlying medical conditions is indicated.
  • These children need ongoing monitoring of their therapy and educational programs to ensure that it is still meeting their individual needs as these needs change over time.
  • The families will also need ongoing counseling and support in dealing with a child having special needs.


Variable depending on the type and severity of delay and the etiology

Additional Reading

  1. Battaglia A, Carey JC. Diagnostic evaluation of developmental delay/mental retardation: an overview. Am J Med Genet C Semin Med Genet. 2003;117C(1):3–14.  [PMID:12561053]
  2. Council on Children With Disabilities, Section on Developmental Behavioral Pediatrics, Bright Futures Steering Committee, et al. Identifying infants and young children with developmental disorders in the medical home: an algorithm for developmental surveillance and screening. Pediatrics. 2006;118(1):405–420.  [PMID:16818591]
  3. Gerber RJ, Wilks T, Erdie-Lalena C. Developmental milestones: motor development. Pediatr Rev. 2010;31(7):267–277.  [PMID:20595440]
  4. Gropman AL, Batshaw ML. Epigenetics, copy number variation, and other molecular mechanisms underlying neurodevelopmental disabilities: new insights and diagnostic approaches. J Dev Behav Pediatr. 2010;31(7):582–591.  [PMID:20814257]
  5. Liptak GS. The pediatrician’s role in caring for the developmentally disabled child. Pediatr Rev. 1996;17(6):203–211.  [PMID:8857199]
  6. Marks KP, LaRosa AC. Understanding developmental-behavioral screening measures. Pediatr Rev. 2012;33(10):448–458.  [PMID:23027599]
  7. McQuiston S, Kloczko N. Speech and language development: monitoring process and problems. Pediatr Rev. 2011;32(6):230–239.  [PMID:21632874]
  8. Moeschler JB, Shevell M; for American Academy of Pediatrics Committee on Genetics. Clinical genetic evaluation of the child with mental retardation or developmental delays. Pediatrics. 2006;117(6):2304–2316.  [PMID:16740881]
  9. Scharf RJ, Scharf GJ, Stroustrup A. Developmental milestones. Pediatr Rev. 2016;37(1):25–37, quiz 38, 47.  [PMID:26729779]
  10. Shevell M. Global developmental delay and mental retardation or intellectual disability: conceptualization, evaluation, and etiology. Pediatr Clin North Am. 2008;55(5):1071–1084.  [PMID:18929052]



  • 315.9 Unspecified delay in development
  • 315.4 Developmental coordination disorder
  • 315.39 Other developmental speech disorder
  • 315.8 Other specified delays in development
  • 315.2 Other specific developmental learning difficulties
  • 315.35 Childhood onset fluency disorder
  • 783.42 Delayed milestones
  • 315.01 Alexia
  • 315.34 Speech and language developmental delay due to hearing loss
  • 315.32 Mixed receptive-expressive language disorder
  • 315.09 Other specific developmental reading disorder
  • 315.5 Mixed development disorder
  • 315.1 Mathematics disorder
  • 315.02 Developmental dyslexia
  • 315.31 Expressive language disorder
  • 315 Developmental reading disorder, unspecified


  • F89 Unspecified disorder of psychological development
  • F82 Specific developmental disorder of motor function
  • F80.9 Developmental disorder of speech and language, unspecified
  • F88 Other disorders of psychological development
  • F81.81 Disorder of written expression
  • F81.89 Other developmental disorders of scholastic skills
  • F81.0 Specific reading disorder
  • F80.4 Speech and language development delay due to hearing loss
  • F80.89 Other developmental disorders of speech and language
  • F80.1 Expressive language disorder
  • F80.0 Phonological disorder
  • F81.2 Mathematics disorder
  • F80.81 Childhood onset fluency disorder
  • F80.2 Mixed receptive-expressive language disorder
  • F81.9 Developmental disorder of scholastic skills, unspecified


  • 248290002 Developmental delay (disorder)
  • 268674003 developmental disorder of motor function (disorder)
  • 278920007 Speech and language dyspraxias (disorder)
  • 425805004 cognitive developmental delay (disorder)
  • 129104009 Developmental mental disorder (disorder)
  • 229729009 Developmental language impairment (disorder)
  • 442059001 Mixed developmental disorder (disorder)
  • 229730004 Expressive language impairment (disorder)


  • Q: When do you test a child for delays?
  • A: A child can have developmental assessments at any age, including infancy. Making a specific diagnosis, for example, for level of intellectual disability, may need to wait until the child is older.
  • Q: When can a child start receiving services?
  • A: Children who qualify can receive therapy services starting at birth and in some cases extending up to age 21 years.
  • Q: The parents are raising a concern about delays, but the general impression in the office is that the child is doing okay. What should be done next?
  • A: Parents or grandparents may be the first to express concerns, especially in a child with milder delays. A more detailed developmental history and more formal developmental screening or testing may be indicated as an initial step.


Rita Panoscha, MD

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