The central decision: seek an evaluation when a developmental concern is meaningful
Parents and caregivers should seek professional guidance whenever a child is consistently missing expected developmental abilities, losing a previously established skill, having sustained difficulty participating in everyday activities, or prompting a persistent concern from someone who knows the child well. An evaluation is also appropriate when a teacher or early childhood professional observes a recurring developmental difficulty, or when a child has a medical condition associated with increased developmental risk. Families do not need to wait for the next routine screening age, a second opinion from relatives, or a formal diagnosis before starting the conversation. The American Academy of Pediatrics clinical guidance recommends surveillance throughout childhood, additional standardized screening when concerns arise, and direct referrals when indicated.
The most useful question is not whether a child is “normal” or “behind” in the abstract. It is whether the child's current developmental trajectory, participation, needs, and possible medical risks justify closer examination. Child development unfolds through connected domains—movement, communication, learning, play, social interaction, regulation, and everyday adaptive skills. Those domains vary within individual children and across their environments. A delay is a description of observed development relative to age-informed expectations; a developmental disorder is a clinical formulation reached through an appropriate assessment. Neither a parental checklist nor an online quiz establishes that diagnosis.
A practical decision is therefore straightforward: identify the specific concern, describe what the child can and cannot yet do across familiar settings, and contact the child's pediatrician or primary care clinician. Request appropriate developmental screening or a fuller evaluation and ask what supportive services can begin now. The CDC's guidance for concerned families also encourages families to contact early intervention directly when appropriate, because support pathways and medical diagnostic pathways can proceed in parallel.
How urgently should a family act?
Emergency assessment for abrupt neurological or medical changes
Sudden loss of the ability to walk, stand, use an arm, communicate, or remain alert; a new seizure with concerning symptoms; altered consciousness; new severe weakness; breathing problems; or another acute neurological change calls for immediate emergency medical assessment. These presentations are medical safety issues rather than routine developmental follow-up. An abrupt change following head injury, possible poisoning, fever with confusion, or another serious illness also warrants emergency services appropriate to local circumstances. The correct urgency depends on the child's current symptoms, not on how long a routine developmental referral usually takes.
Prompt medical assessment for a sustained loss of acquired skills
A child who previously used words regularly and stops using them, loses purposeful hand skills, ceases to perform a motor action previously mastered, or shows a clear persistent decline in previously established social or adaptive abilities should receive prompt medical evaluation. Families should describe when the change began, how long it has lasted, whether the skill returns under familiar circumstances, and any accompanying illness, seizures, weakness, sleep change, or hearing concerns. Ordinary fluctuations in cooperation, performance when tired, or temporarily reduced use of a newly learned skill require clinical context, but a convincing sustained loss deserves attention. The AAP's 2025 report on evaluation of global developmental delay identifies regression as a reason to consider expedited neurology or genetics referral.
Timely outpatient evaluation for persistent developmental differences
Arrange a clinical discussion soon when a child repeatedly misses age-relevant skills, shows difficulty in more than one developmental domain, makes unexpectedly little progress over time, or needs extensive support to perform ordinary tasks for their developmental stage. Examples include ongoing difficulty understanding or expressing communication, limited response to sound or social communication opportunities, asymmetric or unusually effortful movement, persistent challenges with feeding or self-care, and difficulties engaging in everyday play or learning. The assessment should be tailored to the concern and medical history rather than automatically assigned to one diagnosis.
Concerns that arise between scheduled well-child visits
The next routine visit may be months away. Parents can contact the clinic when a new concern arises and ask whether the clinician recommends an earlier appointment, formal screening, hearing or vision testing, or a specialist referral. A child who passes a screening test can still merit further assessment when clinical observations remain persuasive. Likewise, a positive screen signals a need to clarify the child's profile and may lead to services without implying that a particular disorder is present. The CDC monitoring and screening framework treats family concern as a reason to act at any age.
Patterns of development that deserve closer attention
Communication, speech, and understanding
Ask for assessment when a child shows persistent difficulty understanding familiar language, communicating needs, developing new expressive skills, using gestures, participating in reciprocal exchanges, or making progress in age-appropriate communication. A child may express more than they understand or understand far more than they can say; those profiles lead clinicians to ask different questions. Speech sound production, spoken vocabulary, comprehension, social use of language, hearing, and motor speech ability each warrant distinct consideration. Regularly inconsistent response to spoken sound merits hearing evaluation, even when a newborn hearing screen was passed.
Multiple languages should be considered part of the child's developmental context. Vocabulary can be distributed across languages, and opportunities to use each language change over time. A multilingual home does not establish a language disorder or justify stopping a heritage language. Assessment should examine relevant skills across the child's languages and contexts, use appropriate interpretation where necessary, and avoid applying unvalidated monolingual norms to a multilingual child. ASHA's clinical guidance on late language emergence emphasizes hearing status, context, and multilingual assessment when interpreting communication differences.
Motor coordination, posture, strength, and movement
Motor concerns may involve delayed attainment of movement skills, persistent asymmetry, stiffness, unusual weakness, frequent falling beyond the child's developmental context, difficulty manipulating objects, or a striking difference between gross and fine motor abilities. A clinician may review birth and health history, examine tone, reflexes and symmetry, and decide whether pediatric physical therapy, occupational therapy, neurology assessment, or specific medical investigations are needed. Motor delay can be associated with a range of neurological, neuromuscular, sensory, environmental, or musculoskeletal explanations. It should not be explained automatically by a child's motivation or temperament.
Social communication, interaction, and play
A developmental discussion is appropriate when concerns persist about shared attention, reciprocal engagement, imitation, communicative gestures, social response, symbolic play, or flexibility in everyday activities. These observations may reflect language, hearing, sensory, environmental, developmental, or neurodevelopmental differences. Autism-specific evaluation can be appropriate when social-communication differences occur alongside other relevant patterns; no single behavior, such as eye contact or an interest in repetitive play, can establish autism. The AAP autism clinical report describes assessment as a combination of developmental history, direct observation, clinical judgment, and condition-specific diagnostic criteria.
Learning, problem-solving, and adaptive participation
Persistent difficulty learning familiar routines, transferring a newly learned skill to a similar context, following developmentally appropriate directions, or becoming more independent in ordinary activities can justify evaluation. Clinicians consider opportunities for learning, accessible instruction, health, sensory abilities, cultural expectations, and the supports available in the child's setting. Difficulties in cognition and daily adaptive skills can have different explanations; an evaluation must examine their pattern rather than infer intellectual disability from one early milestone or test result.
Emotional, behavioral, and attention concerns
Toddler tantrums, shyness, activity, separation distress, and uneven self-control can be part of ordinary development. Assessment becomes more important when distress, avoidance, dysregulation, or behavior creates persistent impairment, marked suffering, unsafe situations, or a substantial decline in the child's ability to take part in family life, childcare, or school. Medical problems, communication differences, sleep, trauma exposure, learning context, caregiver stress, and developmental stage may all shape the behavior. Caregiver-child regulation is relational and changes with age; the existing article on emotion regulation in children addresses that specific scientific domain.
Hearing, vision, feeding, and sensory function
Hearing and vision are central to access to communication, relationships, play, and learning. A child who often seems unable to hear, frequently misses visual information, or experiences persistent sensory difficulties affecting eating, sleep, movement, or participation deserves a professional discussion. Feeding refusal, swallowing concerns, choking, inadequate growth, or loss of feeding ability requires medical assessment, with urgency determined by safety and nutrition. These findings may be part of a developmental profile or may point to a different medical problem. The clinician's task is to investigate rather than assume an underlying cause.
Developmental variation, delay, and disorder: interpreting the pattern
Children acquire new abilities through interdependent processes, and age-associated milestones describe distributions of development rather than a single fixed timetable. One child may walk before another, acquire words at a different pace, prefer solitary play in a particular setting, or need more time to adjust to new people. Variation is compatible with healthy development. What strengthens a concern is persistence, a widening discrepancy between current skills and age-informed expectations, multiple affected domains, functional consequences, associated medical features, or genuine loss of established skills.
The CDC's revised milestones were selected to represent skills expected in at least approximately 75% of children at the specified ages, where evidence allowed. Their purpose is to support conversation and developmental surveillance. They are neither diagnostic thresholds nor validated screening tests, and evidence is uneven for some social-emotional and cognitive items. The methodological paper by Zubler and colleagues explains the evidence and judgment involved, and the CDC's methodological notes warn against treating checklists as a diagnostic instrument.
A child with one missing checklist item may have a variation in timing or limited opportunity to demonstrate the behavior; the result still merits discussion because the list is designed to prompt action. A child who meets the listed milestones might nonetheless have difficulties in less visible skills or contexts and could need assessment. Developmental evaluation is therefore guided by the whole story: the child's strengths, history, health, context, functioning, observations over time, and concerns voiced by family members and professionals.
How prematurity changes interpretation
For children born prematurely, age adjustment may matter when evaluating early developmental milestones, especially in infancy and the first years of life. A clinician can explain when and how corrected age is used and when chronological age becomes more informative. Gestational age, neonatal complications, hearing and vision history, growth, and the child's actual trajectory all contribute to interpretation. Prematurity also may warrant more frequent follow-up because certain medical and developmental risks are higher in some preterm populations. Age correction informs assessment; it should not become a reason to disregard a persistent concern or functional difficulty.
Cultural context, disability, and neurodiversity
Developmental behavior is shaped by language exposure, family practices, schooling, accessibility, cultural expectations, and neurobiological variation. Children differ in the ways they communicate, play, learn, and seek sensory experiences. An evaluator should ask whether a task was accessible, meaningful, and familiar, and whether the tool was validated for the child's language and circumstances. In the context of established disability, the evaluation seeks current strengths, new concerns, and useful supports; it does not require treating every difference as something to eliminate.
The four stages of professional assessment
Developmental monitoring and surveillance
Monitoring means observing abilities and changes in real life. Families, caregivers, childcare professionals, and teachers notice everyday progress and record concerns; the pediatric clinician integrates those observations with medical and developmental history at health-supervision visits. A milestone checklist can make conversations specific, particularly when caregivers report what happened, when, and in which setting. Monitoring is ongoing and broad, so it can capture concerns that arise before or after recommended screening ages. It cannot independently identify a medical cause or provide a clinical diagnosis.
Standardized developmental screening
A standardized screen uses a validated questionnaire or structured instrument to estimate whether the child is at increased likelihood of a developmental difficulty and should receive closer evaluation. A screening tool is selected according to age, target domains, language, and setting, and its results are interpreted alongside clinical judgment and caregiver information. Every tool has potential false positives and false negatives. Professional screening can be repeated, supplemented with another relevant instrument, or followed by direct referral, depending on the concern. Online milestone trackers and informal internet questionnaires are not equivalent to professionally selected validated screens.
Under AAP recommendations, universal general developmental screening occurs at approximately 9, 18, and 30 months, with autism-specific screening at 18 and 24 months. Screening is additionally appropriate whenever developmental surveillance identifies concern; referral can be made directly when the need is apparent. These schedules concern US preventive pediatric practice and are not the only ages at which an assessment can take place. Other countries have their own programs and clinical pathways. The AAP report by Lipkin and Macias and CDC screening guidance specify the US schedule.
Comprehensive developmental and medical evaluation
An evaluation addresses questions that a screen cannot settle: which developmental domains are affected, which abilities are relative strengths, how the child's skills function in everyday settings, whether medical or sensory explanations are plausible, which services could help, and whether condition-specific diagnostic criteria are met. Depending on the presenting concern, the process can include a developmental and medical history; physical and neurological examinations; hearing and vision assessment; caregiver and educator interviews; standardized developmental or language testing; observation; and targeted laboratory or genetic evaluation. A multidisciplinary team may be useful for complex profiles, while an isolated concern sometimes needs one focused assessment.
Assessment methods are chosen because they answer an actual question. Comprehensive genetic testing, neuroimaging, or extensive laboratory panels are not standard first steps for every child whose development prompts a concern. When a child has global developmental delay, associated physical or neurological findings, or possible genetic causes, the 2025 AAP genetic evaluation clinical report describes a phenotype-informed diagnostic approach. Hearing and vision assessment are particularly important when the relevant developmental domains depend on sensory access.
Diagnosis, eligibility, and functional support
A diagnosis is a clinical conclusion about a specified condition, grounded in applicable criteria and a professional assessment. Eligibility for an educational or early-intervention service is determined by the rules of the relevant service system and is not the same thing as a medical diagnosis. A family may need a medical diagnosis to guide clinical treatment or investigation, while an early-intervention program may assess the child for services based on developmental need or eligibility rules. Both pathways can move forward at once. A child who needs support should not be left without guidance while waiting for a specialist's diagnostic label.
Who should evaluate the child?
The child's pediatrician or primary care clinician is usually the first coordinator. They can examine medical contributors, review growth and health history, perform or arrange screening, determine the urgency of a change, and refer to qualified professionals. Developmental-behavioral pediatricians assess complex developmental and behavioral profiles; pediatric neurologists assess concerning neurological features; audiologists examine hearing; ophthalmologists evaluate vision; speech-language pathologists assess communication and feeding-related issues within their scope; physical and occupational therapists assess movement and everyday participation; and psychologists can assess developmental, cognitive, emotional, and behavioral functioning. Child psychiatrists and other clinicians may be indicated for significant mental-health or safety concerns.
A child may see several professionals without needing every specialty. A coordinated referral strategy avoids redundant appointments and identifies which unanswered questions have the greatest clinical and practical importance. For families whose child already receives school or community services, sharing useful evaluation reports with consent can connect medical, therapy, and educational perspectives. The goal is an integrated profile of strengths and needs, with a plan families can understand and use.
The US referral pathway: medical care, early intervention, and public schools
Birth through age two: Part C early intervention
In the United States, families concerned about a child younger than three can request an evaluation through their state's or territory's early-intervention program under Part C of the Individuals with Disabilities Education Act (IDEA). A pediatric referral is helpful but a family can generally contact the early-intervention system directly. The evaluation process considers development and program eligibility, and, when appropriate, leads to an Individualized Family Service Plan identifying supports in daily environments. Under federal Part C rules, the initial evaluation, assessments, and initial IFSP meeting generally fall within 45 days of receiving the referral, subject to specified documented exceptions. The federal IDEA regulation and US Department of Education guidance on evaluation describe this framework.
Age three and older: the local public school system
From age three, families may contact their local public school district about evaluation for preschool special education or related services, even if the child does not attend a public school. Parents of school-age children can request an educational evaluation when developmental or learning concerns affect access, participation, or progress in education. Educational evaluations and pediatric medical evaluations address overlapping but distinct questions. Schools assess eligibility for educational services and appropriate supports; clinicians address health conditions, diagnostic clarification, and medical care. Both perspectives can be necessary, especially when concerns appear mainly in one context.
Outside the United States
Health-system and educational referral arrangements differ among countries and regions. A family can begin with a licensed primary care or child health professional, ask about public developmental assessment and early childhood services, and request information in the family's strongest language. Regardless of the service structure, timely assessment, accessible communication, hearing and vision considerations, and developmentally appropriate support remain sound practice principles. The US age boundaries and statutory deadlines above should not be assumed to apply elsewhere.
How to prepare for a developmental appointment
A useful description starts with concrete situations: what the child does, what was expected in that setting, whether the behavior appears at home and in childcare, when it began, how often it occurs, whether it has changed, and what makes participation easier. Bring relevant medical information, developmental or learning reports, screening questionnaires, and caregiver observations. Short videos of everyday activities can sometimes help a clinician understand a concern that is difficult to reproduce in the office, provided recording respects the child's privacy. It is equally important to document what the child enjoys and can already do well.
Families can ask: Which domain are we evaluating? Do we need a validated developmental screen or a direct specialist assessment? Should hearing or vision be checked? What is the urgency? Is an early-intervention or school referral appropriate today? What support can begin while we await the evaluation? What findings would change the plan? When will we review progress? A clear action plan should identify the next service, the reason for it, and an agreed follow-up point.
When a family encounters a language barrier, limited transportation, cost concerns, uncertain insurance coverage, or long waits, asking for a care coordinator, interpreter, social worker, community program, or alternative referral center is appropriate. Families may keep copies of referrals and ask whom to contact if an appointment cannot be obtained. An assessment process becomes more useful when the recommendations can actually be implemented within the child's daily life and community.
What to do while waiting for evaluation
A family can support development while maintaining ordinary routines. Responsive conversation, shared book reading, accessible play, opportunities for movement, a predictable and supportive environment, and adaptation of activities to the child's interests can promote interaction and learning. If a child communicates through gesture, pictures, assistive communication, or another accessible channel, caregivers should use the most effective available means of connection while professional assessment proceeds. Waiting for an appointment is not a reason to withdraw supportive interaction or postpone an available early-intervention referral.
The World Health Organization guideline on early childhood development recommends responsive caregiving and early learning opportunities as important components of population-level support. A global systematic review and meta-analysis of parenting interventions found average benefits across several early developmental domains, while also documenting variability across intervention designs and populations. Those findings support appropriate family-centered programs; they do not prove that every household activity will correct an identified delay or that caregivers caused the concern.
Intervention is matched to the child's functional needs, evidence base, priorities, and available supports. A specific speech or motor concern may require focused professional treatment; a broad developmental profile may benefit from coordinated services; a medical cause may require condition-specific care. Families should avoid costly unvalidated programs that promise to guarantee typical development, and should discuss proposed treatments with qualified clinicians. Developmental diversity and disability remain compatible with well-being, learning, autonomy, and meaningful participation.
What scientific evidence can and cannot establish
Established evidence: surveillance, assessment, and responsive referral pathways
Professional guidance consistently supports eliciting caregiver concerns, maintaining developmental surveillance, using appropriately validated screening instruments, and pursuing a fuller evaluation when a concern persists. This is a clinical practice framework grounded in observational research, studies of screening tools, developmental science, and professional consensus. The AAP surveillance and screening report emphasizes linking identification to follow-up care rather than considering a completed screen the endpoint of the process. The CDC's public guidance likewise describes monitoring and screening as complementary.
Supported but heterogeneous evidence: early developmental interventions
Randomized trials and systematic reviews provide evidence that some responsive-caregiving and early-learning interventions can improve developmental outcomes on average, while effects depend on the intervention, age, baseline needs, outcome measure, and implementation. A pooled estimate across different programs is not a prediction for any one child or a guarantee that a particular intervention will prevent a future diagnosis. Practical decisions should weigh intervention specificity, family priorities, accessibility, treatment burden, and whether progress is meaningfully measured over time. Jeong and colleagues' meta-analysis and the WHO guideline provide relevant evidence syntheses.
Limits and disagreements: population screening and causal inference
Routine autism screening offers an instructive example of evidence standards. The AAP recommends autism-specific screening at 18 and 24 months, while the US Preventive Services Task Force found insufficient evidence to judge the overall benefits and harms of universal autism screening among very young children for whom neither parents nor clinicians had already expressed concern. That position is an evidence-insufficiency statement for an asymptomatic population, not a recommendation to ignore a child whose development raises concerns. Referral and evaluation for a child with identified concerns remain justified on their own clinical grounds. See the AAP autism report and USPSTF recommendation statement.
Screening sensitivity and specificity vary with the tool, age, population, cutoff, language, and follow-up method. Observational associations between developmental concerns, family conditions, and later outcomes cannot alone identify the cause of one child's difficulties. Early identification increases the opportunity to access help, but high-quality research is still needed to compare service pathways, identify who benefits most from different supports, reduce unequal access, and measure long-term outcomes. Scientific precision therefore includes reporting uncertainty in prediction while acting appropriately on present needs.
Why follow-up is essential after the first evaluation
Assessment is a process of clinical clarification. Some children demonstrate rapid new learning as language access, healthcare needs, or environmental supports improve. Others show stable developmental differences or emerging functional needs that become more apparent with age. An initial evaluation may identify a clear condition, describe a provisional profile, or recommend observation and further testing. Follow-up allows clinicians and families to determine whether a proposed plan is working and whether new evidence changes the interpretation.
Families should leave with a summary of strengths, concerns, any completed assessments, referrals made, the expected timing of contact, what circumstances require earlier review, and a plan for monitoring meaningful progress. Useful measures include the child's ability to communicate needs, participate in play and relationships, access daily routines, and learn personally relevant skills. Progress can take different forms and need not imply movement toward a single universal developmental profile.
Frequently asked questions
Should I wait until my child misses several milestones?
No. A single missed milestone or credible concern is enough to discuss with a clinician. The clinician can interpret that observation in context, arrange a screen, or refer directly where indicated. Several persistent concerns or regression generally increase the reason for prompt action; missing multiple checklist items is not a prerequisite for seeking advice.
Does a missed milestone mean my child has a developmental disorder?
No. Milestones are communication prompts and age-informed observations, not a clinical diagnosis. Some children show ordinary timing variation; others need medical, sensory, developmental, or educational assessment. A professional evaluation considers the complete developmental and functional picture, and the cause may remain uncertain after initial assessment.
Can my child need an evaluation despite passing screening?
Yes. No screening tool identifies every developmental concern. A persistent caregiver observation, functional difficulty, medical red flag, or other clinical finding may justify further evaluation after a low-risk screening result. Share the specific concern and ask how the proposed follow-up plan addresses it.
Is late talking always a reason for autism evaluation?
Late talking has multiple possible explanations, including language differences, hearing difficulties, communication disorders, and broader developmental profiles. Clinicians assess receptive and expressive language, social communication, hearing, context, and other developmental domains. Autism assessment is appropriate when the overall pattern raises that specific possibility; it is not established by delayed words alone.
Should a multilingual family stop speaking its home language?
No. Evaluation should consider all relevant languages and the child's access to communication. Exposure to more than one language does not by itself establish a developmental disorder. A speech-language professional can examine the child's communication across languages and advise on supports that preserve meaningful family interaction. See ASHA's clinical guidance.
What if a doctor says to wait but concerns continue?
Ask what findings justify monitoring rather than referral, what changes should trigger a return visit, and when reassessment will occur. Parents may request a second clinical opinion or seek an early-intervention evaluation directly where their local system permits it. A collaborative discussion should take both clinical findings and caregiver observations seriously.
Is early intervention only for children with a confirmed diagnosis?
Not necessarily. Eligibility rules differ by location and program, and service systems may evaluate developmental needs without first requiring a particular medical diagnosis. In the United States, families can contact Part C early intervention for a child under three or the public school system for children three and older to inquire about evaluations and eligibility. Medical investigation and service assessment can occur in parallel.
How can an evaluation help if no specific disorder is diagnosed?
Evaluation may identify hearing or vision needs, clarify strengths and vulnerabilities, suggest accessible communication methods, reveal environmental barriers, recommend developmental supports, or establish a plan for follow-up. It can also provide reassurance grounded in assessment when current differences are consistent with expected variation. The value lies in better understanding and action, not simply acquiring a label.
Related Articles
Cluster Child Development and Parenting — the published scientific chapter on developmental systems, caregiving, learning, and child-directed support.
Early Intervention for Children With Intellectual and Developmental Disabilities — the condition-focused evidence and services pathway for children with identified disability-related needs.
Early Signs of Intellectual Disability in Children: Development and Evaluation — understanding learning and adaptive-functioning findings within a comprehensive clinical assessment.
Emotion Regulation in Children: Development and Support — developmental interpretation of emotional abilities and practical family support.
Co-Regulation: How People Help Each Other Manage Emotions — the relational mechanisms through which people support one another's regulation.
References
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Centers for Disease Control and Prevention (CDC). Concerned About Your Child's Development? Learn the Signs. Act Early. Updated 2026. Official guidance.
Centers for Disease Control and Prevention (CDC). Developmental Monitoring and Screening. Learn the Signs. Act Early. Updated 2026. Official guidance.
Centers for Disease Control and Prevention (CDC). Key Points about CDC's Developmental Milestone Checklists. Learn the Signs. Act Early. Updated 2026. Official methods and interpretation.
Hyman, S. L., Levy, S. E., and Myers, S. M. (2020). Identification, Evaluation, and Management of Children With Autism Spectrum Disorder. Pediatrics, 145(1), e20193447. https://doi.org/10.1542/peds.2019-3447.
Jeong, J., Franchett, E. E., Ramos de Oliveira, C. V., Rehmani, K., and Yousafzai, A. K. (2021). Parenting interventions to promote early child development in the first three years of life: A global systematic review and meta-analysis. PLOS Medicine, 18(5), e1003602. https://doi.org/10.1371/journal.pmed.1003602.
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Rodan, L. H., Stoler, J., Chen, E., and Geleske, T. (2025). Genetic Evaluation of the Child With Intellectual Disability or Global Developmental Delay: Clinical Report. Pediatrics, 156(1), e2025072219. https://doi.org/10.1542/peds.2025-072219.
United States Department of Education. IDEA Part C Evaluation and Assessment: Technical Assistance Resources. Official resource.
United States Department of Education. Individuals with Disabilities Education Act, 34 CFR §303.310: Post-Referral Timeline (45 Days). Federal regulation.
United States Preventive Services Task Force (USPSTF). (2016). Autism Spectrum Disorder in Young Children: Screening. Official recommendation statement.
World Health Organization (WHO). (2020). Improving Early Childhood Development: WHO Guideline. Official publication.
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