Signs of Autism in Babies and Children: What to Watch For and When to Seek Help
Dra. Paula Andrade
CRM-SP 204778 | RQE 131771 | Título SBP 2024
Licensed in Brazil — Itaim Bibi, São Paulo
If you are here, you have probably noticed something different about your child's behavior — perhaps they do not look you in the eye the way other children do, do not respond when you call their name, or play in a way you did not expect. First and foremost: paying attention and seeking information is an act of love. This guide will help you understand the early signs of Autism Spectrum Disorder (ASD), what to observe at each age, and when to seek professional evaluation. Remember: only a specialized team can diagnose autism — and many of the signs that concern parents may have different explanations. The most important thing is not to ignore your concerns and to talk to your child's pediatrician. For expat families in Brazil, understanding how the local healthcare system approaches developmental screening can give you confidence in navigating this journey.
Quick Summary
→ASD is a spectrum: each child presents different signs, with varying intensities
→Signs may appear between 6 and 24 months, but formal diagnosis typically occurs from age 2 onward
→The M-CHAT-R/F is a screening tool administered at 18 and 24 months during well-child visits
→Early intervention makes a difference: the sooner the support, the better the outcomes for the child
→In Brazil, the pediatrician screens and refers — the diagnosis is made by a multidisciplinary team led by a neuropediatrician
What Is Autism Spectrum Disorder (ASD)
Autism Spectrum Disorder (ASD) is a neurodevelopmental condition that affects social communication, interaction, and behavior. The DSM-5 (Diagnostic and Statistical Manual of Mental Disorders) defines ASD as a spectrum— this means there is no single “type” of autism. Each child may present very different characteristics, ranging from mild to significant.
In terms of prevalence, CDC data (2023) indicate that approximately 1 in 36 children in the United States is on the autism spectrum. In Brazil, although epidemiological data are still limited, the prevalence is estimated to be similar. The increase in numbers largely reflects better diagnostic criteria and greater awareness, rather than a true increase in cases.
Important
Autism is not caused by vaccines, by the way parents raise their children, or by any family shortcoming. It is a condition with a neurobiological basis. The recommended vaccination schedule continues to be safe and essential for all children. This has been confirmed by extensive research worldwide.
Signs of Autism by Age
ASD signs can be subtle in the first months and become more evident as the child grows. Knowing the developmental milestones helps identify what is expected for each age range. Below are the signs that deserve attention:
6 to 12 Months
- •Little or no eye contact during interactions
- •Does not respond to their own name when called
- •Does not point to objects or people
- •Limited facial expression or reduced social smile
- •Does not imitate simple gestures (waving bye-bye, clapping hands)
12 to 18 Months
- •Does not speak any meaningful word by 16 months
- •Does not engage in pretend play (pretending to feed a doll, for example)
- •Does not share interest — does not show objects to parents
- •Seems not to hear when spoken to
- •Prefers to play alone and shows no interest in other children
18 to 24 Months
- •Loss of previously acquired skills (regression) — stopped talking or interacting
- •Does not combine 2 words by 24 months (“want water,” “mommy give”)
- •Difficulty following simple instructions (“get the ball”)
- •Repetitive movements (body rocking, hand flapping)
- •Intense fixation on parts of objects (wheels, lights)
2 to 3 Years
- •Difficulty with social interaction— does not play with other children, does not respond to others' emotions
- •Repetitive speech (echolalia — repeats heard phrases without context)
- •Repetitive behaviors and rigid rituals
- •Sensory sensitivity — reacts intensely to sounds, textures, or lights
- •Resistance to changes in routine (meltdowns when something changes)
3 to 5 Years
- •Difficulty making friends or engaging in cooperative play
- •Very restricted and intense interests (knows everything about one specific subject)
- •Difficulty understanding others' feelings and expressing their own
- •Atypical language (“robotic” speech, difficulty with pronouns, literal interpretation)
- •Difficulty with transitions between activities at school or daycare
Have you noticed any of these signs in your child?
The first step is to talk to a pediatrician. Dr. Paula provides developmental assessments with warmth and time for all your questions.
Talk to the PediatricianThe 3 Areas of ASD Signs (DSM-5)
The DSM-5 organizes autism signs into two broad categories (social communication/interaction and repetitive behaviors), which we can break down into three areas to make it easier for parents to understand:
Social Communication
- • Speech delay or absence of speech
- • Difficulty initiating or maintaining conversation
- • Limited use of gestures (pointing, waving)
- • Difficulty understanding non-verbal language (tone of voice, facial expressions)
- • Echolalia (repeating phrases without context)
Social Interaction
- • Limited eye contact
- • Difficulty sharing emotions and interests
- • Does not respond to their name or to interaction attempts
- • Difficulty making and maintaining friendships
- • Difficulty understanding implicit social rules
Repetitive Behaviors
- • Motor stereotypies (hand flapping, rocking, spinning objects)
- • Rigid rituals and resistance to changes
- • Intense and restricted interests
- • Hyper- or hyposensitivity to sensory input (sounds, textures, lights)
- • Need for predictability and fixed routines
Signs That Are NOT Necessarily Autism
Do not be alarmed if your child shows only ONE of these signs in isolation:
- Isolated speech delay: many children take longer to speak without being on the spectrum — especially if they understand well and communicate with gestures. Bilingual households (common among expat families) may also see a temporary speech delay that is not autism-related
- Shyness: some children are naturally more reserved with strangers but interact well with familiar people
- Preferring to play alone sometimes: moments of solitary play are normal, especially in younger children
- Tantrums and meltdowns: these are part of typical development, especially between ages 1 and 3
- Being very interested in one topic: intense fascination with dinosaurs, cars, or characters is common in childhood and, on its own, does not indicate ASD
ASD is defined by the combination of signs across multiple areas (communication, interaction, and behavior), not by a single isolated sign. When in doubt, talk to your pediatrician.
M-CHAT-R/F Screening: What It Is and How It Works
The M-CHAT-R/F (Modified Checklist for Autism in Toddlers, Revised with Follow-Up) is the most widely used autism screening tool in the world. It is recommended by both the Brazilian Society of Pediatrics (SBP) and the American Academy of Pediatrics (AAP).
In Brazil, pediatricians routinely administer the M-CHAT-R/F during the 18-month and 24-month well-child checkups. If you are an expat family and your child is being seen by a Brazilian pediatrician, this screening will be part of the standard care protocol — the same tool used internationally, applied in the same way.
How It Works
- • 20 yes-or-no questions answered by parents
- • Administered at the 18- and 24-month visits
- • Takes approximately 5 to 10 minutes
- • Results classify risk as low, medium, or high
Limitations
- • It is not a diagnosis — it is a screening tool
- • May produce false positives (indicate risk without ASD)
- • May produce false negatives (miss milder cases)
- • A positive result indicates the need for evaluation, not a confirmed diagnosis
Pediatrician's Tip
The M-CHAT-R/F should be administered even in children who appear to be developing well. Universal screening is important because some signs can be subtle and go unnoticed. During routine well-child visits, the pediatrician administers the questionnaire and guides the next steps.
The Pediatrician's Role in Identifying ASD
The pediatrician is, in most cases, the first healthcare professional to have regular contact with the child. Their role is essential in early screening and referral, rather than in diagnosis itself. It is important for expat families in Brazil to understand that Brazilian pediatricians screen for developmental concerns at every well-child visit, following protocols aligned with international standards. During well-child visits, the pediatrician:
- Tracks developmental milestones at each age
- Administers the M-CHAT-R/F at 18 and 24 months
- Listens to parents' concerns — no one knows the child better than you
- Refers for specialized evaluation when necessary (neuropediatrician, child psychiatrist, speech therapist, occupational therapist)
- Rules out other causes for the observed signs (hearing problems, vision issues, global developmental delay)
Understanding the Brazilian Healthcare System
In Brazil, the diagnostic pathway for ASD involves two tiers of professionals. The pediatrician is the first contact — they screen, monitor development, and identify concerns. When further evaluation is needed, the pediatrician refers to a neuropediatrician (neuropediatra), who leads the diagnostic process alongside a multidisciplinary team.
Both private healthcare and the public system (SUS) offer developmental evaluation, though wait times in the public system can be significantly longer. Through private care in São Paulo, referrals to specialists typically happen within days, and multidisciplinary evaluations can begin promptly.
How Autism Is Diagnosed
The diagnosis of ASD is clinical and multidisciplinary. There is no blood test or imaging study that confirms autism. The process involves:
Evaluation by a neuropediatrician or child psychiatrist
Detailed interview with parents about the child's developmental history, behavior, and concerns.
Direct observation of the child
The specialist observes how the child plays, communicates, and interacts. Tools such as the ADOS-2 may be used.
Speech therapy and occupational therapy assessment
Evaluation of language, communication, sensory processing, and motor skills.
Neuropsychological assessment (when indicated)
Standardized tests to evaluate cognitive, adaptive, and behavioral abilities.
The importance of early diagnosisis not about “labeling” the child, but about opening doors to interventions that can make an enormous difference in development. Children diagnosed and treated before age 3 tend to have better long-term outcomes.
Early Intervention: Why It Matters So Much
The child's brain in the first years of life has an extraordinary capacity to reorganize itself — this is what we call neuroplasticity. The sooner the child receives appropriate therapeutic support, the greater the chances of developing communication, interaction, and independence skills.
Key Therapies
- • ABA (Applied Behavior Analysis): evidence-based approach to teaching skills and reducing challenging behaviors
- • Denver Model (ESDM): naturalistic intervention for children 12 to 48 months, based on play
- • Speech Therapy (fonoaudiologia in Brazil): language work, communication, and when needed, alternative communication (AAC)
- • Occupational Therapy: sensory processing, fine motor skills, and activities of daily living
What the Evidence Shows
- • Children who begin intervention before age 3 show significant gains in language and interaction
- • Early intervention can improve IQ, language, and adaptive behavior
- • Parents are an essential part of the process — parent coaching is fundamental
- • Each child responds differently — the therapeutic plan must be individualized
It is important that the approach be integrative and individualized, considering the specific needs of each child and family. There is no single protocol that works for everyone. In São Paulo, families have access to excellent multidisciplinary teams in both the private and public healthcare systems.
A Message for You, Mom and Dad
It is not your fault. Autism is not caused by something you did or did not do. It is not the result of a lack of affection, of routine, or of stimulation.
Seeking help is an act of love. Looking for information, observing your child carefully, and talking to your pediatrician shows how much you care.
A diagnosis does not define your child. They are still the same child you love — the diagnosis is a tool to help them receive the support they need.
You are not alone. There are support networks, parent groups, dedicated professionals, and rights protected by Brazilian law (Lei Berenice Piana, No. 12.764/2012, guarantees rights for individuals with ASD). Asking for help is the first step. If you are an expat family in São Paulo, know that bilingual support is available to help you navigate every step of this process.
Want to discuss your child's development?
During the consultation, we assess your child's development thoroughly and compassionately, with time and attention for all your concerns.
Talk to the PediatricianWhen to See the Pediatrician: Warning Signs
Although every child develops at their own pace, certain signs warrant professional evaluation. See your pediatrician if you observe:
Seek Evaluation if the Child:
- ❌Has lost skills they previously had (stopped talking, interacting, or walking) — at any age
- ❌Does not make eye contact or makes very little
- ❌Does not respond to their name by 12 months
- ❌Does not speak any word by 16 months
- ❌Does not combine 2 words by 24 months
- ❌Does not point, wave, or use communicative gestures
- ❌Exhibits frequent repetitive movements (flapping, rocking, spinning)
- ❌Shows no interest in other children or in social interaction
Important: the presence of one or more signs does not mean the child has autism. It means it is worth investigating with a professional.
Pediatrician's Tip
Trust your instincts.If you feel something is different about your child's development, do not wait — talk to your pediatrician. It is much better to evaluate and find out everything is fine than to wait and miss an important intervention window. Bring videos of the child's behavior at home to the appointment — observation in the natural environment is very helpful for assessment. Keep your well-child checkups up to date — they are the best opportunity to monitor development. If you need a telemedicine consultation to discuss initial concerns before an in-person visit, that is also an option.
Frequently Asked Questions
At what age can signs of autism be identified?
Some signs can be observed as early as 6 to 12 months, such as limited eye contact and not responding to their name. However, a formal diagnosis is usually made from age 2 onward, when signs become more evident. In Brazil, pediatricians administer the M-CHAT-R/F screening at 18 and 24 months as part of routine well-child visits.
My child is not talking yet — could it be autism?
A speech delay alone does not mean autism. Many children take longer to speak without being on the spectrum. ASD involves difficulties in multiple areas: social communication, interaction, and repetitive behaviors. If speech delay is accompanied by limited eye contact, absence of gestures, or difficulty interacting, it is important to talk to your pediatrician. For bilingual families, remember that children learning two languages may take slightly longer to start speaking, which is developmentally normal.
What is the M-CHAT and how does it work?
The M-CHAT-R/Fis a screening questionnaire with 20 questions answered by parents about the child's behavior, administered at 18 and 24 months. A positive result does not mean a diagnosis — it indicates the need for more detailed evaluation by specialists. In Brazil, this is a standard part of pediatric well-child care.
Is there a cure for autism?
No — autism is not a disease; it is a neurodevelopmental condition. There is no cure, but with early intervention and appropriate support, children can develop important skills and enjoy an excellent quality of life. The earlier the support begins, the better the outcomes.
Which doctor diagnoses autism in Brazil?
The diagnosis is made by a multidisciplinary team, typically led by a neuropediatrician (neuropediatra) or child psychiatrist, with support from a speech therapist, psychologist, and occupational therapist. The pediatrician plays a key role in screening and early referral. For expat families, an English-speaking pediatrician can coordinate the entire referral process and help you understand each step.
Concerned About Your Child's Development?
Schedule a developmental assessment with Dr. Paula. Bilingual, compassionate care with time for all your questions.
Consultório no Itaim Bibi, São Paulo | CRM-SP 204778 | RQE 131771
Related Articles
Speech Delay in Children: When to Worry and What to Do
Speech delay in children: language milestones by age, delay vs disorder, when to see a speech therapist and pediatrician. Evidence-based guide for parents in Sao Paulo.
Child DevelopmentBaby Development Milestones Month by Month: Complete First-Year Guide
Is your baby developing well? Month-by-month milestones (motor, language, social) from 0 to 12 months. Warning signs and when to see a pediatrician.