Learn the signs of autism in babies and toddlers at every age, from newborns to 24 months, and when to talk to your child's doctor.
As a parent, you know your baby better than anyone. If something feels different — if your little one isn't making eye contact the way you expected, or isn't responding to your voice the way other babies seem to — it's natural to have questions.
Those instincts are worth listening to.
Autism spectrum disorder (ASD) is a developmental condition that affects how a person communicates, connects with others, and experiences the world around them.
The earlier those signs of autism in babies are recognized, the sooner a child can access support. But many families don't know what to look for, or aren't sure when to raise concerns with their child's doctor.
Autism spectrum disorder is a developmental condition that affects how a person communicates, interacts with others, and processes the world around them.
It's called a "spectrum" because it looks different in every person. Some people living with autism need significant daily support, while others live largely independently.
ASD isn't a disease, nor is it caused by anything a parent did or didn't do. It's a difference in how the brain develops, and it's present from birth, even when signs aren't immediately visible.
The most recent data from the CDC's Autism and Developmental Disabilities Monitoring Network estimates that 1 in every 31 children has ASD — based on records of 8-year-old children across 16 U.S. sites in 2022.
Autism occurs in all racial, ethnic, and socioeconomic groups, and is more than three times as common in boys as in girls.
Signs of autism can appear in the first year of life, though they're not always easy to recognize early on. Some children show clear differences in their first few months.
Others develop typically at first, then lose skills they had previously gained — a pattern known as regression.
2025 CDC data estimates that the median age of the earliest known ASD diagnosis is around 47 months — nearly four years old — but many of the signs that lead to that diagnosis are visible much sooner.
Noticing signs early doesn't automatically mean your child has autism. But it does mean you can start asking questions sooner — and if support is needed, your child can access it during the years when it can make the biggest difference.
The first three years of life are a critical window for brain development. During this time, the brain is rapidly forming connections, and children are especially responsive to targeted support and therapy.
Research consistently shows that children who receive early intervention services develop stronger communication skills, better social connections, and greater independence over time.
The sooner a child's needs are identified, the sooner families can connect with the right supports — including speech and language therapy, Applied Behavior Analysis (ABA), occupational therapy, and developmental pediatric services.
For example, early ABA therapy has been shown to make a meaningful difference, particularly when started in the toddler years.
Early intervention looks different for every child, depending on their needs and the services available in your area.
It might include speech and language therapy, occupational therapy, or behavioral support. If you're not sure what to expect, this overview of the early intervention evaluation process is a helpful starting point.
Before exploring the signs of autism in babies, it helps to understand what typical development looks like in the first two years.
These milestones aren't a strict checklist, and there's natural variation in when children reach them, but they give you a useful frame of reference.
Identifying signs of autism in newborns is difficult, and it's important to note that a diagnosis can not be made this early.
But for some babies, subtle differences in social responsiveness can be present from the very beginning. These aren't definitive indicators on their own, but you should bring these behaviors to your pediatrician’s attention.
Signs of autism in newborns (0–3 months) may include:
Most newborns are drawn to faces and voices almost immediately, as these are among the first ways they begin connecting with the world.
Babies who later receive an autism diagnosis sometimes show less interest in faces and voices during this period. They may not turn toward a caregiver's voice, or may seem to look past faces rather than at them.
Social smiling — smiling in response to a person rather than as a reflex — typically begins around 6 to 8 weeks. Babies who show few or no social smiles by the end of their third month may be showing an early sign that warrants a discussion with your pediatrician.
On its own, a delayed social smile doesn't mean a baby has autism, but combined with other signs, it's useful information.
By 6 months, most babies are smiling, laughing, and beginning to engage in simple back-and-forth interactions. If those behaviors are absent or limited, it may be worth paying closer attention.
Signs of autism in babies at 6 months may include:
Most babies this age light up when a caregiver enters the room. They make sounds that invite a response, and they watch faces closely.
A baby who consistently seems more interested in objects than people, or who rarely makes eye contact even with familiar caregivers, may be showing early signs that should be monitored.
It's important to note what's typical at this age: some babies are simply quieter or more independent by temperament. A single missed milestone isn't cause for alarm.
But if several of these signs are present together, or if something just feels off, trust that instinct and bring it up at your next pediatric visit.
At 9 months, babies are typically babbling, making eye contact, and engaging in simple social games. They're also beginning to show that they understand the people around them are paying attention to the same things they are.
Signs of autism in babies at 9 months may include:
One of the key milestones at this age is responding to your name. Most babies will turn toward a familiar voice or name by 9 months.
A baby who consistently doesn't respond — or responds only sometimes — may be showing an early sign of autism. This behavior is different from a hearing problem, though hearing should also be checked if there are concerns about responsiveness.
Back-and-forth interaction is another important marker. By 9 months, most babies are "conversing" in their own way, either by making a sound, waiting, or responding when you reply.
When that reciprocal quality is missing, it's important to discuss it with your pediatrician.
The 12-month mark is one of the most important developmental checkpoints in a child's first year.
By now, most babies are babbling, using gestures, and responding consistently to their name. When those milestones are absent or significantly delayed, speak to your child's doctor about your concerns.
Signs of autism in 1-year-olds may include:
Babbling and gesturing are a baby's first attempts at communication.
By 12 months, most babies are stringing together consonant-vowel sounds and using gestures to show interest, make requests, or share something exciting. A baby who isn't babbling at all, or who rarely points or waves, may be showing early signs of autism.
By this age, most babies also respond reliably when their name is called, even from across the room. They follow a caregiver's gaze, look where someone is pointing, and show awareness of the social world around them. It should be taken seriously when these responses are consistently absent.
By 16 months, most toddlers have at least a few words and are using them intentionally, whether to ask for things, name objects, or get a caregiver's attention.
Around 16 months is also the age when some children who developed typically in their first year begin to show signs of regression.
Signs of autism in toddlers at 16 months may include:
The absence of any words by 16 months is one of the clearest early indicators clinicians look for. But regression — the loss of skills a child previously had — can be just as significant. If your toddler was babbling or saying a word or two and has stopped, speak with your pediatrician right away, even if other development seems on track.
It's also common at this stage for parents to wonder if their child is simply a late talker. Some are. But when delayed speech is accompanied by limited eye contact, reduced social interest, or repetitive behaviors, it paints a fuller picture that should be explored further.
By 18 to 24 months, most toddlers are rapidly expanding their vocabulary, beginning to combine words, and engaging in simple pretend play.
One and a half to two years is often the time when signs of autism become more visible, and many families first raise concerns with their child's doctor.
Signs of autism in toddlers at 18–24 months may include:
By 24 months, most toddlers are putting two words together to form short sentences, like "more juice," "daddy go," or "big dog."
A toddler who isn't combining words by this age, or who has lost words they previously used, may be showing a sign you should discuss with your pediatrician. Language development at this stage is one of the most closely watched indicators during routine developmental screenings.
Repetitive behaviors, such as hand flapping, rocking, spinning, or lining up toys in a specific order, are among the more recognizable signs of autism in toddlers. So is a strong insistence on sameness.
Speak with your pediatrician if your toddler becomes significantly distressed when a routine changes, or insists on doing things in a very specific way every time, as they may be showing early signs of autism.
Many toddlers with autism also process sensory information differently from their peers. They may cover their ears to everyday sounds, react strongly to certain food textures, or seem unusually unbothered by pain or loud noises. They might also seek out sensory input in unusual ways, such as staring at spinning objects or mouthing non-food items.
Other Signs of Autism to Watch For at Any Age
Not all signs of autism follow a predictable timeline.
Some show up early and persist, while others become more noticeable as a child grows and social expectations increase. These are signs that can appear across a range of ages and are worth knowing, regardless of your child’s developmental stage.
Signs of autism that may appear at any age include:
Some children with autism have moments of distress that can be hard to understand from the outside — a reaction that seems out of proportion to what happened, or an emotional response that's difficult to soothe.
Learning strategies to support your child during overwhelming moments can make a real difference for the whole family.
If you've noticed some of the signs described above, it's natural to wonder what's behind them. Not every developmental difference points to autism, and getting clarity starts with ruling out other possibilities.
Some signs of autism overlap closely with hearing loss.
For example, not responding to their name, limited babbling, and delayed speech.
Before assuming a developmental cause, it's important to rule out a hearing problem. A pediatrician can refer you for a hearing evaluation, which is typically one of the first steps when communication delays are a concern.
A child can have both a hearing difference and autism, so one doesn't necessarily rule out the other.
Some children have developmental delays that aren't related to autism, such as delays in speech, motor, or cognitive development due to other causes.
The key distinction is that autism involves a specific pattern of differences in social communication and interaction, alongside restricted or repetitive behaviors.
A child with a general developmental delay may be behind in several areas without showing the social and behavioral patterns associated with ASD.
Some children are quieter, more independent, or slower to talk than their peers and go on to develop typically.
Late talking on its own doesn't mean your child has autism. But when delayed speech is accompanied by limited eye contact, reduced social interest, or repetitive behaviors, it warrants a closer look. Temperament and personality don't usually explain a consistent pattern of missed social milestones.
If you've noticed signs that concern you, whether your child is 3 months old or nearly 2 years old, it's never too early to bring them up with your pediatrician.
You don't need to have all the answers before you make the call. But it’s important that you schedule the visit right away.
It helps to come prepared. Before your appointment, jot down specific behaviors you've noticed when they happen, how often, and in what context.
Videos can be especially useful, as children often behave differently in a clinical setting than at home. Be as specific as possible: "She doesn't respond when I call her name" is more useful than "she seems distant."
Some questions to ask your pediatrician:
The American Academy of Pediatrics recommends autism-specific screening at the 18-month and 24-month well-child visits.
These screenings are brief questionnaires that help identify children who may need further evaluation. If your child hasn't been screened yet, you can ask for it at any visit.
Bringing up concerns with your pediatrician is the first step, but it's helpful to know what comes next.
The process of evaluating a child for autism typically unfolds in stages, and understanding what to expect can make it feel a lot less overwhelming.
At a well-child visit, your pediatrician may use a standardized screening tool to assess your child's development.
The most common is the M-CHAT-R/F — the Modified Checklist for Autism in Toddlers — a brief parent-reported questionnaire used at the 18- and 24-month visits. A screening is not a diagnosis. It's a way of identifying children who may benefit from a closer look.
If the screening raises concerns, your pediatrician will typically refer you to a developmental pediatrician, child psychologist, or neurologist for a more comprehensive evaluation.
A formal autism evaluation is more in-depth than a screening.
It usually involves direct observation of your child, structured assessments, and detailed interviews with parents or caregivers about your child's development and behavior. It may take place over one or more appointments.
The goal is to get a complete picture of your child's strengths and challenges — not just to arrive at a label, but to understand what kind of support will help most.
If your child receives an autism diagnosis, or even if concerns are identified before a formal diagnosis, early intervention services can begin right away.
Applied behavior analysis (ABA) is one of the most researched approaches for young children with autism spectrum disorder. Pediatric Partners, a Sevita company, provides ABA therapy and early intervention services for children and families navigating an autism diagnosis. Knowing what to expect from the evaluation process can help you feel more prepared as you move forward.
Autism cannot be diagnosed at birth. However, subtle differences in social responsiveness — such as limited interest in faces or voices — can be present in the earliest months of life. Most signs become more apparent between 6 and 24 months, when social and communication milestones are more clearly defined.
Some of the earliest signs include limited eye contact, few or no social smiles by 6 to 8 weeks, not responding to familiar voices, and seeming unusually difficult to engage. These signs on their own don't confirm autism, but should be discussed with your child's pediatrician.
Autism can be reliably diagnosed as early as 18 to 24 months in some children, though many aren't diagnosed until later.
The CDC's most recent data puts the median age of the earliest known diagnosis at around 47 months. Earlier identification is possible and beneficial, which is why routine developmental screenings at 18 and 24 months are so important.
Not always. Some children show clear signs in their first year, while others develop typically and then begin to regress — losing skills they had previously gained. And for some children, particularly girls, signs may be subtler and go unrecognized until later childhood.
Start by talking to your child's pediatrician. Bring notes about specific behaviors you've observed — when they happen, how often, and in what context. You can also request a free developmental screening through Pediatric Partners without waiting for a scheduled well-child visit.
Yes. According to the CDC, autism is more than three times as common in boys as in girls. However, girls may be underdiagnosed because they often show subtler signs or are more likely to mask their differences. If you have concerns about your daughter's development, don't let the statistics discourage you from seeking an evaluation.
Noticing signs of autism in your baby or toddler can bring up a lot of emotions, including worry, uncertainty, and questions you're not sure how to answer yet. That's completely normal. You don't need to have it all figured out right away.
What matters most is that you're paying attention, asking questions, and taking steps to understand your child's needs. Early action, even before a formal diagnosis, can open doors to support that makes a real difference.
If you're looking for guidance on where to start, autism services can help children build communication skills, confidence, and independence while celebrating who they are.
With the right support, children can thrive in ways that feel meaningful to them and to your whole family.
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