Early Signs of Autism in Babies and Toddlers: A Guide by Age

Early signs of autism often show up in how a baby or toddler communicates, plays, and connects with others. Examples include not responding to their name by 9 months, using few or no gestures by 12 months, and not pointing to show you something interesting by 18 months. Every child develops differently, and no single sign means a child is autistic. If you notice a pattern, talk with your pediatrician.

Key takeaways

• Early signs of autism usually involve social communication, play, and repetitive behaviors or interests.
• The CDC lists signs by age, starting as early as 9 months.
• A child may show some, all, or none of these signs. Signs are not a diagnosis.
• The AAP recommends autism screening at 18 and 24 months, but you can ask for one any time.
• If you are concerned, act now. You do not need a diagnosis to ask for help.

What autism is, in brief

Autism spectrum disorder is a developmental difference that affects how a person communicates, interacts with others, and experiences the world. Every autistic child has their own strengths, interests, and challenges. Our guide to autism spectrum disorder in children covers this in more depth.

The signs below come from the Centers for Disease Control and Prevention (CDC) signs and symptoms page. The CDC also cautions that children with autism may not have all, or any, of the behaviors it lists as examples. Use them as a guide for a conversation with your child’s doctor, not as a checklist to score at home.

Early signs of autism by age

The CDC groups many social communication signs by the age when most children have developed the skill. Here they are in order.

By this age	A possible early sign
Any age	Avoids or does not keep eye contact
9 months	Does not respond to their name
9 months	Does not show facial expressions like happy, sad, angry, and surprised
12 months	Does not play simple interactive games like pat-a-cake
12 months	Uses few or no gestures, for example does not wave goodbye
15 months	Does not share interests with others, for example showing you a toy they like
18 months	Does not point to show you something interesting
24 months (2 years)	Does not notice when others are hurt or upset
36 months (3 years)	Does not notice other children and join them in play
48 months (4 years)	Does not pretend to be something else, like a teacher or superhero, during play
60 months (5 years)	Does not sing, dance, or act for you

Early signs of autism in babies (up to 12 months)

In the first year, the signs are mostly about connection. You might notice that your baby:

• Rarely turns when you call their name, even when they can clearly hear other sounds
• Shows few facial expressions, such as smiling back at you or looking surprised
• Is not interested in back-and-forth games like peekaboo or pat-a-cake
• Does not wave, reach to be picked up, or use other gestures

Babies vary a lot in this stage. One missed milestone is common. A pattern across several areas is more worth mentioning.

Early signs of autism in toddlers (12 to 24 months)

This is when many parents first notice differences. Around 15 to 18 months, most children begin to share their world with you. They hold up a toy to show you or point at a dog across the street and look back to see if you saw it too.

A toddler who may be autistic might:

• Bring you objects only to get help, not to share them
• Not point to show you something interesting
• Lead you by the hand to what they want instead of pointing or using words
• Seem very absorbed in their own activity and less interested in what you are doing

Signs of autism in a 2-year-old

By age 2, differences in social awareness and play can become clearer. The CDC lists not noticing when others are hurt or upset by 24 months as one sign.

At this age, you might also see:

• Play that looks the same every time, such as spinning a wheel or opening and closing a door
• Strong upset when a routine changes
• Repeating words or phrases they heard earlier instead of using them to communicate
• Limited interest in playing near other children

Many 2-year-olds are late talkers or love routines. What matters is the overall picture and how these patterns affect daily life.

Signs from ages 3 to 5

The CDC notes that many children are not diagnosed until later in childhood. By 3, most children begin to notice other kids and join them. By 4, most enjoy pretend play. By 5, many like to sing, dance, or perform for family.

A preschool teacher may be the first to mention differences in how your child plays with classmates, follows group routines, or handles transitions.

Repetitive behaviors and focused interests

Autism also includes restricted or repetitive behaviors and interests. The CDC lists examples such as:

• Lining up toys or other objects and getting upset when the order is changed
• Repeating words or phrases over and over (called echolalia)
• Playing with toys the same way every time
• Focusing on parts of objects, such as wheels
• Getting upset by minor changes
• Having intense, focused interests
• Needing to follow certain routines
• Flapping hands, rocking, or spinning in circles
• Reacting in unusual ways to how things sound, smell, taste, look, or feel

Many of these behaviors serve a purpose for your child. For some children, rocking or hand-flapping may be a way to calm down or show excitement. The goal of support is not to stop every repetitive behavior. It is to help your child communicate, feel safe, and take part in the activities that matter to them.

If sensory differences stand out for your child, such as covering their ears at the blender or avoiding certain clothing textures, our article on sensory processing and autism explains more.

Other differences some autistic children have

The CDC also notes that some autistic children have:

• Delayed language, movement, or thinking and learning skills
• Hyperactive or inattentive behavior
• Unusual eating or sleeping habits
• Stomach or digestive issues
• Anxiety, or more or less fear than expected

These can also happen in children who are not autistic. They are worth mentioning to your doctor either way.

What early signs are not

It helps to keep a few things in mind:

• Signs are not a diagnosis. Only a qualified professional can diagnose autism, through an evaluation.
• Every child is different. An autistic child may not show many of these signs, and a child with several of them may not be autistic.
• There is no blood test. The CDC explains that there is no medical test, such as a blood test, to diagnose autism. Diagnosis is based on a child’s development and behavior.

What to do if you notice early signs of autism

If you are seeing some of these signs, here is a practical path forward.

1. Track milestones

The CDC’s free Milestone Tracker app, part of its Learn the Signs. Act Early. program, lets you track your child’s milestones from 2 months through 5 years. It is a simple way to organize what you are seeing before a doctor visit.

2. Write down examples and take short videos

Doctors only see your child for a few minutes. Short phone videos of everyday moments, like calling your child’s name or playtime, can show what you see at home. Also note if your child seems to lose words or skills they used to have.

3. Talk with your pediatrician and ask about screening

According to the CDC, the American Academy of Pediatrics recommends that all children be screened specifically for autism at 18 and 24 months, and have general developmental screening at 9, 18, and 30 months. You can ask for a screening sooner or in between if you have concerns.

If the screening or your doctor’s observations point to a need for a closer look, the next step is a diagnostic evaluation. Our guide on when to get an autism evaluation explains who diagnoses autism and how to prepare.

4. Ask about early intervention

You do not need to wait for a diagnosis to get help. In California, Early Start serves infants and toddlers from birth to 3 with developmental delays or at risk for a developmental disability. You can call the Early Start BabyLine at 800-515-2229. In Orange County, Early Start is offered through the Regional Center of Orange County.

The NICHD notes that early diagnosis and intervention, such as during preschool or before, are more likely to have major positive effects on symptoms and later skills. Learn more in our article on early intervention for autism.

Please talk with your pediatrician or a qualified professional about your child’s specific development.

How United Autism Therapy can help

United Autism Therapy does not diagnose autism. We work with children after a diagnosis or referral, and we are glad to talk through next steps with families who are just starting to ask questions.

Our BCBA- and RBT-certified team provides ABA therapy at our Westminster center, at home, and in schools across Orange County, along with speech therapy, occupational therapy, and parent training.

Talk with our team

If you have noticed some early signs and want to talk them through, we are here. We offer a free consultation. Call (714) 709-7819, Monday through Saturday, 8 AM to 6 PM, or contact us online.