Signs of Autism in Babies and Toddlers

As a mom of three children with Autism, people ask me what signs of Autism they should look for. My answer often confuses them: look for nothing and everything. While it’s important to keep track of milestones, there are some children with Autism that meet every milestone on time but then suddenly regress and lose skills. Tracking a child’s development isn’t just a checklist but instead making sure that progress continues to be made after the checkbox is marked. 

The False Comfort of Milestones

The biggest issue with milestones is the misconception about what they really mean. A milestone is what 90% of children are able to do whereas the average is what 50% of children are able to do. If a child says their first word right at the milestone age, they are actually in the lowest 10% of children. If a child says their first word later than the milestone age they are below the 10% mark. Check out this amazing visual by MrsSpeechieP explaining what milestones actually mean:

Credit: MrsSpeechieP

Another issue with milestones is that not everyone knows the definitions of each milestone. Pediatricians often ask parents if their infant smiles–but what they don’t tell you is that not all smiles are equal. While all babies can smile at toys, a noise, or when they are tickled or pass gas, what doctors are asking about is a “social smile”. Social smiles are warm smiles in response to silent social interaction with direct eye contact. The adult smiles at the baby and the baby smiles back. Babies with Autism smile at toys but may not smile when their mother holds them close and smiles at them. 

Signs of Autism from Birth through Age 2

Two Month Olds

By two months old all babies should have a social smile. When an adult initiates a smile towards them they should frequently smile back. Being delayed with this skill or only doing it infrequently is an early indicator of Autism. My oldest had a social smile at 2 months and 3 weeks old which is a 3 week delay. My middle son had a social smile at 1 month 1 week old but later regressed as a toddler. My youngest was 1 month and 3 weeks old when her social smile emerged but was inconsistent with her smiles. All three kids went on to have Autism. 

Many neurodivergent babies start to show signs of some sensory processing issues by this age. They may only sleep when a parent has their hand laying on them or cry every time they lay on certain fabrics. Certain positions may bother them. 

Three Month Olds

By three months old most babies have back and forth cooing conversations with adults. During these interactions the adult and infant take turns making direct eye contact, making vowel sounds “ahh” or “ooo” and smiling at each other. It is important to note that grunting and squealing sounds are not considered cooing. My oldest made lots of noises but did not coo until he was a year old. My youngest didn’t coo until she was 7 months old. Babies who look away while cooing or do not coo at all should be monitored closely.

By this age infants with Autism may stare at objects in an unusual way, this pattern often becomes more apparent with time. For many, this is due to difficulty “tracking” an object with their eyes or becoming easily fatigued by this task. Keeping their eyes focused on people is harder than staring at a non-moving object and therefore the stationary object becomes more preferred. 

Six Month Olds

By six months old the previously mentioned cooing conversations should continue but instead of “oo” or “ahh” the infant makes a variety of sounds like “a-da” or “ga-ga”. A lack of progression from “oo” to “ga-ga” is often an early sign of Autism.

Repetitive hand or body movements usually become more obvious as the baby becomes stronger and more mobile. Around this age my youngest started to wiggle her fingers in front of her face.

Sensory processing difficulties continue to increase. Babies might be especially sensitive to noises or refuse to eat certain textures despite repeated attempts.

Nine Month Olds

The majority of nine months old will hear their name and turn to make direct eye contact with another person. Babies with Autism may not turn or they may turn but not make eye contact with the person who said their name.

Nine month old babbling conversations should expand to include more and more sounds, giggles and social games like peekaboo. Babies with Autism tend to dislike playing peekaboo at this age or may giggle without looking at the other person.

Twelve Month Olds

At a year old, toddlers should frequently get an adult’s attention by making eye contact WHILE pointing, using gestures or making sounds. Toddlers with Autism may do this inconsistently or may not be able to coordinate eye contact with gestures. For example, they might point to an object but not make eye contact at the same time. 

Most toddlers have a few words and use them during warm back and forth interactions with adults. Any delay in speech or social eye contact during conversations warrants a call to your state’s early intervention services for an evaluation.

By this age sensory processing difficulties amplify. With increased mobility and curiosity, toddlers begin to explore what feels good to them. Sensory seekers often start climbing, jumping, diving and doing other unsafe things. Sensory avoiders appear to be fearful or clingy. 

Eighteen Month Olds

By eighteen months old nearly all children will have at least 10 words and the average child will have 50. Their conversations with adults continue to include nonverbal cues like pointing WHILE talking for example a toddler may say “plane!” while pointing up at the sky and looking back at the adult to ensure they saw the plane. 

Pretend play should begin to emerge during this time. A toddler should naturally be able to: feed a doll, give a “sad” bear a hug, talk on a play phone or make a car drive. Toddlers with Autism may line up or make piles of toys instead of having imaginative play. They might spin tires on toy cars instead of driving them. Or they might open and close the doors of a play kitchen instead of cooking.

Twenty-Four Month Olds

At two years old nearly all children should have 50 words and the average child will have 200-300 words. They will be able to use simple two word sentences “ball go” or “more eat”. They will continue to coordinate nonverbal cues like eye contact and a variety of gestures with their simple sentences. Some toddlers with Autism have a normal amount of words, but they mainly use those words to request items or have one-sided conversations instead of a warm back and forth exchange. 

Pretend play should continue to expand and a two year old will often create imaginative scenes surrounding their play. When playing “house” they feed a doll, change it’s diaper then put it down for a nap. When playing “fireman” they drive to the emergency, put out the imaginary fire and drive back to the station.

A toddler with Autism may have some form of imaginative play but it might be delayed or seem memorized. Children who memorize pretend play learn new play schemes but struggle when the script changes or they are required to “mix” play schemes into a new one.

With increased language, most toddlers with sensory processing difficulties can begin to articulate that they don’t like certain tastes, textures or smells. They may defiantly refuse to wear certain clothes or eat certain foods. Behavioral issues become common by this age. 

The Dangers of Wait and See

Many people prefer to “wait and see” if their child catches up naturally. While it is true that all children develop at their own speeds, it never hurts to give children a boost with any skill. Best case scenario the boost was enough to help them naturally flourish and worse case scenario the child truly needs more support and already has a head start. 

Another consideration is how the diagnostic system works in this country. If you notice a delay when your child is 8 months old and wait until they are 18 months old to call for an evaluation, you are going to be on a waitlist for at least another 6-24 months. Your child could be three and half years old before you get the evaluation done and by then they may have found enough skills to mask their true symptoms and not get diagnosed at all or the opposite where they are struggling so severely and you cannot access the treatment they need without a formal diagnosis. I always recommend calling for an evaluation as soon as you have a list of concerns and if things improve while you’re on the waitlist go ahead and cancel that appointment. It’s easier to cancel an appointment then get moved up on a waitlist. 

The most important thing to remember is it is okay if your child has a developmental delay. You can recognize their struggle, become aware of their needs and make decisions about whether therapeutic intervention is needed or not. If the idea of having a child with a delay is too overwhelming I highly recommend getting support from a parent coach, support group or mental health professional. Ignoring the delay is not going to make it disappear, but your chance to get them the support they need might.