Early Signs of Autism Can Be Hard to Spot — Here's What Experts Want You to Know

Autism spectrum disorder is a developmental disability caused by differences in the brain that impacts about one in 44 children in the US, making it a fairly common health condition. Autism can present itself in various ways, with some children experiencing delayed developmental milestones while others have severe disabilities.

With that, it's understandable to want to have early signs of autism on your radar. But these early signs can be tough to notice. "Symptoms of autism are not always obvious due to the fact that the presentation of symptoms can vary significantly across the spectrum from relatively mild to very severe," says Steven Pastyrnak, PhD, pediatric psychologist, Corewell Health Helen DeVos Children's Hospital.

Daniel Ganjian, MD, a pediatrician at Providence Saint John's Health Center in Santa Monica, CA, agrees. "Autism is a spectrum, so there is mild, moderate, and severe autism," he explains. "The severe ones are easier to diagnose, but the mild and moderate cases are harder to spot."

While your child should be screened for autism during routine visits to the pediatrician, given that you spend the most time with your little one, you may be able to spot something their provider misses. If you have concerns about your child's development, keep this information for early signs of autism in mind.

What Are Early Signs of Autism in Toddlers and Babies?

According to the NIH, these are more typical early signs that babies and toddlers have autism:

  • Problems with eye contact
  • Not responding to his or her name
  • Problems following another person's gaze or pointed finger to an object
  • Poor skills in pretend play and imitation
  • Problems with nonverbal communication

Children may also have the following laundry list of symptoms of autism, the CDC says:

  • Avoids or does not keep eye contact
  • Does not respond to name by 9 months of age
  • Does not show facial expressions like happy, sad, angry, and surprised by 9 months of age
  • Does not play simple interactive games like pat-a-cake by 12 months of age
  • Uses few or no gestures by 12 months of age
  • Does not share interests with others by 15 months of age
  • Does not point to show you something interesting by 18 months of age
  • Does not notice when others are hurt or upset by 24 months of age
  • Does not notice other children and join them in play by 36 months of age
  • Does not pretend to be something else, like a teacher or superhero, during play by 48 months of age
  • Does not sing, dance, or act for you by 60 months of age
  • Lines up toys or other objects and gets upset when order is changed
  • Repeats words or phrases over and over
  • Plays with toys the same way every time
  • Is focused on parts of objects
  • Gets upset by minor changes
  • Has obsessive interests
  • Must follow certain routines
  • Flaps hands, rocks body, or spins self in circles
  • Has unusual reactions to the way things sound, smell, taste, look, or feel
  • Delayed language skills
  • Delayed movement skills
  • Delayed cognitive or learning skills
  • Hyperactive, impulsive, and/or inattentive behavior
  • Epilepsy or seizure disorder
  • Unusual eating and sleeping habits
  • Gastrointestinal issues like constipation
  • Unusual mood or emotional reactions
  • Anxiety, stress, or excessive worry
  • Lack of fear or more fear than expected

But doctors warn against assuming your child has autism if they have just one of the symptoms listed above. "I always tell parents it's a cluster of signs, not just one or two," Ganjian says.

What Are Developmental Red Flags For Autism?

The Centers for Disease Control and Prevention (CDC) has created developmental milestones that break down what skills babies and toddlers are generally expected to have mastered by particular ages. Developmental milestones, the CDC explains, are things most children can do by a certain age.

When it comes to red flags for autism, "delayed speech and limited interest in others are two of the first signs that we look for," Pastyrnak says. Regression of speech, which is when a child uses a number of words to communicate and then seemingly stops using those words, happens in nearly a quarter of children with autism, Pastyrnak says.

"Atypical sensory processing, repetitive motor behaviors, and repetitive speech can also be early signs," he says.

If you have concerns about your child's development, Jennifer Twachtman-Bassett, MS, autism clinical specialist at Connecticut Children's, recommends looking at the CDC's developmental milestones and seeing how well your child meets the expectations for their age.

When Is Autism Diagnosed?

Many children show symptoms of autism by 12 to 18 months of age or earlier, according to the National Institutes of Health (NIH). "We typically start to see symptoms as early as 9 to 12 months, although we may see symptoms earlier," says Twachtman-Bassett. "A lot of times, the symptoms before 9 months aren't as reliable." Plus, many of the symptoms of autism are nonverbal "so it's not as easy as whether a child says their first words on time," Twachtman-Bassett says.

What Does Early Autism Intervention Look Like?

Again, your child should be screened for autism spectrum disorder by their pediatrician during routine visits, but "sometimes parents do notice things earlier than we do," Ganjian says.

He recommends bringing up your concerns to your child's pediatrician. They can evaluate your child to see if they may benefit from more intensive testing that can be done by a behavioral psychologist or other specialist, Ganjian says.

Pastyrnak agrees. "Early identification is ideal as there are typically interventions and school-based services available to help," he says. These early intervention programs may include family training, speech therapy, hearing impairment services, physical therapy, and nutrition services, according to the NIH. And they typically begin at or before preschool age, as early as 2 or 3 years of age, to ensure that they are as effective as possible.

"With early intervention, some children with autism make so much progress that they are no longer on the autism spectrum when they are older," the NIH reports.