Some early signs of autism in infants and young children may include avoidance of eye contact and delays in language development.

Autism, or autism spectrum disorder (ASD), is a developmental condition that can affect how a person behaves, interacts, and communicates.

Healthcare professionals use the term ASD because autism is a spectrum, meaning that it can cause a variety of behaviors and characteristics that range in severity.

They refer to it as a developmental disorder because it usually develops before a person is 2 years old. However, a person can receive a diagnosis of ASD at any age.

ASD is not an illness, and it does not require treatment. A person may find it easier to manage some characteristics of ASD with support or therapies, though.

Having support from an early age can help improve an autistic child’s development, language, and interactive skills.

This article lists the possible early signs of ASD and explains what steps to take following a diagnosis.

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In general, a baby will show signs of ASD between the ages of 12⁠ and 24 months. However, signs of ASD in babies can develop outside of this age range.

The Centers for Disease Control and Prevention (CDC) note that a baby can show signs of ASD from the age of 9 months. However, the Autism Science Foundation states that early signs of ASD may appear in babies as young as 2 months of age.

Diagnosing ASD is challenging. One reason for this is that the condition presents differently in all individuals.

Babies can reach developmental milestones at slightly different ages, even when they do not have any health conditions. However, some developmental differences indicate that a baby may be autistic. These include:

Lack of eye contact and joint attention

Joint attention refers to two people sharing a focus on the same object after one alerts the other to the item using verbal or nonverbal cues. For example, a parent or caregiver will point to a toy or tell the child about it, and the child will then look at the toy. Joint attention is an important way of connecting and interacting with other people.

According to a 2016 article in PLOS ONE, from about 9 months old, a baby should be able to make regular eye contact and share focus with their caregivers.

Autistic babies can find it challenging to pick up on these social cues and may ignore the person or the object that they are pointing out.

Not responding to their name

According to the CDC, a baby should be able to respond to their name from about 6 months old.

However, a 2017 study found that babies developing ASD often do not respond to their name at 9 months old.

Difficulty with nonverbal communication

The CDC states that from around 9 months old, a baby should be able to point things out. At this age, they should also be able to copy the sounds and gestures of other people.

Research from 2019 found that at 18 months, autistic children pointed and gestured much less than children who were not autistic. A lack of nonverbal communication could indicate delays in language development.

Limited facial expressions

By the age of 4 months, a person can expect a baby to be able to copy facial expressions, such as smiling or frowning. A baby should also be able to smile spontaneously and let others know if they are sad. At 6 months, a baby should recognize other people’s emotions and be able to respond to them.

An autistic baby, on the other hand, may not respond to a smile or other facial expressions. They may also respond to certain expressions or experiences with facial expressions that are inappropriate.

Delays in language development

By the age of 1 year, a child should be able to say one to three single words and try to copy words that other people say.

The National Institute on Deafness and Other Communication Disorders notes that autistic children may have trouble developing language skills and understanding what other people say. According to March of Dimes, about 40% of autistic children do not speak at all.

Regression

Regression is where a baby starts to lose skills they previously had, such as verbal communication or social behaviors. A study from 2015 found that close to one-third of autistic children lose some skills around preschool age.

According to the Autism Science Foundation, a person should talk with a doctor if a 2-month-old infant is not doing the following:

  • responding to loud sounds
  • watching things as they move
  • smiling at others
  • bringing their hands to their mouth
  • holding their head up when lying on their tummy and pushing up

A person should talk with a doctor if a 4-month-old baby is not doing the following:

  • holding their head steady
  • making sounds
  • bringing objects to their mouth
  • pushing down with their legs when a parent or caregiver places their feet on hard surfaces
  • moving both eyes in every direction

It is advisable to seek medical advice for a 6-month-old baby who appears unusually floppy or stiff or who is not:

  • reaching for objects
  • displaying affection for their parents or caregivers
  • responding to sounds around them
  • making vowel sounds
  • laughing

A person can expect a healthy 9-month-old baby to be:

  • looking to where a person is pointing
  • responding to their name
  • babbling
  • recognizing people
  • sitting without help
  • playing back-and-forth games
  • putting their weight on their legs, with support
  • transferring toys between their hands

A person should talk with a doctor if a 12-month-old infant is showing signs of regression or is not:

  • pointing to objects
  • gesturing, such as waving or shaking their head
  • saying single words, such as up, bye, or juice
  • crawling
  • standing, with support

ASD is a possibility if an 18-month-old child is losing skills that they previously had or is not:

  • pointing to show things to others
  • recognizing familiar objects, such as spoons or cups
  • imitating others
  • using at least six words
  • showing an ability to learn new words
  • reacting when a parent or caregiver leaves or comes back
  • walking

If a person thinks that their baby may be autistic, they should contact a doctor. The doctor will begin the diagnosis by observing and evaluating the baby’s behavior.

If the doctor suspects ASD, they may recommend further testing.

The CDC notes that 1 in 54 children in the United States have autism.

Developmental delay screenings involve a doctor observing the baby. The doctor will also ask the parent or caregiver questions about the baby’s behavior.

The American Academy of Pediatrics (AAP) recommends that babies have a routine development assessment at all visits and developmental delay screenings when they are 9, 18, and 24 or 30 months old. A doctor should perform ASD-specific screenings when the baby is 18 and 24 months old.

Although certain developmental delays can be concerning, babies develop and grow at their own pace. It can, however, be helpful to have an indication of what milestones a baby should be reaching and when.

If a person would like to track how their baby is developing, the CDC offers a list of developmental milestones. The CDC also has a milestone tracker app, which includes a checklist, tips, and advice.

ASD is a developmental condition, and it is possible for a baby to be autistic. The sooner a healthcare professional diagnoses ASD, the sooner the child can receive any necessary support.

A person can look for various signs if they think that their baby is autistic. Although healthcare professionals typically diagnose ASD in children below the age of 2 years old, a person can first show signs of ASD at any age. The AAP recommends that babies receive regular screening for ASD and other developmental conditions.

Anyone who notices signs of autism in a child in their care should talk with a doctor.