Early Signs Of Autism In Babies, Causes, Diagnosis & Treatment

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Autism in babies could lead to significant behavioral, communication, and social challenges. It is a developmental disability alternatively known as an autism spectrum disorder (ASD). The American Psychiatric Association gave the term ASD in 2013. This umbrella term includes pervasive autism disorder, developmental disorder not otherwise specified (PDD-NOS), and Asperger syndrome (1) (2).

Infants may start developing the signs of autism in the first few months, becoming noticeable as the child becomes two to three years old (3). Read on to know more about the signs of autism, its causes, diagnosis, and management.

Signs And Symptoms Of Autism In Babies

The signs of autism can vastly vary across babies, depending on several factors, including the severity of the condition. Parents may be able to spot certain signs and symptoms based on the baby’s age. Do note that these signs and symptoms are not always conclusive indicators of autism, and you must flag your concerns to a pediatrician who can run appropriate tests for diagnosis (1) (2) (3).

Below are signs and symptoms that usually may exhibit at specific ages.

At six months:

  • Does not smile or exhibit joyful expressions
  • No eye contact

At nine months:

  • Does not smile, does not make sounds, and does not make faces with the parents

At 12 months:

  • Does not make babbling sounds
  • Does not depict gestures such as showing, pointing, reaching, or waving
  • Little or no response when called by their name

At 16 months:

  • Does not utter any words

At 24 months:

  • Does not engage in meaningful or two-word phrases (repetition and imitation does not count)

Below are signs of autism that the little one may show at any stage of infancy and toddlerhood.

  • Loss of speech, babbling, or social skills
  • Avoids eye contact and physical contact like cuddling
  • Prefers to be by themselves
  • Has an inability to understand other’s feelings and expressing their feelings
  • Delayed language and speech development
  • Does not respond to being called by their name or responds inconsistently for a prolonged period
  • Does not exhibit interest in other people and has trouble relating to people
  • May show interest in other people but does not know how to talk, play, interact, or relate
  • Appears to be unaware of people talking around but is responsive to other sounds
  • Repeats or echoes words and phrases instead of normal language
  • Has difficulty in expressing what they need using words or motions
  • Does not indulge in pretend-play games
  • Repeats the same actions again and again
  • Has trouble adapting and accepting any new change to the routine
  • Exhibits unusual reactions to sensory stimuli such as smell, taste, sensation, or sound

Causes Of Autism In Babies

The exact cause of autism in babies is not known. However, with increasing cases and increasing research, a few environmental, genetic, and biological risk factors have been identified. One or a combination of the following factors may put a baby at a higher risk of developing ASD (2).

  • Genetic predisposal due to family history
  • Siblings with ASD
  • Chromosomal abnormalities such as fragile X syndrome or tuberous sclerosis
  • Maternal use of prescription drugs such as valproic acid and thalidomide during pregnancy

Risk Factors For Autism In Babies

Certain conditions or situations unrelated to autism or genetic factors may increase the baby’s risk of ASD for unknown reasons (1) (2).

  • Low birth weight
  • Premature birth
  • Older parental age
  • Gender; autism is about four times more common in boys than girls

Diagnosis Of Autism In Babies

There are no laboratory tests or tools devised for the diagnosis of autism. The doctors diagnose ASD based on the baby’s behavior and development.

ASD requires specific developmental screening with relevant tools, consisting of questionnaires and checklists for the parents and tests for the baby. The screening can be conducted before the age of 18 months, and autism may be diagnosed. Nevertheless, an autism-specific screening test is done at 18 and 24 months of age when behavioral attributes associated with the disorder can be more discernible to the parents and the healthcare provider (1) (4).

The prognosis of diagnosis may vary according to the case. For instance, some babies may be referred to a speech-language pathologist for further evaluation or the elimination of other suspected problems. If your baby has a positive result on an autism-specific screening tool, discuss the results extensively with the pediatrician and determine the next step.

Treatment For Autism In Babies

There is no treatment for autism yet. Thankfully, several interventions have been designed that could reduce the symptoms, improve the child’s abilities, and polish their social skills.

The impact of ASD differs from person to person, and the treatment plan is customized for each patient according to their needs. The multidisciplinary treatment plans may require active parental participation.

The behavioral intervention strategies work on the following attributes that are often affected in those with autism.

  • Communication skills
  • Social skills
  • Restricted interests
  • Repetitive behavior

Occupational therapy, speech therapy, and complementary medications could also be suggested for the baby as they grow older. Most intervention strategies may be introduced once the baby has reached early childhood.

Frequently Asked Questions

1. How common is autism spectrum disorder?

According to the US Centers for Disease Control and Prevention, autism affects an estimated one in 54 children in the United States today (5).

2. Does watching TV cause autism?

There is no evidence that TV-watching can cause autism. Excessive screen exposure may lead babies to show autism-like behavior. However, more research is needed to establish a claim (6).

3. Do babies with autism smile?

Babies with ASD do smile, but they smile lesser than other babies of the same age (7).

4. Do babies with autism clap?

Babies with autism can clap their hands, but they might not do it as often as other babies who do not have autism (8).

5. Do toddlers with autism cry a lot?

Some researchers say that infants with autism have difficulty managing their emotions and may transition from mild whimpering to intense crying quickly (9). However, there is no conclusive evidence that toddlers with autism cry more than their peers without autism.

6. What are other medical issues associated with autism?

Autism in infants may be accompanied by other health issues such as gastrointestinal disorders, seizures, sleep disorders, anxiety, depression, and attention issues (10).

7. Are siblings at greater risk for ASD?

Yes, if one child is diagnosed with ASD, the next child is at about 20% higher risk of developing ASD, and the third child is at about 32% greater risk of ASD (1).

8. Do vaccines cause autism?

No. Vaccines do not have any role to play in the occurrence of autism in babies (1).

9. How is the prognosis for people with ASD?

The symptoms of ASD may become less pronounced as the child gets older. Children with autism may have a normal life as they grow, but they may require support for several functions and activities in their lives (1).

According to the US CDC, 1 in 54 children had confirmed diagnosis of autism in 2016 compared to the incidence of 1 in 150 children in 2000 (11). These data indicate that autism has become more common in children. Although the incident has increased, advances in medicine could provide better ways of diagnosis, treatment, and preventive measures for autism spectrum disorders than in the past. Parental awareness of autism symptoms plays a key role in early diagnosis and interventions. Never delay pediatric consultations if you notice concerning symptoms or potential developmental delays in your baby.

Key Pointers

  • If your baby doesn’t smile, make eye contact, or babbling sounds, respond to their names at a recommended age; they could be having autism.
  • Factors such as genetic predisposition, familial history, and chromosomal abnormalities could increase the risk of autism in babies.
  • Contact a specialist if you suspect autism in your baby.


MomJunction's articles are written after analyzing the research works of expert authors and institutions. Our references consist of resources established by authorities in their respective fields. You can learn more about the authenticity of the information we present in our editorial policy.
1. What is Autism Spectrum Disorder?; Centers for Disease Control and Prevention
2. Autism Spectrum Disorder; Cleveland Clinic
3. What are the signs of autism?; Autism Speaks organization
4. Screening and Diagnosis of Autism Spectrum Disorder; Centers for Disease Control and Prevention
5. Autism Statistics and Facts; Autism Speaks organization
6. Donna Hermawatiet al., Early electronic screen exposure and autistic-like symptoms; Intractable & Rare Diseases Research journal
7. Infants with autism smile less at 1 year of age; Simons Foundation
8. Five early signs of autism; Regents of University of California
9. Early signs distinguish autism from other disorders; Simons Foundation
10. What Is Autism?; Autism Speaks organization
11. Data & Statistics on Autism Spectrum Disorder; Centers for Disease Control and Prevention
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Dr. Ritika Shah

Dr. Ritika Shah is a certified lactation counsellor from iNational Health Care Academy, Singapore and a dental surgeon with more than seven years of clinical experience across various cities in India. She did her graduation in Dentistry from KM Shah Dental College. During her clinical practice, pediatric dentistry was her particular area of interest, and she constantly thrived to inculcate... more