Signs Of Autism During Pregnancy: Causes & Risks 2023

Carrying a child is one of the most natural things in the world. However, if you’re a pregnant woman, you already know the stresses and worries this time can bring.

You may experience a constant stream of anxious thoughts running through your head, such as, “Will this harm my baby?” or “What can I do to make sure they grow healthy and strong?”

One such neurodevelopmental disorder you may worry about is autism, which can significantly impact your and your child’s life.

In this article, we’ll explore signs of autism during pregnancy and how you can reduce the risk of your unborn child developing this neurodevelopmental disorder. 

Common Signs Of Autism During Pregnancy

Research hasn’t yet found common signs of autism during pregnancy for parents to look out for. However, magnetic resonance imaging scans can detect brain abnormalities that may indicate autism pre-birth and in a child’s first two years of life.

As a prospective parent, being aware of the risk factors associated with autism is key to reducing your unborn child’s risk of developing this neurodevelopmental disorder. Risk factors can be both pregnancy-related and environmental, such as:

  • Taking certain antiepileptic and antidepressant medications.
  • Maternal infection.
  • Poor maternal health, including obesity and high-stress levels.
  • Exposure to toxins and harmful chemicals.

Symptoms Of Autism Already Evident During Pregnancy

You might ask, “Can autism be detected before birth?” Evidence suggests at least two signs of autism during pregnancy within the first two years of life. However, these early signs of autism may not be visible on the surface.

Instead, it may require medical testing, such as magnetic resonance imaging scans, as the symptoms appear related to the child’s developing brain.

MRIs of unborn children can detect differences in their developing brains. For example, one study found that children with autism spectrum disorder were likelier to have subcortical lesions[1] — areas with damaged brain tissue.

Research has also indicated that certain brain areas[2] may be enlarged in children with autism spectrum disorder, which may be visible before birth.

So, can you test for autism before birth? Yes, technically, you can, but only with intensive scanning. Autism becomes much more apparent in the first two years of life, with children often showing characteristic signs of autism at nine months. These typically include being less responsive[3] to things like eye gaze, facial expressions, and sounds.

Children also show signs of autism at 12 months,[4] such as:

  • Difficulties giving direct eye contact.
  • Not responding to their name.
  • Challenges with pretend play and imitation.
  • Difficulties understanding non-verbal communication.

Nevertheless, there are certain things pregnant women can do to reduce the risk of autism during pregnancy and birth.

How Pregnancy May Shape A Child’s Autism

signs of autism during pregnancy
ASD may arise due to environmental and genetic factors as well as health issues during pregnancy and taking certain medications. Photo: Evgeny Atamanenko/Shutterstock

While much is still unknown about autism spectrum disorder, ASD, recent findings[5] suggest that pregnancy may shape a child’s autism in several ways.

Research suggests that ASD may arise due to environmental and genetic factors as well as health issues during pregnancy and taking certain medications. Below, we explore the various causes and risk factors for autism during pregnancy.

However, it’s important to note that autism research cannot show a definitive causal relationship between autism and factors during pregnancy. Instead, it can only show a link, meaning when one thing occurs, the risk of autism increases.

What Causes Autism During Pregnancy & Autism Risk Factors 

You may be wondering, what causes autism during pregnancy? There appear to be various risk factors for autism during pregnancy. Let’s take a look at these next.

Pregnancy-Related Risk Factors For Autism

Taking Antiepileptic Drugs During Pregnancy

Mothers taking certain antiepileptic drugs containing valproic acid[6] during pregnancy have shown a potential link with autism and attention deficit hyperactivity disorder development in their children. Other antiepileptic drugs, such as lamotrigine, showed no relationship.

Paternal And Maternal Ages

The age of the father and pregnant woman also appears to affect the child’s risk of developing autism. Evidence suggests that parents within an older age bracket[7] — mothers 40-49 years and fathers above 50 years — are more likely to have a child with an ASD diagnosis later down the line.

However, one surprising finding of the same autism research is that the younger maternal age — below 20 years — is also associated with autism spectrum disorders in the child in the future.

These patterns are supposedly true for both female and male autistic children.

Maternal Use Of Antidepressant Drugs

A meta-analysis and systematic review found that maternal use of the common antidepressant drug[8] selective serotonin reuptake inhibitors can increase the risk of autism spectrum disorder in the unborn child.

Being Born Premature

Strong evidence suggests that being born prematurely can increase a child’s risk of autism. A meta-analysis including 3,366 preterm infants[9] found that the overall prevalence of autism spectrum disorder in children born preterm is 7%.

Maternal Gestational Diabetes

Research on the relationship between diabetes in pregnant women and neurodevelopmental disorders in the preborn child is limited. However, a recent meta-analysis[10] shows that maternal gestational diabetes was related to an increased risk of autism spectrum disorder in the child but not attention deficit hyperactivity disorder.

A systematic literature review[11] also looking into the link between maternal diabetes and autism risk in the offspring reported the same finding.

Maternal Infection

Some studies suggest maternal infection can increase a child’s autism risk, while others show differently. However, a recent meta-analysis comparing 15 studies and 40,000 ASD[12] cases found that maternal infection during pregnancy was one of the genetic risk variants for a child to develop autism. This finding was especially evident in mothers hospitalized due to their infection.

This research suggests that maternal infection can influence the unborn child’s brain development, potentially due to inflammation, as the infection likely triggers the child’s immune system.

Environmental Factors Increasing Risk For Autism

Certain environmental factors have been found to increase the risk of pregnant women giving birth to an autistic child, including:

  • Environmental toxins: If pregnant women are exposed to toxins[13] like phthalates, brominated flame retardants, aromatic polycyclic hydrocarbons, and bisphenol-A, this can increase the child’s risk of autism.
  • Environmental exposures: Maternal exposure to products containing human-created chemicals[13] like pesticides, plastics, cosmetics, and sometimes food can increase a child’s risk of autism. Heavy metals also appear to play a role in disrupting the fetal brain.

These chemicals are believed to affect the unborn child’s endocrine system,[14] the body’s network of hormones responsible for our energy levels, growth and development, metabolism, stress, and mood. 

Reducing The Risk Of Autism During Pregnancy And Birth

Consider The Risk Factors

Thinking about the risk factors of having children beforehand is important for any prospective parents. For example, ensuring you and your partner are within the healthy age bracket, avoiding depression and antiepileptic medication, and reducing toxins as much as possible, can help reduce the risk of your child developing autism.

Look After Your Health

As we have seen from the research, pregnant women must take care of themselves during pregnancy to reduce the risk factors through such things as:

  • Taking pregnancy vitamins: Certain pregnancy vitamins[15] may help boost the mother’s health while pregnant. Folic acid is one pregnancy vitamin that appears to boost the mother’s health prenatally and during early pregnancy. 
  • Using natural remedies: This could include taking natural remedies for headaches and other pain and illnesses.
  • Maintaining a healthy weight during pregnancy: Research shows that maintaining a healthy weight[16] during pregnancy can reduce the risk of your child developing autism.
  • Taking time to relax: Taking time to relax is vital during pregnancy as anxiety can put the unborn baby at risk of pregnancy and birth complications[17] and developing ASD.[18]


As pregnant mothers, we all want to keep our babies happy and healthy, including from neurodevelopmental conditions like autism. But what does this actually look like?

Various pregnancy-related factors can reduce an unborn child’s risk of developing autism, such as the mother taking certain drugs, having an infection during pregnancy, and age at conception. The environment can also pose a risk to unborn children, with exposure to certain toxins and environmental factors potentially increasing a child’s risk of developing autism.

As a pregnant mother, you can make reasonable adjustments to your life to reduce the risk of your child developing autism during pregnancy, including considering the risk factors and looking after your health. 

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