Autism is a complex neurodevelopmental disorder marked by impaired social interactions, communication, and restricted interests.

The prevalence of autism has been increasing in recent years, and is estimated to affect around 1 in 68 children in the United States (CDC, 2021). While the exact causes of autism are still unknown, research suggests that multiple factors may be involved in its development, including genetic, environmental, and immunological factors.

In particular, microbial infections during pregnancy have been suggested as a potential risk factor for autism.

Microbial Infections During Pregnancy and Autism

Microbial infections are common during pregnancy, and can be caused by various bacteria and viruses. While many of these infections are mild or asymptomatic, some can have serious consequences for both the mother and the developing fetus.

For example, certain infections have been linked to an increased risk of preterm labor, miscarriage, stillbirth, and congenital abnormalities.

Recent studies have also suggested that maternal infections may increase the risk of autism in offspring.

One study found that children born to mothers who had an infection during pregnancy had a 37% higher risk of developing autism, compared to children born to mothers without infections (Atladóttir et al., 2010). Another study found that children born to mothers who had a fever during pregnancy were at a higher risk of developing autism, particularly if the fever occurred during the second trimester (Zerbo et al., 2018).

It is still unclear exactly how maternal infections might contribute to the development of autism in offspring. However, researchers have proposed several possible mechanisms.

One theory is that infections may activate the mother’s immune system, leading to inflammation and oxidative stress, which may in turn affect fetal brain development and increase the risk of autism (Patterson, 2011). Another theory is that infections may directly interfere with fetal brain development by crossing the placenta and infecting the fetus (Boulanger-Bertolus et al., 2018).

Types of Microbial Infections and Autism Risk

Not all types of microbial infections during pregnancy are associated with an increased risk of autism. Some infections, such as the common cold or urinary tract infections, are usually mild and do not seem to pose a significant risk.

However, other infections can be more serious and may increase the risk of autism in offspring. Here are some examples:.

Flu

Influenza, or flu, is a viral infection that is more common during the fall and winter months. While most people recover from the flu without complications, it can be dangerous for people with weakened immune systems, such as pregnant women.

In addition to causing respiratory symptoms, the flu can also lead to fever and inflammation, which may increase the risk of autism in offspring (Zerbo et al., 2013).

Cytomegalovirus

Cytomegalovirus, or CMV, is a common virus that is typically asymptomatic in healthy individuals.

However, if a pregnant woman is infected with CMV, it can be transmitted to the fetus and cause serious complications, including hearing loss, developmental delays, and intellectual disability. Some studies have also suggested that CMV infection during pregnancy may increase the risk of autism in offspring (Boulanger-Bertolus et al., 2018).

Toxoplasmosis

Toxoplasmosis is an infection caused by the parasite Toxoplasma gondii, which is commonly found in cat feces and undercooked meat.

While most people with toxoplasmosis have no symptoms, it can be dangerous for pregnant women, as it can be transmitted to the fetus and cause serious complications, including eye damage, brain damage, and intellectual disability. Some studies have also suggested that toxoplasmosis during pregnancy may increase the risk of autism in offspring (Jones et al., 2018).

Lyme Disease

Lyme disease is a bacterial infection that is transmitted by ticks. While most cases of Lyme disease can be effectively treated with antibiotics, some people develop chronic symptoms that can last for months or even years.

Lyme disease during pregnancy has been linked to an increased risk of miscarriage and stillbirth, but its association with autism risk is still unclear (Jones et al., 2018).

Prevention and Treatment

Preventing and treating microbial infections during pregnancy is important for both the mother and the developing fetus. Here are some tips for reducing the risk of infection:.

Wash hands frequently and thoroughly with soap and water
Avoid close contact with people who are sick
Avoid sharing food, drinks, or utensils with others
Cook meat and poultry thoroughly to kill bacteria and parasites
Clean and disinfect contaminated surfaces and objects
Get vaccinated against influenza and other diseases recommended by your healthcare provider
If you think you have an infection, seek medical attention promptly

If you are pregnant and have an infection, your healthcare provider may recommend antibiotics or antiviral medications to treat the infection and reduce the risk of complications.

However, not all infections can be treated with medication, and some may require more intensive treatment, such as hospitalization or surgery. It is important to follow your healthcare provider’s advice and take all medications as prescribed.

Conclusion

While the link between microbial infections during pregnancy and autism risk is still unclear, research suggests that some types of infections may increase the risk of autism in offspring.

Preventing and treating infections during pregnancy is important for both the mother and the developing fetus, and may help reduce the risk of complications, including autism. If you are pregnant and have concerns about infections, speak to your healthcare provider for advice and guidance.