Prenatal factors associated with autism spectrum disorder (ASD)

Area of Science:

• Neurodevelopmental Disorders
• Environmental Health
• Maternal-Fetal Medicine

Background:

• Autism spectrum disorder (ASD) affects approximately 1% of children and is linked to complex genetic and environmental factors.
• Prenatal exposures are increasingly recognized as significant contributors to ASD etiology.
• Understanding these factors is crucial for developing effective prevention strategies.

Purpose of the Study:

• To review and discuss known prenatal risk factors associated with autism spectrum disorder (ASD).
• To summarize evidence, including animal data where relevant, for various prenatal exposures and ASD.
• To highlight areas requiring further epidemiological investigation for potential ASD prevention.

Main Methods:

• Literature review and synthesis of existing epidemiological and animal studies.
• Identification and categorization of prenatal risk factors including maternal diseases, medications, and environmental exposures.
• Discussion of the role of inflammatory cytokines and other biological mechanisms.

Main Results:

• Maternal conditions like pregestational/gestational diabetes mellitus (PGDM/GDM), infections (rubella, CMV), fever, and inflammation are associated with ASD.
• Exposure to certain medications (valproic acid, thalidomide, SSRIs) and substances (ethanol, cocaine) during pregnancy are linked to ASD risk.
• Environmental factors such as heavy metals, smoking, folic acid deficiency, pesticides, and air pollution show potential associations with ASD.

Conclusions:

• Multiple prenatal factors, including maternal health, medication use, and environmental exposures, are associated with ASD development.
• While associations exist, more epidemiological data is needed to confirm causality for many factors.
• Confirmed prenatal risk factors could offer promising avenues for future ASD prevention efforts.