Washington DC: The new research on autism has examined a wide body of earlier reviews assessing possible risks associated with acetaminophen use during pregnancy.
The authors have reported that these past studies are limited in quality, with most showing low or critically low reliability after being evaluated through established assessment tools.
The researchers conducted an umbrella review to address earlier inconsistent findings. They examined nine systematic reviews covering 40 observational studies. These studies looked at prenatal acetaminophen exposure and later neurodevelopmental outcomes like autism and ADHD.
Each review was evaluated for bias, overlap, and overall quality. While some reviews suggested a link between prenatal acetaminophen use and autism or ADHD, the evidence was not strong. The researchers found that most studies failed to account for important family-related confounding factors like genetics, parental mental health, and lifestyle.
Overall confidence in the earlier evidence was rated as low for two reviews and critically low for seven. Only one review included well-controlled sibling studies that properly addressed shared genetic and environmental influences.

In those studies, the apparent link between prenatal acetaminophen exposure and autism was greatly reduced or disappeared once these familial factors were taken into account. According to the authors, this suggests that genetics and home environment may explain most of the earlier observed associations.
The researchers have also noted several limitations in existing studies, including inconsistent methods, varying definitions of exposure, and the absence of information on dosage or timing.
Despite these gaps, acetaminophen, also known as paracetamol in many countries, continues to be recommended by regulators and healthcare providers as the safest option for managing pain and fever during pregnancy.
The authors stated that more high-quality research is needed to fully understand whether any measurable connection exists between acetaminophen exposure before birth and later neurodevelopmental outcomes.
They added that future studies should better control for family-related confounders while examining other potential developmental effects. For now, the review highlights the lack of strong evidence linking acetaminophen use in pregnancy to autism.

