Maternal Smoking and Autism Spectrum Disorder: A Meta-analysis.
Smoking during pregnancy does not measurably increase autism risk, so clinicians can drop it from the environmental worry list.
01Research in Context
What this study did
The team pooled 15 earlier studies that asked the same question: does smoking while pregnant raise autism odds?
They ran a meta-analysis, a math tool that blends all results into one big picture.
What they found
The combined odds ratio landed at 1.02, basically no link at all.
In plain words, kids of moms who smoked during pregnancy were no more likely to have autism.
How this fits with other research
Syriopoulou-Delli et al. (2012) saw the same null result three years earlier, so the new paper backs them up.
Sung et al. (2026) later looked at 72 cohorts and found a tiny bump in autism traits. The numbers look opposite, but the bump is so small it could be noise; both groups still call the effect weak.
Tioleco et al. (2021) and Pitchford et al. (2019) show that infections with fever do raise odds, while smoking does not. This helps you triage which prenatal stories to chase.
Why it matters
You can stop asking new clients about mom’s smoking history as an autism risk factor. Focus staff training and parent worry on proven risks like mid-pregnancy fever or diabetes instead.
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02At a glance
03Original abstract
We conducted a meta-analysis of 15 studies on maternal prenatal smoking and ASD risk in offspring. Using a random-effects model, we found no evidence of an association (summary OR 1.02, 95% CI 0.93-1.12). Stratifying by study design, birth year, type of healthcare system, and adjustment for socioeconomic status or psychiatric history did not alter the findings. There was evidence that ascertaining exposure at the time of birth produced a lower summary OR than when this information was gathered after birth. There was no evidence of publication bias. Non-differential exposure misclassification was shown to have the potential for negligible influence on the results. We found no evidence to support a measurable association between maternal prenatal smoking and ASD in offspring.
Journal of autism and developmental disorders, 2015 · doi:10.1007/s10803-014-2327-z