Maternal Exposure to Occupational Asthmagens During Pregnancy and Autism Spectrum Disorder in the Study to Explore Early Development.

Mothers reported jobs and health conditions after the child's status was known, so recall may differ between mothers of children with ASD, developmental delay, and population controls. Exposure was estimated from job titles and a published job-exposure table, not from workplace measurements, so some mothers may have been classified incorrectly. The analysis was restricted to mothers who reported a job overlapping pregnancy and had complete covariate data; unemployed mothers and mothers with missing job timing were not included in exposure analyses. Population controls may not represent the source population because maternal age, race-ethnicity, and education differed. The study could not test the proposed immune or oxygen pathways because it did not measure cytokines or fetal oxygenation. It did not account for paternal take-home exposures, non-work exposures, timing of exposure during pregnancy, or personal protective equipment. Subgroup results were based on small numbers and did not show statistical evidence of heterogeneity.

Funders named were Autism Speaks and the Centers for Disease Control and Prevention.

Do not conclude that maternal occupational asthmagens cause autism from the subgroup estimates. The primary analysis did not show a significant association, and the interaction tests did not show statistical evidence of a different effect by child sex, maternal allergy, or maternal asthma.