Can PFAS exposure during pregnancy cause asthma and allergies in children?

What's actually in it

PFAS from nonstick cookware, food packaging, and stain-resistant products cross the placenta during pregnancy. The fetal immune system is still forming during this period. PFAS are known to disrupt immune cell development, particularly the Th1/Th2 balance that governs allergic versus non-allergic immune responses.

Allergic diseases like asthma and eczema involve an overactive Th2 immune response. When PFAS shift the immune balance toward Th2 during fetal development, the child is born with an immune system already tilted toward allergic reactions.

What the research says

The 2026 Shanghai Birth Cohort study in Environ Int enrolled thousands of mother-child pairs, measured PFAS in maternal blood during pregnancy, and tracked the children for allergic disease outcomes. Children born to mothers with higher prenatal PFAS had higher rates of eczema, wheezing, and diagnosed asthma.

The associations were dose-dependent: higher prenatal PFAS predicted more severe and more frequent allergic outcomes. Multiple individual PFAS compounds showed the effect, not just one specific chemical.

The Shanghai cohort is large enough that the findings carry statistical weight. The associations held after adjusting for parental allergy history, household factors, and socioeconomic variables.

For families with allergy history, reducing PFAS exposure during pregnancy removes one of the few modifiable risk factors for childhood allergic disease. The key sources to target: nonstick cookware, PFAS-treated textiles, and PFAS-contaminated drinking water.