Can sunscreen chemicals absorbed during pregnancy affect a child's cognitive development?

What's actually in it

UV filter chemicals in sunscreen include oxybenzone (benzophenone-3), avobenzone, octocrylene, octinoxate, and others. These are absorbed through skin into the bloodstream. Studies have detected them in blood, urine, breast milk, and amniotic fluid. They act as endocrine disruptors, particularly affecting estrogen and thyroid hormone pathways.

Thyroid hormones are essential architects of fetal brain development. They control the timing of neural migration, synapse formation, and myelination. UV filters that disrupt thyroid signaling during pregnancy can alter these precisely timed developmental processes in ways that show up later as cognitive and behavioral differences.

What the research says

A 2026 longitudinal study in Environ Pollut measured UV filter chemicals in pregnant women and followed their children through developmental assessments. Higher prenatal UV filter exposure was linked to lower cognitive scores and worse neurobehavioral outcomes in the children at follow-up.

Multiple UV filter compounds contributed to the associations. The effect was consistent across cognitive and behavioral measures, suggesting UV filters broadly disrupt neurodevelopmental programming rather than affecting one specific brain function.

Pregnant people who use sunscreen daily have ongoing skin exposure to these chemicals throughout pregnancy. Mineral-only sunscreens (with zinc oxide or titanium dioxide as the only UV filters) provide effective sun protection without chemical UV filter absorption. Physical sun protection (clothing, shade, hats) combined with mineral sunscreen avoids chemical filter exposure entirely.