Can phthalate exposure during pregnancy slow language development in babies?

What's actually in it

Phthalates are plasticizers in PVC products, personal care items (fragrance, shampoo, lotion), and some food packaging. They're detected in nearly every pregnant person tested. They cross the placenta and disrupt hormone signaling during fetal brain development, particularly thyroid and sex hormone pathways that drive language and cognitive development.

The developing brain builds its language circuitry during fetal and early infant stages. Disruptions during this window don't necessarily create obvious problems at birth, but they show up as slower language acquisition in the toddler years.

What the research says

A 2026 study in Int J Environ Health Res tracked language development in siblings of children with autism across early childhood. Mothers with higher phthalate levels during pregnancy had children who followed slower language growth trajectories, with fewer words and lower language scores at multiple time points through toddlerhood.

Using siblings makes the finding more robust: it controls for family genetics, parenting environment, and socioeconomic factors that vary between families but not within them. The phthalate effect showed up even against this tightly controlled comparison.

The main phthalate sources during pregnancy are fragrance products (perfume, scented lotion, air fresheners), soft vinyl products (shower curtains, vinyl flooring), and some food packaging. Switching to fragrance-free personal care products and glass or stainless containers for food is the highest-impact step for pregnant people.