Can phthalates in breast milk from preterm deliveries expose premature babies to higher levels?

What's actually in it

Phthalates enter the body through fragrance products, soft plastic food packaging, vinyl materials, and personal care items. They metabolize quickly but are continuously replenished from daily exposure. When phthalates are in a mother's blood, some transfer into breast milk.

Premature babies face a special challenge: their organs, especially the liver and kidneys that detoxify chemicals, are not fully developed. Phthalates that a full-term infant could clear more easily may linger longer and have stronger effects in a premature baby's body.

What the research says

A 2026 study in Toxics measured phthalate metabolites in urine and breast milk from mothers who delivered very preterm. Phthalates were detected in breast milk, and the levels correlated with the mother's urinary phthalate concentrations, confirming the transfer pathway. Higher maternal exposure meant higher breast milk levels.

The study focused on the matrix concordance (how well urine levels predict milk levels) to understand which mothers are at higher risk of passing more phthalates to their preterm infants. Mothers with fragrance-heavy personal care routines had higher urinary levels, which predicted higher milk levels.

Breast milk still provides irreplaceable immune and developmental benefits that far outweigh phthalate exposure risk for most infants. But for mothers of premature babies specifically, reducing phthalate exposure during the period of active breastfeeding can reduce the concentration transferred. Switching to fragrance-free shampoo, lotion, and household products is the most direct step.