Can phthalate exposure at birth raise a boy's risk of testicular cancer later?

What's actually in it

Phthalates are plasticizer chemicals found in soft PVC plastic. Newborns encounter them from multiple sources: medical tubing in the hospital (IV lines and feeding tubes are often PVC), plastic baby bottles, soft vinyl toys, and food that touched plastic packaging. Phthalates also pass from mother to baby through the placenta and breast milk.

The first hours and days of life are a period of intense chemical exposure. A baby in a neonatal unit may be connected to several PVC tubes at once, each one leaching phthalates directly into their bloodstream.

What the research says

A 2026 study in JNCI Cancer Spectrum measured phthalate levels in newborns and then followed them for years to see who developed testicular cancer during adolescence and young adulthood.

Boys with higher phthalate levels at birth had a greater risk of developing testicular cancer later. Testicular cancer is the most common cancer in young men aged 15 to 35, and its rates have been climbing for decades. Researchers have long suspected that something in the environment is behind the rise.

Phthalates are known anti-androgens. They block or reduce the action of male hormones like testosterone. During the critical window right around birth, testosterone is essential for normal development of the testes. When phthalates interfere with that process, they may set the stage for cancer that shows up 15 or 20 years later.

This study is among the first to directly measure phthalates at the time of birth and link them to cancer outcomes years down the road. That long follow-up is what makes it so valuable.

To lower a newborn's exposure, ask your hospital about phthalate-free medical tubing (many hospitals are switching). At home, use glass bottles, avoid soft PVC toys, and store breast milk or formula in glass containers instead of plastic.