Can newer BPA substitutes in baby products trigger preterm birth?

What's actually in it

Many baby bottles, sippy cups, and food containers now carry a "BPA-free" label. But manufacturers often swap BPA for newer chemicals like bisphenol S (BPS), bisphenol F (BPF), and bisphenol AF (BPAF). These substitutes show up in plastics, thermal receipt paper, and canned food liners.

Like BPA, these replacement chemicals are endocrine disruptors. They mimic hormones in your body and can cross from a pregnant person's blood into the placenta and the developing baby.

What the research says

A 2026 study in Environ Toxicol Pharmacol measured levels of emerging bisphenols in pregnant women's blood and placental tissue. The researchers found detectable levels of BPS, BPF, and BPAF in most samples.

Women with higher bisphenol levels had a stronger link to iatrogenic preterm birth, which is early delivery triggered by pregnancy complications like preeclampsia. The chemicals appeared to disrupt placental hormone signaling, which can cause blood pressure problems and poor blood flow to the baby.

The study confirmed that these newer bisphenols cross the placental barrier just as easily as BPA does. Some were found at higher concentrations in placental tissue than in maternal blood, suggesting the placenta may actually concentrate them.

Switching to "BPA-free" plastics doesn't eliminate the risk. For safer options during pregnancy, use glass or stainless steel containers for food and drinks. Avoid heating plastic containers in the microwave, since heat speeds up chemical leaching.