Prenatal BPA Exposure Linked to Sex-Specific Health Risks

Study finds chemical can feminize males and masculinize females, with lasting metabolic and immune impacts.

Jan. 29, 2026 at 9:47am

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New research suggests that even low-level exposure to the industrial chemical bisphenol A (BPA) in the womb can disrupt fetal development, feminizing males and masculinizing females. Scientists found these prenatal changes may permanently alter metabolism, immunity, and disease risk, potentially setting the stage for chronic illnesses later in life.

Why it matters

BPA is a widely used chemical found in many consumer products, and over 90% of Americans have detectable levels in their blood. Previous studies have linked BPA exposure to a range of health problems, especially in vulnerable populations like babies and children. This new research highlights the concerning impacts BPA can have on sexual development and long-term health, even at low doses.

The details

In the study, pregnant rats were given drinking water containing BPA at two doses - one matching typical human exposure and a higher dose once considered safe. When the offspring reached adulthood, researchers found lasting effects on gene expression, metabolism, and the immune system. Females were masculinized, while males were feminized, with metabolic shifts in opposite directions - females drifted toward a cancer-like state, while males showed signs of metabolic syndrome. The immune system was also impacted, with T cell activity increasing in males but decreasing in females.

  • The study was conducted by researchers at Uppsala University in Sweden.

The players

Thomas Lind

The study's first author.

European Union

Has banned BPA from being used in nearly all food-contact materials, with a phase-out period currently underway.

U.S. Food and Drug Administration (FDA)

Has barred the use of BPA in baby bottles, sippy cups and infant formula packaging, but there is no nationwide ban.

New York

State law prohibits the manufacture or sale of BPA-containing childcare products intended for children under 3, including pacifiers, bottles and other beverage containers.

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What they’re saying

“We saw lasting effects in the adult rat. Even very low doses changed how the genes were expressed. Females were masculinized, and males were feminized.”

— Thomas Lind, Study's first author

“The results also corroborate previous human studies, where women with the hormone disorder PCOS have exhibited higher levels of bisphenol A in the blood, which correlates with an increased influence of male sex hormones.”

— Thomas Lind, Study's first author

What’s next

The authors say their findings strengthen the case for cutting BPA out of food and beverage packaging, and pressure is building for more regulations on the chemical's use, especially in products intended for children.

The takeaway

This study adds to growing evidence that even low-level exposure to BPA during pregnancy can have significant and lasting impacts on sexual development and long-term health, underscoring the need for stricter regulations on this widely used industrial chemical.