In Pilot Study, Researchers Find Estrogen-Like Contaminant in Every Pregnant Participant Tested

Rutgers scientists examine hormone-mimicking mycotoxins linked to corn and other grains, calling for awareness of an emerging food contaminant in the U.S.

Consuming common foods such as corn chips and popcorn may put pregnant women at risk of being exposed to mycotoxins - harmful substances produced by mold - according to Rutgers researchers.

Their study, published in the Journal of Exposure Science & Environmental Epidemiology, found hormone-mimicking mycotoxins in 100% of participants and linked exposure levels to the amount of corn and grain products consumed.

One such mycotoxin is zearalenone, a compound produced by Fusarium fungi that contaminate staple crops such as corn, wheat and oats. Zearalenone can indirectly enter human food supplies through meat and dairy from animals that eat contaminated feed. It also is heat-stable, so it can survive cooking and food processing.

Our findings confirm that grain-based foods are important contributors to mycoestrogen exposure among pregnant women in the U.S.

Zorimar Rivera-Núñez

Assistant Professor, Rutgers School of Public Health

As zearalenone can mimic estrogen, a hormone critical to pregnancy and fetal development, it is a mycotoxin that is more specifically classified as a mycoestrogen. Other studies suggest that exposure to mycoestrogens may contribute to greater gestational weight gain and lower infant birthweight.

"Mycoestrogens are among the most common food contaminants worldwide, yet evidence on their dietary sources in the United States has been limited," said Zorimar Rivera-Núñez, an assistant professor at Rutgers School of Public Health and the lead author of the study. "They have potent estrogenic properties, but we know very little about how these exposures may affect pregnant women and their developing babies."

The researchers said the pilot study, known as the Jersey Babies pilot study, is among the first in the U.S. to pair pregnant women's dietary intake with mycoestrogen biomarkers collected at the same time. This approach can help researchers pinpoint specific dietary sources of mycoestrogen exposure.

The study followed 33 pregnant women recruited from obstetric clinics at Saint Peter's University Hospital and Rutgers Robert Wood Johnson University Hospital in New Brunswick, N.J. Participants provided urine samples and completed detailed 24-hour dietary recalls at three points in pregnancy, allowing the researchers to closely match what participants ate with what showed up in their urine.

Researchers analyzed the urine samples for several mycoestrogens, including zearalenone. Findings showed at least one mycoestrogen was detected in every single urine sample collected.

Zearalenone itself was detected in most participant samples at all three visits. Its levels remained relatively stable across pregnancy for several participants, suggesting that exposure was persistent rather than a one-time event.

"Our findings confirm that grain-based foods are important contributors to mycoestrogen exposure among pregnant women in the U.S.," Rivera-Núñez said, who also is a member of the Rutgers Environmental and Occupational Health Sciences Institute.

Researchers found that consumption of corn and other grain products in the 24 hours before a urine sample was collected was strongly associated with higher mycoestrogen levels.

Corn-based foods, including corn, corn chips and corn tortillas, showed the strongest associations, followed by more modest links to cereal grains and oils. By contrast, consumption of chicken and pork showed weaker, inverse associations, suggesting corn and grain products, rather than meat, were the primary dietary contributors to exposure in this study group.

The study's findings also suggest differences by ethnicity.

Participants who identified as Hispanic had mycoestrogen levels that were higher than non-Hispanic participants across the three study visits. Hispanic participants also reported eating more corn and corn-based products, as well as more dairy, than non-Hispanic participants.

"Identifying groups with higher exposures is a critical first step for our mycoestrogen research program," Rivera-Núñez said. "It helps us understand the factors driving those exposures and provides the information needed to develop strategies that protect maternal and child health."

According to the researchers, the U.S. Food and Drug Administration added zearalenone to its Mycotoxin Compliance Program in 2024 but hasn't yet established maximum allowable limits in food. On a global scale, the European Commission has set limits for zearalenone in cereals, baked goods and infant food.

The researchers said the findings establish mycoestrogens as an emerging and understudied exposure among U.S. pregnant women, setting a foundation for future research into potential reproductive, developmental and child health outcomes.

"Pregnancy represents a unique opportunity for prevention," Rivera-Núñez said. "By understanding how everyday dietary choices contribute to environmental chemical exposures, we can provide families with information that supports both maternal and child health."