Pregnant Women Exposed to Common Chemical May Face Early Birth Risk

0 Share Newsweek is a Trust Project member See more of our trusted coverage when you search. Prefer Newsweek on Google to see more of our trusted coverage when you search. Pregnant women exposed to higher levels of a widely used weed-killing chemical may face an increased risk of giving birth prematurely, according to new research.

The study, published in the journal Environmental Pollution , found that exposure to glyphosate—the active ingredient in many herbicides, including Roundup—during mid-pregnancy was associated with a greater likelihood of preterm birth, defined as delivery before 37 weeks of gestation.

Researchers from NYU Langone Health analyzed data from 1,450 women enrolled in the Children's Health and Environmental Study, a prospective birth cohort in New York City between 2016 and 2019.

Participants provided urine samples during early pregnancy and again between 18 and 25 weeks of gestation, allowing scientists to measure levels of glyphosate and its primary breakdown product, aminomethylphosphonic acid (AMPA).

Overall, 7 percent of births in the cohort were preterm.

The researchers found that higher glyphosate concentrations measured between 18 and 25 weeks of pregnancy were associated with a 35 percent increase in the odds of preterm birth.

The risk was even more pronounced for spontaneous preterm birth—when labor begins naturally rather than being medically induced—with participants showing roughly double the odds compared with those who had lower exposure levels.

"Some practical steps to help reduce exposure include choosing organic foods when possible, washing produce and avoiding direct contact with herbicides at home or in the garden," lead author Teresa Herrera, a doctoral candidate in the Department of Population Health at NYU Grossman School of Medicine, told Newsweek .

Herrera added that anyone concerned about chemical exposures during pregnancy should speak with their doctor.

The association was not observed for glyphosate exposure measured earlier in pregnancy, nor did researchers find a link between AMPA levels and preterm birth.

The study also found no evidence that glyphosate was associated with medically indicated preterm births, such as those resulting from complications like preeclampsia or poor fetal growth.

Glyphosate is one of the most widely used herbicides in the world . It is commonly sprayed on commercial crops and in residential gardens, and residues have been detected in foods ranging from cereals and snacks to fruits and vegetables.

According to the researchers, more than 80 percent of Americans are estimated to have detectable levels of glyphosate in their urine.

Preterm birth remains a major public health concern and is a leading cause of illness and death among newborns.

Babies born too early face higher risks of breathing difficulties, infections and long-term developmental challenges.

While the study does not prove glyphosate causes premature labor, the authors say it adds to a growing body of evidence suggesting the chemical may affect biological pathways involved in pregnancy.

Previous laboratory research has indicated that glyphosate could trigger inflammatory responses linked to the onset of labor.

Herrera said it is not uncommon for environmental exposures to have greater effects during specific stages of pregnancy because of the physiological changes taking place at those times.

"For glyphosate, the exact mechanisms are still being studied," she explained, adding that environmental chemicals may influence pregnancy through a number of different biological pathways.

The researchers concluded that pregnancy may represent a particularly vulnerable period for glyphosate exposure and said further studies are needed to better understand how the herbicide could influence birth outcomes.

Newsweek reached out to Bayer, the manufacturer of Roundup, via email for comment.

Herrera, T., Fragoman, F., Ghassabian, A., Cowell, W., Cajachagua Torres, K.N., Ard, N., Kannan, K., Li, Z., Mehta-Lee, S., Liu, M., Burris, H.H. and Trasande, L. (2026). Associations of Glyphosate Exposure in Pregnancy with Preterm Birth: a Longitudinal Birth Cohort Study. Environmental Pollution , [online] p.128775. doi:10.1016/j.envpol.2026.128775 .

Contact Newsweek editors on this story: Charlotte Nisbet and Emma Lee-Sang

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