A new study from NYU researchers has found that pregnant women with detectable levels of glyphosate in their bodies at mid-pregnancy were 37% more likely to deliver prematurely, adding to a growing scientific record around the world’s most widely used herbicide.
The study, published in the journal Environmental Pollution, tested expectant mothers for glyphosate through urine samples taken at 18 to 25 weeks of pregnancy. Women who showed the chemical at that stage were twice as likely to experience spontaneous preterm birth, the kind that happens without a planned medical reason. Preterm birth is the leading cause of death in children under five, according to the World Health Organization.
“Our findings add to a growing body of evidence that exposure to glyphosate early in life may lead to health concerns that can echo throughout a lifetime,” said lead author Teresa Herrera, a doctoral candidate at NYU’s Department of Environmental Medicine.
Glyphosate is the active ingredient in Roundup, the Bayer-manufactured weedkiller used on farms and in backyards across the country. More than 80% of Americans over the age of six have measurable glyphosate in their systems, according to prior research. The chemical is present in soil, water, and a wide range of food products including honey, olive oil, fruits, nuts, and cereals.
The Make America Healthy Again movement, led by Health and Human Services Secretary Robert F. Kennedy Jr., has targeted glyphosate as a likely carcinogen and a contributor to the chronic disease epidemic Kennedy has made central to his agenda.
Bayer has proposed a $7.25 billion settlement to resolve tens of thousands of lawsuits linking Roundup to non-Hodgkin lymphoma. A hearing on the settlement was scheduled for August.
The new findings complicate the political picture for the Trump administration. In February, President Trump signed an executive order directing federal agencies to ramp up domestic production of phosphorus and glyphosate, citing food security and national defense. The order noted that phosphorus, a key ingredient in glyphosate, is also used in military munitions and semiconductors.
Kennedy declined to oppose the order publicly. “I support President Trump’s executive order to bring agricultural chemical production back to the United States and end our near-total reliance on adversarial nations,” Kennedy said at the time, according to the Associated Press.
The NYU study found that exposure to AMPA, a byproduct created when soil microbes break down glyphosate, did not carry the same association with preterm births. Researchers said this suggests unprocessed glyphosate may be the primary driver of the observed effects, though the exact mechanism remains under investigation. Theories include endocrine disruption, oxidative stress, and inflammation.
The findings apply only to mid-pregnancy exposure. Women with glyphosate detectable before 18 weeks did not show the same elevated risk, according to the study.
