Texas researchers are launching a federally funded investigation into whether the microplastics now found throughout the human body may be contributing to one of the most expensive and persistent complications in American pregnancy: preterm birth.
Preterm birth, defined as delivery before 37 weeks, affects roughly 10% of pregnancies worldwide, and U.S. rates have climbed 12% since 2014 despite advances in prenatal care. The annual cost to the American healthcare system exceeds $25 billion. Texas has one of the worst preterm birth rates in the nation, at 11.2% in 2023, earning a D+ grade from the March of Dimes.
The researchers' own preliminary data sharpened the question. Using placental tissue samples, they found that microplastic concentrations in the placenta were 23.9 times higher than in the blood. More striking: placentas from preterm births contained significantly more microplastics than those from full-term births, 224.7 versus 175.5 micrograms per gram of tissue, a statistically significant difference. Specific plastic polymers were present at 17% to 157% higher concentrations in preterm cases.
A $639,797 grant from the National Institute of Environmental Health Sciences will fund a systematic investigation into whether that association holds up across a larger sample and whether there is a biological mechanism driving it. The research will draw on a completed cohort study conducted in Texas, the BABS Trial, which tracked 585 pregnancies from the first trimester through six weeks postpartum and collected more than 93,000 biospecimens. Of those pregnancies, 103 ended preterm.
Researchers will analyze roughly 3,500 specimens for 12 different plastic polymers and examine 1,200 samples for inflammatory markers to test whether microplastic accumulation disrupts the placenta's immune function in ways that could trigger early labor. Thirty placentas will undergo spatial transcriptomics, a high-resolution technique that maps immune cell activity across tissue.
The microplastics question has moved quickly from environmental concern to clinical alarm. A landmark 2024 study published in the New England Journal of Medicine found microplastics embedded in arterial plaque and linked them to higher rates of cardiovascular events, drawing wide attention to the idea that plastics in human tissue may have direct health consequences. Similar concerns about microplastics and human health have driven federal funding in other areas, including research in Michigan on whether so-called forever chemicals may trigger autoimmune disease.
The preterm birth connection is less explored. If the Texas study confirms that microplastic accumulation in the placenta triggers inflammatory responses that cause early delivery, it would reframe how researchers and clinicians think about one of America's most common and costly pregnancy complications, and potentially point toward modifiable risks in an era of ubiquitous plastic exposure.
The BABS Trial cohort reflects Texas's demographic diversity and its unique environmental context: the state's Gulf Coast is home to one of the nation's largest petrochemical corridors, the industrial source of many of the polymers that break down into microplastics. Results from the analysis are expected to inform the design of future mechanistic studies and, researchers say, provide evidence-based guidance for reducing exposures during pregnancy.
