Pregnant women exposed to disease-causing 'forever chemicals' could be at a greater risk of developing gestational diabetes, a study suggests.
PFAS (per- and polyfluoroalkyl substances) are toxic chemicals that don't break down in the body, instead leeching from nonstick cookware, waterproof textiles and takeout containers into food and the skin and building up in vital organs, increasing the risk of organ failure, reproductive complications and some forms of cancer.
Virtually all humans are exposed to PFAS, or 'forever chemicals,' on a regular basis, going back to even before birth.
Now, researchers in New York City have found that mothers exposed to PFAS may pass the toxins on to fetuses, raising the risk of gestational diabetes, which affects up to one in 10 US pregnancies and has been on the rise for the last decade.
The team combed through 79 animal and human studies evaluating the relationship between PFAS, diabetes and pregnancy.
They found that higher amounts of exposure to PFAS led to consistently higher insulin resistance in pregnant mothers and rates of gestational diabetes.
Researchers warned that the condition can lead to a host of long-term consequences for both mother and baby, including obesity, type 2 diabetes and high blood pressure.
Dr Sandra India-aldana, co-first study author and postdoctoral fellow at the Icahn School of Medicine at Mount Sinai, said: 'This is the most comprehensive synthesis of evidence to date examining how PFAS exposure relates not only to diabetes risk, but also to the underlying clinical markers that precede disease.
'Our findings suggest that pregnancy may be a particularly sensitive window during which PFAS exposure may increase risk for gestational diabetes.'
The meta-analysis, published this week in the journal eClinical Medicine, looked at 79 studies that were based on clinical tests, electronic health records or self-reported conditions and symptoms.
The studies included measures of 18 different forms of PFAS.
The team found PFAS exposure led to increased insulin resistance in pregnant mothers, meaning their bodies' cells were not responding to insulin, causing glucose to build up in the blood. Over time, this can lead to type 2 diabetes.
In pregnancy, hormones produced by the placenta like estrogen and cortisol block the body's cells from using insulin effectively, leading to gestational diabetes.
The findings led the team to conclude that PFAS exposure consistently is linked to a higher risk of gestational diabetes. Obesity, which causes insulin resistance, also been linked to gestational diabetes.
In babies, gestational diabetes may lead to a high birth weight - above nine pounds - preterm labor and obesity and type 2 diabetes later in life.
Mothers may also be at risk of high blood pressure and developing diabetes in the future.
Gestational diabetes rates have also increased every year in the US since 2016, a December 2025 study in JAMA Internal Medicine found. Over nine years, rates shot up 36 percent, from 58 to 79 cases per 1,000 births. That team suggested unhealthy diets and growing rates of pre-existing conditions like obesity may be to blame.
Dr Xin Yu, co-first study author and postdoctoral fellow at the Icahn School of Medicine at Mount Sinai, said: 'Gestational diabetes has lasting implications for both mother and child.
'This research supports the growing recognition that environmental exposures like PFAS should be part of conversations around preventive care and risk reduction during pregnancy.'
The research team noted that while their findings are comprehensive, more long-term research is still needed on the relationship between PFAS.
Dr Damaskini Valvi, senior study author and professor and Director of Graduate Education in Public Health at Icahn School of Medicine at Mount Sinai, said: 'These results are alarming as almost everyone is exposed to PFAS, and gestational diabetes can have severe long-term complications for mothers and their children.
'We need larger longitudinal studies with well-characterized type 1 and type 2 diabetes cases to fully characterize PFAS impacts on diabetes risk and its long-term complications for affected individuals and their families.
'These results underscore the importance of considering PFAS and other hazardous environmental chemical exposures as part of comprehensive clinical risk assessment and preventive care, particularly during pregnancy.'
