Babies Exposed to More ‘Forever Chemicals’ in Womb Than Previously Thought: Study

Babies born in the United States between 2003 and 2006 carried a significantly higher burden of “forever chemicals” in their systems than previously understood, according to a new study applying advanced chemical analysis to umbilical cord blood. These per- and polyfluoroalkyl substances (PFAS), used in countless everyday products, are linked to a range of health concerns, and this research highlights the extent of prenatal exposure and the complexities of measuring it.

The findings, published in Environmental Science & Technology, challenge earlier assumptions about PFAS exposure patterns and underscore the need for more comprehensive monitoring and preventative measures. Researchers, led by Dr. Shelley H. Liu of the Icahn School of Medicine at Mount Sinai, utilized a novel “PFAS-omics” approach to assess the total PFAS load in newborns, revealing a far more diverse and substantial chemical mix than traditional testing methods typically detect.

What are PFAS and Why are They a Concern?

PFAS are a large family of man-made chemicals that have been used since the 1940s in a wide array of consumer and industrial products. Their ability to repel water, oil, and heat makes them valuable in items like nonstick cookware, stain-resistant fabrics, firefighting foams, and food packaging. However, the very properties that build PFAS useful also make them incredibly persistent in the environment and in the human body – earning them the moniker “forever chemicals.” As Science magazine explains, this persistence is due to the strong carbon-fluorine bonds that make up these compounds.

Exposure to PFAS has been linked to a growing list of health problems, including certain types of cancer (kidney, testicular, breast, and ovarian), increased cholesterol levels, and immune system dysfunction. The Science of the Total Environment details these concerns, noting that the EPA began investigating PFOA, a legacy PFAS, in 2003 following legal action against DuPont.

A Broader Glance at Prenatal Exposure

The study focused on analyzing umbilical cord blood samples originally collected between 2003 and 2006 from 120 babies participating in the Cincinnati-based HOME Study. Instead of focusing on a limited panel of well-known PFAS compounds, Dr. Liu’s team employed a non-targeted chemical analysis. This technique scans for hundreds, even thousands, of chemicals simultaneously, rather than specifically testing for a pre-defined list.

This broader approach revealed 42 confirmed or tentatively identified PFAS chemicals in the cord blood. Crucially, many of these substances are not routinely included in standard PFAS testing panels, meaning their presence and potential health effects have been largely overlooked. The identified compounds included perfluorinated chemicals, polyfluorinated chemicals, and fluorotelomers – representing a diverse range of PFAS types.

PFAS-Omics and Shifting Understandings

To quantify overall exposure, the researchers developed “PFAS-omics burden scores” using a sophisticated statistical method called item response theory. These scores provide a comprehensive snapshot of a newborn’s total PFAS exposure at a given time.

Interestingly, when this more comprehensive measurement was applied, the researchers did not find significant differences in PFAS exposure between babies born to first-time mothers and those born to mothers who had previous pregnancies. Earlier studies, relying on narrower PFAS panels, had suggested such differences. “Our findings suggest that how we measure PFAS really matters,” Dr. Liu explained in a statement. “When we look more comprehensively, we see that babies are exposed to far more PFAS chemicals before birth than we previously realized – and some of the patterns we thought we understood may change.”

Why Prenatal Exposure Matters: A Critical Window

Pregnancy represents a particularly vulnerable period for development, and prenatal PFAS exposure has been linked to a range of adverse outcomes. Previous research has associated it with low birth weight, preterm birth, altered immune responses to vaccines, metabolic changes, and other developmental concerns. Research published in PubMed also explores potential linkages between PFAS exposure and autoimmune diseases, though the study did not find a discernible link.

The American College of Obstetricians and Gynecologists (ACOG) recognizes reducing exposure to environmental toxins like PFAS as a “critical area of intervention,” highlighting the importance of addressing this issue during pregnancy.

Implications for Clinical Practice and Prevention

Currently, PFAS exposure is not routinely measured in clinical settings, despite growing evidence of its potential health impacts. The new “PFAS-omics” approach offers a way to more fully estimate cumulative PFAS exposure. In the future, tools like this could assist clinicians identify individuals with higher exposure burdens, monitor at-risk populations more closely, and inform preventive medicine strategies.

“For now, this work helps lay the scientific foundation,” Dr. Liu said. “Our goal is to move toward earlier identification and prevention, especially during sensitive windows like pregnancy.”

Looking Ahead: Refining Measurement and Assessing Health Outcomes

The research team is now planning to investigate whether higher cumulative PFAS exposure in early life is associated with negative health outcomes as the children from the HOME Study grow into adolescence. They also aim to study the potential health effects of the newly identified and understudied PFAS found in cord blood and to continue refining tools for primary disease prevention. This ongoing work, funded by the National Institutes of Health, will be crucial for understanding the long-term consequences of early-life PFAS exposure and developing effective strategies to protect child health.

The study’s findings emphasize the need for continued research, improved monitoring, and proactive measures to reduce PFAS exposure across the population, particularly for pregnant women and developing children. Understanding the full scope of PFAS exposure is essential for safeguarding public health and mitigating the risks associated with these persistent “forever chemicals.”