PFAS linked to lower birthweight

The largest study to date to examine the role of PFAS (per- and polyfluoroalkyl substances) in birth outcomes reveals widespread exposure to five PFAS in pregnant women and lower birthweight among those with higher PFAS levels.

Published today in the journal Environmental Health Perspectives, the study involved more than 3,000 pregnant participants from 11 different Environmental influences on Child Health Outcomes (ECHO) program research sites across the United States.

Amy Padula, PhD, MSc, an ECHO Program investigator at the University of California, San Francisco, and the study’s lead author said:

The evidence is clear that PFAS are having an adverse impact on birth weight… We examined how PFAS was affecting birthweight both from individual PFAS and mixtures. Either way, lower birthweight was linked to higher levels of PFAS in the mother.”

The study also showed that the timing of exposure to the chemicals during pregnancy did not make a difference, refuting the reverse causality hypothesis promoted in earlier studies, in part, by people working for industry.

PFAS are a class of thousands of persistent and ubiquitous chemicals that are used in a range of products and have now contaminated air, food, and water. While results of previous studies on the links between PFAS and adverse birth outcomes have been inconsistent, this study found a clear connection between PFAS and lower birthweight.

Four PFAS were detected in 96%–100% of participants (PFOS, PFOA, PFNA, and PFHxS) and concentrations were lower than those measured in the National Health and Nutrition Examination Survey (NHANES) dataset. Despite this, pregnant people are not usually tested for PFAS outside of research studies and are often unaware of the potential harms.

“We found that higher levels of several PFAS [PFOA, PFOS, PFNA, PFHxS, and PFDA] were associated with lower birthweight,” the authors write in the study, Birth Outcomes in Relation to Prenatal Exposure to Per- and Polyfluoroalkyl Substances and Stress in the Environmental Influences on Child Health Outcomes (ECHO) Program.

The researchers conclude that interventions and prevention must be addressed because everyone is exposed, and this study adds to the long list of established health threats from PFAS.

“Studies like these are important to inform policymakers about how we can reduce harmful chemical exposures and improve maternal and child health,” said Padula.

The study’s senior author, UCSF Professor and Director of the Program on Reproductive Health and the Environment, Tracey J. Wooduff, PhD, MPH, said, “This study also confirms that government efforts to phase out PFOA/PFOS resulted in a decline of exposures among pregnant people, showing the importance of systematic changes to address harmful exposures.”

The ECHO program is a National Institutes of Health initiative to better understand environmental influences on children’s health. ECHO comprises 69 cohorts from across the United States and includes over 57,000 mother–child pairs.

The study was funded by the National Institutes of Health.

The content of the study and this blog are solely the responsibility of the authors and do not necessarily represent the official views of the National Institutes of Health.