Scientists Found 45 Chemicals in Pregnant Women Linked to Birth Risks

New Delhi, India Jul 6, 2026 ALN: One of the largest investigations ever conducted into chemical exposure during pregnancy has revealed that pregnant women regularly encounter a wide array of chemicals commonly found in everyday life. This comprehensive study, which involved over 5,000 mother-child pairs, has significant implications for public , particularly concerning the of newborns. Researchers have concluded that many of these substances may influence how early a baby is born and how much the baby weighs at birth—two critical factors that can affect outcomes well beyond infancy.

The research was spearheaded by teams from the UNC Gillings School of Global Public , Stanford University School of Medicine, and the Woods Institute for the Environment. The findings were published in the peer-reviewed journal JAMA Network Open, which underscores the credibility and importance of the study within the scientific community.

In this extensive investigation, researchers discovered that participants were exposed to an average of 45 different chemicals. These substances included phthalates, replacement plasticizers, polycyclic aromatic hydrocarbons (PAHs), and halogenated phenols. Such chemicals are ubiquitous in modern life, often found in food, drinking water, air pollution, personal care products, fragrances, and a variety of household items. The prevalence of these chemicals raises concerns about their potential effects, particularly during critical periods of development such as pregnancy.

Challenges in Avoiding Harmful Chemicals

First author Jessie Buckley, PhD, a professor of epidemiology at the Gillings School, emphasized the difficulties in avoiding these harmful chemicals. "These chemicals are difficult to avoid because they're found in a wide range of products we use every day. It can be difficult to know whether products contain them, and even when we do know, we have limited control over exposures," Buckley stated. This sentiment reflects a broader concern among experts regarding the pervasive nature of chemical exposure in contemporary society. While there are some practical steps individuals can take to reduce exposure, the researchers argue that the most effective way to protect children and families is to reduce harmful chemicals at the source.

Phthalates and Replacement Chemicals Remain Widespread

Phthalates and replacement plasticizers were among the chemicals identified in the study. These substances are commonly used in products designed for babies and children, including toys, diaper creams, shampoos, and other consumer goods. In 2017, the United States Consumer Product Safety Commission took significant action by permanently banning or significantly restricting eight commonly used phthalates in children's toys and products due to evidence linking these chemicals to harmful effects. However, the restrictions did not extend to many other products that may be used during pregnancy, leaving a gap in protections for expectant mothers and their unborn children.

The new research detected several phthalates in participants' urine samples, including some that have been introduced as replacements for previously restricted chemicals. This raises a critical question about the safety of replacement chemicals, as the study found a range of plasticizer compounds in the urine samples collected during the research. The findings suggest that even newer alternatives may pose similar risks to those they were designed to replace.

More Than 5,000 Mother-Child Pairs Studied

The analysis included data from over 5,000 mothers and their children born between 2000 and 2021. Researchers meticulously measured chemicals in maternal urine samples and compared those findings with pregnancy duration and birth weight. This robust dataset allows for a comprehensive understanding of the relationship between chemical exposure and birth outcomes.

The research team tested for 113 chemicals commonly present in homes and in air, food, and water. On average, each sample contained 45 chemicals, with the highest number detected in a single sample reaching 64. The researchers then evaluated how these exposures were associated with differences in gestational age and birth weight. The implications of these findings are profound, as both gestational age and birth weight are critical indicators of neonatal and can have lasting effects on a child's development.

Several phthalates and alternative plasticizers were consistently associated with shorter pregnancies, while phthalates, replacement plasticizers, and PAHs were linked to lower birth weight. Additionally, some lesser-studied chemicals, including halogenated phenols, showed associations with lower birth weight. The research highlights the need for a broader understanding of how various chemicals interact and their cumulative effects on .

Interestingly, the researchers also detected newer plasticizers that were introduced as alternatives to more widely recognized toxic chemicals such as phthalates. However, the study found that these replacement chemicals appeared to have effects similar to the substances they were intended to replace, raising concerns about the efficacy of current regulatory measures.

Researchers Call for Stronger Chemical Safety Policies

In light of these findings, the researchers are advocating for stronger policies to protect people from toxic chemicals. Senior researcher Tracey Woodruff, PhD, a professor of epidemiology and population at Stanford, stated, "Our study highlights the need for stronger policies to protect people from toxic chemicals. For example, we found that several newer chemicals used to replace toxic ones are also harmful, which underscores why new and replacement chemicals must be properly evaluated before they are put on the market." This call for action is particularly timely, as the public increasingly demands greater accountability from both government agencies and corporations regarding chemical safety.

Woodruff further emphasized that government agencies tasked with evaluating risks for toxic chemicals like phthalates should incorporate the findings from this research to reduce exposures and ensure ier pregnancies. The implications of this research extend beyond individual , as it raises questions about the regulatory frameworks governing chemical safety in consumer products.

Buckley reiterated the importance of limiting chemical exposures during pregnancy, noting that even small changes in birth weight or gestational age can have significant impacts on children's long-term . The findings contribute to a growing body of evidence that suggests a need for systemic changes to protect vulnerable populations, particularly pregnant women and their children.

Woodruff concluded by highlighting the multifaceted nature of chemical exposure, stating, "Pregnant people are at risk of chemical exposure through multiple sources, many of them beyond their control. Governments and companies need to do a better job of reducing harmful chemicals in everyday products and ensuring new chemicals are safe, which will lead to ier children and families." This statement underscores the collective responsibility of society to ensure a safer environment for future generations.

The research reported in this publication was supported by the Environmental influences on Child Outcomes (ECHO) Program, Office of the Director, National Institutes of . As the conversation around chemical safety continues to evolve, this study serves as a crucial piece of evidence in the ongoing dialogue about public , regulatory practices, and the protection of vulnerable populations.