Phthalates are a group of widely used plasticizers commonly found in a variety of cosmetics and personal care products, such as shampoos, soaps, and detergents, as well as plastic food and beverage containers. Previous research showed phthalates can affect hormones and suggested they may be linked to health effects in mothers and babies.

The study, led by researchers at Emory’s Rollins School of Public Health and published in Nature Communications on Wednesday, was the first to explore and find evidence of how a pregnant woman’s exposure to phthalates influences their baby’s metabolism at birth.

Main Takeaways

• Prenatal phthalate levels in the mother’s blood during pregnancy were associated with lower levels of key neurotransmitter precursors (related to tyrosine and tryptophan metabolism) important for brain development in the newborn’s blood soon after birth.
• Higher prenatal phthalate levels were also associated with biological changes linked to lower information processing (or attention) and excitability (or arousal) scores in newborns.
• These findings suggest that a mother’s exposure to phthalates during pregnancy may influence her newborn’s metabolism soon after birth. Furthermore, exposure to phthalates while babies are still in the uterus may also have lasting effects on infant brain development.

What The Experts Say

“This was the first study to demonstrate that a mother’s exposure to phthalates can impact their baby’s metabolome and also the first to show that these biological changes can impact newborn development. This is important because there is a common belief that the placenta protects the baby from a lot of harmful substances, but this study supports that phthalates are able to cross through the placenta and actually impact the baby’s biology before they are even born and negatively affect their development over time,” said Susan Hoffman, PhD, study first author and recent graduate of the Epidemiology PhD program at the Rollins School of Public Health.

“We are seeing that once pregnant women are exposed to phthalates, these chemicals not only enter their body and disrupt maternal metabolism, but these exposures also impact the metabolism and neurobehavioral functioning of newborns. And we found these substances are staying with them in the body after they are born, as we did see some indication of a biological disruption occurring among the newborn babies that has a further impact on the neurodevelopment system,” says Donghai Liang, PhD, study lead author and associate professor of environmental health at the Rollins School of Public Health.