Study Overview
A new study published in the Journal of the Endocrine Society suggests that phthalates—chemicals widely used in plastics, personal care products, and hundreds of consumer goods—may contribute to high blood pressure in pregnant women. The research, conducted by scientists at Harvard T.H. Chan School of Public Health, adds to growing evidence that environmental chemicals can influence pregnancy outcomes.
Hypertensive disorders of pregnancy, including preeclampsia, are a leading cause of maternal mortality in the United States. Elevated blood pressure during pregnancy is associated with adverse outcomes for both mother and child, such as preterm birth, low birth weight, and long-term cardiovascular risks. While known risk factors include family history, obesity, and lifestyle, this study points to a potential modifiable environmental factor.
Key Findings
The researchers analyzed data from 338 pregnant women enrolled in The Environmental Reproductive and Glucose Outcomes (ERGO) Study. Urine samples were collected at three points during pregnancy to measure concentrations of phthalate metabolites. Blood pressure was measured at the same visits. The team examined both individual phthalates and mixtures to assess cumulative effects.
Results showed that women with higher urinary concentrations of phthalates commonly found in personal care products—especially those associated with fragrances—had significantly higher systolic and diastolic blood pressure. Approximately 13% of participants developed a pregnancy-related hypertensive disorder, and those with higher phthalate levels were more likely to fall into this group.
"Our study suggests that having higher concentrations of personal care products-associated chemicals, known as phthalates, in the body might contribute to elevated blood pressure in pregnancy," said lead author Kimberly Parra, Ph.D., of Harvard T.H. Chan School of Public Health. "While our study does not show that phthalates cause high blood pressure during pregnancy, it suggests that reducing exposure to this class of chemicals by limiting personal care products containing these ingredients, particularly those with fragrance, may be a way to address high blood pressure in pregnancy and improve pregnancy health."
Understanding Phthalates
Phthalates are a group of chemicals used to make plastics more flexible and to carry fragrances in personal care products. They are found in items such as shampoos, lotions, cosmetics, and even food packaging. Because they are not chemically bound to products, they can leach out and enter the body through ingestion, inhalation, or skin contact. Once inside, they can interfere with the endocrine system, mimicking or blocking natural hormones.
Previous research has linked phthalate exposure to reproductive issues, metabolic problems, and cardiovascular risks. This study specifically focuses on pregnancy, a time when hormonal balance is critical and blood pressure changes can have serious consequences.
Implications for Pregnant Women
The findings suggest that pregnant women may be able to reduce their risk of high blood pressure by choosing personal care products labeled "phthalate-free" or "fragrance-free." However, the authors caution that more research is needed to establish causation and to understand the exact mechanisms involved.
"This is an observational study, so we cannot say phthalates cause high blood pressure," Parra emphasized. "But given the widespread exposure and the seriousness of hypertensive disorders in pregnancy, it is prudent to consider minimizing exposure where possible."
The study also highlights the importance of regulatory and policy efforts to reduce phthalate use in consumer products. Some phthalates have already been restricted in children's toys and certain cosmetics, but they remain common in many other items.
Expert Commentary
While the study is not the first to link environmental chemicals to pregnancy complications, it adds robust data from a well-characterized cohort. "The ERGO study is a valuable resource because it follows women prospectively and measures both exposure and outcomes at multiple time points," noted an editorial accompanying the paper. "The findings are consistent with a growing body of evidence that phthalates may have cardiovascular effects."
However, experts also point out limitations. The sample size is moderate, and the study relies on spot urine samples, which may not perfectly capture long-term exposure. Additionally, the population was predominantly white and well-educated, so results may not be generalizable to other groups.
Practical Advice
For pregnant women concerned about phthalate exposure, the authors suggest simple steps:
- Read labels and avoid products with "fragrance" or "parfum" listed as ingredients, as these often contain phthalates.
- Choose unscented or naturally scented personal care products.
- Use glass or stainless steel containers for food and beverages instead of plastic when possible.
- Wash hands before eating and avoid microwaving food in plastic containers.
These measures not only reduce phthalate exposure but may also limit other endocrine disruptors.
Future Research
The research team plans to continue following the ERGO cohort to assess long-term outcomes in mothers and children. They also hope to investigate whether certain genetic or nutritional factors make some women more susceptible to phthalate effects.
"Our ultimate goal is to identify actionable interventions that can improve pregnancy health," Parra said. "If we can confirm that reducing phthalate exposure lowers blood pressure, that would be a simple, low-cost strategy to prevent complications."
The study was funded by the National Institutes of Health and published in the Journal of the Endocrine Society.
This article is based on reporting by Medical Xpress. Read the original article.
Originally published on medicalxpress.com
