Phthalates, chemicals commonly used in plastics and many consumer products including personal care items, were evaluated for associations with blood pressure during pregnancy in a study published in the Journal of the Endocrine Society. The investigators report that higher urinary concentrations of certain phthalates, particularly those associated with fragranced personal care products, were linked to higher blood pressure markers in pregnant women. The authors emphasize that the study demonstrates association but does not prove causation.
The analysis used data from 338 pregnant participants enrolled in The Environmental Reproductive and Glucose Outcomes (ERGO) Study. Investigators measured urinary phthalate metabolite and replacement chemical concentrations and assessed blood pressure at three time points during pregnancy. The team analyzed whether individual phthalate biomarkers and mixtures were related to gestational blood pressure outcomes and the risk of pregnancy-related hypertensive disorders.
Participants with higher urine concentrations of fragrance-associated phthalates and phthalates common in personal care products exhibited higher systolic and diastolic blood pressure measures. The pattern of associations suggested an increased risk profile for hypertensive disorders of pregnancy among those with elevated phthalate biomarker levels. The study highlights the signal seen for phthalates used in personal care products rather than providing a definitive causal pathway.
About 13% of the 338 participants developed a pregnancy-related high blood pressure disorder during the study period. Women who had higher concentrations of certain phthalates, especially those found in personal care products, tended to have higher blood pressure later in pregnancy, consistent with the reported associations.
The authors explicitly state that the study does not prove that phthalates cause high blood pressure during pregnancy. Observational associations can be influenced by residual confounding, exposure measurement timing, and correlated lifestyle or product-use behaviors that were not fully captured. The report calls for caution in interpreting causality and notes that mechanistic pathways remain unclear. The investigators recommend further research to determine whether effects are mediated by changes in estrogen-related pathways and to evaluate other phthalates and their replacement chemicals.
Based on their findings, the study team suggests that reducing exposure to phthalates found in personal care products—particularly fragranced products—could be a potential strategy to help address higher blood pressure in pregnancy and improve pregnancy health. They frame this recommendation as a cautious, preventive measure, noting the associative nature of the evidence rather than a proven causal relationship.
The authors identify several areas for additional study: clarifying biological mechanisms (including the potential role of estrogen-related pathways), evaluating a broader range of phthalates and replacement chemicals, and confirming findings in other cohorts with varied exposure distributions and clinical outcomes. They also highlight the need to determine whether reducing personal care product–related exposures can translate into measurable improvements in gestational blood pressure and hypertensive disorder incidence.
The study, titled “Associations of Urinary Phthalate Metabolite and Replacement Chemical Concentrations with Gestational Blood Pressure,” lists lead and contributing authors from Harvard T.H. Chan School of Public Health, Beth Israel Deaconess Medical Center, Harvard Medical School, and the Centers for Disease Control and Prevention. Specific named authors include Kimberly Parra, PhD; Emma Preston; Marlee Quinn; Paige Williams; Tamarra James-Todd; Michele Hacker; Blair Wylie; Thomas McElrath; David Cantonwine; Camille Powe; Ellen Seely; Antonia Calafat; and Julianne Cook Botelho.
Funding for the research came from multiple sources reported by the authors: the National Institute of Environmental Health Sciences, the National Institute of Diabetes and Digestive and Kidney Diseases, the Eunice Kennedy Shriver National Institute of Child Health and Human Development, the National Center for Advancing Translational Sciences, the Robert Wood Johnson Foundation’s Harold Amos Medical Faculty Development Program, and the Massachusetts General Hospital Claflin Distinguished Scholar Award.
In this ERGO cohort analysis of 338 pregnant women, higher urinary concentrations of certain phthalates—notably those associated with fragranced personal care products—were associated with higher systolic and diastolic blood pressure and a pattern consistent with increased risk of hypertensive disorders of pregnancy. The study is observational, and authors call for more research to clarify mechanisms and to evaluate whether exposure reduction strategies affect clinical outcomes.