Study finds common chemicals linked to pregnancy-related hypertension

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A study recently published in Environmental Health Perspectives has revealed a link between exposure to certain commonly used chemicals and the development of hypertension during pregnancy. The study, which focused on a cohort of pregnant women in Puerto Rico, suggested that phenols and parabens—chemicals commonly found in various consumer products—could significantly increase the risk of hypertension. This condition poses risks to both expectant mothers and their unborn children.

The research was conducted as part of the ongoing PROTECT (Puerto Rico Testsite for Exploring Contamination Threats) cohort study, which aims to examine the effects of environmental exposures on health outcomes, particularly in vulnerable populations.

This study enrolled 1,433 pregnant women in 2010, whose phenols and parabens exposure were monitored through urine samples collected at 2 stages of pregnancy: 16 to 20 weeks and 24 to 28 weeks’ gestation.

Researchers used statistical analyses, including linear mixed models and quantile g-computation, to assess the impact of these chemicals both individually and as part of a mixture. Their findings revealed that women exposed to a combination of phenols and parabens had a significantly higher risk of developing stage 1 or stage 2 hypertension during pregnancy.

Additionally, the results demonstrated a 57% increase in the likelihood of developing hypertension compared to those with lower levels of exposure. The researchers also noted that the relationship between chemical exposure and hypertension appeared to increase as the pregnancy progressed, highlighting the importance of ongoing monitoring and risk assessment throughout the gestation period.

Further analysis of individual chemicals within the mixture provided more insights into the specific health risks posed by phenols and parabens. Methyl paraben and propyl paraben, two chemicals commonly used as preservatives in cosmetics and pharmaceuticals, were found to be associated with increased diastolic blood pressure throughout pregnancy. This consistent rise in diastolic blood pressure is a key indicator of hypertension, which can lead to severe complications if not properly managed.

The study also identified a paradoxical effect with bisphenol A (BPA), a chemical commonly found in plastics and food packaging. While BPA exposure was linked to decreased systolic blood pressure, this effect was particularly noted in women carrying female fetuses. This finding suggests that the impact of BPA may vary depending on fetal sex, although the mechanisms behind this relationship are not yet fully understood.

The implications of this study are far-reaching, especially considering the widespread use of these chemicals in everyday products. Phenols and parabens are omnipresent in the environment, making it difficult for individuals, especially pregnant women, to avoid exposure. The study's authors emphasize the need for increased public awareness and regulatory action to reduce the risks associated with these chemicals. They also call for further research to explore how these substances affect blood pressure and cardiovascular health during pregnancy.

Because of these findings, the study authors urge health care providers consider more thorough monitoring for signs of hypertension in pregnant women, particularly those with exposure to phenols and parabens.

“Additional research of the relationships between gestational phenol–paraben exposure, maternal BP, and adverse pregnancy outcomes will facilitate further understanding of how the prenatal exposome impacts health and development across the life course,” the study authors conclude. “Additional research on how these relationships may be more pronounced in other susceptible and highly exposed study populations is also warranted.”

Reference:

Varshavsky JR, Meeker JD, Zimmerman E, et al. Association of Phenols, Parabens, and Their Mixture with Maternal Blood Pressure Measurements in the PROTECT Cohort. Environmental Health Perspectives. 2024;132(8). doi:https://doi.org/10.1289/EHP14008