New research indicates that residing within 0.3 miles of areas where pesticides are used before and during the first trimester of pregnancy could significantly elevate the risk of stillbirths. The study, conducted by the Mel and Enid Zuckerman College of Public Health in collaboration with the Southwest Environmental Health Sciences Center, was published in the American Journal of Epidemiology.
The research highlights a concerning association between pesticide exposure and stillbirth. It particularly focuses on organophosphates and other specific pesticides, which were linked to an increased risk of stillbirth both during the first trimester and within a 90-day preconception period. The study, titled “Pesticide Exposure During the First Trimester and Its Associations With Stillbirth,” underscores the need for a closer examination of individual pesticide types rather than broad categories.
Melissa Furlong, PhD, the lead author and assistant professor at the Zuckerman College of Public Health, noted the significance of these findings. “Certain pesticide ingredients showed substantial associations with stillbirth risk,” she said. “This emphasizes the importance of examining specific chemicals and their potential unique risks. The results also suggest that exposure before pregnancy might impact reproductive outcomes.”
The study analyzed pesticide use records for 27 different substances in Arizona, cross-referenced with birth certificate data from 1,237,750 births and 2,290 stillbirths recorded between 2006 and 2020. The analysis revealed that living within 0.31 miles (500 meters) of applications of pyrethroid, organophosphate, or carbamate pesticides during the 90 days before conception or throughout the first trimester was associated with a heightened risk of stillbirth.
Particularly, pesticides such as cyfluthrin, zeta-cypermethrin, malathion, carbaryl, and propamocarb hydrochloride were linked to increased stillbirth rates prior to conception. During the first trimester, exposure to fenpropathrin, permethrin, acephate, and formetanate hydrochloride was associated with a higher risk of stillbirth.
Paloma Beamer, PhD, a co-author of the study and professor at the Zuckerman College of Public Health, highlighted that acephate, an organophosphate, was notably linked to a doubling of stillbirth risk when exposure occurred during the first trimester. “Cyfluthrin exposure during the preconception period also nearly doubled the risk of stillbirth,” Beamer added.
Pesticides are chemicals used to manage pests across various environments and are categorized into classes such as organophosphates, pyrethroids, and carbamates. While the primary exposure route is typically through diet, other significant exposure pathways include household use, agricultural drift, and occupational exposure. Although some pesticides were not directly implicated in this study, they may still pose risks to maternal and fetal health.
Pregnant women are especially vulnerable to the effects of pesticides due to physiological changes that occur during pregnancy, including increased metabolic rates, altered hormone levels, and immune system modifications. The developing fetus may be particularly susceptible to the toxic effects of these chemicals.
“Additional research is crucial to fully understand the safety profiles of various pesticides and the mechanisms behind pesticide-induced stillbirths,” Furlong concluded. “This study highlights the urgent need for strategies to mitigate exposure and safeguard maternal and fetal health.”
