Pesticide Exposure Before Pregnancy Linked to Lower Newborn Health Scores

Even before conception, a woman’s exposure to certain agricultural pesticides may influence the health of her future newborn, according to a new University of Arizona study. Researchers have found a link between preconception pesticide exposure and lower Apgar scores, a standard measure of a newborn’s physical condition at birth, raising questions about the broader impact of these chemicals on early development.

Understanding Apgar Scores and Newborn Health

Apgar scores are assessed at one and five minutes after birth, evaluating a baby’s heart rate, breathing, muscle tone, reflexes, and skin color. While a single low score isn’t necessarily cause for alarm, consistently lower scores are correlated with increased risk of long-term health challenges. Research has shown a connection between Apgar scores and infant mortality, as well as neurological outcomes later in childhood.

The University of Arizona-led study, published in the Journal of Exposure Science & Environmental Epidemiology, focused on the impact of specific pesticide classes – organophosphates, pyrethroids, and carbamates – during the preconception period. These are commonly used in agriculture to control insects, and weeds. The research involved collaboration with Harvard Chan School of Public Health and UCLA Fielding School of Public Health.

How the Study Was Conducted

Researchers analyzed comprehensive pesticide use registries in Arizona, one of only two states in the U.S. That maintains such detailed records. These registries document every pesticide application, including the crop, pest targeted, brand name, and active ingredient. This data was then linked to Arizona birth certificate records, allowing the team to assess pesticide exposure during both the preconception period and pregnancy in relation to Apgar scores. The study encompassed data from 2006 to 2020.

“Pesticides are designed to be toxic—very often, the biological mechanisms that they act on are present not just in insects and weeds, but similarly in humans,” explained Melissa Furlong, an assistant professor at the Mel and Enid Zuckerman College of Public Health and the study’s senior author. “They have demonstrable biological effects on human health.”

Identifying a Critical Window of Exposure

The research revealed that exposure to these pesticide classes during the preconception period – the time leading up to pregnancy – was associated with lower Apgar scores. Audrey Yang, a graduate student at the College of Medicine—Tucson and the study’s first author, highlighted the significance of this finding. “What’s new in this study is that we identified the preconception period as a possible sensitive window of exposure to some of the commonly used pesticides,” she said.

It’s important to note that the study demonstrates a correlation, not necessarily causation. While a link was observed, it doesn’t definitively prove that pesticide exposure causes lower Apgar scores. Other factors could be at play, and further research is needed to establish a causal relationship.

What This Means for Maternal and Child Health

The findings underscore the potential for environmental exposures to impact reproductive health and early child development. While a “blanket ban” on all pesticides isn’t being advocated, Furlong suggests a need for more comprehensive evaluation of individual pesticide ingredients. “It’s not like these ingredients are irreplaceable, she said, as almost every active ingredient has an alternative, and not all pesticides are equally toxic.” She proposes focusing on regulating those ingredients that pose the greatest harm.

The study also emphasizes the importance of open communication between patients and their healthcare providers. “If you think you have increased pesticide exposure, I think it’s a notable piece of information to share with your physician,” Yang advised.

Reducing Pesticide Exposure: Practical Steps

Researchers are actively working to raise awareness among clinicians about the potential health effects of pesticides, particularly for patients living in agricultural areas. The Southwest Environmental Health Science Center is involved in outreach efforts, educating both healthcare professionals and pregnant women about ways to minimize exposure.

Simple household measures can help reduce pesticide load, including frequent vacuuming and dusting, using doormats, and removing shoes at the door. For those who rely on well water, using water filters may be beneficial. During pesticide spray seasons, changing air filters monthly is also recommended. More recommendations are available from the Southwest Environmental Health Science Center.

For residential pesticide use, Furlong recommends avoiding products containing beta-cyfluthrin, cypermethrin, esfenvalerate, and fenpropathrin, as these were associated with lower Apgar scores in the study. She strongly advises against using indoor insecticides during pregnancy.

Future Research and Ongoing Investigation

Furlong’s team plans to analyze Medicaid records in Arizona to determine if the observed association between pesticide exposure and lower Apgar scores translates into an increased risk of neurodevelopmental disorders in children as they grow. This will provide a more comprehensive understanding of the long-term health consequences of early-life pesticide exposure.

The researchers acknowledge the limitations of their study, including the potential for unmeasured confounding factors. However, the findings provide valuable insights into a critical window of vulnerability and highlight the need for continued research and proactive measures to protect maternal and child health. The team is also working to expand this research to other states with pesticide use registries.

This research builds on previous findings linking pesticide exposure to adverse birth outcomes. A University of Arizona study from earlier in 2026 expanded the window of risk to include the period before pregnancy.