New research expands pesticide risk window to before pregnancy
Peer-reviewed study suggests exposure is associated with lower Apgar scores for newborns.
Newly-published research links womens’ exposure to agricultural pesticides, even before becoming pregnant, to poorer health in infants.
The peer-reviewed study, published in the March edition of the Journal of Exposure Science & Environmental Epidemiology, found that exposure during preconception to certain commonly applied pesticides - particularly those belonging to the classes of organophosphates, pyrethroids and carbamates - was associated with lower Apgar scores. The score is a commonly-used measure given to newborns within five minutes of birth and is strongly correlated with long-term health outcomes of the baby, researchers said.
“Pesticide exposures disrupt biological functions in humans, raising concerns about potential effects on newborn health and development,” said Dr. Beate Ritz, a co-author of the study and professor in the UCLA Fielding School of Public Health’s departments of Environmental Health Sciences and Epidemiology. “These findings suggest that interventions aimed at mitigating maternal agricultural pesticide exposures may improve newborn health.”
Along with Ritz and Dr. Kimberly C. Paul, assistant professor at the David Geffen School of Medicine at UCLA and a UCLA Fielding alum (MPH ’14 and PhD ’26), the multi-institutional study included researchers from Harvard Chan School of Public Health, and was led by scholars from the University of Arizona.
“Pesticides are designed to be toxic - very often, the biological mechanisms that they act on are present not just in insects and weeds, but also in humans. They have demonstrable biological effects on human health," said Dr. Melissa Furlong, an assistant professor at the University of Arizona’s Mel and Enid Zuckerman College of Public Health and the senior author of the study.
The research group analyzed pesticide use registries that consist of comprehensive records of every pesticide application made across the state. Arizona is one of the two states in the U.S. that maintain pesticide use registries. The registries include information such as crop type, pests, brand name and active ingredient of the pesticides used.
The team collected all birth certificate records in the state of Arizona and linked them to the Arizona pesticide registry. They found that exposure to certain classes of pesticides during preconception and pregnancy were associated with low Apgar scores, a unique metric that is predictive of certain neurological outcomes of newborns and is correlated with a baby's health through childhood.
Though the study found a strong correlation, it does not definitively state that pesticide exposure during preconception and pregnancy deteriorates the health of newborns. However, in the future, the team will examine Medicaid records in the state of Arizona and see if this association pans out for actual neurodevelopmental disorders through childhood.
The team shared a few recommendations to reduce pesticide load in households that are close to agricultural areas. Simple measures like vacuuming and dusting homes, using doormats and avoiding walking with shoes inside the house can lower the pesticide load. For those who use well water, it may be beneficial to use water filters. For those in agricultural areas, it is important to change air filters at least once a month during pesticide spray seasons.
"Most importantly, try not to use indoor insecticides during pregnancy," Furlong said.
Research methodology
The researchers used pesticide use registry and birth certificate data from 2006 to 2020, linked as part of the Arizona Pregnant Women’s Environmental and Reproductive Outcomes Study (Az-PEARS). Exposures were measured as binary variables and defined as living within 500 m of an agricultural pesticide application during preconception (T0, 90 days before conception) and each trimester (T1–T3). Five-minute Apgar scores (low: <8, high: ≥8) were analyzed using log-binomial regression and a meta-analytic approach to estimate adjusted odds ratios (aOR) and 95% confidence intervals (CI), adjusting for newborn and maternal demographics..
Research support and funding
This work was supported by the National Institutes of Health (grant number R00ES028743).
