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• Posted March 19, 2026

Pesticide Exposure Before Pregnancy Might Risk Newborn Health

Pesticides can affect a newborn’s health before they’re even conceived, a new study says.

Women exposed to agricultural pesticides prior to pregnancy are up to three times more likely to give birth to sickly babies, researchers reported this month in the Journal of Exposure Science & Environmental Epidemiology.

"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," Audrey Yang, a graduate student at the University of Arizona, said in a news release.

For the study, researchers analyzed the health of more than 1.1 million babies born in Arizona between 2006 and 2020.

The team looked specifically at Apgar scores — the health score given a newborn immediately after delivery. The test measures a baby’s heart rate, breathing, muscle tone, reflex response and color.

Children with low Apgar scores are more likely to have neurological problems like seizures, and they tend to be sicker throughout childhood, researchers said in background notes.

Researchers compared newborns’ Apgar scores to whether their mom lived within 500 meters of farm fields exposed to agricultural pesticides.

Birth certificates supplied the mother’s home address, and researchers used an Arizona pesticide use registry to track use of the chemicals on nearby farmland.

Results showed a higher risk of low Apgar scores if women were exposed to several different pesticide chemicals either before or during pregnancy, including: 

• A doubled risk from exposure to carbaryl

• A 3.5 times increased risk from formetanate hydrochloride

• A 67% higher risk from diazinon

• A 39% increased risk from tribufos

• A 49% increased risk from cypermethrin

"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," senior researcher Melissa Furlong, an assistant professor at the University of Arizona, said in a news release. "They have demonstrable biological effects on human health." 

Researchers noted that the study only shows an association between pesticide use and newborn health, not a direct cause-and-effect link.

In the future, the team plans to use Medicaid records to track whether pesticide exposure has long-term consequences for a child’s development.

Furlong said farmers should consider using less toxic pesticides to protect the health of newborns.

"I'm not suggesting a blanket ban on all pesticides," she said. "I’m just suggesting we do some more comprehensive legislative or policy initiatives for individual ingredients that exert the most harm."

In the meantime, women should let their doctor know if it’s likely that they have been exposed to pesticides.

"If you think you have increased pesticide exposure, I think it's a notable piece of information to share with your physician," Yang said.

People also can take steps to lower their exposure to pesticides if they live in agricultural areas. These are some ways to do so:

• Regularly vacuum and dust homes.

• Use doormats and take shoes off when entering the house.

• Install a water filter if your home uses well water.

• Change air filters at least once a month during pesticide spraying seasons.

People should be careful of the household weed and bug killers they use, too, researchers said. Furlong specifically warned against using products with ingredients like beta-cyfluthrin, cypermethrin, esfenvalerate and fenpropathrin, as they were associated with lower Apgar scores in the study.

"Most importantly, try not to use indoor insecticides during pregnancy," Furlong said.

More information

The American Academy of Pediatrics has more on Apgar scores.

SOURCE: University of Arizona, news release, March 13, 2026