An extensive research study, led by scientists at the Keck School of Medicine of USC, has shed light on the potential dangers of fluoride exposure during pregnancy. The study, which involved more than 220 mother-child pairs, found that higher levels of fluoride in the mother’s body during pregnancy were associated with a nearly doubled chance of the child exhibiting neurobehavioral problems at age three.
The findings, published in JAMA Network Open, indicated that a 0.68 milligram per liter increase in fluoride exposure was linked to a higher likelihood of children displaying neurobehavioral issues. These issues included emotional reactivity, anxiety, somatic complaints, and symptoms associated with autism.
“Women with higher fluoride exposure levels in their bodies during pregnancy tended to rate their 3-year-old children higher on overall neurobehavioral problems and internalizing symptoms,” said Tracy Bastain, Ph.D., an associate professor of clinical population and public health sciences and senior author of the study.
These results align with previous animal studies and data from other countries, which have shown that prenatal exposure to fluoride can negatively impact brain development and lower IQ in early childhood.
The researchers hope that these findings will help raise awareness among policymakers, healthcare providers, and the public about the risks of consuming fluoride during pregnancy. “This is the first U.S.-based study to examine this association,” said Ashley Malin, Ph.D., an assistant professor of epidemiology at the University of Florida’s College of Public Health and Health Professions and College of Medicine. “Our findings are noteworthy, given that the women in this study were exposed to pretty low levels of fluoride—levels that are typical of those living in fluoridated regions within North America.”
The study’s data came from the Maternal and Developmental Risks from Environmental and Social stressors (MADRES) Center for Environmental Health Disparities at the Keck School of Medicine. MADRES follows predominantly Hispanic families in Los Angeles from pregnancy throughout childhood.
The researchers analyzed urine samples from the third trimester of pregnancy to calculate fluoride exposure. Children were then assessed at age three using the Preschool Child Behavior Checklist, which measures a child’s social and emotional functioning based on parent reports.
Children exposed to an additional 0.68 milligrams per liter of fluoride in the womb were 1.83 times more likely to show behavioral problems considered to be clinically significant or borderline clinically significant.
However, no association was found with several other neurobehavioral symptoms, including “externalizing behaviors” such as aggression and attention problems.
Despite the lack of official recommendations for limiting fluoride consumption during pregnancy, the researchers hope these findings will stimulate change. “There are no known benefits to the fetus from ingesting fluoride,” Malin said. “And yet now we have several studies conducted in North America suggesting that there may be a pretty significant risk to the developing brain during that time.”
The research team plans to further investigate the impact of fluoride exposure during pregnancy on brain development among infants in the MADRES study. They also suggest that additional studies in other regions of the country can help determine the extent of the problem and the best way forward.
“While this is the first U.S.-based study of fluoride exposure during pregnancy, more studies are urgently needed to understand and mitigate the impacts in the entire U.S. population,” Bastain said.