Study Fluoride exposure during pregnancy linked to increased risk of childhood neurobehavioral problems (May 2024, n=229 mother-child pairs) Maternal Urinary Fluoride and Child Neurobehavior at Age 36 Months

Michael Harrop

Active member
Jul 6, 2023

A new study, led by researchers at the Keck School of Medicine of USC

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. Specifically, children exposed to more fluoride had more problems with emotional reactivity, somatic complaints (such as headaches and stomachaches), anxiety and symptoms linked to autism.

These population-level findings add to existing evidence from animal studies showing that fluoride can harm neurodevelopment, as well as data from studies conducted in Canada, Mexico and other countries showing that prenatal exposure to fluoride is linked with a lower IQ in early childhood.

"This is the first U.S.-based study to examine this association. 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,"

Currently, no official recommendations exist for limiting fluoride consumption during pregnancy, but the researchers hope these findings can help 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."

Key Points​

Question Is prenatal fluoride exposure associated with child neurobehavior in a US-based sample?

Findings In this cohort study of 229 pregnant women and their children, a 0.68 mg/L (ie, 1 IQR) increase in specific gravity–adjusted maternal urinary fluoride during pregnancy was associated with nearly double the odds of T scores for total child neurobehavioral problems being in the borderline clinical or clinical range.

Meaning These findings suggest that prenatal fluoride exposure may increase risk of neurobehavioral problems among children living in an optimally fluoridated area in the US.


Importance Recent studies in Canadian and Mexican populations suggest an association of higher prenatal fluoride exposure with poorer neurobehavioral development, but whether this association holds for US-based populations is unknown.

Objective To examine associations of third trimester maternal urinary fluoride (MUF) with child neurobehavior at age 3 years in the US.

Design, Setting, and Participants This prospective cohort study utilized urine samples archived from 2017 to 2020 and neurobehavioral data assessed from 2020 to 2023 from the Maternal and Developmental Risks from Environmental and Social Stressors (MADRES) pregnancy cohort, which consisted of predominately Hispanic women residing in Los Angeles, California. Cohort eligibility criteria at recruitment included being 18 years of age or older, less than 30 weeks’ gestation, and a fluent English or Spanish speaker. Exclusion criteria included having a disability preventing participation or provision of informed consent, being HIV positive or incarcerated, and having a multiple gestation pregnancy. There were 263 mother-child pairs who completed the 3-year study visit. In this analysis, women who reported prenatal smoking were excluded. Data analysis was conducted from October 2022 to March 2024.

Exposure Specific gravity-adjusted MUF (MUFSG), a biomarker of prenatal fluoride exposure.

Main Outcomes and Measures Neurobehavior was quantified using the Preschool Child Behavior Checklist (CBCL), which included composite scores for Total Problems, Internalizing Problems, and Externalizing Problems. CBCL composite T scores range from 28 to 100. T scores from 60 to 63 are in the borderline clinical range, whereas scores above 63 are in the clinical range. Linear and logistic regression models adjusted for covariates were conducted.

Results A total of 229 mother-child pairs (mean [SD] maternal age, 29.45 [5.67] years; 116 female children [50.7%] and 113 male children [49.3%]) who had MUFSG measured were included in the study. Median (IQR) MUFSG was 0.76 (0.51-1.19) mg/L, and 32 participants (14.0%) had a Total Problems T score in the borderline clinical or clinical range. A 1-IQR (0.68 mg/L) increase in MUFSG was associated with nearly double the odds of the Total Problems T score being in the borderline clinical or clinical range (odds ratio, 1.83; 95% CI, 1.17-2.86; P = .008), as well as with a 2.29-point increase in T score for the Internalizing Problems composite (B = 2.29; 95% CI, 0.47-4.11; P = .01) and a 2.14-point increase in T score for the Total Problems composite (B = 2.14; 95% CI, 0.29-3.98; P = .02).

Conclusions and Relevance In this prospective cohort study of mother-child pairs in Los Angeles, California, prenatal fluoride exposure was associated with increased neurobehavioral problems. These findings suggest that there may be a need to establish recommendations for limiting fluoride exposure during the prenatal period.
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That's really interesting. I gave up fluoride when I was 29, I'm 43 now. Instead I use Uncle Henry's Tooth Powder and I get compliments all the time in my teeth. I read a study or 2 about how Flouride can calcify the pineal gland and that's why I switched. I was fluoride free when I had my son and he has never had fluoride and is 7. Teeth look good and he uses the tooth powder I use.