HealthDay News — Maternal exposure to higher levels of fluoride during pregnancy may be associated with lower IQ scores in young children, according to a study published online Aug. 19 in JAMA Pediatrics.
Rivka Green, from York University in Toronto, and colleagues conducted a prospective, multicenter birth cohort study using information from the Maternal-Infant Research on Environmental Chemicals cohort. Data were included for 512 mother-child pairs recruited from 6 major cities in Canada; data on maternal fluoride intake and children’s IQ (assessed at 3 to 4 years of age) were available for 400 pairs.
The researchers observed a significant interaction between child sex and maternal urinary fluoride adjusted for specific gravity (MUFSG). In boys, a 1-mg/L increase in MUFSG correlated with a 4.49-point lower IQ score (95% confidence interval, −8.38 to −0.60); no statistically significant association with IQ scores was seen in girls (95% confidence interval, −2.53 to 7.33). Among pregnant women, a 1-mg higher daily intake of fluoride correlated with a 3.66-point lower IQ score in both boys and girls (95% confidence interval, −7.16 to −0.14).
“The mission of the journal is to ensure that child health is optimized by bringing the best available evidence to the fore,” Dimitri A. Christakis, MD, MPH, wrote in an editorial note to explain the decision to publish this study. “This study is neither the first, nor will it be the last, to test the association between prenatal fluoride exposure and cognitive development. We hope that purveyors and consumers of these findings are mindful of that as the implications of this study are debated in the public arena.”
One author disclosed serving as an expert witness in an upcoming case involving the US Environmental Protection Agency and water fluoridation.