Green R, Lanphear B, Hornung R, et al. - In a prospective birth cohort, researchers explored the connection between fluoride exposure during pregnancy and IQ scores. In areas with fluoridated tap water (n = 141) vs nonfluoridated water (n = 228), women living in the former area had significantly higher mean (SD) maternal urinary fluoride (MUF_SG) concentrations and fluoride consumption levels. Girls showed significantly greater mean (SD) Full-Scale IQ scores than boys. A notable synergy between child gender and MUF_SG was observed symbolizing a differential relation between boys and girls. A 1-mg/L rise in MUF_SG was linked to a 4.49-point lower IQ score in boys. However, there was no statistically important correlation with IQ scores in girls. A 1-mg higher daily consumption of fluoride among pregnant women was related to a 3.66 lower IQ score in boys and girls. Therefore, in children aged 3 to 4 years, maternal exposure to greater levels of fluoride during pregnancy was correlated with lower IQ scores. Such findings indicate that fluoride intake during pregnancy may need to be reduced.