Green R, Lanphear B, Hornung R, et al. - In a prospective multicenter birth cohort study that used information from the Maternal-Infant Research on Environmental Chemicals cohort, researchers investigated the correlation between fluoride exposure during pregnancy and IQ scores in a prospective birth cohort. 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 exhibited 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 related to a 4.49-point lower IQ score in boys, although, 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. Thus, in children aged 3 to 4 years, maternal exposure to greater levels of fluoride during pregnancy was correlated with lower IQ scores. These findings intimate the possible requirement to decrease fluoride consumption during pregnancy.