Fluoridation Is Not Tied to Birth Weight, New Study Shows

Some scientists have proposed that fluoride might affect a child’s I.Q. through a mother’s thyroid function. But that mechanism is hard to square with the new results, Tomar said, because thyroid problems in pregnancy also tend to influence birth weight. “In general, birth weight and brain weight are aligned,” said Patricia Braun, a pediatrician at Denver Health [and professor of pediatrics].