Overview
- Researchers analyzed more than 11 million singleton births using a difference-in-differences design that compared counties before and after fluoridation with never-fluoridated controls.
- Estimated changes in birth weight after fluoridation ranged from −8.4 grams to +7.2 grams and were not statistically meaningful.
- Sensitivity analyses found no associations with low birth weight, gestational length, or risk of prematurity.
- Exposure was measured at the community level, which could misclassify individual fluoride intake and coincide with other water-treatment changes.
- The multi-institutional team led by Columbia University reported the findings in JAMA Network Open with support from the National Institute on Aging and the Swiss National Science Foundation.