Content of review 1, reviewed on November 08, 2020

Abstract, Title and References: The study has a clear objective of examining the association between fluoride exposure in pregnancy and IQ scores of said offspring. The title is informative of this, and the abstract gives an overview of study design and results. The references are of recent publication and relevant to the fields of study; pregnancy and fluoride exposure. The referencing format appears correct. The relevancy of the study is supported by existing literature which continue to question the harmful versus beneficial nature of water fluoridation. The study was designed to fill in the gaps of current research, examining fetal brain development with exposure to fluoridated water.

Introduction/Background While the harmful nature of fluoride has been documented already, it was at exposures higher than what is recommended. Furthermore, these studies did not measure fetal brain development. Hence, the examination of cognitive defecits in children of optimally-fluoridated areas is a justified field of research to examine.

Methodology The process of subject selection is clearly appropriate as participants with known fetal abnormalities, medical complications or illicit drug use were excluded. The study was approved by the board of ethics and all women signed consent for themselves and their babies. The variables are defined scientifically to exclude ambiguity. The methods section is appropriate overall, and is of sufficient detail to be replicated by an outside source.

Results While the overall presentation of data was appropriate and easy to follow, there was no comparison of demographics to the general Canadian population. There is use of appropriate units, rounding and decimals. There are no obvious errors in labelling and categories are grouped logically. The text within the results section adds to the overall depiction. Statistical analysis is described but the description of statistically significant versus insignificant results could have been explicitly stated.

Discussion and Conclusions The conclusion that higher levels of fluoride exposure during pregnancy were associated with lower IQ scores in children is supported by the data collected in this experiment. There is also some support from existing cited literature. Note, however that some referenced studies do not fully support the data here, including one paper which only saw a decreased IQ in male babies. Some limitations of the study are discussed including the short urinary half-life of fluoride, consumption of bottled water and swallowing toothpaste which were addressed using 3 urine samples. Also, maternal fluoride exposure may not be exactly reflective of fetal exposure. Furthermore, it is unreliable to use area level data for assessing fluoride intake. This too, was addressed using 3 urine samples. There could have been a more detailed address of the resultant errors in findings due to these limitations and discussion as to improvement in future experiment. The limitations could have been discussed further, and some information in the discussion is more relevant to the introduction. The lack of scientific evidence and logical thought processes is clear in the discussion.

Overall, the study has limited use practically other than as a brand name journal to cite in false anti-fluoride advertisements to the lay public.


    © 2020 the Reviewer.