Pregnant women living in areas of endemic fluorosis in Senegal and low birth weight newborns: Case–control study by M. Diouf , D. Cisse, C.M.M. Lo, M. Ly, D. Faye, O. Ndiaye

In developing countries, maternal and neonatal mortality rates remain high [1]. Amongst mortality causes during the neonatal period, low birth weight is decisive. It has been defined by the World Health Organization as a birth weight under 2500 g.  According to the EDS III survey (Health and Demographic Survey) [2] in Senegal, 13.5% of women on average give birth to newborn infants weighing less than 2500 g. These newborn babies are a daily concern due to the difficulties related to their care and the frequent negative impact of low weight on their growth. The high burden of infectious and/or inflammatory disease is amongst the most determinant causes of death. To that we can add dental pathologies, enamel defects, congenital or acquired [3]. Just like other chemicals, fluorine and fluorides have both beneficial and toxic effects with significant implications on public health. Even though we have noted that an optimal dose of 1 mg of fluoride per litre in drinking water is beneficial for the prevention of tooth decay, extended exposure to higher concentrations can lead to adverse effects on enamel and bones [4,5]. In fact, a concentration of fluoride higher than 2 mg/l causes enamel deterioration increasing with fluoride intake, and this can occur in conjunction with other conditions or might increase certain risks. In pregnant women, placental transport of fluorides happens as early as the 19th week of pregnancy [6–9]. In some countries, and more specifically  in the United States, several studies have focused on dental fluorosis and low birth weight [3,10,11]. One of the pretexts used to justify water fluoridation is a high prevalence of low birth weight. But fluoridation is beneficial only for newborn infants whose birth weight is greater than or equal to  3400 g [12]. These studies focused on the increase of the prevalence of dental fluorosis due to the fact that a significant proportion of newborns have a low birth weight (under 2500 g).

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