Role of placenta to combat fluorosis (in fetus) in endemic fluorosis area.

ABSTRACT

Fluoride (F) is known to cross the placenta from the maternal blood to the growing fetus. However, there are few studies on the role of placenta in conditions of high F intake in fluorosis endemic area. The present study is the first of its kind carried out in Nalgonda district, an endemic fluorosis area of Andhra Pradesh, India with an average ground and drinking water F of 10.94+2.09 ppm and 4.4+1.6 ppm respectively. The aim of the study is to determine the role of placenta in the transport of F from the maternal blood to the fetus in fluorosis endemic area. 200 healthy pregnant women aged 17-36 years were inducted in the study. All the women had normal and uneventful delivery. Samples collected were maternal blood, cord blood & placenta. The placenta was divided into three parts- peripheral, maternal and fetal surfaces. Placental extracts were obtained and stored at -20° C until processed. F concentrations of the newborn were well within the normal reference range despite high maternal F concentrations (1.62±0.78 ppm). Placental F concentration on the peripheral side (2.54±1.55 ppm) was two fold higher than the maternal serum F (1.62±0.78 ppm; p< 0.001) and six fold higher than the cord F (0.45±0.35 ppm; p< 0.001). Placental F on the maternal (1.62±0.78 ppm) and fetal surfaces (1.41±0.77 ppm) were three fold higher than that of cord blood (p<0.001). On the peripheral part of placenta F was found to be 1.5 times higher than maternal and fetal surfaces. Thus, it can be deduced that placenta does accumulate F especially in the peripheral part when women are exposed to relatively high F concentrations in water and food. The study also suggests that placenta can act as a backstop or guard for the passage of F to the fetus; thus protecting the developing fetus against neonatal fluoride complications.