Neonatal thyroid-stimulating hormone level and perchlorate in drinking water

Background: The effect of perchlorate in drinking water on neonatal blood t hyroid-stimulating hormone (thyrotropin; TSH) levels was examined for Las V egas and Reno, Nevada. Methods: The neonatal blood TSH levels in Las Vegas [with up to 15 mug/L (p pb) perchlorate in drinking water) and in Reno (with no perchlorate detecte d in the drinking water) from December 1998 to October 1999 were analyzed a nd compared. The study samples were from newborns in their first month of l ife (excluding the first day of life) with birth weights of 2,500-4,500 g. A multivariate analysis of logarithmically transformed TSH levels was used to compare the mean TSH levels between Las Vegas and Reno newborns, with ag e and sex being controlled as potential confounders. Results: This study of neonatal TSH levels in the first month of life found no effect from living in the areas with environmental perchlorate exposure s of less than or equal to 15 mug/L (P = 0.97). Conclusions: This study, which was sensitive enough to detect the effects o f age and gender on neonatal blood TSH levels, detected no effect from envi ronmental exposures to perchlorate. (C) 2000 Wiley-Liss, Inc.