Association between chlorination of drinking water and adverse pregnancy outcome in Taiwan

Chlorination has been the major means of disinfecting drinking water in Tai wan. The use of chlorinated water has been hypothesized to lead to several adverse birth outcomes, including low birth weight and preterm delivery. We performed a study to examine the relationship between the use of chlorinat ed water and adverse birth outcomes in Taiwan. The study areas included 14 chlorinating municipalities (CHMs), which were defined as municipalities in which > 90% of the municipal population was served by chlorinated water, a nd 14 matched nonchlorinating municipalities (NCHMs), defined as municipali ties in which < 5% of the municipal population is served by chlorinated wat er. The CHMs and NCHMs were similar to one another in terms of level of urb anization and sociodemographic characteristics. The study population compri sed 18,025 women residing in the 28 municipalities who had a first parity s ingleton birth between 1 January 1994 and 31 December 1996 and for which co mplete information on maternal age, education, gestational age, birth weigh t, and sex of the baby were available. The results of our study suggest cha t there was no association between consumption of chlorinated drinking wate r and the risk of low birth weight.