Currently, there is contradictory evidence for the risk of adverse pregnancy outcomes associated with maternal exposure to disinfection byproducts (DBPs). We examine the association between maternal exposure to trihalomethanes (THMs) in drinking water and adverse pregnancy outcomes, including premature birth, low birth weight (LBW) and small for gestational age (SGA). In total, 1,167 women older than 18 years were enrolled at public antenatal venues in two geographical districts. For each district, we measured the levels of residential drinking water DBPs (measured in THMs) through regulatory data and routine water sampling. We estimated the individual uptake of water of each woman by combining individual water use and uptake factors. Increased daily internal dose of total THMs during the third trimester of pregnancy significantly increased the risk of delivering premature infants (AOR 3.13, 95% CI 1.36–7.17). The risk of premature birth was also positiviely associated with exposure to total THMs during the whole pregnancy (AOR 2.89, 95% CI 1.25–6.68). The risk of delivering an SGA and LBW infant was not associated with maternal exposure to THMs. Our findings suggest that exposure to THMs is associated with certain negative pregnancy outcomes. The levels of THMs in water should be routinely monitored.

当前，与母亲接触消毒副产物（DBPs）相关的不良妊娠结局的风险证据相互矛盾。我们检查了母亲在饮用水中暴露于三卤甲烷（THMs）与不良妊娠结局之间的关联，包括早产，低出生体重（LBW）和小胎龄（SGA）。共有1167名18岁以上的妇女在两个地理区域的公共产前场所就读。对于每个地区，我们通过监管数据和常规水采样来测量居民饮用水DBP（以THMs为单位）的水平。通过结合个人用水和摄取因子，我们估计了每个女人的个人摄取水量。在妊娠中期，总THM的每日内部剂量增加会显着增加分娩早产婴儿的风险（AOR 3.13，95％CI 1.36-7.17）。在整个怀孕期间，早产的风险也与总THM的暴露呈正相关（AOR 2.89，95％CI 1.25–6.68）。分娩SGA和LBW婴儿的风险与母亲暴露于THM无关。我们的发现表明，暴露于THM与某些阴性妊娠结局有关。应定期监测水中THM的水平。分娩SGA和LBW婴儿的风险与母亲暴露于THM无关。我们的发现表明，暴露于THM与某些阴性妊娠结局有关。应定期监测水中THM的水平。分娩SGA和LBW婴儿的风险与母亲暴露于THM无关。我们的发现表明，暴露于THM与某些阴性妊娠结局有关。应定期监测水中THM的水平。