The associations between exposure to trihalomethanes during pregnancy and adverse birth outcomes: A systematic review and meta-analysis.

The study aimed to examine the associations between the level of trihalomethanes and its metabolites in pregnancy and the risks of adverse birth outcomes. We searched the databases of the China National Knowledge Infrastructure, WanFang, Vip, PubMed, and Elsevier Science Direct from database establishment to July 14, 2021 and performed a systematic review and meta-analysis of observational studies reporting associations between trihalomethanes level and abnormally low birth weight and preterm birth. The pooled odds ratio (OR), pooled risk ratio, and pooled risk difference with their 95% confidence interval (CI) were calculated for risk estimates.