Association between maternal exposure to arsenic by drinking water during pregnancy and risk of preterm birth: a systematic review and meta-analysis

The relation of exposure to arsenic in drinking water during pregnancy to the risk of preterm birth (PTB) was contradictory. This meta-analysis aimed to examine the association between drinking water arsenic and PTB. A systematic search in PubMed and Scopus was performed to achieve all relevant studies. Odds ratios (OR) and 95% confidence intervals (CI) were used to pool data using the random-effect models. Overall, 11 studies with a total sample size of 3,404,189 participants were included in the meta-analysis. Arsenic exposure through drinking water during pregnancy was related to an increased risk of PTB (OR = 1.06; 95%CI = 1.01–1.10 for highest versus lowest category of arsenic), with significant heterogeneity across the studies (I² = 84.8%, P = 0.001). This finding was supported by cohort studies (OR = 1.05; 95%CI = 1.01–1.10). This meta-analysis proposes that higher arsenic exposure in drinking water may be a risk factor for PTB.