Meta-analysis and Mendelian randomization study on the association between exposure to chlorinated disinfection byproducts and preterm birth risk.

Objective: This study aims to investigate the correlation between exposure to disinfection byproducts of chlorination and preterm birth (PTB) through evidence-based medicine Meta-analysis and Mendelian randomization (MR) analysis.

Study Design: Meta-analysis was conducted on 17 studies involving 1,251,426 neonates, revealing a higher risk of PTB with exposure to total trihalomethanes (TTHMs) and chloroform. Mendelian randomization (MR) analysis confirmed a causal relationship between chlorides and PTB.

Results: TTHMs and chloroform were associated with increased PTB risk, while haloacetic acids showed no significant association. TTHMs were linked to small gestational age. Ethnicity and study design influenced heterogeneity.

Conclusions: Exposure to chlorination byproducts, particularly TTHMs and chloroform, poses a significant risk for PTB. MR analysis supports a causal relationship between chlorides and PTB, highlighting the importance of water disinfection byproduct control in preventing PTB.