Systematic Review Association between Environmental Dioxin-Related Toxicants Exposure and Adverse Pregnancy Outcome: Systematic Review and Meta-Analysis

Dioxin-related compounds are associated with teratogenic and mutagenic risks in lab-oratory animals, and result in adverse pregnancy outcomes. However, there were in-consistent results in epidemiology studies. In view of this difference, we conducted a systematic review and meta-analysis to examine this association and to assess the het-erogeneity among studies. Comprehensive literature searches were performed to search for relevant articles published in English up to 15 May 2012. In total, we identified 15 studies which included 9 cohort and 6 case control studies. The Cochrane Q test and index of heterogeneity (I2) were used to evaluate heterogeneity. In either cohort studies (I2=0.89, p<0.0001) or case control studies (I2=0.69, p=0.02), significant heterogeneity of risk estimates were observed. Subgroup analyses found no significant increased risk of adverse pregnancy outcome with air dioxin-related compounds exposure (RR=0.99, 95 % CI:0.85–1.16), no significant increased risk of spontaneous abortion (SAB) with ex-posure to food dioxin-related compounds (RR=1.05, 95 % CI:0.80–1.37), higher signifi-cant risks of low birth weight (LBW) with exposure to food dioxin-related compound