Association of Pentachlorophenol with Fetal Risk of Prolonged Bradycardia: A Systematic Review and Meta-Analysis

OBJECTIVE: This study explored the systematic evaluation and meta-analysis of different concentrations of PCP on the risk of long-term bradycardia in fetuses. METHODS: Cochrane Library, Embase, PubMed, China Biomedical Literature Service, CNCNKI, and Wanfang database were computerized to collect all case-control studies on the association between variety classes and different concentrations of environmental pollutant gas to fetal of prolonged bradycardia. After evaluating the quality of the inclusion study and extracting valid data, meta-analysis was performed using Stata15 software. Relative hazards were calculated using the Mantel-Haenszel method and the random effect model, and P values and I(2) values were used for heterogeneity evaluation. When heterogeneity occurs, subgroup analysis and sensitivity analysis were used to explore the sources. RESULTS: A total of 15 studies were included, including 1202 patients with fetal of prolonged bradycardia and 1380 in the control population. Meta-analysis showed that there was no statistical difference in PCP < 0.1 mg/L between the experimental group and control group (OR = 1.03, 95% CI (0.62, 1.72), P=0.90, I(2) = 0%, Z = 0.13), but there was a statistical difference in PCP > 5 mg/L (OR = 1.73, 95% CI (1.15, 2.58), P=0.008, I(2) = 0%, Z = 2.65), PCP > 10 mg/L (OR = 1.75, 95% CI (1.19, 2.57), P=0.004, I(2) = 14%, Z = 2.85), and PCP >15 mg/L (OR = 2.02, 95% CI (1.38, 2.95), P=0.0003, I(2) = 77%, Z = 3.61). CONCLUSION: In this study, we found that different concentrations of PCP increased the risk of long-term bradycardia in fetuses, and the risk coefficient increased with the increase of PCP concentration.