Title: Association between exposure to particulate matter during pregnancy and birthweight: a systematic review and a meta-analysis of birth cohort studies
Authors: Yinwen Ji1,2,3, Fei Song4, Bo Xu1,2, Yining Zhu5, Chuncheng Lu1,2, Yankai Xia1,2
Institutions: 1State Key Laboratory of Reproductive Medicine, Institute of Toxicology, Nanjing, China; 2Key Laboratory of Modern Toxicology of Ministry of Education, School of Public Health, Nanjing, China; 3School of Public Health, Nanjing Medical University, 818 East Tianyuan Road, Nanjing, China; 4Tianjin Medical University,Department of Epidemiology and Biostatistics, School of Public Health Tianjin Medical University, Tianjin, China; 5The First School of Clinical Medicine, Nanjing Medical University, China. 300 Guangzhou Road, Nanjing, China.
Abstract: Studies of the associations between maternal exposure to particulate matter (PM) and risk of adverse effects on fetal growth are inconsistent and inconclusive. Birth cohort studies are the best available study designed to answer this question, but so far the evidence from such studies has not been combined. We sought to assess the association between maternal exposure to PM and low birthweight (LBW) across 14 studies from 11 centers, and to explore the influence of trimester and exposure assessment methods on between-center heterogeneity in this association. Data were derived from PubMed, Embase, Google Scholar, CNKI, and WanFang database, references from relevant articles, and results from published studies until March 2017. A random-effects meta-analysis was used to combine the coefficient and odds ratios (OR) of individual studies conducted among 14 birth cohort studies. Results from random-effect meta-analysis suggested that a 17% and 6% increase in risk of LBW was associated with a 10 mg/m3 increase in PM2.5 and PM10 exposure concentrations at 3rd trimester (pooled odds ratios (OR), 1.17 and 1.06; 95% confidence interval (CI), 0.94–1.46 and 0.97-1.15, respectively), but our 95% CI included the null value. Our results showed a positive association between exposure to PM2.5 and PM10 during pregnancy and LBW based on birth cohort studies. However, neither reached formal statistical significance. This suggested that maternal exposure to PM may have adverse effects on birth outcomes. Additional mechanistic studies are necessary to confirm the relationship between PM pollution and LBW.
Keywords: low birth weight, meta-analysis, birth cohort studies, particulate matter, pregnancy
J Biomed Res published on 30 May 2017, doi:10.7555/JBR.31.20170038