Association between exposure to particulate matter during pregnancy and birthweight: a systematic review and a meta-analysis of birth cohort studies
- Available Online: 2018-03-01
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.