Ambient air pollution and adverse birth outcomes: a systematic review and meta-analysis

室外空气污染和不良出生结局的相关性研究:一项系统回顾和荟萃分析（英文）

Several reviews have assessed the relationship between exposure to ambient air pollution and adverse birth outcomes during pregnancy,but the results remain controversial.The objective of this study was to assess this correlation quantitatively and to explore sources of heterogeneity.We included all published case-control or cohort studies that evaluated the correlation between ambient air pollution and low birth weight(LBW),preterm birth(PTB),and small for gestational age(SGA).Analytical methods and inclusion criteria were provided on the PROSPERO website(CRD42018085816).We evaluated pooled effects and heterogeneity.Subgroup analyses(grouped by exposure period,study settings,study design,exposure types,data source,Newcastle-Ottawa quality score(NOS),and adjustment for smoking or meteorological factors)were also conducted and publication bias was examined.The risk of bias in systematic reviews(ROBIS)tool was used to evaluate the overall risk of bias in this review.Forty studies met the inclusion criteria.We observed pooled odds ratios(ORs)of 1.03–1.21 for LBW and 0.97–1.06 for PTB when mothers were exposed to CO,NO2,NOx,O3,PM2.5,PM10,or SO2 throughout their pregnancy.For SGA,the pooled estimate was 1.02 in relation to NO2 concentrations.Subgroup analysis and sensitivity analysis decreased the heterogeneity to some extent,such as the subgroups of continuous measures(OR=0.98(0.97–0.99),I2=0.0%)and NOS>7(OR=0.98(0.97–0.99),I2=0.0%)in evaluating the association between PTB and NO2.This review was completed with a low risk of bias.High concentrations of air pollution were significantly related to the higher risk of adverse birth outcomes.However,the sources of heterogeneity among studies should be further explored.

目的:孕期妇女暴露于室外空气污染与子代不良出生结局的发生风险有关,但是结果仍然有争议。本研究旨在定量评估这种相关性并探讨异质性的来源。创新点:报告了三种不良出生结局和七种污染物之间的联系,进行了一系列的亚组分析和敏感性分析。同时,考虑了之前荟萃(meta)分析中未涉及到的气象因素的作用。此外,首次使用系统回顾偏倚风险(ROBIS)工具评估相关领域meta分析的偏倚性。方法:收集已发表的评估室外空气污染与低出生体重、早产、小于胎龄儿关系的病例对照研究或队列研究,具体的纳入标准和分析方法已在PROSPERO网站(CRD42018085816)提供。本研究评估了混合效应和异质性,进一步进行了亚组分析和出版偏倚分析,并采用ROBIS工具评估总体的偏倚性。结论:这项系统回顾和荟萃分析是在低偏倚风险下完成的。结果发现高浓度的空气污染暴露与子代不良出生结局的发生风险有关,且研究间异质性较大。不同的暴露测量方式等亚组分析在一定程度上解释了异质性来源,但仍需进一步探讨。