Objective: To explore the spatial distribution of low birth weight (LBW) and the potential environmental risk factors and provide the evidence for the prevention and intervention of LBW. Methods: Data were from a surveillance system for newly born population and adverse pregnancy outcome between 2007 and 2012 in Pingding county, Shanxi province. The data from 313 villages were analyzed. Spatial hierarchical Bayesian model was used to adjust the risk of LBW at village level, Moran's I and Getis-Ord Gi* were used to analyze the difference in distribution of LBW risk area. Spatial negative binomial model was used to evaluate the association between the risk of LBW and chemical fertilizer application. Results: A total of 18 749 new births were recorded between 2007 and 2012, including 911 LBW cases, the total incidence of LBW was 4.86%. The result of the spatial hierarchical Bayesian model showed that high-risk area of LBW was in the southeast of Pingding and low-risk area was in the middle west of Pingding. The result of Moran's I showed that there was a clustering pattern of LBW risk, and Getis-Ord Gi* found a high risk (hot spot) area in the south area. Moreover, the findings of association analysis showed that the risk of LBW increased with the increased chemical fertilizer application at village level. Conclusions: There were area specific differences in the risk of LBW, and dose-response relationship between chemical fertilizer application and the risk of LBW. Our findings suggest that maternal exposure to chemical fertilizer during pregnancy might be a potential risk factor for LBW in rural area.
目的： 探索低出生体重（LBW）发生风险在区域分布上的差异及可能的环境危险因素，为LBW的预防和干预提供依据。 方法： 利用山西省平定县2007年10月至2012年9月期间的出生人口和不良妊娠结局监测数据，以313个村为研究单位，利用空间贝叶斯分层模型评估村级区域的LBW发生风险，采用空间自相关指标（Moran’s I）及冷热点探测指标（Getis-Ord Gi*统计），分析LBW发生风险的区域分布差异，并探索村级水平化肥施用量与LBW发生风险的关联。 结果： 2007－2012年监测期间的出生总数为18 749例，LBW 911例，发生率为4.86%。空间贝叶斯分层模型分析结果显示，高发生风险区域集中在平定县东南部，低发生风险区域集中在中部偏西一带；空间相关性检验结果显示，LBW发生风险在村级尺度上存在空间自相关，即呈聚集性分布；Getis-Ord Gi*统计显示，LBW高发（空间热点）位于平定县南部区域。村级水平的化肥施用量与LBW关联分析结果发现，随着村级水平化肥施用量的增加，LBW发生风险升高。 结论： LBW发生风险存在区域分布差异，村级化肥施用量与LBW发生风险之间存在剂量-反应关系，提示农村地区妇女孕期化肥暴露可能是LBW发生的危险因素。.
Keywords: Chemical fertilizer exposure; Cluster; Low birth weight; Spatial distribution difference.