妇女孕期化肥暴露与其子代低出生体重发生风险关联研究

Associations between maternal exposure to chemical fertilizers during pregnancy and the risk of offspring＇ s low birth weights

目的了解农村化肥施用量与低出生体重（LBW）发生风险的关系，为LBW的预防，提高出生人口素质提供参考。方法利用山西省平定县2007年10月至2012年9月的出生人口监测数据，随访获得153例早产LBW病例和179例足月LBW病例。从同时期出生、无任何体表缺陷、孕周≥37周的正常体重（2 500-4 000 g）新生儿中，随机选择204例作为对照组。将早产LBW和足月LBW组分别与对照组比较，采用分层多因素logistic回归分析，探索LBW发生风险与母亲化肥暴露之间的关联。结果2007－2012年总出生数为18 749例，LBW总发生率为48.5‰，其中早产和足月LBW发生率分别为19.4‰和29.1‰。早产LBW病例对照研究结果显示，调整混杂因素后，村级水平年化肥施用量达到≥100吨的妇女生育早产LBW婴儿的风险是村级水平年化肥施用量〈50吨妇女的2.51（95%CI：1.05-5.99）倍，妇女家庭年化肥施用量与早产LBW风险间关联无统计学意义。足月LBW病例和对照研究结果显示，调整混杂因素后，村级水平年化肥施用量达到≥100吨的妇女生育足月LBW婴儿风险是村级水平年化肥施用量〈50吨妇女的4.03（95%CI：1.63-9.92）倍；妇女家庭年化肥施用量与足月LBW风险间关联无统计学意义。结论妇女孕期暴露于化肥与LBW发生风险存在关联，提示农村化肥施用可能与其他不良妊娠结局发生风险有关，建议在妇女孕期尽量避免化肥暴露，减少农村地区的化肥施用。

Objective To explore the association between the consumption of chemical fertilizers and the risk of low birth weight （LBW）, to provide references for prevention programs on LBW and to improve the birth outcomes.Methods Stratified multivariate logistic regression method was used in this study involving 153 preterm LBW infants, 179 term LBW infants and 204 normal control infants that were randomly selected from the birth monitoring data between October 2007 and September 2012 in Pingding county, Shanxi province. Associations between the risk of LBW and maternal exposure to chemical fertilizers during pregnancy were identified. A normal control group was set up to compare results between preterm and term LBW groups.Results Totally, 18 749 infants were born between 2007 and 2012, with the total incidence rates of LBW as 48.5‰, preterm LBW as 19.4‰, and term LBW as 29.1‰. Concerning the case control study on preterm LBW, after adjustment for confounding factors, the risk of preterm LBW appeared 2.51 （95%CI： 1.05-5.99） times higher in villages with annual consumption of chemical fertilizer ≥100 tons than those villages that using chemical fertilizer less than 50 tons. No significant statistical associations were found between the amounts of household chemical fertilizer consumption and the risks of preterm LBW. Regarding the case control study on term LBW, after adjustment for confounding factors, in villages with ≥100 tons annual consumption of chemical fertilizers, the risk of term LBW was 4.03 （95%CI： 1.63-9.92） times of the risk in villages where the annal use of chemical fertilizers was less than 50 tons. There was no significant association between household consumption of chemical fertilizers and the risk of term LBW.Conclusions Maternal exposure to chemical fertilizers during pregnancy was associated with the risk of LBW. Our findings suggested that the amount of chemical fertilizer consumption in rural areas seemed also associated with the risks of other adverse pregnancy outcomes. Women should avoid the chance of exposure to chemical fertilizers during pregnancy and the consumption of chemical fertilizers should be carefully managed.