围孕期大气中一氧化碳暴露与孕早期稽留流产的关系

目的探讨围孕期暴露于大气污染物一氧化碳（CO）气体与孕早期稽留流产的相关性。方法采用回顾性病例对照研究的方法。从天津市环境监测中心获取2001年至2007年市内6个行政区国控监测点的大气中CO的月平均浓度。以天津市市内六区15家综合性医院和妇产科专科医院计划生育门诊2001年1月至2007年8月诊断为稽留流产的患者为病例组（n=975），同期各医院按照年龄段行1：1配比，随机选取正常妊娠要求行人工流产手术者作为对照组。采用SPSS11．0软件进行统计学分析，探讨围孕期CO的暴露以及年龄、自然流产次数、孕次、产次等因素与孕早期稽留流产的关系。结果大气中CO气体采暖期平均浓度显著高于非采暖期。采暖期稽留流产占所有人工流产的百分比高于非采暖期。病例组孕后一个月CO的暴露水平高于对照组。在中高暴露组与低暴露组、高暴露组与低暴露组比较，稽留流产的发生率均有统计学差异，OR分别为1．609、1．662。结论孕妇孕后一个月暴露于较高浓度的CO，可能会增加稽留流产发生的危险性。暴露浓度越高，发生稽留流产的危险性越大。

Relationship between missed abortion and exposure to carbon monoxide in the air during peri-conception period

Objective： To analyze the relationship between missed abortion and exposure to carbon monoxide in the air during peri-conception period. Methods： The relationship between exposure to carbon monoxide and missed abortion was analyzed using retrospective case-control method. The data of monthly average levels of CO were gained from the national monitoring stations in six districts of urban area in Tianjin from 2001 to 2007. The data of missed abortion group （case group） and induced abortion group （control group） were from 15 general hospitals and birth control out-patient clinic in Tianjin from 2001 to 2007. There were 975 women in missed abortion group. In accordance with same-age group, the same numbers of induced abortion women were matched as control group. All data were analyzed by using SPSS 11.0 software. The correlations between exposure to CO and other factors such as age, frequency of spontaneous abortion, gravidity, parity et al during peri- conception period and missed abortion were analyzed. Results： The OC concentrations in the heating period were significantly higher than the non-heating period. The CO concentrations exposed in missed abortion group were significant higher than those in induced abortion groups in the month after pregnancy. The incidences of missed abortion were significantly higher in middle-high-exposure and in high-exposure group than in low-exposure group. The odds ratio （OR） were 1. 609 and 1. 662 respectively. Conclusion： Exposure to higher concentrations of carbon monoxide in the month after pregnancy might increase the risk of missed abortion. The findings suggested that the higher CO concentration exposed, the higher the risk of missed abortion.