孕期环境温度对早产风险的影响

Effect of ambient temperature during pregnancy on the risk of preterm birth

目的探讨济南市孕妇孕期环境温度对早产风险的影响,识别暴露的关键窗口期和敏感人群。方法依托于2018年1月至2019年12月在济南市建立的出生队列的基线人群,以婴儿母亲为研究对象,收集研究期间每日环境温度数据,观察其对早产的影响。采用分布滞后非线性模型(DLNM)结合Cox比例风险模型来估计孕期环境温度对早产风险的影响并识别关键窗口期。采用似然比检验分析家庭主妇与环境温度间是否存在交互作用,再将研究对象按照家庭主妇进行分层分析以观察其效应修饰作用。结果 (1)在纳入研究的6 501位母亲中,有285位早产,占4.38%。(2)与孕期中等温度相比,较低和较高的环境温度与早产风险存在统计学联系,较低温时的关键窗口期在第1~27孕周;较高温时的关键窗口期在第1~29周,其危险比(HR)峰值出现在第13~18孕周,危险比HR为1.13(95%CI:1.07~1.20)。(3)似然比检验发现,家庭主妇与温度存在交互作用(χ^(2)=8.73,P=0.013)。(4)在家庭主妇人群中,极端0℃时的效应峰值为4.00(95%CI:1.63~9.82),高于非家庭主妇[1.71(95%CI:1.08~2.73)];极端30℃时的效应峰值为3.45(95%CI:1.56~7.60),高于非家庭主妇[1.79(95%CI:1.12~2.84)]。结论孕期暴露于较低和较高的环境温度可能会增加早产风险,关键窗口期分别是第1~27孕周和第1~29孕周,家庭主妇人群对极端气温更敏感。

Objective To explore the effect of maternal ambient temperature exposure during pregnancy on the risk of preterm birth in Jinan City, and to identify the critical window period of exposure and sensitive population. Methods The study was based on the baseline population of the birth cohort conducted in Jinan from January 2018 to December 2019. The study subjects were the mother of infant, and the study outcome was preterm birth. The daily ambient temperature data during the study period were collected. The distributed lag nonlinear model(DLNM) combined with Cox proportional hazards model was used to estimate the effect of ambient temperature during pregnancy on the risk of preterm birth and identify the critical window period of exposure. A likelihood ratio test was used to analyze whether there was interaction between housewives and ambient temperature. Then, stratified analysis was carried out according to whether the subjects were housewives to observe the effect modification. Results(1) This study included 6,501 mothers. Of these, 285 had preterm birth, accounting for 4.38%.(2) Compared with the middle temperature on the duration of pregnancy, the lower and higher temperature were statistically associated with the risk of preterm birth. The critical window period at lower temperature was from the 1 st to 27 th gestational weeks, while that at higher temperature was from the 1 st to 29 th gestational weeks, and its peak hazard ratio were found in the 13 th to 18 th gestational weeks(HR = 1.13, 95%CI: 1.07-1.20).(3) A likelihood ratio test showed that housewives and temperature had an interaction effect(χ^(2)=8.73, P=0.013).(4) Among housewives, the peak effect for extreme 0 ℃ was 4.00(95%CI:1.63-9.82), which was higher than that of non-housewives [1.71(95%CI:1.08-2.73)];the peak effect for extreme 30 ℃ was 3.45(95%CI:1.56-7.60), which was higher than that of non-housewives [1.79(95%CI:1.12-2.84)]. Conclusion Exposure to low or high ambient temperature during pregnancy may increase the risk of preterm birth, and the critical window periods were the 1 st-27 th gestational weeks and the 1 st-29 th gestational weeks, respectively. The housewives may more sensitive to extreme temperatures.