运用倾向值匹配法分析孕妇早期呼吸道感染与新生儿出生孕周的关联

目的 探讨孕妇呼吸道感染与活产单胎新生儿出生孕周之间的关联。方法 采用分层随机整群抽样方法，抽取陕西省30个区（县）。面对面问卷调查2010－2013年符合纳入指标的育龄妇女及其生育子女。应用倾向值匹配法，对孕早期呼吸道感染组和无呼吸道感染组进行1∶1匹配。以母亲孕早期呼吸道感染和子女出生孕周分别作为自变量和因变量，通过逐步校正混杂因素共建立3个线性回归模型，其中模型1仅分析匹配前呼吸道感染变量，模型2在模型1的基础上进一步校正母亲及新生儿个体差异因素，模型3仅分析匹配后呼吸道感染变量。结果 共纳入28 848人，孕早期呼吸道感染3 676人（12.74%）。匹配后感染组和非感染组分别为2 762人。模型1显示母亲孕早期出现呼吸道感染，新生儿出生孕周减少0.111周（P<0.001），模型2减少0.058周（P=0.025），模型3减少0.076周（P=0.036）。结论 孕妇出现呼吸道感染与子代出生孕周减少有关。

A propensity score-matched study on relationship between maternal respiratory infection in early pregnancy and gestational age

Objective To explore the association between maternal respiratory infection in early pregnancy and gestational age of single live birth. Methods A face to face questionnaire survey was conducted among child bearing aged women in 30 counties (district) of Shaanxi province selected through stratified multistage sampling. Propensity score (PS) matched (1:1) analysis was used to match participants with respiratory infections to those without respiratory infections. A multilevel linear model was used to investigate the association between respiratory infections and gestational age. Through the control of the confounders step by step, three models were established in this study:model 1 for the variable of respiratory infections before PS matching, model 2 was adjusted for variables in model 1 plus some other individual differences of mother and baby, and model 3 for the variable of respiratory infections after PS matching. Results Of 28 848 child bearing aged women surveyed, 3 676 (12.74%) had respiratory infections in early pregnancy. After PS matching, 2 762 pairs were matched. Analysis with model 1 indicated that a decrease of 0.111 week (P<0.001) in gestational age was associated with a respiratory infection during the first trimester. Analysis with model 2 and model 3 indicated that a decrease of 0.058 week (P=0.025) and a decrease of 0.076 week (P=0.036) were associated with respiratory infection during the first trimester, respectively. Conclusion The respiratory infection during the first trimester was associated with the decrease of the gestational age of newborn.