目的: 探索自然受孕、单胎妊娠、阴道自然分娩妇女围受孕期服用叶酸或含叶酸的多种微量营养素补充剂与早产发生风险的关联。方法: 基于北京市通州区妇幼保健院孕期保健系统和医院信息系统开展回顾性队列研究，收集2015年1月至2018年12月自然受孕、单胎妊娠、在北京市通州区妇幼保健院进行产前保健并阴道自然分娩的16 332名孕产妇的信息，将妇女服用营养补充剂的开始时间与频率相结合形成依从性得分。采用Logistic回归模型分析妇女围受孕期是否服用单纯叶酸片(folic acid，FA)或含叶酸的多种微量营养素补充剂(multiple-micronutrients containing folic acid，MMFA)、服用方式、服用依从性得分与早产率的关系。结果: 研究人群的早产率(孕周 < 37周)为3.8%，平均孕龄为(38.98±1.37)周，其中，有6 174(37.8%)名妇女在围受孕期服用了FA，8 646(52.9%)名服用了MMFA，1 512(9.3%)名未服用任何营养补充剂。与未服用营养补充剂的妇女相比，服用FA或MMFA与早产的关联没有统计学意义[调整后的比值比(adjusted odds ratio，aOR)=1.01，95%CI：0.74~1.37]，服用营养补充剂的种类、开始服用时间及频率与早产的关联也未见统计学意义；同样，也未发现围受孕期服用营养补充剂的依从性得分与早产的关联有统计学意义。结论: 尚未发现自然受孕、单胎妊娠、阴道自然分娩的妇女在围受孕期服用FA或MMFA与早产之间的关联，未来需要开展更多的多中心、大规模前瞻性队列研究或随机对照研究来论证妇女围受孕期服用FA或MMFA与早产之间的关联。

Objective: To explore the association between periconceptional supplementation of folic acid or multiple-micronutrients containing folic acid(MMFA) and risk of preterm delivery in women with natural conception, singleton pregnancy and vaginal delivery. Methods: A retrospective cohort study was performed based on the prenatal health care system and hospital information system of Tongzhou Maternal and Child Health Hospital of Beijing and the women who had their prenatal care in the hospital from January 2015 to December 2018 were included. The information of 16 332 women who conceived naturally, had a singleton pregnancy, and delivered vaginally was collected. Compliance scores were constructed based on the time of initiation and the frequency of taking nutritional supplements. The association between maternal periconceptional micronutrient supplementation, including pure folic acid (FA) pills or MMFA and the rate of preterm delivery was evaluated using Logistic regression models. Results: The preterm delivery rate (gestational week < 37 weeks) of the study population was 3.8%, and the mean (standard deviation) of gestational age was (38.98±1.37) weeks. A total of 6 174 (37.8%) women took FA during the periconceptional period, 8 646 (52.9%) women took MMFA, and 1 512 (9.3%) women did not take any nutritional supplements. The association between periconceptional supplementation of FA or MMFA and risk of preterm delivery in women was not statistically significant [adjusted odds ratio (aOR)=1.01, 95%CI: 0.74-1.37]. The associations with preterm birth were not statistically significant in further analysis by the type of nutritional supplements, time of initiation, and the frequency of supplementation. In addition, the association between the compliance score of taking supplements and the rate of preterm delivery was not statistically significant, either. Conclusion: This study did not find an association between the risk of preterm delivery and the use of FA or MMFA during the periconcep-tional period in women with natural conception, singleton pregnancy, and vaginal delivery. In the future, multicenter studies with large-scale prospective cohort or population-based randomized controlled trials are warranted to confirm the association between taking FA or MMFA during the periconceptional period and preterm delivery among women.