摘要目的:比较单胎妊娠中不同年龄分层孕妇的早产发生率，并分析早产的高危因素。方法:回顾性分析2013年1月至2019年5月在重庆医科大学附属第一医院住院分娩、≥孕28周的单活胎孕妇的临产资料，根据年龄分为适龄组（分娩时年龄<35岁）、高龄组（分娩时年龄35~39岁）和超高龄组（分娩时年龄≥40岁），比较3组的早产发生率并分析其高危因素。结果:本研究共纳入分娩孕妇48 288例，有3 351例发生早产，总体早产发生率为6.94%（3 351/48 288）；其中适龄组分娩孕妇42 020例，早产2 699例（6.42%，2 699/42 020）；高龄组5 061例，早产491例（9.70%，491/5 061）；超高龄组1 207例，早产161例（13.34%，161/1 207）。自发性早产发生率（分别为3.72%、4.51%和5.88%）和治疗性早产发生率（分别为2.70%、5.20%和7.46%）均随孕妇年龄增大逐渐升高，差异均有统计学意义（ P<0.05）。3组自发性早产和治疗性早产的早产分期分别比较，差异均无统计学意义（ P>0.05）。高龄组和超高龄组治疗性早产孕妇中前置胎盘的发生率显著高于适龄组，而适龄组妊娠期肝内胆汁淤积症和胎儿窘迫的发生率显著高于高龄组和超高龄组，差异均有统计学意义（ P<0.05）。 结论:对于自发性和治疗性早产，母亲年龄都是早产的重要风险因素，且年龄越大，早产风险越高；在治疗性早产方面，与适龄孕妇相比，前置胎盘是高龄孕妇的高风险因素，对高龄妊娠治疗性早产发生率有重要影响。

abstractsObjective:To compare the preterm birth rate among different age groups and analyze relative high-risk factors of preterm birth.Methods:A retrospective analysis was conducted on clinical data of single pregnant women ≥28 gestational weeks from January 2013 to May 2019 in the First Affiliated Hospital of Chongqing Medical Hospital. All involved women were divided into three groups according to age, Group 1 (aged<35 years), Group 2 (aged 35-39 years), and Group 3 (aged ≥40 years). The preterm birth rate among 3 groups was compared and their high-risk factors were analyzed.Results:There were 48 288 singleton pregnancies during the study period, of which 3 351 were preterm births， preterm birth rate was 6.94% (3 351/48 288). In Group 1, there were 42 020 women, of which 2 699 were preterm births (6.42%, 2 699/42 020); in Group 2, there were 5 061 women, of which 491 were preterm births (9.70%, 491/5 061); and in Group 3, there were 1 207 women, of which 161 were preterm births (13.34%, 161/1 207). Comparing the spontaneous preterm birth rates among the three groups, Group 1 was the lowest one and Group 3 was the highest one (3.72% vs 4.51% vs 5.88%); comparing the medical preterm birth rates among the three groups, Group 1 also was the lowest one and Group 3 also was the highest one (2.70% vs 5.20% vs 7.46%); the differences were statistically significant ( P<0.05). The incidence of spontaneous and medical preterm birth according gestational weeks were compared among three groups and there were no significant differences ( P>0.05). Comparing and analyzing the high-risk factors of medical preterm birth, the incidence of intrahepatic cholestasis of pregnancy and fetal distress in Group 1 were higher than those in Group 2 and 3; the incidence of placenta praevia were significantly higher in Group 2 and 3 than that in Group 1; the differences were statistically significant ( P<0.05). Conclusions:Maternal age is a significant high-risk factor of both spontaneous preterm birth and medical preterm birth, and the risk of preterm birth increases with age. For medical preterm birth, compared with right-age pregnant women, placenta praevia is the high-risk factor for women in advanced maternal age(AMA), which have great effect on medical preterm birth rate of AMA.