Abstract: Background　Preventing premature birth is an important task in the perinatal period of modern medicine.It is also the key to reducing neonatal morbidity and mortality.Objective　To investigate the value of cervical length （CL） combined with PAMG-1 in cervical secretions in predicting preterm labor in women with threatened preterm labor.Methods　From Jinhua Maternal and Child Healthcare Hospital，252 pregnant women of appropriate reproductive age（20-32） with threatened preterm birth were enrolled from January 2017 to January 2020，and divided into three groups by gestational age and other research results：group 1（28-30 gestational weeks），group 2（31-33 gestational weeks） and group 3（34-36 gestational weeks）.CL was measured by transvaginal ultrasound and PAMG-1 in cervical secretions was detected.Clinical preterm birth was used as the gold standard for evaluating the predictive value of CL，PAMG-1 in cervical secretions or the combination of the two for preterm birth.The relationships of CL and PAMG-1 in cervical with preterm birth were analyzed in the three groups.The predictive values of CL，PAMG-1 in cervical and CL combined with PAMG-1 in cervical for preterm birth in each group were estimated.The quantitative relationships of CL and PAMG-1 in cervical with preterm birth was explored.Results　There were 67，95，and 90 cases in groups 1，2，and 3，respectively.Those with a CL<2.5 cm and PAMG-1（+） in cervical had higher risk of preterm birth in all groups（P<0.05）.The incidence of preterm birth predicted by CL with PAMG-1 in cervical differed across the groups（P<0.05）.In the prediction of preterm birth，in group 1，the sensitivity of CL<2.5 cm，PAMG-1（+）in cervical and CL<2.5 cm with PAMG-1（+） in cervical was 69%，63%，56%，respectively，and the specificity of the three was 67%，75%，and 78%，respectively.In group 2，the sensitivity of CL<2.5 cm，PAMG-1（+） in cervical and CL<2.5 cm with PAMG-1（+） in cervical was 74%，56%，and 53%，respectively，and the specificity of the three was 79%，66%，and 87%，respectively.In group 3，the sensitivity of CL<2.5 cm，PAMG-1（+） in cervical and CL<2.5 cm with PAMG-1（+） in cervical was 76%，83%，and 62%，respectively，and the specificity of the three was 56%，65%，and 71%，respectively.Multivariate Logistic regression analysis showed that CL〔OR=0.331，95%CI（0.182，0.601）〕 and PAMG-1 in cervical 〔OR=0.332，95%CI（0.182，0.605）〕 had a quantitative relationship with preterm birth （P<0.05）.Conclusion　CL and PAMG-1 in cervical may be used for the prediction of preterm birth occurring in different gestational weeks.The combination of the two may improve the predictive specificity，but slightly reduce the sensitivity，which is more suitable for the prediction of preterm birth during 31-33 gestational weeks.

Key words: Premature birth, Threatened premature labor, Cervical length measurement, Ultrasonography, Placental alpha microglobulin-1, Forecasting

摘要： 背景　预防早产是现代医学围生期的一项重要任务，也是降低新生儿发病率和死亡率的关键。目的　探究宫颈长度（CL）联合宫颈分泌物胎盘α-1微球蛋白（PAMG-1）预测先兆早产孕妇早产的价值。方法　选取2017年1月—2020年1月在金华市妇幼保健院就诊的适龄（20~32岁）先兆早产孕妇252例为研究对象。依据孕周及其他研究结果将研究对象划分为3个阶段，第一阶段为妊娠28~30周，第二阶段为妊娠31~33周，第三阶段为妊娠34~36周。采用经阴道超声测量孕妇CL，并检测宫颈分泌物PAMG-1。以先兆早产孕妇临床是否发生早产为金标准，比较第一阶段、第二阶段、第三阶段不同CL、PAMG-1先兆早产孕妇早产发生率；分析各阶段CL、PAMG-1及CL联合PAMG-1对先兆早产孕妇早产的预测价值；探究CL、PAMG-1与先兆早产孕妇早产的定量关系。结果　252例先兆早产孕妇处于第一阶段67例、第二阶段95例、第三阶段90例。第一、二、三阶段CL<2.5 cm、PAMG-1（+）先兆早产孕妇早产发生率高（P<0.05）；第一、二、三阶段不同CL联合PAMG-1情况先兆早产孕妇早产发生率比较，差异有统计学意义（P<0.05）。第一阶段CL<2.5 cm预测先兆早产孕妇早产的灵敏度和特异度分别为69%和67%，PAMG-1（+）的灵敏度和特异度分别为63%和75%，CL<2.5 cm联合PAMG-1（+）的灵敏度和特异度分别为56%和78%；第二阶段CL<2.5 cm预测先兆早产孕妇早产的灵敏度和特异度分别为74%和79%，PAMG-1（+）的灵敏度和特异度分别为56%和66%，CL<2.5 cm联合PAMG-1（+）的灵敏度和特异度分别为53%和87%；第三阶段CL<2.5 cm预测先兆早产孕妇早产的灵敏度和特异度分别为76%和56%，PAMG-1（+）的灵敏度和特异度分别为83%和65%，CL<2.5 cm联合PAMG-1（+）的灵敏度和特异度分别为62%和71%。多因素Logistic回归分析结果显示，CL〔OR=0.331，95%CI（0.182，0.601）〕、PAMG-1〔OR=0.332，95%CI（0.182，0.605）〕与先兆早产孕妇早产有定量关系（P<0.05）。结论　CL、PAMG-1对预测先兆早产孕妇各阶段早产具有一定的指导价值，CL联合PAMG-1提高了早产预测的特异度，而灵敏度稍有降低；CL联合PAMG-1对预测妊娠31~33周先兆早产孕妇早产具有较高的价值。

关键词: 早产；先兆早产；宫颈长度测量；超声检查；胎盘&alpha, -1微球蛋白；预测