目的:研究孕中、晚期经阴道超声测量宫颈长度对预测早产的临床价值。方法:回顾性分析无任何严重合并症或并发症的单胎头位初产妇241例(A组),包括早产55例(A1组)、足月产186例(A2组),在孕中期14￣15+6周及23￣24+6周分别行阴道超声测量宫颈长度;另选择同期住院的先兆早产孕妇63例(孕28￣34+6周)(B组)行阴道超声测量宫颈长度。所有对象均于初次产检时取阴道分泌物进行生殖道感染的筛查,分析宫颈长度变化、生殖道感染与早产的关系。结果:①A1组与A2组孕中期不同孕周的宫颈长度组间比较无显著差异(P>0.05),孕23￣24+6周的宫颈长度明显长于孕14￣15+6周的(P<0.05)。63例先兆早产孕妇中,妊娠结局为早产者(B1组)的宫颈长度略短于足月产组(B2组)(P>0.05),但1周后复测宫颈长度的21例中,12例早产者(C1组)宫颈长度的缩短明显大于足月产的9例(C2组),两者间比较有显著性差异(P<0.05)。②A1组的支原体感染率显著高于A2组(P<0.05);A1组合并2种或以上感染者高于B组,组间比较亦有显著性差异(P<0.05)。结论:阴道超声动态检测宫颈可预测早产,但孕中期超声测量宫颈长度对正常孕妇预测早产的意义不大;对先兆早产孕妇发生早产有一定的预测价值。对孕期出现生殖道感染的孕妇尤其是支原体感染或同时存在2种或以上感染者更应加以重视,预防早产。 Objective: To study the clinical value of transvaginal ultrasonography in detecting the length of the cervix in predicting premature labor. Methods: A total of 241 primiparous single mothers (group A) without any serious complications or complications were retrospectively analyzed. Among them, 55 cases were preterm labor (group A1), 186 cases were full term (group A2) Cervical length was measured by transvaginal sonography at 15 + 6 weeks and 23-24 + 6 weeks respectively. Another 63 pregnant women (28-34 + 6 weeks pregnant) with preeclampsia who were hospitalized in the same period (group B) underwent vaginal ultrasound to measure the length of the cervix. All subjects were vaginal discharge at the time of initial screening reproductive tract infections screening, analysis of cervical length changes, reproductive tract infections and preterm birth. Results: ① There was no significant difference in cervical length at different gestational weeks between the groups A1 and A2 (P> 0.05), and the length of the cervix from 23 to 24 + 6 weeks was significantly longer than that from 14 to 15 + 6 weeks (P < 0.05). Among 63 pregnant women with threatened preterm birth, the cervical length of the preterm labor group (group B1) was slightly shorter than that of the full-term group (group B2) (P> 0.05). However, of the 21 patients who tested the cervical length one week later, (C1 group), the shortening of cervical length was significantly larger than that of full term (9 cases, C2 group). There was a significant difference between the two groups (P <0.05). ② The infection rate of Mycoplasma in group A1 was significantly higher than that in group A2 (P <0.05). There were significant differences between group A1 and group A with two or more infections (P <0.05). Conclusions: Vaginal ultrasound dynamic detection of cervical premature labor, but the second trimester ultrasound measurement of cervical length of normal pregnant women predict preterm delivery of little significance; Preterm birth of threatened premature pregnant women have some predictive value. Pregnant women with genital tract infection during pregnancy, especially Mycoplasma infection or coexistence of two or more infections should pay more attention to prevent premature birth.